Ultrasound Guidance and Monitoring of Laser-Based Fat Removal

PubMed Central

Shah, Jignesh; Thomsen, Sharon; Milner, Thomas E.; Emelianov, Stanislav Y.

2009-01-01

Background and Objectives We report on a study to investigate feasibility of utilizing ultrasound imaging to guide laser removal of subcutaneous fat. Ultrasound imaging can be used to identify the tissue composition and to monitor the temperature increase in response to laser irradiation. Study Design/Materials and Methods Laser heating was performed on ex vivo porcine subcutaneous fat through the overlying skin using a continuous wave laser operating at 1,210 nm optical wavelength. Ultrasound images were recorded using a 10 MHz linear array-based ultrasound imaging system. Results Ultrasound imaging was utilized to differentiate between water-based and lipid-based regions within the porcine tissue and to identify the dermis-fat junction. Temperature maps during the laser exposure in the skin and fatty tissue layers were computed. Conclusions Results of our study demonstrate the potential of using ultrasound imaging to guide laser fat removal. PMID:19065554

Cost Analysis of Following Up Incomplete Low-Risk Fetal Anatomy Ultrasounds.

PubMed

O'Brien, Karen; Shainker, Scott A; Modest, Anna M; Spiel, Melissa H; Resetkova, Nina; Shah, Neel; Hacker, Michele R

2017-03-01

To examine the clinical utility and cost of follow-up ultrasounds performed as a result of suboptimal views at the time of initial second-trimester ultrasound in a cohort of low-risk pregnant women. We conducted a retrospective cohort study of women at low risk for fetal structural anomalies who had second-trimester ultrasounds at 16 to less than 24 weeks of gestation from 2011 to 2013. We determined the probability of women having follow-up ultrasounds as a result of suboptimal views at the time of the initial second-trimester ultrasound, and calculated the probability of detecting an anomaly on follow-up ultrasound. These probabilities were used to estimate the national cost of our current ultrasound practice, and the cost to identify one fetal anomaly on follow-up ultrasound. During the study period, 1,752 women met inclusion criteria. Four fetuses (0.23% [95% CI 0.06-0.58]) were found to have anomalies at the initial ultrasound. Because of suboptimal views, 205 women (11.7%) returned for a follow-up ultrasound, and one (0.49% [95% CI 0.01-2.7]) anomaly was detected. Two women (0.11%) still had suboptimal views and returned for an additional follow-up ultrasound, with no anomalies detected. When the incidence of incomplete ultrasounds was applied to a similar low-risk national cohort, the annual cost of these follow-up scans was estimated at $85,457,160. In our cohort, the cost to detect an anomaly on follow-up ultrasound was approximately $55,000. The clinical yield of performing follow-up ultrasounds because of suboptimal views on low-risk second-trimester ultrasounds is low. Since so few fetal abnormalities were identified on follow-up scans, this added cost and patient burden may not be warranted. © 2016 Wiley Periodicals, Inc.

A Preliminary Study on the Possibility of Using Ultrasound in Driver Assistance Systems

NASA Astrophysics Data System (ADS)

Takahashi, Hiroshi; Honda, Hirohiko

This paper presents a preliminary study on the possibility of using ultrasound in driver assistance systems. Subjects' lap time in a driving video game was measured as an index of their performance of driving operations under acoustic conditions with and without an ultrasound signal at 23kHz, 70dB. The results show that the performance characteristics of the subjects changed when the ultrasound signal was presented. Ultrasound signal tends to concentrate on handling the vehicle and decreasing an attention to check the over speed driving, as a second task. We prove the possibility to apply ultrasound signal to control operator's attention and behavior.

Accreta placentation: a systematic review of prenatal ultrasound imaging and grading of villous invasiveness.

PubMed

Jauniaux, Eric; Collins, Sally L; Jurkovic, Davor; Burton, Graham J

2016-12-01

Determining the depth of villous invasiveness before delivery is pivotal in planning individual management of placenta accreta. We have evaluated the value of various ultrasound signs proposed in the international literature for the prenatal diagnosis of accreta placentation and assessment of the depth of villous invasiveness. We undertook a PubMed and MEDLINE search of the relevant studies published from the first prenatal ultrasound description of placenta accreta in 1982 through March 30, 2016, using key words "placenta accreta," "placenta increta," "placenta percreta," "abnormally invasive placenta," "morbidly adherent placenta," and "placenta adhesive disorder" as related to "sonography," "ultrasound diagnosis," "prenatal diagnosis," "gray-scale imaging," "3-dimensional ultrasound", and "color Doppler imaging." The primary eligibility criteria were articles that correlated prenatal ultrasound imaging with pregnancy outcome. A total of 84 studies, including 31 case reports describing 38 cases of placenta accreta and 53 series describing 1078 cases were analyzed. Placenta accreta was subdivided into placenta creta to describe superficially adherent placentation and placenta increta and placenta percreta to describe invasive placentation. Of the 53 study series, 23 did not provide data on the depth of villous myometrial invasion on ultrasound imaging or at delivery. Detailed correlations between ultrasound findings and placenta accreta grading were found in 72 cases. A loss of clear zone (62.1%) and the presence of bridging vessels (71.4%) were the most common ultrasound signs in cases of placenta creta. In placenta increta, a loss of clear zone (84.6%) and subplacental hypervascularity (60%) were the most common ultrasound signs, whereas placental lacunae (82.4%) and subplacental hypervascularity (54.5%) were the most common ultrasound signs in placenta percreta. No ultrasound sign or a combination of ultrasound signs were specific of the depth of accreta placentation. The wide heterogeneity in terminology used to describe the grades of accreta placentation and differences in study design limits the evaluation of the accuracy of ultrasound imaging in the screening and diagnosis of placenta accreta. This review emphasizes the need for further prospective studies using a standardized evidence-based approach including a systematic correlation between ultrasound signs of placenta accreta and detailed clinical and pathologic examinations at delivery. Copyright © 2016 Elsevier Inc. All rights reserved.

All-optical pulse-echo ultrasound probe for intravascular imaging (Conference Presentation)

NASA Astrophysics Data System (ADS)

Colchester, Richard J.; Noimark, Sacha; Mosse, Charles A.; Zhang, Edward Z.; Beard, Paul C.; Parkin, Ivan P.; Papakonstantinou, Ioannis; Desjardins, Adrien E.

2016-02-01

High frequency ultrasound probes such as intravascular ultrasound (IVUS) and intracardiac echocardiography (ICE) catheters can be invaluable for guiding minimally invasive medical procedures in cardiology such as coronary stent placement and ablation. With current-generation ultrasound probes, ultrasound is generated and received electrically. The complexities involved with fabricating these electrical probes can result in high costs that limit their clinical applicability. Additionally, it can be challenging to achieve wide transmission bandwidths and adequate wideband reception sensitivity with small piezoelectric elements. Optical methods for transmitting and receiving ultrasound are emerging as alternatives to their electrical counterparts. They offer several distinguishing advantages, including the potential to generate and detect the broadband ultrasound fields (tens of MHz) required for high resolution imaging. In this study, we developed a miniature, side-looking, pulse-echo ultrasound probe for intravascular imaging, with fibre-optic transmission and reception. The axial resolution was better than 70 microns, and the imaging depth in tissue was greater than 1 cm. Ultrasound transmission was performed by photoacoustic excitation of a carbon nanotube/polydimethylsiloxane composite material; ultrasound reception, with a fibre-optic Fabry-Perot cavity. Ex vivo tissue studies, which included healthy swine tissue and diseased human tissue, demonstrated the strong potential of this technique. To our knowledge, this is the first study to achieve an all-optical pulse-echo ultrasound probe for intravascular imaging. The potential for performing all-optical B-mode imaging (2D and 3D) with virtual arrays of transmit/receive elements, and hybrid imaging with pulse-echo ultrasound and photoacoustic sensing are discussed.

Medical students benefit from the use of ultrasound when learning peripheral IV techniques.

PubMed

Osborn, Scott R; Borhart, Joelle; Antonis, Michael S

2012-03-06

Recent studies support high success rates after a short learning period of ultrasound IV technique, and increased patient and provider satisfaction when using ultrasound as an adjunct to peripheral IV placement. No study to date has addressed the efficacy for instructing ultrasound-naive providers. We studied the introduction of ultrasound to the teaching technique of peripheral IV insertion on first- and second-year medical students. This was a prospective, randomized, and controlled trial. A total of 69 medical students were randomly assigned to the control group with a classic, landmark-based approach (n = 36) or the real-time ultrasound-guided group (n = 33). Both groups observed a 20-min tutorial on IV placement using both techniques and then attempted vein cannulation. Students were given a survey to report their results and observations by a 10-cm visual analog scale. The survey response rate was 100%. In the two groups, 73.9% stated that they attempted an IV previously, and 63.7% of students had used an ultrasound machine prior to the study. None had used ultrasound for IV access prior to our session. The average number of attempts at cannulation was 1.42 in either group. There was no difference between the control and ultrasound groups in terms of number of attempts (p = 0.31). In both groups, 66.7% of learners were able to cannulate in one attempt, 21.7% in two attempts, and 11.6% in three attempts. The study group commented that they felt they gained more knowledge from the experience (p < 0.005) and that it was easier with ultrasound guidance (p < 0.005). Medical students feel they learn more when using ultrasound after a 20-min tutorial to place IVs and cannulation of the vein feels easier. Success rates are comparable between the traditional and ultrasound teaching approaches.

Novel ultrasound-responsive chitosan/perfluorohexane nanodroplets for image-guided smart delivery of an anticancer agent: Curcumin.

PubMed

Baghbani, Fatemeh; Chegeni, Mahdieh; Moztarzadeh, Fathollah; Hadian-Ghazvini, Samaneh; Raz, Majid

2017-05-01

Ultrasound-responsive nanodroplets are a class of new emerging smart drug delivery systems which provide image-guided nano-therapy of various diseases, especially cancers. Here, we developed multifunctional smart curcumin-loaded chitosan/perfluorohexane nanodroplets for contrast-ultrasound imaging and on-demand drug delivery. The nanodroplets were synthesized via nanoemulsion process. The optimal formulation with the size of 101.2nm and 77.8% curcumin entrapment was chosen for release study and cytotoxicity evaluation. Sonication at the frequency of 1MHz, 2W/cm 2 for 4min triggered the release of 63.5% of curcumin from optimal formulation (Cur-NDs-2). Ultrasound aided release study indicated that the concentration of perfluorohexane and the degree of acoustic droplet vaporization play important role in ultrasound-active drug release. B-mode ultrasound imaging confirmed strong ultrasound contrast of chitosan nanodroplets even at low concentrations via droplet to bubble transition. Finally, cytotoxicity of the ultrasound-responsive nanodroplets in the presence of ultrasound was evaluated in-vitro on 4T1 human breast cancer cells. Cell growth inhibitory effects of curcumin-loaded nanodroplets significantly increased by ultrasound exposure. According to the obtained results, these ultrasound responsive curcumin-loaded chitosan/perfluorohexane nanodroplets have a great potential for imaged-guided cancer therapy. Copyright © 2016 Elsevier B.V. All rights reserved.

Histological and Ultrastructural Effects of Ultrasound-induced Cavitation on Human Skin Adipose Tissue.

PubMed

Bani, Daniele; Quattrini Li, Alessandro; Freschi, Giancarlo; Russo, Giulia Lo

2013-09-01

In aesthetic medicine, the most promising techniques for noninvasive body sculpturing purposes are based on ultrasound-induced fat cavitation. Liporeductive ultrasound devices afford clinically relevant subcutaneous fat pad reduction without significant adverse reactions. This study aims at evaluating the histological and ultrastructural changes induced by ultrasound cavitation on the different cell components of human skin. Control and ultrasound-treated ex vivo abdominal full-thickness skin samples and skin biopsies from patients pretreated with or without ultrasound cavitation were studied histologically, morphometrically, and ultrastructurally to evaluate possible changes in adipocyte size and morphology. Adipocyte apoptosis and triglyceride release were also assayed. Clinical evaluation of the effects of 4 weekly ultrasound vs sham treatments was performed by plicometry. Compared with the sham-treated control samples, ultrasound cavitation induced a statistically significant reduction in the size of the adipocytes (P < 0.001), the appearance of micropores and triglyceride leakage and release in the conditioned medium (P < 0.05 at 15 min), or adipose tissue interstitium, without appreciable changes in microvascular, stromal, and epidermal components and in the number of apoptotic adipocytes. Clinically, the ultrasound treatment caused a significant reduction of abdominal fat. This study further strengthens the current notion that noninvasive transcutaneous ultrasound cavitation is a promising and safe technology for localized reduction of fat and provides experimental evidence for its specific mechanism of action on the adipocytes.

Machine Learning in Ultrasound Computer-Aided Diagnostic Systems: A Survey

PubMed Central

Zhang, Fan; Li, Xuelong

2018-01-01

The ultrasound imaging is one of the most common schemes to detect diseases in the clinical practice. There are many advantages of ultrasound imaging such as safety, convenience, and low cost. However, reading ultrasound imaging is not easy. To support the diagnosis of clinicians and reduce the load of doctors, many ultrasound computer-aided diagnosis (CAD) systems are proposed. In recent years, the success of deep learning in the image classification and segmentation led to more and more scholars realizing the potential of performance improvement brought by utilizing the deep learning in the ultrasound CAD system. This paper summarized the research which focuses on the ultrasound CAD system utilizing machine learning technology in recent years. This study divided the ultrasound CAD system into two categories. One is the traditional ultrasound CAD system which employed the manmade feature and the other is the deep learning ultrasound CAD system. The major feature and the classifier employed by the traditional ultrasound CAD system are introduced. As for the deep learning ultrasound CAD, newest applications are summarized. This paper will be useful for researchers who focus on the ultrasound CAD system. PMID:29687000

Machine Learning in Ultrasound Computer-Aided Diagnostic Systems: A Survey.

PubMed

Huang, Qinghua; Zhang, Fan; Li, Xuelong

2018-01-01

The ultrasound imaging is one of the most common schemes to detect diseases in the clinical practice. There are many advantages of ultrasound imaging such as safety, convenience, and low cost. However, reading ultrasound imaging is not easy. To support the diagnosis of clinicians and reduce the load of doctors, many ultrasound computer-aided diagnosis (CAD) systems are proposed. In recent years, the success of deep learning in the image classification and segmentation led to more and more scholars realizing the potential of performance improvement brought by utilizing the deep learning in the ultrasound CAD system. This paper summarized the research which focuses on the ultrasound CAD system utilizing machine learning technology in recent years. This study divided the ultrasound CAD system into two categories. One is the traditional ultrasound CAD system which employed the manmade feature and the other is the deep learning ultrasound CAD system. The major feature and the classifier employed by the traditional ultrasound CAD system are introduced. As for the deep learning ultrasound CAD, newest applications are summarized. This paper will be useful for researchers who focus on the ultrasound CAD system.

Head and Neck Ultrasound Education-A Multimodal Educational Approach in the Predoctoral Setting: A Pilot Study.

PubMed

Bernard, Stewart; Richardson, Clare; Hamann, Carsten R; Lee, Steve; Dinh, Vi Am

2015-08-01

With the increased implementation of ultrasound in medical education, it is important to continually improve instructional methods. In this study, we demonstrate that by augmenting the traditional methods of instructor demonstration and student practice on a healthy volunteer with additional modalities, such as didactic presentation, simulated pathologic cases, and simulated procedures, students gain a more comprehensive understanding of and confidence in ultrasound technique and pathology. A multimodal curriculum was developed and applied to head and neck ultrasound sessions of our institution's Ultrasound Symposium. Participants were asked to fill out surveys rating each instructional modality as well as preinstructional and postinstructional confidence. The survey results were divided into a group of first- and second-year medical students who had previous ultrasound training and a group of third- and fourth-year students who were ultrasound "naïve." The survey showed that the first- and second-year student group (n = 8) had an average preinstructional confidence of 4.14/10 compared to 1.44/10 in the third- and fourth-year student group (n = 9) (P = .003). Following the instructional sessions, the students' confidence increased respectively to 8.14/10 and 7.78/10 (P= .53), showing a 4.00 (96%) increase in the first- and second-year group and a 6.34 (440%) increase in the third- and fourth-year group. The combined results of all student teaching modality ratings showed that instructor demonstration was rated the highest (9.47) and computerized simulation lowest (8.25). Overall, our study shows that multimodal ultrasound instruction was beneficial in increasing both ultrasound-trained and ultrasound-naïve medical students' confidence in head and neck ultrasound. © 2015 by the American Institute of Ultrasound in Medicine.

Misuse of ultrasound for palpable undescended testis by primary care providers: A prospective study

PubMed Central

Wong, Nathan C.; Bansal, Rahul K.; Lorenzo, Armando J.; DeMaria, Jorge; Braga, Luis H.

2015-01-01

Introduction: Although previous evidence has shown that ultrasound is unreliable to diagnose undescended testis, many primary care providers (PCP) continue to misuse it. We assessed the performance of ultrasound as a diagnostic tool for palpable undescended testis, as well as the diagnostic agreement between PCP and pediatric urologists. Methods: We performed a prospective observational cohort study between 2011 and 2013 for consecutive boys referred with a diagnosis of undescended testis to our tertiary pediatric hospital. Patients referred without an ultrasound and those with non-palpable testes were excluded. Data on referring diagnosis, pediatric urology examination and ultrasound reports were analyzed. Results: Our study consisted of 339 boys. Of these, patients without an ultrasound (n = 132) and those with non-palpable testes (n = 38) were excluded. In the end, there were 169 pateints in this study. Ultrasound was performed in 50% of referred boys showing 256 undescended testis. The mean age at time of referral was 45 months. When ultrasound was compared to physical examination by the pediatric urologist, agreement was only 34%. The performance of ultrasound for palpable undescended testis was: sensitivity = 100%; specificity = 16%; positive predictive value = 34%; negative predictive value = 100%; positive likelihood ratio = 1.2; and negative likelihood ratio = 0. Diagnosis of undescended testis by PCP was confirmed by physical examination in 30% of cases, with 70% re-diagnosed with normal or retractile testes. Conclusion: Ultrasound performed poorly to assess for palpable undescended testis in boys and should not be used. Although the study has important limitations, there is an increasing need for education and evidence-based guidelines for PCP in the management of undescended testis. PMID:26788226

The role of abdominal ultrasound in the diagnosis of typhoid fever: an observational study.

PubMed

Younis, Saeed Nadhim

2014-01-01

To study the usefulness of abdominal ultrasound in the diagnosis of typhoid fever and to determine the common ultrasound findings early in the course of the disease. Abdominal ultrasound examination was performed within the first week of initiation of symptoms in 350 cases with clinical diagnosis of typhoid fever. Subsequent ultrasound follow-up examination was done 15 days later (beginning of the third week). All the patients proved to have positive Widal test and Sallmonella culture. The study was performed in Erbil-Iraq from the period January 1993 to October 2010. The following ultrasound findings were reported: hepatomegaly (31.4%), prominent intrahepatic bile ducts (64.85%), splenomegaly (100%), mesenteric lymphadenopathy (42.85%), bowel wall thickening (35.71%), acalculous cholecystitis (16.28%), perforations (1.14%), and ascites in (3.4%). The current study showed that the findings are typical enough to justify initiation of treatment for typhoid fever when serology is equivocal and culture is negative, and is fairly safe to say that normal ultrasound examination early in the course of febrile illness rules out typhoid fever. Copyright © 2013 Elsevier Ltd. All rights reserved.

Detecting breast microcalcifications using super-resolution ultrasound imaging: a clinical study

NASA Astrophysics Data System (ADS)

Huang, Lianjie; Labyed, Yassin; Hanson, Kenneth; Sandoval, Daniel; Pohl, Jennifer; Williamson, Michael

2013-03-01

Imaging breast microcalcifications is crucial for early detection and diagnosis of breast cancer. It is challenging for current clinical ultrasound to image breast microcalcifications. However, new imaging techniques using data acquired with a synthetic-aperture ultrasound system have the potential to significantly improve ultrasound imaging. We recently developed a super-resolution ultrasound imaging method termed the phase-coherent multiple-signal classification (PC-MUSIC). This signal subspace method accounts for the phase response of transducer elements to improve image resolution. In this paper, we investigate the clinical feasibility of our super-resolution ultrasound imaging method for detecting breast microcalcifications. We use our custom-built, real-time synthetic-aperture ultrasound system to acquire breast ultrasound data for 40 patients whose mammograms show the presence of breast microcalcifications. We apply our super-resolution ultrasound imaging method to the patient data, and produce clear images of breast calcifications. Our super-resolution ultrasound PC-MUSIC imaging with synthetic-aperture ultrasound data can provide a new imaging modality for detecting breast microcalcifications in clinic without using ionizing radiation.

Implementation of a pediatric critical care focused bedside ultrasound training program in a large academic PICU.

PubMed

Conlon, Thomas W; Himebauch, Adam S; Fitzgerald, Julie C; Chen, Aaron E; Dean, Anthony J; Panebianco, Nova; Darge, Kassa; Cohen, Meryl S; Greeley, William J; Berg, Robert A; Nishisaki, Akira

2015-03-01

To determine the feasibility and describe the process of implementing a pediatric critical care bedside ultrasound program in a large academic PICU and to evaluate the impact of bedside ultrasound on clinical management. Retrospective case series, description of program implementation. Single-center quaternary noncardiac PICU in a children's hospital. Consecutive patients from January 22, 2012, to July 22, 2012, with bedside ultrasounds performed and interpreted by pediatric critical care practitioners. A pediatric critical care bedside ultrasound program consisting of a 2-day immersive course followed by clinical performance with internal quality assurance review was implemented. Studies performed in the PICU following training were documented and reviewed against reference standards including subspecialist-performed ultrasound or clinical response. Seventeen critical care faculties and eight fellows recorded 201 bedside ultrasound studies over 6 months in defined core applications: 57 procedural (28%), 76 hemodynamic (38%), 35 thoracic (17%), and 33 abdominal (16%). A quality assurance review identified 23 studies (16% of all nonprocedural studies) as critical (affected clinical management or gave valuable information). Forty-eight percent of those studies (11/23) were within the hemodynamic core. The proportion of critical studies were not significantly different across the applications (hemodynamic, 11/76 [15%] vs thoracic and abdominal, 12/68 [18%]; p = 0.65). Examples of critical studies include evidence of tamponade secondary to pleural effusions, identification of pulmonary hypertension, hemodynamic assessment before tracheal intubation, recognition of hypovolemia and systemic vascular resistance abnormalities, determination of pneumothorax, location of chest tube and urinary catheter, and differentiation of pleural fluid from pulmonary consolidation. Implementation of a critical care bedside ultrasound program for critical care providers in a large academic PICU is feasible. Bedside ultrasound evaluation and interpretation by intensivists affected the management of critically ill children.

Renal denervation by intravascular ultrasound: Preliminary in vivo study

NASA Astrophysics Data System (ADS)

Sinelnikov, Yegor; McClain, Steve; Zou, Yong; Smith, David; Warnking, Reinhard

2012-10-01

Ultrasound denervation has recently become a subject of intense research in connection with the treatment of complex medical conditions including neurological conditions, development of pain management, reproduction of skin sensation, neuropathic pain and spasticity. The objective of this study is to investigate the use of intravascular ultrasound to produce nerve damage in renal sympathetic nerves without significant injury to the renal artery. This technique may potentially be used to treat various medical conditions, such as hypertension. The study was approved by the Institutional Animal Care and Use Committee. Ultrasound was applied to renal nerves of the swine model for histopathological evaluation. Therapeutic ultrasound energy was delivered circumferentially by an intravascular catheter maneuvered into the renal arteries. Fluoroscopic imaging was conducted pre-and post-ultrasound treatment. Animals were recovered and euthanized up to 30 hours post procedure, followed by necropsy and tissue sample collection. Histopathological examination showed evidence of extensive damage to renal nerves, characterized by nuclear pyknosis, hyalinization of stroma and multifocal hemorrhages, with little or no damage to renal arteries. This study demonstrates the feasibility of intravascular ultrasound as a minimally invasive renal denervation technique. Further studies are necessary to evaluate the long-term safety and efficacy of this technique and its related clinical significance.

Immediate postpartum ultrasound evaluation for suspected retained placental tissue in patients undergoing manual removal of placenta.

PubMed

Weissbach, T; Haikin-Herzberger, E; Bacci-Hugger, K; Shechter-Maor, G; Fejgin, M; Biron-Shental, T

2015-09-01

Approximately 1% of term deliveries are complicated by retained products of conception. Untreated, this condition may cause bleeding, infection and intrauterine adhesions. This study assessed whether performing routine bedside uterine ultrasound immediately after manual removal of the placenta reduced the occurrence of undiagnosed, retained products of conception and its associated complications. A retrospective study was conducted using the records of patients who delivered and underwent manual removal of placenta at a single obstetrics center over a 6-year period. The outcomes of patients who were assessed using immediate bedside ultrasound were compared to a similar group who were treated based on clinical evaluation alone. All patients underwent ultrasound examination prior to discharge. Outcome variables included the rate of additional interventions (medical or surgical), abnormal pre-discharge uterine ultrasound findings, postpartum hemorrhage rate, puerperal fever and length of hospital stay. A total of 399 charts were reviewed. Immediate post-procedural ultrasound was performed in 235 patients. The remaining 164 women did not undergo immediate post-procedural ultrasound. All patients underwent an ultrasound examination prior to discharge. Among the patients who had an immediate post-procedural ultrasound, 12 (5.1%) received immediate re-intervention (2 methergine, 6 curettage and 4 manual uterine revision) vs. no intervention in the second group (p<0.001). No statistically significant difference was found between the group of patients who had immediate post-procedural ultrasound and those who did not, in the rates of postpartum hemorrhage (3.1% vs. 0.7%, p=0.13), abnormal ultrasound findings prior to discharge (14.9% vs. 14.8%, p=0.96) or additional late intervention (7.2% vs. 7.9%, p=0.79), respectively. Our findings suggest that immediate, bedside uterine ultrasound examination after manual removal of placenta might not change patient outcomes. Furthermore, it might increase unnecessary interventions. Further studies are needed to prospectively assess the benefit of routine uterine ultrasound examination after manual removal of placenta. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Characterization of controlled bone defects using 2D and 3D ultrasound imaging techniques.

PubMed

Parmar, Biren J; Longsine, Whitney; Sabonghy, Eric P; Han, Arum; Tasciotti, Ennio; Weiner, Bradley K; Ferrari, Mauro; Righetti, Raffaella

2010-08-21

Ultrasound is emerging as an attractive alternative modality to standard x-ray and CT methods for bone assessment applications. As of today, however, there is a lack of systematic studies that investigate the performance of diagnostic ultrasound techniques in bone imaging applications. This study aims at understanding the performance limitations of new ultrasound techniques for imaging bones in controlled experiments in vitro. Experiments are performed on samples of mammalian and non-mammalian bones with controlled defects with size ranging from 400 microm to 5 mm. Ultrasound findings are statistically compared with those obtained from the same samples using standard x-ray imaging modalities and optical microscopy. The results of this study demonstrate that it is feasible to use diagnostic ultrasound imaging techniques to assess sub-millimeter bone defects in real time and with high accuracy and precision. These results also demonstrate that ultrasound imaging techniques perform comparably better than x-ray imaging and optical imaging methods, in the assessment of a wide range of controlled defects both in mammalian and non-mammalian bones. In the future, ultrasound imaging techniques might provide a cost-effective, real-time, safe and portable diagnostic tool for bone imaging applications.

The comparison of measurement between ultrasound and computed tomography for abnormal degenerative facet joints: A STROBE-compliant article.

PubMed

Shi, Wen; Tian, Dan; Liu, Da; Yin, Jing; Huang, Ying

2017-08-01

Besides the study on examining facet joints of lumbar spine by ultrasound in normal population, there has not been any related report about examining normal facet joints of lumbar spine by ultrasound so far. This study was aimed to explore the feasibility of ultrasound assessment of lumber spine facet joints by comparing ultrasound measure values of normal and degenerative lumber spine facet joints, and by comparing measure values of ultrasound and computed tomography (CT) of degenerative lumber spine facet joints.This study included 15 patients who had chronic low back pain because of degenerative change in lumbar vertebrae, and 19 volunteers who did not have low back pain or pain in the lower limb. The ultrasound measure values (height [H] and width [W]) of normal and degenerative lumber spine facet joints were compared. And the differentiation between measure values (H and W) of ultrasound and CT of degenerative lumber spine facet joints was also analyzed.The ultrasound clearly showed abnormal facet joints lesion, which was characterized by hyperostosis on the edge of joints, bone destruction under joints, and thinner or thicker articular cartilage. There were significant differences between the ultrasound measure values of the normal (H: 1.26 ± 0.03 cm, W: 0.18 ± 0.01 cm) and abnormal facet joints (H: 1.43 ± 0.05 cm, W: 0.15 ± 0.02 cm) (all P < .05). However, there were no significant differences between the measure values of the ultrasound (H: 1.43 ± 0.17 cm, W: 0.15 ± 0.03 cm) and CT (H: 1.42 ± 0.16, W: 0.14 ± 0.03) of the degenerative lumber spine facet joints (all P > .05).Ultrasound can clearly show the structure of facet joints of lumbar spine. It is precise and feasible to assess facet joints of lumbar spine by ultrasound. This study has important significance for the diagnosis of lumbar facet joint degeneration.

Ultrasound detection of placenta accreta in the first trimester of pregnancy.

PubMed

Rahimi-Sharbaf, Fatemeh; Jamal, Ashraf; Mesdaghinia, Elaheh; Abedzadeh-Kalahroudi, Masoumeh; Niroomanesh, Shirin; Atoof, Fatemeh

2014-06-01

Placenta accreta is considered a life-threatening condition and the main cause of maternal mortality. Prenatal diagnosis of placenta accreta usually is made by clinical presentation, imaging studies like ultrasound and MRI in the second and third trimester. To determine accuracy of ultrasound findings for placenta accreta in the first trimester of pregnancy. In a longitudinal study 323 high risk patients for placenta accreta were assessed. The eligible women were examined by vaginal and abdominal ultrasound for gestational sac and placental localization and they were followed up until the end of pregnancy. The ultrasound findings were compared with histopathological examinations as a gold standard. The sensitivity, specificity, positive and negative predictive value of ultrasound were estimated for the first trimester and compared with other 2 trimesters in the case of repeated ultrasound examination. Ultrasound examinations in the first trimester revealed that 28 cases had the findings in favor of placenta accreta which ultimately was confirmed in 7 cases. The ultrasound sensitivity and specificity for detecting placenta accreta in the first trimester was 41% [95% CI: 16.2-62.7] and 88% [95% CI: 88.2-94.6] respectively. Ultrasound screening for placenta accreta in the first trimester of pregnancy could not achieve the high sensitivity as second and third trimester of pregnancy.

Transperineal ultrasound compared to evacuation proctography for diagnosing enteroceles and intussusceptions.

PubMed

Weemhoff, M; Kluivers, K B; Govaert, B; Evers, J L H; Kessels, A G H; Baeten, C G

2013-03-01

This study concerns the level of agreement between transperineal ultrasound and evacuation proctography for diagnosing enteroceles and intussusceptions. In a prospective observational study, 50 consecutive women who were planned to have an evacuation proctography underwent transperineal ultrasound too. Sensitivity, specificity, positive (PPV) and negative predictive value, as well as the positive and negative likelihood ratio of transperineal ultrasound were assessed in comparison to evacuation proctography. To determine the interobserver agreement of transperineal ultrasound, the quadratic weighted kappa was calculated. Furthermore, receiver operating characteristic curves were generated to show the diagnostic capability of transperineal ultrasound. For diagnosing intussusceptions (PPV 1.00), a positive finding on transperineal ultrasound was predictive of an abnormal evacuation proctography. Sensitivity of transperineal ultrasound was poor for intussusceptions (0.25). For diagnosing enteroceles, the positive likelihood ratio was 2.10 and the negative likelihood ratio, 0.85. There are many false-positive findings of enteroceles on ultrasonography (PPV 0.29). The interobserver agreement of the two ultrasonographers assessed as the quadratic weighted kappa of diagnosing enteroceles was 0.44 and that of diagnosing intussusceptions was 0.23. An intussusception on ultrasound is predictive of an abnormal evacuation proctography. For diagnosing enteroceles, the diagnostic quality of transperineal ultrasound was limited compared to evacuation proctography.

Establishment of ultrasound as a diagnostic aid in the referral of patients with abdominal pain in an emergency department – a pilot study

PubMed Central

Poulsen, Liv la Cour; Bækgaard, Emilie Stokholm; Istre, Per Grosen; Schmidt, Thomas Andersen; Larsen, Torben

2015-01-01

Purpose Ultrasonography is a noninvasive, cheap, and fast way of assessing abdominal pain in an emergency department. Many physicians working in emergency departments do not have pre-existing ultrasound experience. The purpose of this study was to investigate the ability of first-year internship doctors to perform a reliable ultrasound examination on patients with abdominal pain in an emergency setting. Materials and methods This study took place in an emergency department in Denmark. Following a 1-day ultrasound introduction course, three doctors without prior ultrasound experience scanned 45 patients during a 2-month period. The applicability of the examinations was evaluated by subsequent control examination: computed tomography, operation, or ultrasound by a trained radiologist or gynecologist or, in cases where the patient was immediately discharged, by ultrasound image evaluation. Results In 14 out of 21 patients with a control examination, there was diagnostic agreement between the project ultrasound examination and the control. Image evaluation of all patients showed useful images of the gallbladder, kidneys, liver, abdominal aorta, and urinary bladder, but no useful images for either the pancreas or colon. Conclusion With only little formal training, it is possible for first-year internship doctors to correctly visualize some abdominal organs with ultrasonography. However, a longer study time frame, including more patients, and an ultrasound course specifically designed for the purpose of use in an emergency department, is needed to enhance the results. PMID:27147884

Temperature Changes During Therapeutic Ultrasound in the Precooled Human Gastrocnemius Muscle

PubMed Central

Rimington, Stephanie J.; Draper, David O.; Durrant, Earlene; Fellingham, Gilbert

1994-01-01

Therapeutic ultrasound is frequently employed as a deep heating rehabilitation modality. It is administered in one of three ways: a) ultrasound with no preceding treatment, b) ultrasound on preheated tissues, or c) ultrasound on precooled tissues. The purpose of this study was to investigate the effect of ultrasound treatments on the tissue temperature rise of precooled human gastrocnemius muscle. Sixteen male subjects had a 23-gauge hypodermic needle microprobe inserted 3 cm deep into the medial aspect of their anesthetized gastrocnemius muscles. Data were gathered on each subject for one of two randomly assigned treatments: a) ultrasound treatment on precooled tissue, or b) ultrasound with no preceding treatment. Each treatment consisted of ultrasound delivered topically at 1.5 watts/cm2 in a continuous mode for 10 minutes. Ultrasound was applied in an overlapping longitudinal motion at 4 cm/s, with temperature readings recorded at 30-second intervals. We discovered a difference between the two treatment methods [t(14) = 16.26, p < .0001]. Ultrasound alone increased tissue temperature an average of 2°C, whereas ultrasound preceded by 15 minutes of ice did not increase tissue temperature even to the original baseline level. We concluded that, at a depth of 3 cm, ultrasound alone provided a greater heating effect than ultrasound preceded by an ice treatment. PMID:16558295

A comparison between the patella and the calcaneus using ultrasound velocity and attenuation as predictors of bone mineral density

NASA Astrophysics Data System (ADS)

Han, S. M.; Davis, J.

1997-10-01

The bone mineral density (BMD), ultrasound velocity (UV) and attenuation were examined in sixteen matched sets of human patellae and calcanei. For the sixteen calcanei, BMD was strongly correlated with all ultrasound parameters. Calcaneal UV appeared to be inferior to attenuation in the ability to predict BMD. For the sixteen patellae, the average UV was found to be greater in the superior/inferior direction than in the anterior/posterior and medial/lateral directions. It was found that patella BMD was significantly correlated with each of three directional ultrasound velocities. The relationship between BMD and ultrasound attenuation parameters was not significant in the patella. A comparative study of the two different bone sets demonstrated that the BMDs of the patella and calcaneus were significantly correlated with each other. Ultrasound velocity of calcaneus, measured in the medial/lateral direction, was not significantly associated with any of three directional ultrasound velocities in the patella. Similarly, ultrasound attenuation parameters of calcaneus were not significantly correlated with those of patella. The present study also demonstrated evidence that when predicting BMDs at their respective sites using ultrasound, the calcaneus appeared to be superior to the patella.

Outcomes of an Advanced Ultrasound Elective: Preparing Medical Students for Residency and Practice.

PubMed

Prats, Michael I; Royall, Nelson A; Panchal, Ashish R; Way, David P; Bahner, David P

2016-05-01

Many medical specialties have adopted the use of ultrasound, creating demands for higher-quality ultrasound training at all levels of medical education. Little is known about the long-term benefit of integrating ultrasound training during undergraduate medical education. This study evaluated the effect of a longitudinal fourth-year undergraduate medical education elective in ultrasound and its impact on the future use of ultrasound in clinical practice. A cross-sectional survey of medical graduates from The Ohio State University College of Medicine (2006-2011) was done, comparing those who participated and those who did not participate in a rigorous ultrasound program for fourth-year medical students. A 38-item questionnaire queried graduates concerning ultrasound education in residency, their proficiency, and their current use of ultrasound in clinical practice. Surveys were completed by 116 respondents, for a return rate of 40.8% (116 of 284). The participants of the undergraduate medical education ultrasound elective (n = 61) reported more hours of ultrasound training after graduation (hands-on training, bedside scanning, and number of scans performed; P < .001), higher ultrasound proficiency (proficiency in using ultrasound for clinical decision making, use in emergency settings, and use of novel techniques; P< .001), and higher rates of ultrasound use in clinical practice (P < .001). The longitudinal undergraduate medical education ultrasound elective produced physicians who were more likely to seek additional training in residency, evaluate themselves as more proficient, and use ultrasound in their clinical practice. Early training in bedside ultrasound during undergraduate medical education yields physicians who are better prepared for integration of ultrasound into clinical practice. © 2016 by the American Institute of Ultrasound in Medicine.

Obstetric and Gynecologic Resident Ultrasound Education Project: Is the Current Level of Gynecologic Ultrasound Training in Canada Meeting the Needs of Residents and Faculty?

PubMed

Green, Jessica; Kahan, Meldon; Wong, Suzanne

2015-09-01

Ultrasound is a critical diagnostic imaging tool in obstetrics and gynecology (Ob/Gyn). Obstetric ultrasound is taught during residency, but we suspected a gap in Gyn ultrasound education. Proficiency in Gyn ultrasound allows real-time interpretation and management of pelvic disease and facilitates technical skill development for trainees learning blinded procedures. This study sought to evaluate ultrasound education in Canada's Ob/Gyn residency programs and assess whether residents and physicians perceived a need for a formalized Gyn ultrasound curriculum. We distributed a needs assessment survey to residents enrolled in Canadian Ob/Gyn residency programs and to all obstetrician/gynecologists registered as members of the Society of Obstetricians and Gynaecologists of Canada. Residents were asked to specify their current training in ultrasound and to rate the adequacy of their curriculum. All respondents rated the importance of proficiency in pelvic ultrasound for practicing obstetrician/gynecologists as well as the perceived need for formalized ultrasound training in Ob/Gyn residency programs. Eighty-two residents and 233 physicians completed the survey. Extents and types of ultrasound training varied across residency programs. Most residents reported inadequate exposure to Gyn ultrasound, and most residents and physicians agreed that it is important for obstetrician/gynecologists to be proficient in Gyn ultrasound and that the development of a standardized Gyn ultrasound curriculum for residency programs is important. Current ultrasound education in Ob/Gyn varies across Canadian residency programs. Training in Gyn ultrasound is lacking, and both trainees and physicians confirmed the need for a standardized Gyn ultrasound curriculum for residency programs in Canada. © 2015 by the American Institute of Ultrasound in Medicine.

Diagnostic Accuracy of Central Venous Catheter Confirmation by Bedside Ultrasound Versus Chest Radiography in Critically Ill Patients: A Systematic Review and Meta-Analysis.

PubMed

Ablordeppey, Enyo A; Drewry, Anne M; Beyer, Alexander B; Theodoro, Daniel L; Fowler, Susan A; Fuller, Brian M; Carpenter, Christopher R

2017-04-01

We performed a systematic review and meta-analysis to examine the accuracy of bedside ultrasound for confirmation of central venous catheter position and exclusion of pneumothorax compared with chest radiography. PubMed, Embase, Cochrane Central Register of Controlled Trials, reference lists, conference proceedings and ClinicalTrials.gov. Articles and abstracts describing the diagnostic accuracy of bedside ultrasound compared with chest radiography for confirmation of central venous catheters in sufficient detail to reconstruct 2 × 2 contingency tables were reviewed. Primary outcomes included the accuracy of confirming catheter positioning and detecting a pneumothorax. Secondary outcomes included feasibility, interrater reliability, and efficiency to complete bedside ultrasound confirmation of central venous catheter position. Investigators abstracted study details including research design and sonographic imaging technique to detect catheter malposition and procedure-related pneumothorax. Diagnostic accuracy measures included pooled sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio. Fifteen studies with 1,553 central venous catheter placements were identified with a pooled sensitivity and specificity of catheter malposition by ultrasound of 0.82 (0.77-0.86) and 0.98 (0.97-0.99), respectively. The pooled positive and negative likelihood ratios of catheter malposition by ultrasound were 31.12 (14.72-65.78) and 0.25 (0.13-0.47). The sensitivity and specificity of ultrasound for pneumothorax detection was nearly 100% in the participating studies. Bedside ultrasound reduced mean central venous catheter confirmation time by 58.3 minutes. Risk of bias and clinical heterogeneity in the studies were high. Bedside ultrasound is faster than radiography at identifying pneumothorax after central venous catheter insertion. When a central venous catheter malposition exists, bedside ultrasound will identify four out of every five earlier than chest radiography.

Temporal comparison of ultrasound vs. auscultation and capnography in verification of endotracheal tube placement.

PubMed

Pfeiffer, P; Rudolph, S S; Børglum, J; Isbye, D L

2011-11-01

This study compared the time consumption of bilateral lung ultrasound with auscultation and capnography for verifying endotracheal intubation. A prospective, paired, and investigator-blinded study carried out in the operating theatre. Twenty-five adult patients requiring endotracheal intubation were included. During intubation, transtracheal ultrasound was performed to visualize passage of the endotracheal tube. During bag ventilation, bilateral lung ultrasound was performed for the detection of lung sliding as a sign of ventilation simultaneous with capnography and auscultation of the epigastrium and chest. Primary outcome measure was time difference to confirmed endotracheal intubation between ultrasound and auscultation alone. Secondary outcome measure was time difference between ultrasound and auscultation combined with capnography. Both methods verified endotracheal tube placement in all patients. In 68% of patients, endotracheal tube placement was visualized by real-time transtracheal ultrasound. Comparing ultrasound with the combination of auscultation and capnography, there was a significant difference between the two methods. Median time for ultrasound was 40 s [interquartile range (IQR) 35-48 s] vs. 48 s (IQR 45-53 s), P < 0.0001. Mean difference was -7.1 s in favour of ultrasound [95% confidence interval (CI) -9.4--4.8 s]. No significant difference was found between ultrasound compared with auscultation alone. Median time for auscultation alone was 42 s (IQR 37-47 s), P = 0.6, with a mean difference of -0.88 s in favour of ultrasound (95% CI -4.2-2.5 s). Verification of endotracheal tube placement with ultrasound is as fast as auscultation alone and faster than the standard method of auscultation and capnography. © 2011 The Authors. Acta Anaesthesiologica Scandinavica © 2011 The Acta Anaesthesiologica Scandinavica Foundation.

Ultrasound of the coracoclavicular ligaments in the acute phase of an acromioclavicular disjonction: Comparison of radiographic, ultrasound and MRI findings.

PubMed

Faruch Bilfeld, Marie; Lapègue, Franck; Chiavassa Gandois, Hélène; Bayol, Marie Aurélie; Bonnevialle, Nicolas; Sans, Nicolas

2017-02-01

Acromioclavicular joint injuries are typically diagnosed by clinical and radiographic assessment with the Rockwood classification, which is crucial for treatment planning. The purpose of this study was to describe how the ultrasound findings of acromioclavicular joint injury compare with radiography and MRI findings. Forty-seven patients with suspected unilateral acromioclavicular joint injury after acute trauma were enrolled in this prospective study. All patients underwent digital radiography, ultrasound and 3T MRI. A modified Rockwood classification was used to evaluate the coracoclavicular ligaments. The classifications of acromioclavicular joint injuries diagnosed with radiography, ultrasound and MRI were compared. MRI was used as the gold standard. The agreement between the ultrasound and MRI findings was very good, with a correlation coefficient of 0.83 (95 % CI: 0.72-0.90; p < 0.0001). Ultrasound detected coracoclavicular ligament injuries with a sensitivity of 88.9 %, specificity of 90.0 %, positive predictive value of 92.3 % and negative predictive value of 85.7 %. The agreement between the ultrasound and radiography findings was poor, with a correlation coefficient of 0.69 (95 % CI: 0.51-0.82; p < 0.0001). Ultrasound is an effective examination for the diagnostic work-up of lesions of the coracoclavicular ligaments in the acute phase of an acromioclavicular injury. • Ultrasound is appropriate for acute acromioclavicular trauma due to its accessibility. • Ultrasound contributes to the diagnostic work-up of acute lesions of the coracoclavicular ligaments. • Ultrasound is appropriate in patients likely to benefit from surgical treatment. • Ultrasound could be a supplement to standard radiography in acute acromioclavicular trauma.

Strain elastography of abnormal axillary nodes in breast cancer patients does not improve diagnostic accuracy compared with conventional ultrasound alone.

PubMed

Park, Young Mi; Fornage, Bruno D; Benveniste, Ana Paula; Fox, Patricia S; Bassett, Roland L; Yang, Wei Tse

2014-12-01

The purpose of this study was to determine the diagnostic value of strain elastography (SE) alone and in combination with gray-scale ultrasound in the diagnosis of benign versus metastatic disease for abnormal axillary lymph nodes in breast cancer patients. Patients with breast cancer and axillary lymph nodes suspicious for metastatic disease on conventional ultrasound who underwent SE of the suspicious node before ultrasound-guided fine-needle aspiration biopsy (FNAB) were included in this study. On conventional ultrasound, the long- and short-axis diameters, long-axis-to-short-axis ratio, cortical echogenicity, thickness, and evenness were documented. The nodal vascularity was assessed on power Doppler imaging. Elastograms were evaluated for the percentage of black (hard) areas in the lymph node, and the SE-ultrasound size ratio was calculated. Two readers assessed the images independently and then in consensus in cases of disagreement. ROC AUCs were calculated for conventional ultrasound, SE, and both methods combined. Interreader reliability was assessed using kappa statistics. A total of 101 patients with 104 nodes were examined; 35 nodes were benign, and 69 had metastases. SE alone showed a significantly lower AUC (62%) than did conventional ultrasound (92%) (p<0.001). There was no difference between the AUC of conventional ultrasound and the AUC of the combination of conventional ultrasound and SE (93%) (p=0.16). Interreader reliability was moderate for all variables (κ≥0.60) except the SE-ultrasound size ratio (κ=0.35). Added SE does not improve the diagnostic ability of conventional ultrasound when evaluating abnormal axillary lymph nodes.

Routine screening for fetal anomalies: expectations.

PubMed

Goldberg, James D

2004-03-01

Ultrasound has become a routine part of prenatal care. Despite this, the sensitivity and specificity of the procedure is unclear to many patients and healthcare providers. In a small study from Canada, 54.9% of women reported that they had received no information about ultrasound before their examination. In addition, 37.2% of women indicated that they were unaware of any fetal problems that ultrasound could not detect. Most centers that perform ultrasound do not have their own statistics regarding sensitivity and specificity; it is necessary to rely on large collaborative studies. Unfortunately, wide variations exist in these studies with detection rates for fetal anomalies between 13.3% and 82.4%. The Eurofetus study is the largest prospective study performed to date and because of the time and expense involved in this type of study, a similar study is not likely to be repeated. The overall fetal detection rate for anomalous fetuses was 64.1%. It is important to note that in this study, ultrasounds were performed in tertiary centers with significant experience in detecting fetal malformations. The RADIUS study also demonstrated a significantly improved detection rate of anomalies before 24 weeks in tertiary versus community centers (35% versus 13%). Two concepts seem to emerge from reviewing these data. First, patients must be made aware of the limitations of ultrasound in detecting fetal anomalies. This information is critical to allow them to make informed decisions whether to undergo ultrasound examination and to prepare them for potential outcomes.Second, to achieve the detection rates reported in the Eurofetus study, ultrasound examination must be performed in centers that have extensive experience in the detection of fetal anomalies.

Feasibility of ultrasound imaging of osteochondral defects in the ankle: a clinical pilot study.

PubMed

Kok, A C; Terra, M P; Muller, S; Askeland, C; van Dijk, C N; Kerkhoffs, G M M J; Tuijthof, G J M

2014-10-01

Talar osteochondral defects (OCDs) are imaged using magnetic resonance imaging (MRI) or computed tomography (CT). For extensive follow-up, ultrasound might be a fast, non-invasive alternative that images both bone and cartilage. In this study the potential of ultrasound, as compared with CT, in the imaging and grading of OCDs is explored. On the basis of prior CT scans, nine ankles of patients without OCDs and nine ankles of patients with anterocentral OCDs were selected and classified using the Loomer CT classification. A blinded expert skeletal radiologist imaged all ankles with ultrasound and recorded the presence of OCDs. Similarly to CT, ultrasound revealed typical morphologic OCD features, for example, cortex irregularities and loose fragments. Cartilage disruptions, Loomer grades IV (displaced fragment) and V (cyst with fibrous roof), were visible as well. This study encourages further research on the use of ultrasound as a follow-up imaging modality for OCDs located anteriorly or centrally on the talar dome. Copyright © 2014 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Ultrasound Assessment of Human Meniscus.

PubMed

Viren, Tuomas; Honkanen, Juuso T; Danso, Elvis K; Rieppo, Lassi; Korhonen, Rami K; Töyräs, Juha

2017-09-01

The aim of the present study was to evaluate the applicability of ultrasound imaging to quantitative assessment of human meniscus in vitro. Meniscus samples (n = 26) were harvested from 13 knee joints of non-arthritic human cadavers. Subsequently, three locations (anterior, center and posterior) from each meniscus were imaged with two ultrasound transducers (frequencies 9 and 40 MHz), and quantitative ultrasound parameters were determined. Furthermore, partial-least-squares regression analysis was applied for ultrasound signal to determine the relations between ultrasound scattering and meniscus integrity. Significant correlations between measured and predicted meniscus compositions and mechanical properties were obtained (R 2  = 0.38-0.69, p < 0.05). The relationship between conventional ultrasound parameters and integrity of the meniscus was weaker. To conclude, ultrasound imaging exhibited a potential for evaluation of meniscus integrity. Higher ultrasound frequency combined with multivariate analysis of ultrasound backscattering was found to be the most sensitive for evaluation of meniscus integrity. Copyright © 2017 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Evaluation of Chest Ultrasound Integrated Teaching of Respiratory System Physiology to Medical Students

ERIC Educational Resources Information Center

Paganini, Matteo; Bondì, Michela; Rubini, Alessandro

2017-01-01

Ultrasound imaging is a widely used diagnostic technique, whose integration in medical education is constantly growing. The aim of this study was to evaluate chest ultrasound usefulness in teaching respiratory system physiology, students' perception of chest ultrasound integration into a traditional lecture in human physiology, and short-term…

Improved heating efficiency with High-Intensity Focused Ultrasound using a new ultrasound source excitation.

PubMed

Bigelow, Timothy A

2009-01-01

High-Intensity Focused Ultrasound (HIFU) is quickly becoming one of the best methods to thermally ablate tissue noninvasively. Unlike RF or Laser ablation, the tissue can be destroyed without inserting any probes into the body minimizing the risk of secondary complications such as infections. In this study, the heating efficiency of HIFU sources is improved by altering the excitation of the ultrasound source to take advantage of nonlinear propagation. For ultrasound, the phase velocity of the ultrasound wave depends on the amplitude of the wave resulting in the generation of higher harmonics. These higher harmonics are more efficiently converted into heat in the body due to the frequency dependence of the ultrasound absorption in tissue. In our study, the generation of the higher harmonics by nonlinear propagation is enhanced by transmitting an ultrasound wave with both the fundamental and a higher harmonic component included. Computer simulations demonstrated up to a 300% increase in temperature increase compared to transmitting at only the fundamental for the same acoustic power transmitted by the source.

[Development of studies on bioeffects of ultrasound-acupuncture therapy and its underlying mechanism].

PubMed

Yang, Yu-Hua; Zhang, Di; Sa, Zhe-Yan; Huang, Meng; Ding, Guang-Hong

2012-08-01

The so-called ultrasound acupuncture is a therapeutic approach for clinical problems and health care by applying the ultrasound energy to the acupoints of the human body directly or indirectly. It has been applied in clinic for about 30 years since 1980s. In the present paper, the authors review the development of both experimental and clinical researches in the past 30 years. Its clinical application includes allergic rhinitis, local pain, mastitis, angina pectoris of coronary heart disease, stroke, etc. Regarding the researches on the underlying mechanism of ultrasound and ultrasound acupuncture, the authors make a summary from 1) bioeffects (thermal and nonthermal effects) of ultrasound intervention; 2) cell lysis and nonlysis effects of ultrasound intervention; and 3) effects of ultrasound acupuncture on the degranulation of mast cells. Based on the idea that "inflammatory reaction caused by mast cell degranulation is one of the initial factors of acupuncture for inducing therapeutic effects", bioeffects including cellular changes, especially mast cell degranulation caused by ultrasound stimulation, are thought to be the main possible mechanisms underlying the favorable efficacy of ultrasound acupuncture intervention. However, the ultrasound metrology and the specific superiority of ultrasound acupuncture remain unknown up to now.

Universal Head Ultrasound Screening in Full-term Neonates: A Retrospective Analysis of 6771 Infants.

PubMed

Ballardini, Elisa; Tarocco, Anna; Rosignoli, Chiara; Baldan, Alessandro; Borgna-Pignatti, Caterina; Garani, Giampaolo

2017-06-01

Full-term neonates may have asymptomatic cranial injuries at birth and head ultrasound screening could be useful for early diagnosis. The aim of this study was to assess the prevalence and type of intracranial abnormalities and the usefulness of head ultrasound screening in these infants. Head ultrasound screening was performed on all full-term neonates (gestational age between 37 and 42 weeks), born at Sant'Anna University Hospital of Ferrara, Italy, from June 1, 2008 through May 31, 2013. Ultrasound findings were categorized into three groups: normal, minor, and major anomalies. All full-term neonates (6771) born at our hospital underwent head ultrasound screening. One hundred fourteen of 6771 (1.7%) presented ultrasound abnormalities, whereas 6657 were normal or exhibited insignificant findings. In 101 of 114 (88.6%), abnormalities were minor, and only 13 infants had major abnormalities (0.19% of all full-term newborns). All neonates with major abnormalities presented with either microcephaly or abnormal neurological evaluations. Only one individual with major abnormalities was detected exclusively by ultrasound. The number of significant anomalies detected by head ultrasound screening in asymptomatic full-term neonates born during the study period was low. Therefore, there is no indication for routine general head ultrasound screening in these patients. However, even if low, in neonates who have neurological abnormalities, risk factors or suspected brain malformations, head ultrasound screening may play an important role in the early diagnosis of intracranial anomalies. Copyright © 2017 Elsevier Inc. All rights reserved.

Ultrasound-enhanced ocular delivery of dexamethasone sodium phosphate: an in vivo study

PubMed Central

2014-01-01

Background The eye's unique anatomy and its physiological and anatomical barriers can limit effective drug delivery into the eye. Methods An in vivo study was designed to determine the effectiveness and safety of ultrasound application in enhancing drug delivery in a rabbit model. Permeability of a steroid ophthalmic drug, dexamethasone sodium phosphate, was investigated in ultrasound- and sham-treated cases. For this study, an eye cup filled with dexamethasone sodium phosphate was placed on the cornea. Ultrasound was applied at intensity of 0.8 W/cm2 and frequency of 400 or 600 kHz for 5 min. The drug concentration in aqueous humor samples, collected 90 min after the treatment, was determined using chromatography methods. Light microscopy observations were done to determine the structural changes in the cornea as a result of ultrasound application. Results An increase in drug concentration in aqueous humor samples of 2.8 times (p < 0.05) with ultrasound application at 400 kHz and 2.4 times (p < 0.01) with ultrasound application at 600 kHz was observed as compared to sham-treated samples. Histological analysis showed that the structural changes in the corneas exposed to ultrasound predominantly consisted of minor epithelial disorganization. Conclusions Ultrasound application enhanced the delivery of an anti-inflammatory ocular drug, dexamethasone sodium phosphate, through the cornea in vivo. Ultrasound-enhanced ocular drug delivery appears to be a promising area of research with a potential future application in a clinical setting. PMID:24921047

Synovial Inflammation Drives Structural Damage in Hand Osteoarthritis: a Narrative Literature Review.

PubMed

Mancarella, Luana; Addimanda, Olga; Cavallari, Carlotta; Meliconi, Riccardo

2017-01-01

Ultrasound is one of the most promising candidates for the detection of inflammation and structural damage in hand osteoarthritis. To evaluate new advances of US as a diagnostic and prognostic tool in hand osteoarthritis assessment. We conducted a Medline on PubMed search for articles about "ultrasonography" and "hand OA" published between January 2012 and 15th April 2016, limiting our search to articles on human adults in English, excluding those involving systemic inflammatory diseases, visualization of joints other than hands, ultrasound guided injections and surgical procedures. Reviews, case reports, letters, position statements and ex vivo studies were excluded. Concordance between ultrasound and conventional radiography and magnetic resonance imaging was evaluated. Total 46 records were identified, and 16 articles were selected: four showed only ultrasound structural damage (osteophytes, cartilage pathology), six only ultrasound inflammatory variables (synovial thickness, effusion and power Doppler signal), six should considered both ultrasound structural and inflammatory features as well as erosions and two were epidemiological studies. Ultrasound synovitis and power Doppler signal were more frequent in erosive hand osteoarthritis. Followup studies found that ultrasound inflammatory features at baseline are independently associated with radiographic progression; power Doppler signal was the strongest predictor of structural damage. Ultrasound is a reliable tool for cartilage and osteophyte assessment (when performed with static images) and shows a good concordance with magnetic resonance imaging for osteophytes, erosions and synovitis. Ultrasound detected inflammation may predict radiographic progression and may be used in prospective clinical trials of hand osteoarthritis and in everyday clinical practice. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Addressing Phonological Questions with Ultrasound

ERIC Educational Resources Information Center

Davidson, Lisa

2005-01-01

Ultrasound can be used to address unresolved questions in phonological theory. To date, some studies have shown that results from ultrasound imaging can shed light on how differences in phonological elements are implemented. Phenomena that have been investigated include transitional schwa, vowel coalescence, and transparent vowels. A study of…

Power ultrasound-assisted cleaner leather dyeing technique: influence of process parameters.

PubMed

Sivakumar, Venkatasubramanian; Rao, Paruchuri Gangadhar

2004-03-01

The application of power ultrasound to leather processing has a significant role in the concept of "clean technology" for leather production. The effect of power ultrasound in leather dyeing has been compared with dyeing in the absence of ultrasound and conventional drumming. The power ultrasound source used in these experiments was ultrasonic cleaner (150 W and 33 kHz). The effect of various process parameters such as amount of dye offer, temperature, and type of dye has been experimentally found out. The effect of presonication of dye solution as well as leather has been studied. Experiments at ultrasonic bath temperature were carried out to find out the combined thermal as well as stirring effects of ultrasound. Dyeing in the presence of ultrasound affords about 37.5 (1.8 times) difference as increase in % dye exhaustion or about 50% decrease in the time required for dyeing compared to dyeing in the absence of ultrasound for 4% acid red dye. About 29 (1.55 times) increase in % dye exhaustion or 30% reduction in time required for dyeing was observed using ultrasound at stationary condition compared with conventional dynamic drumming conditions. The effect of ultrasound at constant temperature conditions with a control experiment has also been studied. The dye exhaustion increases as the temperature increases (30-60 degrees C) and better results are observed at higher temperature due to the use of ultrasound. Presonication of dye solution or crust leather prior to the dyeing process has no significant improvement in dye exhaustion, suggesting ultrasound effect is realized when it is applied during the dyeing process. The results indicate that 1697 and 1416 ppm of dye can be reduced in the spent liquor due to the use of ultrasound for acid red (for 100 min) and acid black (for 3 h) dyes, respectively, thereby reducing the pollution load in the effluent stream. The color yield of the leather as inferred from the reflectance measurement indicates that dye offer can be halved when ultrasound is employed to promote dyeing. Scanning electron microscopy analysis of the cross section of the dyed leather indicates that fiber structure is not affected due to the use of ultrasound under the given process conditions. The present study clearly demonstrates that ultrasound can be used as a tool to improve the rate of exhaustion of dye, reduce pollution load in the spent effluent liquor, and improve the quality of leather produced. The study also offered provision to employ optimum levels of chemicals and increases percentage exhaustion for a given time, thereby limiting the pollution load in the tannery effluent, which is of great social concern.

Using ultrasound to teach medical students cardiac physiology.

PubMed

Bell, Floyd E; Wilson, L Britt; Hoppmann, Richard A

2015-12-01

Ultrasound is being incorporated more into undergraduate medical education. Studies have shown that medical students have positive perceptions about the value of ultrasound in teaching courses like anatomy and physiology. The purpose of the present study was to provide objective evidence of whether ultrasound helps students learn cardiac physiology. In this study, 20 medical students took a pretest to assess their background knowledge of cardiac physiology. Next, they acquired ultrasound video loops of the heart. Faculty members taught them nonelectrical aspects of cardiac physiology using those loops. Finally, students took a posttest to evaluate for improvements in their knowledge. Students also completed an anonymous questionnaire about their experience. The mean pretest score was 4.8 of 9 (53.3%). The mean posttest score was 7.35 of 9 (81.7%). The mean difference was significant at P < 0.0001. Student feedback was very positive about the ultrasound laboratory. Ninety-five percent of the students agreed or strongly agreed that the ultrasound laboratory was a valuable teaching tool and that it improved their understanding of cardiac physiology. All students agreed or strongly agreed the laboratory was helpful from a visual learning standpoint. A hands-on ultrasound laboratory can indeed help medical students learn the nonelectrical components of cardiac physiology. Copyright © 2015 The American Physiological Society.

Impact of Music in Reducing Patient Anxiety During Pediatric Ultrasound

PubMed Central

Kesselman, Andrew; Bergen, Michael; Stefanov, Dimitre; Goldfisher, Rachelle; Amodio, John

2016-01-01

The use of noninvasive ultrasound examinations can potentially result in significant anxiety in the pediatric population. The purpose of this study was to assess the influence of music during pediatric ultrasound examinations to reduce anxiety measured by heart rate. A total of 44 patients were recruited; 21 controls and 23 experimental. Each participant was randomized to either music or no music (control) after parental consent was obtained. Pulse oximeters were used to monitor heart rate at 15 second intervals for a total of 1 minute, with mean values calculated prior to entering the procedure room, during the middle of the procedure, and after the procedure was completed. The total scan time was determined from the initial image acquisition until the last image recorded by the ultrasound technologist. At the completion of each procedure, the ultrasound technologist scored the ease of performance for the scan on a subjective scale of 1-10 based on prior experience. When utilizing music during pediatric ultrasounds examinations, our study demonstrated significantly decreased heart rate variability from pre-procedural to post-procedural periods. There was no statistical significant difference in total scan time or ultrasound technologist scoring between the two groups. This study demonstrates that music is an inexpensive and effective means of reducing anxiety during pediatric ultrasound as indicated by heart rate. PMID:27114817

Diagnostic accuracy of ultrasonography in detection of blunt abdominal trauma and comparison of early and late ultrasonography 24 hours after trauma.

PubMed

Feyzi, Ali; Rad, Masoud Pezeshki; Ahanchi, Navid; Firoozabadi, Jalil

2015-01-01

Despite the advantages of ultrasound scan, its use as a screening tool in blunt abdominal trauma is controversial. The aim of this study was to evaluate the diagnostic value of early and late ultrasound in patients with blunt abdominal trauma (BAT). In this study which was performed in a level I trauma center, firstly, 2418 patients with BAT had ultrasound (US) examination by two trauma expert radiologists. Results were compared with the best available gold standards such as laparotomy, CT, repeated ultrasound or clinical course follow-up. Then, 400 patients with BAT were examined by a trained residency student. In the first phase, sensitivity, specificity, negative predictive value, positive predictive value and accuracy of ultrasound were 97%, 98.1%, 99.7%, 83% and 98% respectively. In the second phase, they were 97.3%, 97.2%, 97.7%, 96.8% and 97.3% for the early and 98.5%, 97.6%, 98.5%, 97.5% and 98% for the late ultrasound respectively. Results obtained from this study indicate that negative ultrasound findings associated with negative clinical observation virtually exclude abdominal injury, and confirmation by performing other tests is unnecessary. High sensitivity and negative predictive value is achieved if ultrasound is performed by expert trauma radiologist.

[Two- and three-dimensional power Doppler ultrasound in the follow-up of placenta accreta treated conservatively].

PubMed

Roulot, A; Barranger, E; Morel, O; Soyer, P; Héquet, D

2015-02-01

To determinate the potential of 2D and 3D-ultrasound in the follow-up of patients with placenta accreta treated conservatively. Seven patients with placenta accreta treated conservatively during June 2007 and September 2009 were included. The follow-up consisted in clinical examination and 2D/3D-ultrasound once a month. Criteria studied included clinical outcome, echogenicity at 2D-ultrasound, vascularisation at colour Doppler, Mean Grey at 3D-ultrasound and vascularisation, flow and perfusion index. Seven women with invasive placenta (3 placentas accreta and 2 percreta) were studied. The mean follow-up was 228 days [75-369]. Mean delay for complete elimination of residual placenta was 280 days [120-365]. The two main results were: presence of an increased anechogenicpart in residual placenta before complete resorption for all patients; a systematic and concomitant stop of genital haemorrhage and vascularisation at colour Doppler. High degrees of variability in parameters measured at 3D-ultrasound were observed between patients so that correlations with clinical outcome were found. Long and regular follow-up is essential after conservative management but the role of 3D-ultrasound compared to 2D-ultrasound was not demonstrated in this study. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Ultrasound detection of placenta accreta in the first trimester of pregnancy

PubMed Central

Rahimi-Sharbaf, Fatemeh; Jamal, Ashraf; Mesdaghinia, Elaheh; Abedzadeh- Kalahroudi, Masoumeh; Niroomanesh, Shirin; Atoof, Fatemeh

2014-01-01

Background: Placenta accreta is considered a life-threatening condition and the main cause of maternal mortality. Prenatal diagnosis of placenta accreta usually is made by clinical presentation, imaging studies like ultrasound and MRI in the second and third trimester. Objective: To determine accuracy of ultrasound findings for placenta accreta in the first trimester of pregnancy. Materials and Methods: In a longitudinal study 323 high risk patients for placenta accreta were assessed. The eligible women were examined by vaginal and abdominal ultrasound for gestational sac and placental localization and they were followed up until the end of pregnancy. The ultrasound findings were compared with histopathological examinations as a gold standard. The sensitivity, specificity, positive and negative predictive value of ultrasound were estimated for the first trimester and compared with other 2 trimesters in the case of repeated ultrasound examination. Results: Ultrasound examinations in the first trimester revealed that 28 cases had the findings in favor of placenta accreta which ultimately was confirmed in 7 cases. The ultrasound sensitivity and specificity for detecting placenta accreta in the first trimester was 41% [95% CI: 16.2-62.7] and 88% [95% CI: 88.2-94.6] respectively. Conclusion: Ultrasound screening for placenta accreta in the first trimester of pregnancy could not achieve the high sensitivity as second and third trimester of pregnancy. PMID:25071851

Accuracy of ultrasound-guided nerve blocks of the cervical zygapophysial joints.

PubMed

Siegenthaler, Andreas; Mlekusch, Sabine; Trelle, Sven; Schliessbach, Juerg; Curatolo, Michele; Eichenberger, Urs

2012-08-01

Cervical zygapophysial joint nerve blocks typically are performed with fluoroscopic needle guidance. Descriptions of ultrasound-guided block of these nerves are available, but only one small study compared ultrasound with fluoroscopy, and only for the third occipital nerve. To evaluate the potential usefulness of ultrasound-guidance in clinical practice, studies that determine the accuracy of this technique using a validated control are essential. The aim of this study was to determine the accuracy of ultrasound-guided nerve blocks of the cervical zygapophysial joints using fluoroscopy as control. Sixty volunteers were studied. Ultrasound-imaging was used to place the needle to the bony target of cervical zygapophysial joint nerve blocks. The levels of needle placement were determined randomly (three levels per volunteer). After ultrasound-guided needle placement and application of 0.2 ml contrast dye, fluoroscopic imaging was performed for later evaluation by a blinded pain physician and considered as gold standard. Raw agreement, chance-corrected agreement κ, and chance-independent agreement Φ between the ultrasound-guided placement and the assessment using fluoroscopy were calculated to quantify accuracy. One hundred eighty needles were placed in 60 volunteers. Raw agreement was 87% (95% CI 81-91%), κ was 0.74 (0.64-0.83), and Φ 0.99 (0.99-0.99). Accuracy varied significantly between the different cervical nerves: it was low for the C7 medial branch, whereas all other levels showed very good accuracy. Ultrasound-imaging is an accurate technique for performing cervical zygapophysial joint nerve blocks in volunteers, except for the medial branch blocks of C7.

A pilot study of comprehensive ultrasound education at the Wayne State University School of Medicine: a pioneer year review.

PubMed

Rao, Sishir; van Holsbeeck, Lodewijk; Musial, Joseph L; Parker, Alton; Bouffard, J Antonio; Bridge, Patrick; Jackson, Matt; Dulchavsky, Scott A

2008-05-01

Ultrasound is a versatile diagnostic modality used in a variety of medical fields. Wayne State University School of Medicine (WSUSOM) is one of the first medical schools in the United States to integrate an ultrasound curriculum through both basic science courses and clinical clerkships. In 2006, 25 portable ultrasound units were donated to WSUSOM. First-year medical students were provided an ultrasound curriculum consisting of 6 organ-system sessions that addressed the basics of ultrasound techniques, anatomy, and procedural skills. After the last session, students were administered 2 anonymous and voluntary evaluations. The first assessed their overall experience with the ultrasound curriculum, and the second assessed their technical skills in applying ultrasound techniques. Eighty-three percent of students agreed or strongly agreed that their experience with ultrasound education was positive. On the summative evaluation, nearly 91% of students agreed or strongly agreed that they would benefit from continued ultrasound education throughout their 4 years of medical school. Student performance on the technical assessment was also very positive, with mean class performance of 87%. As residency programs adopt ultrasound training, medical school faculty should consider incorporating ultrasound education into their curriculum. Portable ultrasound has the potential to be used in many different settings, including rural practice sites and sporting events. The WSUSOM committee's pilot ultrasound curriculum will continue to use student feedback to enhance the ultrasound experience, helping students prepare for challenges that they will face in the future.

Diagnostic accuracy of central venous catheter confirmation by bedside ultrasound versus chest radiography in critically ill patients: A systematic review and meta-analysis

PubMed Central

Ablordeppey, Enyo A.; Drewry, Anne M.; Beyer, Alexander B.; Theodoro, Daniel L.; Fowler, Susan A.; Fuller, Brian M.; Carpenter, Christopher R.

2016-01-01

Objective We performed a systematic review and meta-analysis to examine the accuracy of bedside ultrasound for confirmation of central venous catheter position and exclusion of pneumothorax compared to chest radiography. Data Sources PubMed, EMBASE, Cochrane Central Register of Controlled Trials, reference lists, conference proceedings and ClinicalTrials.gov Study Selection Articles and abstracts describing the diagnostic accuracy of bedside ultrasound compared with chest radiography for confirmation of central venous catheters in sufficient detail to reconstruct 2×2 contingency tables were reviewed. Primary outcomes included the accuracy of confirming catheter positioning and detecting a pneumothorax. Secondary outcomes included feasibility, inter-rater reliability, and efficiency to complete bedside ultrasound confirmation of central venous catheter position. Data Extraction Investigators abstracted study details including research design and sonographic imaging technique to detect catheter malposition and procedure-related pneumothorax. Diagnostic accuracy measures included pooled sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio. Data Synthesis 15 studies with 1553 central venous catheter placements were identified with a pooled sensitivity and specificity of catheter malposition by ultrasound of 0.82 [0.77, 0.86] and 0.98 [0.97, 0.99] respectively. The pooled positive and negative likelihood ratios of catheter malposition by ultrasound were 31.12 [14.72, 65.78] and 0.25 [0.13, 0.47]. The sensitivity and specificity of ultrasound for pneumothorax detection was nearly 100% in the participating studies. Bedside ultrasound reduced mean central venous catheter confirmation time by 58.3 minutes. Risk of bias and clinical heterogeneity in the studies were high. Conclusions Bedside ultrasound is faster than radiography at identifying pneumothorax after central venous catheter insertion. When a central venous catheter malposition exists, bedside ultrasound will identify four out of every five earlier than chest radiography. PMID:27922877

Ultrasound in the evaluation of enthesitis: status and perspectives.

PubMed

Gandjbakhch, Frédérique; Terslev, Lene; Joshua, Fredrick; Wakefield, Richard J; Naredo, Esperanza; D'Agostino, Maria Antonietta

2011-01-01

An increasing number of studies have applied ultrasound to the evaluation of entheses in spondyloarthritis patients. However, no clear agreement exists on the definition of enthesitis, on the number and choice of entheses to examine and on ultrasound technique, which may all affect the results of the examination. The objectives of this study were to first determine the level of homogeneity in the ultrasound definitions for the principal lesions of enthesitis in the published literature and second, to evaluate the metric properties of ultrasound for detecting enthesitis according to the OMERACT filter. Search was performed in PUBMED and EMBASE. Both grey-scale and Doppler definitions of enthesitis, including describing features of enthesitis, were collected and metrological qualities of studies were assessed. After selection, 48 articles were analyzed. The definition of ultrasound enthesitis and elementary features varied among authors. Grey-scale enthesitis was characterized by increasing thickness (94% of studies), hypoechogenicity (83%), enthesophytes (69%), erosions (67%), calcifications (52%), associated bursitis (46%) and cortical irregularities (29%). Only 46% of studies reported the use of Doppler. High discrepancies were observed on frequency, type of probe and Doppler mode used. Face and content validity were the most frequently evaluated criteria (43%) followed by reliability (29%) and responsiveness (19%). Ultrasound has evidence to support face, content validity and reliability for the evaluation of enthesitis, though there is a lack of well-reported methodology in most of the studies. Consensus on elementary lesions and standardization of exam is needed to determine the ultrasound definition of enthesitis in grey-scale and in Doppler for future applications.

Intraoperative Ultrasound in Patients Undergoing Transsphenoidal Surgery for Pituitary Adenoma: Systematic Review [corrected].

PubMed

Marcus, Hani J; Vercauteren, Tom; Ourselin, Sebastien; Dorward, Neil L

2017-10-01

Transsphenoidal surgery is the gold standard for pituitary adenoma resection. However, despite advances in microsurgical and endoscopic techniques, some pituitary adenomas can be challenging to cure. We sought to determine whether, in patients undergoing transsphenoidal surgery for pituitary adenoma, intraoperative ultrasound is a safe and effective technologic adjunct. The PubMed database was searched between January 1996 and January 2016 to identify relevant publications that 1) featured patients undergoing transsphenoidal surgery for pituitary adenoma, 2) used intraoperative ultrasound, and 3) reported on safety or effectiveness. Reference lists were also checked, and expert opinions were sought to identify further publications. Ultimately, 10 studies were included, comprising 1 cohort study, 7 case series, and 2 case reports. One study reported their prototype probe malfunctioned, leading to false-positive results in 2 cases, and another study' prototype probe was too large to safely enter the sphenoid sinus in 2 cases. Otherwise, no safety issues directly related to use of intraoperative ultrasound were reported. In the only comparative study, remission occurred in 89.7% (61/68) of patients with Cushing disease in whom intraoperative ultrasound was used, compared with 83.8% (57/68) in whom it was not. All studies reported that surgeons anecdotally found intraoperative ultrasound helpful. Although there is limited and low-quality evidence available, the use of intraoperative ultrasound appears to be a safe and effective technologic adjunct to transsphenoidal surgery for pituitary adenoma. Advances in ultrasound technology may allow for more widespread use of such devices. Copyright © 2017 Elsevier Inc. All rights reserved.

Prognostic value of three-dimensional ultrasound for fetal hydronephrosis

PubMed Central

WANG, JUNMEI; YING, WEIWEN; TANG, DAXING; YANG, LIMING; LIU, DONGSHENG; LIU, YUANHUI; PAN, JIAOE; XIE, XING

2015-01-01

The present study evaluated the prognostic value of three-dimensional ultrasound for fetal hydronephrosis. Pregnant females with fetal hydronephrosis were enrolled and a novel three-dimensional ultrasound indicator, renal parenchymal volume/kidney volume, was introduced to predict the postnatal prognosis of fetal hydronephrosis in comparison with commonly used ultrasound indicators. All ultrasound indicators of fetal hydronephrosis could predict whether postnatal surgery was required for fetal hydronephrosis; however, the predictive performance of renal parenchymal volume/kidney volume measurements as an individual indicator was the highest. In conclusion, ultrasound is important in predicting whether postnatal surgery is required for fetal hydronephrosis, and the three-dimensional ultrasound indicator renal parenchymal volume/kidney volume has a high predictive performance. Furthermore, the majority of cases of fetal hydronephrosis spontaneously regress subsequent to birth, and the regression time is closely associated with ultrasound indicators. PMID:25667626

Breast ultrasound tomography with two parallel transducer arrays: preliminary clinical results

NASA Astrophysics Data System (ADS)

Huang, Lianjie; Shin, Junseob; Chen, Ting; Lin, Youzuo; Intrator, Miranda; Hanson, Kenneth; Epstein, Katherine; Sandoval, Daniel; Williamson, Michael

2015-03-01

Ultrasound tomography has great potential to provide quantitative estimations of physical properties of breast tumors for accurate characterization of breast cancer. We design and manufacture a new synthetic-aperture breast ultrasound tomography system with two parallel transducer arrays. The distance of these two transducer arrays is adjustable for scanning breasts with different sizes. The ultrasound transducer arrays are translated vertically to scan the entire breast slice by slice and acquires ultrasound transmission and reflection data for whole-breast ultrasound imaging and tomographic reconstructions. We use the system to acquire patient data at the University of New Mexico Hospital for clinical studies. We present some preliminary imaging results of in vivo patient ultrasound data. Our preliminary clinical imaging results show promising of our breast ultrasound tomography system with two parallel transducer arrays for breast cancer imaging and characterization.

Characteristics of pectinase treated with ultrasound both during and after the immobilization process.

PubMed

Ma, Xiaobin; Wang, Danli; Yin, Michelle; Lucente, Juliet; Wang, Wenjun; Ding, Tian; Ye, Xingqian; Liu, Donghong

2017-05-01

In this study, ultrasound was applied both during and after the immobilization process and characteristics of different immobilized pectinase samples were studied. When introduced during the immobilization process, ultrasound at an intensity of 9WmL -1 for 20min increased the immobilization yield 92.28% more than the control. When introduced to the already immobilized pectinase, ultrasound at an intensity of 4.5WmL -1 for 10min increased the pectinase activity by 30.05%. Results of scanning electron microscope demonstrated that ultrasound increased surface area and loosened structures of immobilized enzymes. Higher V max and lower K m were obtained after ultrasound treatment, indicating the increased catalytic efficiency and enhanced affinity of immobilized pectinase. Furthermore, the optimum temperature and pH for free and immobilized pectinase remained unchanged at 50°C and pH 4. Thermostability, reaction stability and reusability of two ultrasound-treated pectinase enzymes slightly decreased due to structural matrix changes. Copyright © 2016 Elsevier B.V. All rights reserved.

Ultrasound as Visual Feedback in Speech Habilitation: Exploring Consultative Use in Rural British Columbia, Canada

ERIC Educational Resources Information Center

Bernhardt, B. May; Bacsfalvi, Penelope; Adler-Bock, Marcy; Shimizu, Reiko; Cheney, Audrey; Giesbrecht, Nathan; O'Connell, Maureen; Sirianni, Jason; Radanov, Bosko

2008-01-01

Ultrasound has shown promise as a visual feedback tool in speech therapy. Rural clients, however, often have minimal access to new technologies. The purpose of the current study was to evaluate consultative treatment using ultrasound in rural communities. Two speech-language pathologists (SLPs) trained in ultrasound use provided consultation with…

Low-Frequency Ultrasound Debridement in Chronic Wound Healing: A Systematic Review of Current Evidence

PubMed Central

Chang, Ying-Ju Ruby; Perry, Julie

2017-01-01

Chronic wounds are painful and debilitating to patients, pose a clinical challenge to physicians, and impose financial burden on the health-care system. New treatment options are therefore highly sought after. Ultrasound debridement is a promising technology that functions to disperse bacterial biofilms and stimulate wound healing. In this review, we focus on low-frequency ultrasound (20-60 kHz) and summarize the findings of 25 recent studies examining ultrasound efficacy. Ultrasound debridement appears to be most effective when used 3 times a week and has the potential to decrease exudate and slough, decrease patient pain, disperse biofilms, and increase healing in wounds of various etiology. Although current studies are generally of smaller size, the results are promising and we recommend the testing of low-frequency ultrasound therapy in clinical practice on a larger scale. PMID:29026808

Comparison of barium swallow and ultrasound in diagnosis of gastro-oesophageal reflux in children.

PubMed Central

Naik, D R; Bolia, A; Moore, D J

1985-01-01

Fifty one infants and older children with suspected gastro-oesophageal reflux entered a study comparing the diagnostic accuracy of a standard barium swallow examination with that of ultrasound scanning. All children were examined by both techniques. In 40 cases there was unequivocal agreement between the examinations. Of the remaining patients, four had definite reflux by ultrasonic criteria but showed no evidence of reflux on barium swallow examination, four had positive findings on ultrasound but showed only minimal reflux on barium swallow, and one showed minimal reflux on ultrasound but had a negative barium meal result. In two children the ultrasound study was inconclusive. Ultrasound has an important role in the diagnosis and follow up of patients under the age of 5 years with gastro-oesophageal reflux. Images FIG 1 FIG 2 PMID:3924317

Effect of pulsed ultrasound in combination with gentamicin on bacterial killing of biofilms on bone cements in vivo

PubMed Central

Ensing, G.T.; Roeder, B.L.; Nelson, J.L.; van Horn, J.R.; van der Mei, H.C.; Busscher, H.J.; Pitt, W.G.

2008-01-01

Aim The aim of this study is to investigate whether pulsed ultrasound in combination with gentamicin yields increased killing of bacterial biofilms on bone cements in vivo. Methods and Results Bacterial survival on bone cement in the presence and absence of ultrasound was compared in a rabbit model. Two bone cement samples with E. coli ATCC 10798 biofilm were implanted in a total of nine rabbits. In two groups bone cement disks loaded with gentamicin were used, and in one group unloaded bone cement disks in combination with systemically administered gentamicin were used. Pulsed ultrasound with a mean acoustic intensity of 167 mW cm−2 and a maximum acoustic intensity of 500 mW cm−2 was applied from 24 h till 72 h post surgery on one of the two implanted disks. After euthanization, the bacteria removed from the disk were quantified. Application of ultrasound, combined with gentamicin, reduced the biofilm in all three groups varying between 58 to 69% compared to the negative control. Ultrasound proved to be safe with respect to creating skin lesions. Conclusions Ultrasound resulted in an tendency of improved efficacy of gentamicin, either applied locally or systemically. Significance and impact of Study This study implies that ultrasound could improve the prevention of infection, especially because the biomaterials, gentamicin and ultrasound used in this model are all in clinical usage, but not yet combined in clinical practice. PMID:16108785

Research interface on a programmable ultrasound scanner.

PubMed

Shamdasani, Vijay; Bae, Unmin; Sikdar, Siddhartha; Yoo, Yang Mo; Karadayi, Kerem; Managuli, Ravi; Kim, Yongmin

2008-07-01

Commercial ultrasound machines in the past did not provide the ultrasound researchers access to raw ultrasound data. Lack of this ability has impeded evaluation and clinical testing of novel ultrasound algorithms and applications. Recently, we developed a flexible ultrasound back-end where all the processing for the conventional ultrasound modes, such as B, M, color flow and spectral Doppler, was performed in software. The back-end has been incorporated into a commercial ultrasound machine, the Hitachi HiVision 5500. The goal of this work is to develop an ultrasound research interface on the back-end for acquiring raw ultrasound data from the machine. The research interface has been designed as a software module on the ultrasound back-end. To increase the amount of raw ultrasound data that can be spooled in the limited memory available on the back-end, we have developed a method that can losslessly compress the ultrasound data in real time. The raw ultrasound data could be obtained in any conventional ultrasound mode, including duplex and triplex modes. Furthermore, use of the research interface does not decrease the frame rate or otherwise affect the clinical usability of the machine. The lossless compression of the ultrasound data in real time can increase the amount of data spooled by approximately 2.3 times, thus allowing more than 6s of raw ultrasound data to be acquired in all the modes. The interface has been used not only for early testing of new ideas with in vitro data from phantoms, but also for acquiring in vivo data for fine-tuning ultrasound applications and conducting clinical studies. We present several examples of how newer ultrasound applications, such as elastography, vibration imaging and 3D imaging, have benefited from this research interface. Since the research interface is entirely implemented in software, it can be deployed on existing HiVision 5500 ultrasound machines and may be easily upgraded in the future. The developed research interface can aid researchers in the rapid testing and clinical evaluation of new ultrasound algorithms and applications. Additionally, we believe that our approach would be applicable to designing research interfaces on other ultrasound machines.

Development of a Cancer Treatment with the Concomitant Use of Low-Intensity Ultrasound: Entering the Age of Simultaneous Diagnosis and Treatment

PubMed Central

Emoto, Makoto

2014-01-01

In recent years, studies using ultrasound energy for cancer treatment have advanced, thus revealing the enhancement of drug effects by employing low-intensity ultrasound. Furthermore, anti-angiogenesis against tumors is now attracting attention as a new cancer treatment. Therefore, we focused on the biological effects and the enhancement of drug effects brought by this low-intensity ultrasound energy and reported on the efficacy against a uterine sarcoma model, by implementing the basic studies, for the first time, including the concomitant use of low-intensity ultrasound irradiation, as an expected new antiangiogenic therapy for cancer treatment. Furthermore, we have succeeded in simultaneously utilizing low-intensity ultrasound in both diagnosis and treatment, upon real time evaluation of the anti-tumor effects and anti-angiogenesis effects using color Doppler ultrasound imaging. Although the biological effects of ultrasound have not yet been completely clarified, transient stomas were formed (Sonoporation) in cancer cells irradiated by low-intensity ultrasound and it is believed that the penetration effect of drugs is enhanced due to the drug being more charged inside the cell through these stomas. Furthermore, it has become clear that the concomitant therapy of anti-angiogenesis drugs and low-intensity ultrasound blocks the angiogenic factor VEGF produced by cancer cells, inhibits the induction of circulating endothelial progenitor cells in the bone marrow, and expedites angiogenic inhibitor TSP-1. Based on research achievements in recent years, we predict that the current diagnostic device for color Doppler ultrasound imaging will be improved in the near future, bringing with it the arrival of an age of “low-intensity ultrasound treatment that simultaneously enables diagnosis and treatment of cancer in real time.” PMID:26852677

Use of Lymph Node Ultrasound Prior to Sentinel Lymph Node Biopsy in 384 Patients with Melanoma: A Cost-Effectiveness Analysis.

PubMed

Olmedo, D; Brotons-Seguí, M; Del Toro, C; González, M; Requena, C; Traves, V; Pla, A; Bolumar, I; Moreno-Ramírez, D; Nagore, E

2017-12-01

Locoregional lymph node ultrasound is not typically included in guidelines as part of the staging process prior to sentinel lymph node biopsy (SLNB). The objective of the present study was to make a clinical and economic analysis of lymph node ultrasound prior to SLNB. We performed a retrospective study of 384 patients with clinical stage I-II primary melanoma who underwent locorregional lymph node ultrasound (with or without ultrasound-guided biopsy) prior to SLNB between 2004 and 2015. We evaluated the reliability and cost-effectiveness of the strategy. Use of locorregional lymph node ultrasound avoided SLNB in 23 patients (6%). Ultrasound had a sensitivity of 46% and specificity of 76% for the detection of metastatic lymph nodes that were not clinically palpable. False negatives were significantly more common in patients aged over 60 years and in tumors with a thickness of less than 2mm. The staging process using SLNB and ultrasound with ultrasound-guided biopsy produced an increase of €16.30 in the unit price. Our cost-effectiveness analysis identified the staging protocol with ultrasound and SLNB as the dominant strategy, with a lower cost-effectiveness ratio than the alternative, consisting of SLNB alone (8,095.24 vs. €28,605.00). Ultrasound with ultrasound-guided biopsy for the diagnostic staging of melanoma prior to SLNB is a useful and cost-effective tool. This procedure does not substitute SLNB, though it does allow to avoid SLNB in a not insignificant proportion of patients. Copyright © 2017 AEDV. Publicado por Elsevier España, S.L.U. All rights reserved.

Thyroid gland visualization with 3D/4D ultrasound: integrated hands-on imaging in anatomical dissection laboratory.

PubMed

Carter, John L; Patel, Ankura; Hocum, Gabriel; Benninger, Brion

2017-05-01

In teaching anatomy, clinical imaging has been utilized to supplement the traditional dissection laboratory promoting education through visualization of spatial relationships of anatomical structures. Viewing the thyroid gland using 3D/4D ultrasound can be valuable to physicians as well as students learning anatomy. The objective of this study was to investigate the perceptions of first-year medical students regarding the integration of 3D/4D ultrasound visualization of spatial anatomy during anatomical education. 108 first-year medical students were introduced to 3D/4D ultrasound imaging of the thyroid gland through a detailed 20-min tutorial taught in small group format. Students then practiced 3D/4D ultrasound imaging on volunteers and donor cadavers before assessment through acquisition and identification of thyroid gland on at least three instructor-verified images. A post-training survey was administered assessing student impression. All students visualized the thyroid gland using 3D/4D ultrasound. Students revealed 88.0% strongly agreed or agreed 3D/4D ultrasound is useful revealing the thyroid gland and surrounding structures and 87.0% rated the experience "Very Easy" or "Easy", demonstrating benefits and ease of use including 3D/4D ultrasound in anatomy courses. When asked, students felt 3D/4D ultrasound is useful in teaching the structure and surrounding anatomy of the thyroid gland, they overwhelmingly responded "Strongly Agree" or "Agree" (90.2%). This study revealed that 3D/4D ultrasound was successfully used and preferred over 2D ultrasound by medical students during anatomy dissection courses to accurately identify the thyroid gland. In addition, 3D/4D ultrasound may nurture and further reinforce stereostructural spatial relationships of the thyroid gland taught during anatomy dissection.

Survey of ultrasound practice amongst podiatrists in the UK.

PubMed

Siddle, Heidi J; Patience, Aimie; Coughtrey, James; Mooney, Jean; Fox, Martin; Cherry, Lindsey

2018-01-01

Ultrasound in podiatry practice encompasses musculoskeletal ultrasound imaging, vascular hand-held Doppler ultrasound and therapeutic ultrasound. Sonography practice is not regulated by the Health and Care Professions Council (HCPC), with no requirement to hold a formal qualification. The College of Podiatry does not currently define ultrasound training and competencies.This study aimed to determine the current use of ultrasound, training received and mentorship received and/or provided by podiatrists using ultrasound. A quantitative study utilising a cross-sectional, on-line, single-event survey was undertaken within the UK. Completed surveys were received from 284 podiatrists; 173 (70%) use ultrasound as part of their general practice, 139 (49%) for musculoskeletal problems, 131 (46%) for vascular assessment and 39 (14%) to support their surgical practice. Almost a quarter ( n  = 62) worked for more than one organisation; 202 (71%) were employed by the NHS and/or private sector ( n  = 118, 41%).Nearly all (93%) respondents report using a hand-held vascular Doppler in their daily practice; 216 (82%) to support decisions regarding treatment options, 102 (39%) to provide diagnostic reports for other health professionals, and 34 (13%) to guide nerve blocks.Ultrasound imaging was used by 104 (37%) respondents primarily to aid clinical decision making ( n  = 81) and guide interventions (steroid injections n  = 67; nerve blocks n  = 39). Ninety-three percent stated they use ultrasound imaging to treat their own patients, while others scan at the request of other podiatrists ( n  = 28) or health professionals ( n  = 18). Few use ultrasound imaging for research ( n  = 7) or education ( n  = 2).Only 32 (11%) respondents ( n  = 20 private sector) use therapeutic ultrasound to treat patients presenting with musculoskeletal complaints, namely tendon pathologies.Few respondents (18%) had completed formal post-graduate CASE (Consortium for the Accreditation of Sonographic Education) accredited ultrasound courses.Forty (14%) respondents receive ultrasound mentorship; the majority from fellow podiatrists ( n  = 17) or medical colleagues ( n  = 15). Over half ( n  = 127) who do not have ultrasound mentorship indicated they would like a mentor predominantly for ultrasound imaging. Fifty-five (19%) report they currently provide ultrasound mentorship for others. Understanding the scope of ultrasound practice, the training undertaken and the requirements for mentorship will underpin the development of competencies and recommendations defined by the College of Podiatry to support professional development and ensure safe practice.

Anthropomorphic cardiac ultrasound phantom.

PubMed

Smith, S W; Rinaldi, J E

1989-10-01

A new phantom is described which simulates the human cardiac anatomy for applications in ultrasound imaging, ultrasound Doppler, and color-flow Doppler imaging. The phantom consists of a polymer left ventricle which includes a prosthetic mitral and aortic valve and is connected to a mock circulatory loop. Aerated tap water serves as a blood simulating fluid and ultrasound contrast medium within the circulatory loop. The left ventricle is housed in a Lexan ultrasound visualization chamber which includes ultrasound viewing ports and acoustic absorbers. A piston pump connected to the visualization chamber by a single port pumps degassed water within the chamber which in turn pumps the left ventricle. Real-time ultrasound images and Doppler studies measure flow patterns through the valves and within the left ventricle.

Evaluating the risk of appendiceal perforation when using ultrasound as the initial diagnostic imaging modality in children with suspected appendicitis.

PubMed

Alerhand, Stephen; Meltzer, James; Tay, Ee Tein

2017-08-01

Ultrasound scan has gained attention for diagnosing appendicitis due to its avoidance of ionizing radiation. However, studies show that ultrasound scan carries inferior sensitivity to computed tomography scan. A non-diagnostic ultrasound scan could increase the time to diagnosis and appendicectomy, particularly if follow-up computed tomography scan is needed. Some studies suggest that delaying appendicectomy increases the risk of perforation. To investigate the risk of appendiceal perforation when using ultrasound scan as the initial diagnostic imaging modality in children with suspected appendicitis. We retrospectively reviewed 1411 charts of children ≤17 years old diagnosed with appendicitis at two urban academic medical centers. Patients who underwent ultrasound scan first were compared to those who underwent computed tomography scan first. In the sub-group analysis, patients who only received ultrasound scan were compared to those who received initial ultrasound scan followed by computed tomography scan. Main outcome measures were appendiceal perforation rate and time from triage to appendicectomy. In 720 children eligible for analysis, there was no significant difference in perforation rate between those who had initial ultrasound scan and those who had initial computed tomography scan (7.3% vs. 8.9%, p = 0.44), nor in those who had ultrasound scan only and those who had initial ultrasound scan followed by computed tomography scan (8.0% vs. 5.6%, p = 0.42). Those patients who had ultrasound scan first had a shorter triage-to-incision time than those who had computed tomography scan first (9.2 (IQR: 5.9, 14.0) vs. 10.2 (IQR: 7.3, 14.3) hours, p = 0.03), whereas those who had ultrasound scan followed by computed tomography scan took longer than those who had ultrasound scan only (7.8 (IQR: 5.3, 11.6) vs. 15.1 (IQR: 10.6, 20.6), p < 0.001). Children < 12 years old receiving ultrasound scan first had lower perforation rate (p = 0.01) and shorter triage-to-incision time (p = 0.003). Children with suspected appendicitis receiving ultrasound scan as the initial diagnostic imaging modality do not have increased risk of perforation compared to those receiving computed tomography scan first. We recommend that children <12 years of age receive ultrasound scan first.

[Occupational risk caused by ultrasound in medicine].

PubMed

Magnavita, N; Fileni, A

1994-01-01

Ultrasound (US) is extensively used in the medical field for its therapeutic and diagnostic applications. US units are commonly found in hospitals and clinics of all sizes, and a growing number of medical staff such as doctors and nurses are exposed to hand-transmitted ultrasound waves in their work-place. This review discusses the available information on the occupational risk of the operators using diagnostic and therapeutic ultrasound devices. The new occupational groups of medical workers who use ultrasound (diagnostic, surgical, sterilization, and physiotherapeutic) equipment are exposed to contact ultrasound waves. Contact ultrasound -- i.e., no airspace between the energy source and the biological tissue -- is much more hazardous than exposure to airborne ultrasound because air transmits less than one percent of this kind of energy. In spite of being a non-ionizing radiation with an excellent safety record, US is likely to induce some changes in the exposed organ. Recent Russian studies indicate that the hospital workers who have been long exposed to ultrasound at work may develop neurovascular dose-dependent disorders of the peripheral nervous system in the form of the angiodystonic syndrome of vegetative polyneuritis of the hands. In some Scandinavian studies, female physiotherapists (exposed to ultrasound and short waves) exhibit increased rate of spontaneous abortions and congenital malformations, but no definite conclusion can be drawn on the basis of these results alone. Trends in exposure for diagnostic ultrasound equipment over the last two decades show a continuous increase. While there is no reason for alarm, there is a growing need for avoiding unnecessary exposure to medical workers.

Evaluation of chest ultrasound integrated teaching of respiratory system physiology to medical students.

PubMed

Paganini, Matteo; Bondì, Michela; Rubini, Alessandro

2017-12-01

Ultrasound imaging is a widely used diagnostic technique, whose integration in medical education is constantly growing. The aim of this study was to evaluate chest ultrasound usefulness in teaching respiratory system physiology, students' perception of chest ultrasound integration into a traditional lecture in human physiology, and short-term concept retention. A lecture about respiratory physiology was integrated with ultrasound and delivered to third-year medical students. It included basic concepts of ultrasound imaging and the physiology of four anatomic sectors of the body of a male volunteer, shown with a portable ultrasound device (pleural sliding, diaphragmatic movement, inferior vena cava diameter variations, cardiac movements). Students' perceptions of the integrated lecture were assessed, and attendance recorded. After 4 mo, four multiple-choice questions about respiratory physiology were administered during the normal human physiology examinations, and the results of students who attended the lesson and those of who did not were compared. One hundred thirty-four students attended the lecture. Most of them showed encouragement for the study of the subject and considered the ultrasound integrated lecture more interesting than a traditional one and pertinent to the syllabus. Exposed students achieved a better score at the examination and committed less errors than did nonexposed students. The chest ultrasound integrated lecture was appreciated by students. A possible association between the exposure to the lecture and short-term concept retention is shown by better performances of the exposed cohort at the examination. A systematic introduction of ultrasound into physiology traditional teaching will be promoted by the Ultrasound-Based Medical Education movement. Copyright © 2017 the American Physiological Society.

Cognitive load predicts point-of-care ultrasound simulator performance.

PubMed

Aldekhyl, Sara; Cavalcanti, Rodrigo B; Naismith, Laura M

2018-02-01

The ability to maintain good performance with low cognitive load is an important marker of expertise. Incorporating cognitive load measurements in the context of simulation training may help to inform judgements of competence. This exploratory study investigated relationships between demographic markers of expertise, cognitive load measures, and simulator performance in the context of point-of-care ultrasonography. Twenty-nine medical trainees and clinicians at the University of Toronto with a range of clinical ultrasound experience were recruited. Participants answered a demographic questionnaire then used an ultrasound simulator to perform targeted scanning tasks based on clinical vignettes. Participants were scored on their ability to both acquire and interpret ultrasound images. Cognitive load measures included participant self-report, eye-based physiological indices, and behavioural measures. Data were analyzed using a multilevel linear modelling approach, wherein observations were clustered by participants. Experienced participants outperformed novice participants on ultrasound image acquisition. Ultrasound image interpretation was comparable between the two groups. Ultrasound image acquisition performance was predicted by level of training, prior ultrasound training, and cognitive load. There was significant convergence between cognitive load measurement techniques. A marginal model of ultrasound image acquisition performance including prior ultrasound training and cognitive load as fixed effects provided the best overall fit for the observed data. In this proof-of-principle study, the combination of demographic and cognitive load measures provided more sensitive metrics to predict ultrasound simulator performance. Performance assessments which include cognitive load can help differentiate between levels of expertise in simulation environments, and may serve as better predictors of skill transfer to clinical practice.

[Is ultrasound equal to X-ray in pediatric fracture diagnosis?].

PubMed

Moritz, J D; Hoffmann, B; Meuser, S H; Sehr, D H; Caliebe, A; Heller, M

2010-08-01

Ultrasound is currently not established for the diagnosis of fractures. The aim of this study was to compare ultrasound and X-ray beyond their use solely for the identification of fractures, i. e., for the detection of fracture type and dislocation for pediatric fracture diagnosis. Limb bones of dead young pigs served as a model for pediatric bones. The fractured bones were examined with ultrasound, X-ray, and CT, which served as the gold standard. 162 of 248 bones were fractured. 130 fractures were identified using ultrasound, and 148 using X-ray. There were some advantages of X-ray over ultrasound in the detection of fracture type (80 correct results using X-ray, 66 correct results using ultrasound). Ultrasound, however, was superior to X-ray for dislocation identification (41 correct results using X-ray, 51 correct results using ultrasound). Both findings were not statistically significant after adjustment for multiple testing. Ultrasound not only has comparable sensitivity to that of X-ray for the identification of limb fractures but is also equally effective for the diagnosis of fracture type and dislocation. Thus, ultrasound can be used as an adequate alternative method to X-ray for pediatric fracture diagnosis. Georg Thieme Verlag KG Stuttgart, New York.

Neonatal Cranial Ultrasound: Are Current Safety Guidelines Appropriate?

PubMed

Lalzad, Assema; Wong, Flora; Schneider, Michal

2017-03-01

Ultrasound can lead to thermal and mechanical effects in interrogated tissues. We reviewed the literature to explore the evidence on ultrasound heating on fetal and neonatal neural tissue. The results of animal studies have suggested that ultrasound exposure of the fetal or neonatal brain may lead to a significant temperature elevation at the bone-brain interface above current recommended safety thresholds. Temperature increases between 4.3 and 5.6°C have been recorded. Such temperature elevations can potentially affect neuronal structure and function and may also affect behavioral and cognitive function, such as memory and learning. However, the majority of these studies were carried out more than 25 y ago using non-diagnostic equipment with power outputs much lower than those of modern machines. New studies to address the safety issues of cranial ultrasound are imperative to provide current clinical guidelines and safety recommendations. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Ultrasound waiting lists: rational queue or extended capacity?

PubMed

Brasted, Christopher

2008-06-01

The features and issues regarding clinical waiting lists in general and general ultrasound waiting lists in particular are reviewed, and operational aspects of providing a general ultrasound service are also discussed. A case study is presented describing a service improvement intervention in a UK NHS hospital's ultrasound department, from which arises requirements for a predictive planning model for an ultrasound waiting list. In the course of this, it becomes apparent that a booking system is a more appropriate way of describing the waiting list than a conventional queue. Distinctive features are identified from the literature and the case study as the basis for a predictive model, and a discrete event simulation model is presented which incorporates the distinctive features.

Two-Dimensional and Three-Dimensional Ultrasound of Artificial Skin.

PubMed

Wortsman, Ximena; Navarrete, Nelson

2017-01-01

Wound healing may be a difficult problem, and variable types of artificial skin prototypes have been developed for supporting this process. Using ultrasound, we studied 4 cellulose-derived artificial skin prototypes and assessed their two-dimensional and three-dimensional morphology. These prototypes were identified on ultrasound both on in vitro and in vivo studies. They allowed the sonographic observation of deeper layers on different types of surfaces of the body with good definition on the in vivo examinations performed on healthy skin and cutaneous ulcers. The ultrasound detection of these artificial biomaterials may potentially support the noninvasive monitoring of wound healing. © 2016 by the American Institute of Ultrasound in Medicine.

Ultrasound-guided fine needle aspiration versus core needle biopsy: comparison of post-biopsy hematoma rates and risk factors.

PubMed

Chae, In Hye; Kim, Eun-Kyung; Moon, Hee Jung; Yoon, Jung Hyun; Park, Vivian Y; Kwak, Jin Young

2017-07-01

To compare post-biopsy hematoma rates between ultrasound guided-fine needle aspiration and ultrasound guided-core needle biopsy, and to investigate risk factors for post-biopsy hematoma. A total of 5304 thyroid nodules which underwent ultrasound guided biopsy were included in this retrospective study. We compared clinical and US features between patients with and without post-biopsy hematoma. Associations between these features and post-biopsy hematoma were analyzed. Post-biopsy hematoma rate was 0.8% (43/5121) for ultrasound guided-fine needle aspiration and 4.9% (9/183) for ultrasound guided-core needle biopsy (P < 0.001). For ultrasound guided-fine needle aspiration, gender, age, size, presence of vascularity, and suspicious US features were not associated with post-biopsy hematoma according to experience level. Post-biopsy hematoma occurred significantly more with ultrasound guided-core needle biopsy (9/179, 5.0%) than with ultrasound guided-fine needle aspiration (9/1138, 0.8%) (P < 0.001) in experienced performers and ultrasound guided-core needle biopsy was the only significant risk factor for post-biopsy hematoma (adjusted Odds Ratio, 6.458, P < 0.001). Post-biopsy hematoma occurred significantly more in ultrasound guided-core needle biopsy than in ultrasound guided-fine needle aspiration and ultrasound guided-core needle biopsy was the only independent factor of post-biopsy hematoma in thyroid nodules.

Doppler Ultrasound: What Is It Used for?

MedlinePlus

... During a Doppler ultrasound, a technician trained in ultrasound imaging (sonographer) presses a small hand-held device (transducer), ... neurologic-disorders/neurologic-tests-and-procedures/other-neurologic-imaging-studies. Accessed Oct. 18, 2016. ... . Mayo Clinic Footer Legal ...

A multimodal image guiding system for Navigated Ultrasound Bronchoscopy (EBUS): A human feasibility study

PubMed Central

Hofstad, Erlend Fagertun; Amundsen, Tore; Langø, Thomas; Bakeng, Janne Beate Lervik; Leira, Håkon Olav

2017-01-01

Background Endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA) is the endoscopic method of choice for confirming lung cancer metastasis to mediastinal lymph nodes. Precision is crucial for correct staging and clinical decision-making. Navigation and multimodal imaging can potentially improve EBUS-TBNA efficiency. Aims To demonstrate the feasibility of a multimodal image guiding system using electromagnetic navigation for ultrasound bronchoschopy in humans. Methods Four patients referred for lung cancer diagnosis and staging with EBUS-TBNA were enrolled in the study. Target lymph nodes were predefined from the preoperative computed tomography (CT) images. A prototype convex probe ultrasound bronchoscope with an attached sensor for position tracking was used for EBUS-TBNA. Electromagnetic tracking of the ultrasound bronchoscope and ultrasound images allowed fusion of preoperative CT and intraoperative ultrasound in the navigation software. Navigated EBUS-TBNA was used to guide target lymph node localization and sampling. Navigation system accuracy was calculated, measured by the deviation between lymph node position in ultrasound and CT in three planes. Procedure time, diagnostic yield and adverse events were recorded. Results Preoperative CT and real-time ultrasound images were successfully fused and displayed in the navigation software during the procedures. Overall navigation accuracy (11 measurements) was 10.0 ± 3.8 mm, maximum 17.6 mm, minimum 4.5 mm. An adequate sample was obtained in 6/6 (100%) of targeted lymph nodes. No adverse events were registered. Conclusions Electromagnetic navigated EBUS-TBNA was feasible, safe and easy in this human pilot study. The clinical usefulness was clearly demonstrated. Fusion of real-time ultrasound, preoperative CT and electromagnetic navigational bronchoscopy provided a controlled guiding to level of target, intraoperative overview and procedure documentation. PMID:28182758

Feasibility of Retrograde Ureteral Contrast Injection to Guide Ultrasonographic Percutaneous Renal Access in the Nondilated Collecting System.

PubMed

Usawachintachit, Manint; Tzou, David T; Mongan, John; Taguchi, Kazumi; Weinstein, Stefanie; Chi, Thomas

2017-02-01

Ultrasound-guided percutaneous nephrolithotomy (PCNL) has become increasingly utilized. Patients with nondilated collecting systems represent a challenge: the target calix is often difficult to visualize. Here we report pilot study results for retrograde ultrasound contrast injection to aid in percutaneous renal access during ultrasound-guided PCNL. From April to July 2016, consecutive patients over the age of 18 years with nondilated collecting systems on preoperative imaging who presented for PCNL were enrolled. B-mode ultrasound imaging was compared with contrast-enhanced mode with simultaneous retrograde injection of Optison™ via an ipsilateral ureteral catheter. Five patients (four males and one female) with renal stones underwent PCNL with retrograde ultrasound contrast injection during the study period. Mean body mass index was 28.3 ± 5.6 kg/m 2 and mean stone size was 24.5 ± 12.0 mm. Under B-mode ultrasound, all patients demonstrated nondilated renal collecting systems that appeared as hyperechoic areas, where it was difficult to identify a target calix for puncture. Retrograde contrast injection facilitated delineation of all renal calices initially difficult to visualize under B-mode ultrasound. Renal puncture was then performed effectively in all cases with a mean puncture time of 55.4 ± 44.8 seconds. All PCNL procedures were completed without intraoperative complications and no adverse events related to ultrasound contrast injection occurred. Retrograde ultrasound contrast injection as an aide for renal puncture during PCNL is a feasible technique. By improving visualization of the collecting system, it facilitates needle placement in challenging patients without hydronephrosis. Future larger scale studies comparing its use to standard ultrasound-guided technique will be required to validate this concept.

Increased Anatomical Specificity of Neuromodulation via Modulated Focused Ultrasound

PubMed Central

Mehić, Edin; Xu, Julia M.; Caler, Connor J.; Coulson, Nathaniel K.; Moritz, Chet T.; Mourad, Pierre D.

2014-01-01

Transcranial ultrasound can alter brain function transiently and nondestructively, offering a new tool to study brain function now and inform future therapies. Previous research on neuromodulation implemented pulsed low-frequency (250–700 kHz) ultrasound with spatial peak temporal average intensities (ISPTA) of 0.1–10 W/cm2. That work used transducers that either insonified relatively large volumes of mouse brain (several mL) with relatively low-frequency ultrasound and produced bilateral motor responses, or relatively small volumes of brain (on the order of 0.06 mL) with relatively high-frequency ultrasound that produced unilateral motor responses. This study seeks to increase anatomical specificity to neuromodulation with modulated focused ultrasound (mFU). Here, ‘modulated’ means modifying a focused 2-MHz carrier signal dynamically with a 500-kHz signal as in vibro-acoustography, thereby creating a low-frequency but small volume (approximately 0.015 mL) source of neuromodulation. Application of transcranial mFU to lightly anesthetized mice produced various motor movements with high spatial selectivity (on the order of 1 mm) that scaled with the temporal average ultrasound intensity. Alone, mFU and focused ultrasound (FUS) each induced motor activity, including unilateral motions, though anatomical location and type of motion varied. Future work should include larger animal models to determine the relative efficacy of mFU versus FUS. Other studies should determine the biophysical processes through which they act. Also of interest is exploration of the potential research and clinical applications for targeted, transcranial neuromodulation created by modulated focused ultrasound, especially mFU’s ability to produce compact sources of ultrasound at the very low frequencies (10–100s of Hertz) that are commensurate with the natural frequencies of the brain. PMID:24504255

Success of ultrasound-guided versus landmark-guided arthrocentesis of hip, ankle, and wrist in a cadaver model.

PubMed

Berona, Kristin; Abdi, Amin; Menchine, Michael; Mailhot, Tom; Kang, Tarina; Seif, Dina; Chilstrom, Mikaela

2017-02-01

The objectives of this study were to evaluate emergency medicine resident-performed ultrasound for diagnosis of effusions, compare the success of a landmark-guided (LM) approach with an ultrasound-guided (US) technique for hip, ankle and wrist arthrocentesis, and compare change in provider confidence with LM and US arthrocentesis. After a brief video on LM and US arthrocentesis, residents were asked to identify artificially created effusions in the hip, ankle and wrist in a cadaver model and to perform US and LM arthrocentesis of the effusions. Outcomes included success of joint aspiration, time to aspiration, and number of attempts. Residents were surveyed regarding their confidence in identifying effusions with ultrasound and performing LM and US arthrocentesis. Eighteen residents completed the study. Sensitivity of ultrasound for detecting joint effusion was 86% and specificity was 90%. Residents were successful with ultrasound in 96% of attempts and with landmark 89% of attempts (p=0.257). Median number of attempts was 1 with ultrasound and 2 with landmarks (p=0.12). Median time to success with ultrasound was 38s and 51s with landmarks (p=0.23). After the session, confidence in both US and LM arthrocentesis improved significantly, however the post intervention confidence in US arthrocentesis was higher than LM (4.3 vs. 3.8, p<0.001). EM residents were able to successfully identify joint effusions with ultrasound, however we were unable to detect significant differences in actual procedural success between the two modalities. Further studies are needed to define the role of ultrasound for arthrocentesis in the emergency department. Copyright © 2016 Elsevier Inc. All rights reserved.

Ultrasound and computed tomography of the iliosacral lymphatic centre in dogs with anal sac gland carcinoma.

PubMed

Pollard, R E; Fuller, M C; Steffey, M A

2017-06-01

In this prospective study, we hypothesized that computed tomography (CT) would identify more normal and abnormal iliosacral lymph nodes (LNs) than abdominal ultrasound in dogs with anal sac gland carcinoma (ASGC). Twelve client-owned dogs with ASGC but without distant metastasis were enrolled. Abdominal ultrasound and contrast-enhanced CT scans of the abdomen were obtained. Iliosacral LNs were counted and assessed for location, laterality and size. Significantly (P < 0.00001) more iliosacral LNs were identified with CT (61) than ultrasound (30), including significantly (P = 0.00012) more medial iliac LNs with CT (33) than ultrasound (19). There was no difference in number of internal iliac LNs identified with CT versus ultrasound. Significantly (P = 0.000061) more sacral LNs were identified with CT (15) than ultrasound (0). Ultrasound identified slightly more (7) abnormal iliosacral LNs than CT (5). Contrast CT was able to identify more normal but not more abnormal LNs than ultrasound. © 2015 John Wiley & Sons Ltd.

Effect of ultrasound on electrochemical chloride extraction from mortar

NASA Astrophysics Data System (ADS)

Chen, Yiqun; Yao, Wu; Zuo, Junqing

2018-03-01

In this paper, the effect of auxiliary ultrasound on electrochemical chloride extraction (ECE) was studied. The chloride removal efficiency was investigated by examining the chloride content with ultrasound-assisted ECE and changing the introducing time of ultrasound. The experimental results showed that removal of chloride ions was noted to be more effective in ECE treatment assisted with ultrasound treatment (UT). In addition, the lower w/c ratio led to more distinct effect of ultrasonic cavitation on chloride removal. Electrochemical behaviors measured with different treatment revealed that UT treatment was effective on moderating the corrosion condition. Microstructural analyses revealed a significant alteration in composition and morphology of cementitious phases with UT treatment. Pull-out tests indicated that ultrasound had a certain negative impact on the bond strength. Although the effect of introducing ultrasound in the first 2 weeks or the last 2 weeks on the extraction efficiency was not obvious, intermittent ultrasound could not only ensure the chloride extraction efficiency, but also reduce the adverse effect of ultrasound on the bond strength.

Contributions to ultrasound monitoring of the process of milk curdling.

PubMed

Jiménez, Antonio; Rufo, Montaña; Paniagua, Jesús M; Crespo, Abel T; Guerrero, M Patricia; Riballo, M José

2017-04-01

Ultrasound evaluation permits the state of milk being curdled to be determined quickly and cheaply, thus satisfying the demands faced by today's dairy product producers. This paper describes the non-invasive ultrasonic method of in situ monitoring the changing physical properties of milk during the renneting process. The basic objectives of the study were, on the one hand, to confirm the usefulness of conventional non-destructive ultrasonic testing (time-of-flight and attenuation of the ultrasound waves) in monitoring the process in the case of ewe's milk, and, on the other, to include other ultrasound parameters which have not previously been considered in studies on this topic, in particular, parameters provided by the Fast Fourier Transform technique. The experimental study was carried out in a dairy industry environment on four 52-l samples of raw milk in which were immersed 500kHz ultrasound transducers. Other physicochemical parameters of the raw milk (pH, dry matter, protein, Gerber fat test, and lactose) were measured, as also were the pH and temperature of the curdled samples simultaneously with the ultrasound tests. Another contribution of this study is the linear correlation analysis of the aforementioned ultrasound parameters and the physicochemical properties of the curdled milk. Copyright © 2017 Elsevier B.V. All rights reserved.

The Role of Ultrasound Simulation in Obstetrics and Gynecology Training: A UK Trainees' Perspective.

PubMed

Patel, Hersha; Chandrasekaran, Dhivya; Myriokefalitaki, Eva; Gebeh, Alpha; Jones, Kate; Jeve, Yadava B

2016-10-01

Ultrasonography is a core skill required by all obstetrics and gynecology trainees; however, training opportunities in clinical ultrasound are declining. Simulation ultrasound training has been proposed as a strategy to overcome this.The study aims were to determine the current availability of clinical and simulation ultrasound training in obstetrics and gynecology in the United Kingdom and to explore the trainees' perspective on the role of ultrasound simulation. All obstetrics and gynecology trainees within the East Midlands Local Education Training Board in the United Kingdom were asked to complete an anonymous web-based survey in July 2014. Of 140 trainees, 70 (50%) responded to the survey, and 69% reported rarely having dedicated clinical ultrasound sessions. Fifty percent had failed to achieve ultrasound competencies required for their stage of training, and 83% felt that the pressures of service provision limited their exposure to clinical ultrasound.Seventy-three percent of the trainees considered ultrasound simulation to be an essential component of training, and 69% agreed that it would help improve their clinical skills. Only 50% had access to an ultrasound simulator. Seventy-seven percent of the trainees thought that it would be useful to have ultrasound simulation integrated into training. Trainees are struggling to achieve minimal ultrasound competences with clinical ultrasound training alone. They believe that ultrasound simulation will shorten the learning curve and improve their clinical skills and knowledge. Despite the cost implications of simulation training, we propose that consideration is given to formal integration of ultrasound simulation into the curriculum as a possible way forward.

Correction of systematic bias in ultrasound dating in studies of small-for-gestational-age birth: an example from the Iowa Health in Pregnancy Study.

PubMed

Harland, Karisa K; Saftlas, Audrey F; Wallis, Anne B; Yankowitz, Jerome; Triche, Elizabeth W; Zimmerman, M Bridget

2012-09-01

The authors examined whether early ultrasound dating (≤20 weeks) of gestational age (GA) in small-for-gestational-age (SGA) fetuses may underestimate gestational duration and therefore the incidence of SGA birth. Within a population-based case-control study (May 2002-June 2005) of Iowa SGA births and preterm deliveries identified from birth records (n = 2,709), the authors illustrate a novel methodological approach with which to assess and correct for systematic underestimation of GA by early ultrasound in women with suspected SGA fetuses. After restricting the analysis to subjects with first-trimester prenatal care, a nonmissing date of the last menstrual period (LMP), and early ultrasound (n = 1,135), SGA subjects' ultrasound GA was 5.5 days less than their LMP GA, on average. Multivariable linear regression was conducted to determine the extent to which ultrasound GA predicted LMP dating and to correct for systematic misclassification that results after applying standard guidelines to adjudicate differences in these measures. In the unadjusted model, SGA subjects required a correction of +1.5 weeks to the ultrasound estimate. With adjustment for maternal age, smoking, and first-trimester vaginal bleeding, standard guidelines for adjudicating differences in ultrasound and LMP dating underestimated SGA birth by 12.9% and overestimated preterm delivery by 8.7%. This methodological approach can be applied by researchers using different study populations in similar research contexts.

Frequency sensitive mechanism in low-intensity ultrasound enhanced bioeffects

PubMed Central

Chama, Abdoulkadri; Subramanian, Anuradha; Viljoen, Hendrik J.

2017-01-01

This study presents two novel theoretical models to elucidate frequency sensitive nuclear mechanisms in low-intensity ultrasound enhanced bioeffects. In contrast to the typical 1.5 MHz pulsed ultrasound regime, our group previously experimentally confirmed that ultrasound stimulation of anchored chondrocytes at resonant frequency maximized gene expression of load inducible genes which are regulatory markers for cellular response to external stimuli. However, ERK phosphorylation displayed no frequency dependency, suggesting that the biochemical mechanisms involved in enhanced gene expression is downstream of ERK phosphorylation. To elucidate such underlying mechanisms, this study presents a theoretical model of an anchored cell, representing an in vitro chondrocyte, in an ultrasound field. The model results showed that the mechanical energy storage is maximized at the chondrocyte’s resonant frequency and the energy density in the nucleus is almost twice as high as in the cytoplasm. Next, a mechanochemical model was developed to link the mechanical stimulation of ultrasound and the increased mechanical energy density in the nucleus to the downstream targets of the ERK pathway. This study showed for the first time that ultrasound stimulation induces frequency dependent gene expression as a result of altered rates of transcription factors binding to chromatin. PMID:28763448

Acoustically active lipospheres containing paclitaxel: a new therapeutic ultrasound contrast agent.

PubMed

Unger, E C; McCreery, T P; Sweitzer, R H; Caldwell, V E; Wu, Y

1998-12-01

Paclitaxel-carrying lipospheres (MRX-552) were developed and evaluated as a new ultrasound contrast agent for chemotherapeutic drug delivery. Paclitaxel was suspended in soybean oil and added to an aqueous suspension of phospholipids in vials. The headspace of the vials was replaced with perfluorobutane gas; the vials were sealed, and they were agitated at 4200 rpm on a shaking device. The resulting lipospheres containing paclitaxel were studied for concentration, size, acute toxicity in mice, and acoustic activity and drug release with ultrasound. Lipospheres containing sudan black dye were produced to demonstrate the acoustically active liposphere (AAL)-ultrasound release concept. Acoustically active lipospheres containing paclitaxel had a mean particle count of approximately 1 x 10(9) particles per mL and a mean size of 2.9 microns. Acute toxicity studies in mice showed a 10-fold reduction in toxicity for paclitaxel in AALs compared with free paclitaxel. The AALs reflected ultrasound as a contrast agent. Increasing amounts of ultrasound energy selectively ruptured the AALs and released the paclitaxel. Acoustically active lipospheres represent a new class of acoustically active drug delivery vehicles. Future studies will assess efficacy of AALs for ultrasound-mediated drug delivery.

Diaphragm breathing movement measurement using ultrasound and radiographic imaging: a concurrent validity.

PubMed

Noh, Dong K; Lee, Jae J; You, Joshua H

2014-01-01

Recent ultrasound imaging evidence asserts that the diaphragm is an important multifunctional muscle to control breathing as well as stabilize the core and posture in humans. However, the validity and accuracy of ultrasound for the measurement of dynamic diaphragm movements during breathing and functional core activities have not been determined. The specific aim of this study was to validate the accuracy of ultrasound imaging measurements of diaphragm movements by concurrently comparing these measurements to the gold standard of radiographic imaging measurements. A total of 14 asymptomatic adults (9 males, 5 females; mean age =28.4 ± 3.0 years) were recruited to participate in the study. Ultrasound and radiographic images were used concurrently to determine diaphragm movement (inspiration, expiration, and excursion) during tidal breathing. Pearson correlation analysis showed strong correlations, ranging from r=0.78 to r=0.83, between ultrasound and radiographic imaging measurements of the diaphragm during inhalation, exhalation, and excursion. These findings suggest that ultrasound imaging measurement is useful to accurately evaluate diaphragm movements during tidal breathing. Clinically, ultrasound imaging measurements can be used to diagnose and treat diaphragm movement impairments in individuals with neuromuscular disorders including spinal cord injuries, stroke, and multiple sclerosis.

Fundamental Study on One-Dimensional-Array Medical Ultrasound Probe with Piezoelectric Polycrystalline Film by Hydrothermal Method: Experimental Fabrication of One-Dimensional-Array Ultrasound Probe

NASA Astrophysics Data System (ADS)

Endo, Akito; Kawashima, Norimichi; Takeuchi, Shinichi; Ishikawa, Mutsuo; Kurosawa, Minoru Kuribayashi

2007-07-01

We deposited a lead zirconate titanete (PZT) polycrystalline film on a titanium substrate by the hydrothermal method and fabricated a transducer using the PZT film for use as an ultrasound probe. A 10 MHz miniature one-dimensional-array medical ultrasound probe containing the PZT film was developed. After sputtering titanium on the surface of a hydroxyapatite substrate, the titanium film on the substrate was etched by the photolithography to form a one-dimensional titanium film electrode array. We could thus fabricate a miniature one-dimensional-array ultrasound probe by the hydrothermal method. Transmitted ultrasound pulses from a 10 MHz commercial ultrasound probe were received by the newly fabricated one-dimensional-array ultrasound probe. The fabrication process of the probe and the results of experiments on receiving waveforms were reported in this paper.

Characterisation of gene delivery using liposomal bubbles and ultrasound

NASA Astrophysics Data System (ADS)

Koshima, Risa; Suzuki, Ryo; Oda, Yusuke; Hirata, Keiichi; Nomura, Tetsuya; Negishi, Yoichi; Utoguchi, Naoki; Kudo, Nobuki; Maruyama, Kazuo

2011-09-01

The combination of nano/microbubbles and ultrasound is a novel technique for a non-viral gene deliver. We have previously developed novel ultrasound sensitive liposomes (Bubble liposomes) which contain the ultrasound imaging gas perfluoropropane. In this study, Bubble liposomes were compared with cationic lipid (CL)-DNA complexes as potential gene delivery carriers into tumors in vivo. The delivery of genes by bubble liposomes depended on the intensity of the applied ultrasound. The transfection efficiency plateaued at 0.7 W/cm2 ultrasound intensity. Bubble liposomes efficiently transferred genes into cultured cells even when the cells were exposed to ultrasound for only 1 s. In addition, bubble liposomes were able to introduce the luciferase gene more effectively than CL-DNA complexes into mouse ascites tumor cells. We conclude that the combination of Bubble liposomes and ultrasound is a good method for gene transfer in vivo.

Ultrasound biomicroscopic findings in hallerman-streiff syndrome.

PubMed

Sato, Miho; Terasaki, Hiroko; Amano, Emil; Okamoto, Yoko; Miyake, Yozo

2002-01-01

To demonstrate the usefulness of ultrasound biomicroscopy in detecting the morphological changes in the lens caused by the spontaneous absorption of lens material and to detect fundus abnormalities in a patient with Hallermann-Streiff syndrome. Case report of an infant diagnosed at the age of 2 months as having Hallermann-Streiff syndrome. Spontaneous lens absorption occurred during the course of follow-up and was detected only by ultrasound biomicroscopy after the patient was prepared for cataract surgery. The changes in the anterior chamber depth and lens shapes were documented by ultrasound biomicroscopy. Retinal folds that were barely observable by conventional ophthalmoscopy because of a dense cataract were clearly shown by ultrasound biomicroscopy. Ultrasound biomicroscopy can be used to examine the lenses of eyes that are not observable with conventional optical instruments. Ultrasound biomicroscopy can also be used to study the posterior segment of microphthalmic eyes. We recommend preoperative ultrasound biomicroscopy to prevent unnecessary anesthesia and surgical preparation.

Does endoscopic ultrasound improve detection of locally recurrent anal squamous-cell cancer?

PubMed

Peterson, Carrie Y; Weiser, Martin R; Paty, Philip B; Guillem, Jose G; Nash, Garrett M; Garcia-Aguilar, Julio; Patil, Sujata; Temple, Larissa K

2015-02-01

Evaluating patients for recurrent anal cancer after primary treatment can be difficult owing to distorted anatomy and scarring. Many institutions incorporate endoscopic ultrasound to improve detection, but the effectiveness is unknown. The aim of this study is to compare the effectiveness of digital rectal examination and endoscopic ultrasound in detecting locally recurrent disease during routine follow-up of patients with anal cancer. This study is a retrospective, single-institution review. This study was conducted at an oncologic tertiary referral center. Included were 175 patients with nonmetastatic anal squamous-cell cancer, without persistent disease after primary chemoradiotherapy, who had at least 1 posttreatment ultrasound and examination by a colorectal surgeon. The primary outcomes measured were the first modality to detect local recurrence, concordance, crude cancer detection rate, sensitivity, specificity, and predictive value. Eight hundred fifty-five endoscopic ultrasounds and 873 digital rectal examinations were performed during 35 months median follow-up. Overall, ultrasound detected 7 (0.8%) mesorectal and 32 (3.7%) anal canal abnormalities; digital examination detected 69 (7.9%) anal canal abnormalities. Locally recurrent disease was found on biopsy in 8 patients, all detected first or only with digital examination. Four patients did not have an ultrasound at the time of diagnosis of recurrence. The concordance of ultrasound and digital examination in detecting recurrent disease was fair at 0.37 (SE, 0.08; 95% CI, 0.21-0.54), and there was no difference in crude cancer detection rate, sensitivity, specificity, and negative or positive predictive values. The heterogeneity of follow-up timing and examinations is not standardized in this study but is reflective of general practice. Endoscopic ultrasound did not provide any advantage over digital rectal examination in identifying locally recurrent anal cancer, and should not be recommended for routine surveillance.

Assessing the effect of different operation techniques on postoperative duplex ultrasound quality after carotid endarterectomy.

PubMed

Grambow, E; Heller, T; Wieneke, P; Weiß, C; Klar, E; Weinrich, M

2018-01-01

Duplex ultrasound is the first choice in diagnostics and surveillance of stenoses of the internal carotid arteries before and even after surgery. Therefore, the quality of duplex ultrasound is crucial to investigate these vascular pathologies. Aim of this study was the evaluation whether different surgical techniques affect the postoperative quality of duplex ultrasound. In a time period from January to May 2015 duplex ultrasound of the cervical vessels was performed in 75 patients after unilateral endarterectomy of the internal carotid artery at our department between 2006 and 2012. Thereby, the non-operated contralateral side served as a control. Study groups were defined by the surgical techniques of eversion- or thrombendarterectomy with patch plasty using different patch materials and/or a haemostatic sealant. Duplex ultrasound analysis included acoustic impedance, extinction of ultrasound, thickness of skin and individual anatomic aspects of the patients. Carotid endarterectomy itself reduced intravascular grey levels, skin thickness and increased extinction of duplex ultrasound when compared to the non-operated side of the neck. In contrast, neither the kind of chosen operative technique nor the use of different patch materials or the application of a haemostatic sealant showed an effect in this regards. Whereas carotid endarterectomy per se worsens the quality of postoperative duplex ultrasound, the different analysed surgical techniques as well as used patches and the application of a haemostatic sealant can be assumed to be equal regarding the quality of postoperative ultrasound.

‘Essential but not always available when needed’ – an interview study of physicians’ experiences and views regarding use of obstetric ultrasound in Tanzania

PubMed Central

Åhman, Annika; Kidanto, Hussein Lesio; Ngarina, Matilda; Edvardsson, Kristina; Small, Rhonda; Mogren, Ingrid

2016-01-01

Background The value of obstetric ultrasound in high-income countries has been extensively explored but evidence is still lacking regarding the role of obstetric ultrasound in low-income countries. Objective We aimed to explore experiences and views among physicians working in obstetric care in Tanzania, on the role of obstetric ultrasound in relation to clinical management. Design A qualitative study design was applied. Data were collected in 2015, through 16 individual interviews with physicians practicing in obstetric care at hospitals in an urban setting in Tanzania. Data were analyzed using qualitative content analysis. Results Use of obstetric ultrasound in the management of complicated pregnancy was much appreciated by participating physicians, although they expressed considerable concern about the lack of ultrasound equipment and staff able to conduct the examinations. These limitations were recognized as restricting physicians’ ability to manage complications adequately during pregnancy and birth. Better availability of ultrasound was requested to improve obstetric management. Concerns were also raised regarding pregnant women's lack of knowledge and understanding of medical issues which could make counseling in relation to obstetric ultrasound difficult. Although the physicians perceived a positive attitude toward ultrasound among most pregnant women, occasionally they came across women who feared that ultrasound might harm the fetus. Conclusions There seems to be a need to provide more physicians in antenatal care in Tanzania with ultrasound training to enable them to conduct obstetric ultrasound examinations and interpret the results themselves. Physicians also need to acquire adequate counseling skills as counseling can be especially challenging in this setting where many expectant parents have low levels of education. Providers of obstetric care and policy makers in Tanzania will need to take measures to ensure appropriate use of the scarce resources in the Tanzanian health care system and prevent the potential risk of overuse of ultrasound in pregnancy. PMID:27452066

Ultrasound speckle tracking for radial, longitudinal and circumferential strain estimation of the carotid artery--an in vitro validation via sonomicrometry using clinical and high-frequency ultrasound.

PubMed

Larsson, Matilda; Heyde, Brecht; Kremer, Florence; Brodin, Lars-Åke; D'hooge, Jan

2015-02-01

Ultrasound speckle tracking for carotid strain assessment has in the past decade gained interest in studies of arterial stiffness and cardiovascular diseases. The aim of this study was to validate and directly contrast carotid strain assessment by speckle tracking applied on clinical and high-frequency ultrasound images in vitro. Four polyvinyl alcohol phantoms mimicking the carotid artery were constructed with different mechanical properties and connected to a pump generating carotid flow profiles. Gray-scale ultrasound long- and short-axis images of the phantoms were obtained using a standard clinical ultrasound system, Vivid 7 (GE Healthcare, Horten, Norway) and a high-frequency ultrasound system, Vevo 2100 (FUJIFILM, VisualSonics, Toronto, Canada) with linear-array transducers (12L/MS250). Radial, longitudinal and circumferential strains were estimated using an in-house speckle tracking algorithm and compared with reference strain acquired by sonomicrometry. Overall, the estimated strain corresponded well with the reference strain. The correlation between estimated peak strain in clinical ultrasound images and reference strain was 0.91 (p<0.001) for radial strain, 0.73 (p<0.001) for longitudinal strain and 0.90 (p<0.001) for circumferential strain and for high-frequency ultrasound images 0.95 (p<0.001) for radial strain, 0.93 (p<0.001) for longitudinal strain and 0.90 (p<0.001) for circumferential strain. A significant larger bias and root mean square error was found for circumferential strain estimation on clinical ultrasound images compared to high frequency ultrasound images, but no significant difference in bias and root mean square error was found for radial and longitudinal strain when comparing estimation on clinical and high-frequency ultrasound images. The agreement between sonomicrometry and speckle tracking demonstrates that carotid strain assessment by ultrasound speckle tracking is feasible. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

Studies on the use of power ultrasound in leather dyeing.

PubMed

Sivakumar, Venkatasubramanian; Rao, Paruchuri Gangadhar

2003-03-01

Uses of power ultrasound for acceleration/performing the chemical as well as physical processes are gaining importance. In conventional leather processing, the diffusion of chemicals through the pores of the skin/hide is achieved by the mechanical agitation caused by the paddle or drumming action. In this work, the use of power ultrasound in the dyeing of leather has been studied with the aim to improve the exhaustion of dye for a given processing time, to reduce the dyeing time and to improve the quality of dyed leather. The effect of power ultrasound in the dyeing of full chrome cow crust leather in a stationary condition is compared with dyeing in the absence of ultrasound as a control experiment both in a stationary as well as conventional drumming condition. An ultrasonic cleaner (150 W and 33 kHz) was used for the experiments. Actual power dissipated into the system was calculated from the calorimetric measurement. Experiments were carried out with variation in type of dye, amount of dye offer, temperature and time. The results show that there is a significant improvement in the percentage exhaustion of dye due to the presence of ultrasound, when compared to dyeing in absence of ultrasound. Experiments on equilibrium dye uptake carried out with or without ultrasound suggest that ultrasound help to improve the kinetics of leather dyeing. The results indicate that leathers dyed in presence of ultrasound have higher colour values, better dye penetration and fastness properties compared to control leathers. The physical testing results show that strength properties of the dyed leathers are not affected due to the application of ultrasound under the given process conditions. Apparent diffusion coefficient during the initial stage of dyeing process, both in presence and in absence of ultrasound was calculated. The values show that ultrasound helps in improving the apparent diffusion coefficient more for the difficult dyeing conditions such as in the case of metal-complex dyes having bigger aggregate size compared to less difficult dyeing conditions.

In vivo demonstration of ultrasound power delivery to charge implanted medical devices via acute and survival porcine studies

PubMed Central

Radziemski, Leon; Makin, Inder Raj S.

2015-01-01

Animal studies are an important step in proving the utility and safety of an ultrasound based implanted battery recharging system. To this end an Ultrasound Electrical Recharging System (USER™) was developed and tested. Experiments in vitro demonstrated power deliveries at the battery of up to 600 mW through 10 – 15 mm of tissue, 50 mW of power available at tissue depths of up to 50 mm, and the feasibility of using transducers bonded to titanium as used in medical implants. Acute in vivo studies in a porcine model were used to test reliability of power delivery, temperature excursions, and cooling techniques. The culminating five-week survival study involved repeated battery charging, a total of 10.5 hours of ultrasound exposure of the intervening living tissue, with an average RF input to electrical charging efficiency of 20%. This study was potentially the first long term cumulative living-tissue exposure using transcutaneous ultrasound power transmission to an implanted receiver in situ. Histology of the exposed tissue showed changes attributable primarily due to surgical implantation of the prototype device, and no damage due to the ultrasound exposure. The in vivo results are indicative of the potential safe delivery of ultrasound energy for a defined set of source conditions for charging batteries within implants. PMID:26243566

In vivo demonstration of ultrasound power delivery to charge implanted medical devices via acute and survival porcine studies.

PubMed

Radziemski, Leon; Makin, Inder Raj S

2016-01-01

Animal studies are an important step in proving the utility and safety of an ultrasound based implanted battery recharging system. To this end an Ultrasound Electrical Recharging System (USER™) was developed and tested. Experiments in vitro demonstrated power deliveries at the battery of up to 600 mW through 10-15 mm of tissue, 50 mW of power available at tissue depths of up to 50 mm, and the feasibility of using transducers bonded to titanium as used in medical implants. Acute in vivo studies in a porcine model were used to test reliability of power delivery, temperature excursions, and cooling techniques. The culminating five-week survival study involved repeated battery charging, a total of 10.5h of ultrasound exposure of the intervening living tissue, with an average RF input to electrical charging efficiency of 20%. This study was potentially the first long term cumulative living-tissue exposure using transcutaneous ultrasound power transmission to an implanted receiver in situ. Histology of the exposed tissue showed changes attributable primarily due to surgical implantation of the prototype device, and no damage due to the ultrasound exposure. The in vivo results are indicative of the potential safe delivery of ultrasound energy for a defined set of source conditions for charging batteries within implants. Copyright © 2015 Elsevier B.V. All rights reserved.

Point-of-care ultrasound education for non-physician clinicians in a resource-limited emergency department.

PubMed

Stolz, Lori A; Muruganandan, Krithika M; Bisanzo, Mark C; Sebikali, Mugisha J; Dreifuss, Bradley A; Hammerstedt, Heather S; Nelson, Sara W; Nayabale, Irene; Adhikari, Srikar; Shah, Sachita P

2015-08-01

To describe the outcomes and curriculum components of an educational programme to train non-physician clinicians working in a rural, Ugandan emergency department in the use of POC ultrasound. The use of point-of-care ultrasound was taught to emergency care providers through lectures, bedsides teaching and hands-on practical sessions. Lectures were tailored to care providers' knowledge base and available therapeutic means. Every ultrasound examination performed by these providers was recorded over 4.5 years. Findings of these examinations were categorised as positive, negative, indeterminate or procedural. Other radiologic studies ordered over this same time period were also recorded. A total of 22,639 patients were evaluated in the emergency department by emergency care providers, and 2185 point-of-care ultrasound examinations were performed on 1886 patients. Most commonly used were the focused assessment with sonography in trauma examination (53.3%) and echocardiography (16.4%). Point-of-care ultrasound studies were performed more frequently than radiology department-performed studies. Positive findings were documented in 46% of all examinations. We describe a novel curriculum for point-of-care ultrasound education of non-physician emergency practitioners in a resource-limited setting. These non-physician clinicians integrated ultrasound into clinical practice and utilised this imaging modality more frequently than traditional radiology department imaging with a large proportion of positive findings. © 2015 John Wiley & Sons Ltd.

Ensuring patient safety when implementing a new diagnostic pathway for thyroid nodules.

PubMed

Brimioulle, M; Al-Lami, A; Marzouk, S; Emerson, H; Balfour, A; Dhar, V; Nixon, I J

2018-05-01

Introduction The aim of this study was to determine whether ultrasound alone is sufficient to safely exclude malignancy in thyroid nodules in a district general hospital setting, to comply with the latest British Thyroid Association guidelines. Methods This retrospective study investigated the quality of ultrasound reporting and the correlation between ultrasound report and histology for individual thyroid nodules. Cases were selected from the thyroid multidisciplinary meeting and included all patients having undergone surgery for a thyroid malignancy in a one-year period. Results Forty-seven patients were included in the study. Ultrasound reports were reviewed and assessed, in which 21 clinicians were involved; 36% of scans included a summary of whether the nodule(s) overall appeared benign, equivocal, suspicious or malignant; 4% of reports included a U classification; 81% of reports commented on cervical lymph nodes. Ultrasound was compared with histology. The sensitivity of ultrasound in correctly identifying nodules requiring further investigation was of 56% and specificity was 81%. Positive predictive value was 81% and negative predictive value was 56%. Discussion These findings suggest that, in a district general hospital setting without a dedicated head and neck radiologist, using only ultrasound and limiting fine-needle aspiration cytology to identify suspicious nodules may not be safe, as a high number of nodules appearing benign on ultrasound may ultimately prove to be malignant.

The combination of ultrasound with antibiotics released from bone cement decreases the viability of planktonic and biofilm bacteria: an in vitro study with clinical strains.

PubMed

Ensing, Geert T; Neut, Daniëlle; van Horn, Jim R; van der Mei, Henny C; Busscher, Henk J

2006-12-01

Antibiotic-loaded bone cements are used for the permanent fixation of joint prostheses. Antibiotic-loaded cements significantly decrease the incidence of infection. The objective of this study was to investigate whether the viability of bacteria derived from patients with a prosthesis-related infection could be further decreased when antibiotic release from bone cements was combined with application of pulsed ultrasound. Escherichia coli ATCC 10798, Staphylococcus aureus 7323, coagulase-negative staphylococci (CoNS 7368 and CoNS 7391) and Pseudomonas aeruginosa 5148 were grown planktonically in suspension and as a biofilm on three different bone cements: Palacos R without gentamicin as control, gentamicin-loaded Palacos R-G and gentamicin/clindamycin-loaded Copal. The viability of planktonic and biofilm bacteria was measured in the absence and presence of pulsed ultrasound for 40 h. Ultrasound itself did not affect bacterial viability. However, application of pulsed ultrasound in combination with antibiotic release by antibiotic-loaded bone cements yielded a reduction of both planktonic and biofilm bacterial viability compared with antibiotic release without application of ultrasound. This study shows that antibiotic release in combination with ultrasound increases the antimicrobial efficacy further than antibiotic release alone against a variety of clinical isolates. Application of ultrasound in combination with antibiotic release in clinical practice could therefore lead to better prevention or treatment of prosthesis-related infections.

The use of ultrasound in the diagnosis of abdominal wall hernias.

PubMed

Young, J; Gilbert, A I; Graham, M F

2007-08-01

The diagnosis of abdominal wall hernias is not always straightforward and may require additional investigative modalities. Real-time ultrasound is accurate, non-invasive, relatively inexpensive, and readily available. The value of ultrasound as an adjunctive tool in the diagnosis of abdominal wall hernias in both pre-operative and post-operative patients was studied. Retrospective analysis of 200 patients treated at the Hernia Institute of Florida was carried out. In these cases, ultrasound had been used to assist with case management. Patients without previous hernia surgery and those with early and late post-herniorrhaphy complaints were studied. Patients with obvious hernias were excluded. Indications for ultrasound examination included patients with abdominal pain without a palpable hernia, a palpable mass of questionable etiology, and patients with inordinate pain or excessive swelling during the early post-operative period. Patients were treated with surgery or conservative therapy depending on the results of the physical examination and ultrasound studies. Cases in which the ultrasound findings influenced the decision-making process by confirming clinical findings or altering the diagnosis and changing the treatment plan are discussed. Of the 200 patients, 144 complained of pain alone and on physical exam no hernia or mass was palpable. Of these 144 patients with pain alone, 21 had a hernia identified on the US examination and were referred for surgery. The 108 that had a negative ultrasound were treated conservatively with rest, heat, and anti-inflammatory drugs, most often with excellent results. Of the 56 remaining patients who had a mass, with or without pain, 22 had hernias identified by means of ultrasound examination. In the other 34, the etiology of the mass was not a hernia. Abdominal wall ultrasound is a valuable tool in the scheme of management of patients in whom the diagnosis of abdominal wall hernia is unclear. Therapeutic decisions can be influenced by the ultrasound findings that can provide more efficient and economical treatment by expediting their clinical management.

Can Ultrasound Accurately Assess Ischiofemoral Space Dimensions? A Validation Study.

PubMed

Finnoff, Jonathan T; Johnson, Adam C; Hollman, John H

2017-04-01

Ischiofemoral impingement is a potential cause of hip and buttock pain. It is evaluated commonly with magnetic resonance imaging (MRI). To our knowledge, no study previously has evaluated the ability of ultrasound to measure the ischiofemoral space (IFS) dimensions reliably. To determine whether ultrasound could accurately measure the IFS dimensions when compared with the gold standard imaging modality of MRI. A methods comparison study. Sports medicine center within a tertiary-care institution. A total of 5 male and 5 female asymptomatic adult subjects (age mean = 29.2 years, range = 23-35 years; body mass index mean = 23.5, range = 19.5-26.6) were recruited to participate in the study. Subjects were secured in a prone position on a MRI table with their hips in a neutral position. Their IFS dimensions were then acquired in a randomized order using diagnostic ultrasound and MRI. The main outcome measurements were the IFS dimensions acquired with ultrasound and MRI. The mean IFS dimensions measured with ultrasound was 29.5 mm (standard deviation [SD] 4.99 mm, standard error mean 1.12 mm), whereas those obtained with MRI were 28.25 mm (SD 5.91 mm, standard error mean 1.32 mm). The mean difference between the ultrasound and MRI measurements was 1.25 mm, which was not statistically significant (SD 3.71 mm, standard error mean 3.71 mm, 95% confidence interval -0.49 mm to 2.98 mm, t 19 = 1.506, P = .15). The Bland-Altman analysis indicated that the 95% limits of agreement between the 2 measurement was -6.0 to 8.5 mm, indicating that there was no systematic bias between the ultrasound and MRI measurements. Our findings suggest that the IFS measurements obtained with ultrasound are very similar to those obtained with MRI. Therefore, when evaluating individuals with suspected ischiofemoral impingement, one could consider using ultrasound to measure their IFS dimensions. III. Copyright © 2017 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

Influence of mixing and ultrasound frequency on antisolvent crystallisation of sodium chloride.

PubMed

Lee, Judy; Ashokkumar, Muthupandian; Kentish, Sandra E

2014-01-01

Ultrasound is known to promote nucleation of crystals and produce a narrower size distribution in a controlled and reproducible manner for the crystallisation process. Although there are various theories that suggest cavitation bubbles are responsible for sonocrystallisation, most studies use power ultrasonic horns that generate both intense shear and cavitation and this can mask the role that cavitation bubbles play. High frequency ultrasound from a plate transducer can be used to examine the effect of cavitation bubbles without the intense shear effect. This study reports the crystal size and morphology with various mixing speeds and ultrasound frequencies. The results show high frequency ultrasound produced sodium chloride crystals of similar size distribution as an ultrasonic horn. In addition, ultrasound generated sodium chloride crystals having a more symmetrical cubic structure compared to crystals produced by a high shear mixer. Copyright © 2013 Elsevier B.V. All rights reserved.

Osteotomy in direct sinus lift. A comparative study of the rotary technique and ultrasound

PubMed Central

Peñarrocha-Diago, Miguel; Sanchez-Recio, Cristina; Peñarrocha-Oltra, David; Romero-Millán, Javier

2012-01-01

Purpose: The present study investigates sinus membrane rupture in direct maxillary sinus lift with the rotary technique and with ultrasound, examining the survival of implants placed after sinus augmentation, and analyzing the bone gain obtained after the operation and 12 months after placement of the prosthetic restoration. Material and Methods: A retrospective study was made of 45 patients requiring maxillary sinus lift or augmentation for implant-prosthetic rehabilitation. Use was made of the hand piece and ostectomy drills for the rotary technique, and of specific tips for ultrasound. The implant success criteria were based on those developed by Buser. The bone gain obtained as a result of sinus lift was calculated from the postoperative panoramic X-rays. Results: A total of 57 direct elevations of the maxillary sinus were carried out: 32 with the rotary technique and 25 with ultrasound. Perforations of Schneider’s membrane with the rotary technique and ultrasound occurred in 7% and 1.7% of the cases, respectively, with membrane integrity being preserved in 91.2%. Of the 100 implants placed, 5 failed after one year of follow-up in the rotary technique group, while one implant failed in the ultrasound group. The rotary technique in turn afforded a bone gain of 5.9 mm, versus 6.7 mm with ultrasound. Conclusions: Perforations of the membrane sinusal in direct lift were more frequent with the rotary technique (7%) than with ultrasound (1.7%). Implant survival and bone gain were both greater when ultrasound was used. Key words:Bone sectioning, maxillary sinus augmentation, piezosurgery. PMID:22143735

Ultrasound detection of pneumothorax compared with chest X-ray and computed tomography scan.

PubMed

Nagarsheth, Khanjan; Kurek, Stanley

2011-04-01

Pneumothorax after trauma can be a life threatening injury and its care requires expeditious and accurate diagnosis and possible intervention. We performed a prospective, single blinded study with convenience sampling at a Level I trauma center comparing thoracic ultrasound with chest X-ray and CT scan in the detection of traumatic pneumothorax. Trauma patients that received a thoracic ultrasound, chest X-ray, and chest CT scan were included in the study. The chest X-rays were read by a radiologist who was blinded to the thoracic ultrasound results. Then both were compared with CT scan results. One hundred and twenty-five patients had a thoracic ultrasound performed in the 24-month period. Forty-six patients were excluded from the study due to lack of either a chest X-ray or chest CT scan. Of the remaining 79 patients there were 22 positive pneumothorax found by CT and of those 18 (82%) were found on ultrasound and 7 (32%) were found on chest X-ray. The sensitivity of thoracic ultrasound was found to be 81.8 per cent and the specificity was found to be 100 per cent. The sensitivity of chest X-ray was found to be 31.8 per cent and again the specificity was found to be 100 per cent. The negative predictive value of thoracic ultrasound for pneumothorax was 0.934 and the negative predictive value for chest X-ray for pneumothorax was found to be 0.792. We advocate the use of chest ultrasound for detection of pneumothorax in trauma patients.

Use of ultrasound imaging for the diagnosis of abnormal uterine bleeding in the bonnet macaque ( Macaca radiata).

PubMed

Chaudhari, Uddhav K; Imran, M; Manjramkar, Dhananjay D; Metkari, Siddhanath M; Sable, Nilesh P; Gavhane, Dnyaneshwar S; Katkam, Rajendra R; Sachdeva, Geetanjali; Thakur, Meenakshi H; Kholkute, Sanjeeva D

2017-02-01

Ultrasound is a powerful, low-cost, non-invasive medical tool used by laboratory animal veterinarians for diagnostic imaging. Sonohysterography and transvaginal ultrasound are frequently used to assess uterine anomalies in women presenting with abnormal uterine bleeding (AUB). In the present study, we have evaluated the abdominal ultrasound of bonnet monkeys ( n = 8) showing spontaneous ovulatory ( n = 5) and anovulatory ( n = 3) AUB. The ovulatory ( n = 5) macaques showed cyclic AUB for 7-8 days. The anovulatory ( n = 3) macaques had irregular AUB with menstrual cycles of 40-45 days. The B-mode abdominal, colour Doppler and 3D ultrasound scans were performed during the proliferative phase of the menstrual cycle. Ultrasound examination revealed endometrial polyps in five macaques and endometrial hyperplasia in three animals. The width and length of endometrial polyps was around 0.5-1 cm (average 0.51 ± 0.23 cm × 0.96 ± 0.16 cm) with significant increase in endometrial thickness ( P < 0.0002). 3D ultrasound also showed a homogeneous mass in the uterine cavity and colour Doppler ultrasound showed increased vascularity in the endometrial polyps. Endometrial hyperplasia characteristically appeared as a thickened echogenic endometrium ( P < 0.0002). This study demonstrates the use of non-invasive ultrasound techniques in the diagnosis of AUB in macaques.

Scalable Directed Self-Assembly Using Ultrasound Waves

DTIC Science & Technology

2015-09-04

SECURITY CLASSIFICATION OF: We aim to understand how ultrasound waves can be used to create organized patterns of nanoparticles in a host medium such...as a polymer matrix material. The critical difference between the ultrasound technology studied in this project, and other directed self-assembly...of nanoparticles dispersed in a host medium are assembled by means of standing ultrasound waves. Additionally, we have obtained experimental

Diagnostic image quality in gynaecological ultrasound: Who should measure it, what should we measure and how?

PubMed Central

Knapp, Karen

2013-01-01

Assessment of diagnostic image quality in gynaecological ultrasound is an important aspect of imaging department quality assurance. This may be addressed through audit, but who should undertake the audit, what should be measured and how, remains contentious. The aim of this study was to identify whether peer audit is a suitable method of assessing the diagnostic quality of gynaecological ultrasound images. Nineteen gynaecological ultrasound studies were independently assessed by six sonographers utilising a pilot version of an audit tool. Outcome measures were levels of inter-rater agreement using different data collection methods (binary scores, Likert scale, continuous scale), effect of ultrasound study difficulty on study score and whether systematic differences were present between reviewers of different clinical grades and length of experience. Inter-rater agreement ranged from moderate to good depending on the data collection method. A continuous scale gave the highest level of inter-rater agreement with an intra-class correlation coefficient of 0.73. A strong correlation (r = 0.89) between study difficulty and study score was yielded. Length of clinical experience between reviewers had no effect on the audit scores, but individuals of a higher clinical grade gave significantly lower scores than those of a lower grade (p = 0.04). Peer audit is a promising tool in the assessment of ultrasound image quality. Continuous scales seem to be the best method of data collection implying a strong element of heuristically driven decision making by reviewing ultrasound practitioners. PMID:27433192

The Use of Ultrasound in Remediation of North American English /r/ in 2 Adolescents

ERIC Educational Resources Information Center

Adler-Bock, Marcy; Bernhardt, Barbara May; Gick, Bryan; Bacsfalvi, Penelope

2007-01-01

Purpose: Ultrasound can provide images of the tongue during speech production. The present study set out to examine the potential utility of ultrasound in remediation of North American English /r/. Method: The participants were 2 Canadian English-speaking adolescents who had not yet acquired /r/. The study included an initial period without…

Quantitative Contrast-Enhanced Ultrasound Parameters in Crohn Disease: Their Role in Disease Activity Determination With Ultrasound.

PubMed

Medellin-Kowalewski, Alexandra; Wilkens, Rune; Wilson, Alexandra; Ruan, Ji; Wilson, Stephanie R

2016-01-01

The primary objective of our study was to examine the association between contrast-enhanced ultrasound (CEUS) parameters and established gray-scale ultrasound with color Doppler imaging (CDI) for the determination of disease activity in patients with Crohn disease. Our secondary objective was to develop quantitative time-signal intensity curve thresholds for disease activity. One hundred twenty-seven patients with Crohn disease underwent ultrasound with CDI and CEUS. Reviewers graded wall thickness, inflammatory fat, and mural blood flow as showing remission or inflammation (mild, moderate, or severe). If both gray-scale ultrasound and CDI predicted equal levels of disease activity, the studies were considered concordant. If ultrasound images suggested active disease not supported by CDI findings, the ultrasound results for disease activity were indeterminate. Time-signal intensity curves from CEUS were acquired with calculation of peak enhancement (PE), and AUCs. Interobserver variation and associations between PE and ultrasound parameters were examined. Multiclass ROC analysis was used to develop CEUS thresholds for activity. Ninety-six (76%) studies were concordant, 19 of which showed severe disease, and 31 (24%) studies were indeterminate. Kappa analyses revealed good interobserver agreement on grades for CDI (κ = 0.76) and ultrasound (κ = 0.80) assessments. PE values on CEUS and wall thickness showed good association with the Spearman rank correlation coefficient for the entire population (ρ = 0.62, p < 0.01) and for the concordant group (ρ = 0.70, p < 0.01). Multiclass ROC analyses of the concordant group using wall thickness alone as the reference standard showed cutoff points of 18.2 dB for differentiating mild versus moderate activity (sensitivity, 89.0% and specificity, 87.0%) and 23.0 dB for differentiating moderate versus severe (sensitivity, 90% and specificity, 86.8%). Almost identical cutoff points were observed when using ultrasound global assessment as the reference standard: using 18.2 dB to differentiate mild versus moderate activity yielded sensitivity of 89.2% and specificity of 90.9% and using 22.9 dB to differentiate moderate versus severe activity yielded sensitivity of 89.5% and specificity of 83.1%. Quantitative CEUS parameters integrated into inflammatory assessments with ultrasound reduce indeterminate results and improve disease activity level determinations.

Bypassing multidrug resistant ovarian cancer using ultrasound responsive doxorubicin/curcumin co-deliver alginate nanodroplets.

PubMed

Baghbani, Fatemeh; Moztarzadeh, Fathollah

2017-05-01

Ultrasound-responsive perfluorocarbon nanoemulsions are a class of new multifunctional smart nanocarriers which combine diagnostic properties with therapeutic properties and release their drug payload in a controlled manner in response to ultrasound. Therefore, combination therapy using chemotherapeutic and chemosensitizing agents co-entrapped in these nanocarriers seems beneficial for cancer treatment. In the present study, multifunctional smart alginate/perfluorohexane nanodroplets were developed for co-delivery of doxorubicin and curcumin (a strong chemosensitizer). The nanodroplets with the average particle size of 55.1nm were synthesized via nanoemulsion process. The entrapment efficiency of doxorubicin was 92.3%. To improve curcumin entrapment into the alginate shell, Span 60 was added to the formulation as a co-surfactant and finally curcumin entrapment of about 40% was achieved. Ultrasound-mediated drug release kinetic was evaluated at two different frequencies of 28kHz (low frequency) and 1MHz (high frequency). Low frequency ultrasound resulted in higher triggered drug release from nanodroplets. The nanodroplets showed strong ultrasound contrast via droplet to bubble transition as confirmed via B-mode ultrasound imaging. Enhanced cytotoxicity in adriamycin-resistant A2780 ovarian cancer cells was observed for Dox-Cur-NDs compared to Dox-NDs because of the synergistic effects of doxorubicin and curcumin. However, ultrasound irradiation significantly increased the cytotoxicity of Dox-Cur-NDs. Finally, in vivo ovarian cancer treatment using Dox/Cur-NDs combined with ultrasound irradiation resulted in efficient tumor regression. According to the present study, nanotherapy of multidrug resistant human ovarian cancer using ultrasound responsive doxorubicin/curcumin co-loaded alginate-shelled nanodroplets combined with ultrasound irradiation could be a promising modality for the future of cancer treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

Comparison of translabial three-dimensional ultrasound with magnetic resonance imaging for measurement of levator hiatal biometry at rest.

PubMed

Vergeldt, T F M; Notten, K J B; Stoker, J; Fütterer, J J; Beets-Tan, R G; Vliegen, R F A; Schweitzer, K J; Mulder, F E M; van Kuijk, S M J; Roovers, J P W R; Kluivers, K B; Weemhoff, M

2016-05-01

To compare translabial three-dimensional (3D) ultrasound with magnetic resonance imaging (MRI) for the measurement of levator hiatal biometry at rest in women with pelvic organ prolapse, and to determine the interobserver reliability between two independent observers for ultrasound and MRI measurements. Data were derived from a multicenter prospective cohort study in which women scheduled for conventional anterior colporrhaphy underwent translabial 3D ultrasound and MRI prior to surgery. Intraclass correlation coefficients (ICCs) were calculated to estimate interobserver reliability between two independent observers and determine the agreement between ultrasound and MRI measurements. Bland-Altman plots were created to assess the agreement between ultrasound and MRI measurements. Data from 139 women from nine hospitals were included in the study. The interobserver reliability of ultrasound assessment at rest, during Valsalva maneuver and during contraction and of MRI assessment at rest were moderate or good. The agreement between ultrasound and MRI for the measurement of levator hiatal biometry at rest was moderate, with ICCs of 0.52 (95%CI, 0.32-0.66) for levator hiatal area, 0.44 (95%CI, 0.21-0.60) for anteroposterior diameter and 0.44 (95%CI, 0.22-0.60) for transverse diameter. Levator hiatal biometry measurements were statistically significantly larger on MRI than on translabial 3D ultrasound. The agreement between translabial 3D ultrasound and MRI for measurement of the levator hiatus at rest in women with pelvic organ prolapse was only moderate. The results of translabial 3D ultrasound and MRI should therefore not be used interchangeably in daily practice or in clinical research. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Physicians' experiences and views on the role of obstetric ultrasound in rural and urban Rwanda: a qualitative study.

PubMed

Edvardsson, Kristina; Ntaganira, Joseph; Åhman, Annika; Sengoma, Jean Paul Semasaka; Small, Rhonda; Mogren, Ingrid

2016-07-01

To explore Rwandan physicians' experiences and views on the role of obstetric ultrasound in clinical management of pregnancy, and in situations where maternal and fetal health interests conflict. Physicians (n = 19) in public and private health facilities in urban and rural Rwanda were interviewed in 2015 as part of the CROss-Country Ultrasound Study (CROCUS). Data were analysed qualitatively. Ultrasound was described as an important tool in maternity care. Availability and quality of equipment varied across sites, and considerable disparities in obstetric ultrasound utilisation between rural and urban areas were described. The physicians wanted more ultrasound training and saw the potential for midwives to perform basic scans. Information about fetal sex and well-being was described as women's main expectations of ultrasound. Although women's right to autonomy in pregnancy was supported in principle by participating physicians, fetal rights were sometimes seen as needing physician 'protection'. There appears to be increasing use and demand for obstetric ultrasound in Rwanda, particularly in urban areas. It seems important to monitor this development closely to secure wise and fair allocation of scarce obstetric expertise and resources and to prevent overuse or misuse of ultrasound. Raising awareness about the benefits of all aspects of antenatal care, including ultrasound may be an important step to improve pregnant women's uptake of services. Increased opportunities for formal ultrasound training, including the training of midwives to perform basic scans, seem warranted. Moreover, in parallel with the transition to more medico-technical maternity care, a dialogue about maternal rights to autonomy in pregnancy and childbirth is imperative. © 2016 John Wiley & Sons Ltd.

Ultrasound arthroscopy of human knee cartilage and subchondral bone in vivo.

PubMed

Liukkonen, Jukka; Lehenkari, Petri; Hirvasniemi, Jukka; Joukainen, Antti; Virén, Tuomas; Saarakkala, Simo; Nieminen, Miika T; Jurvelin, Jukka S; Töyräs, Juha

2014-09-01

Arthroscopic ultrasound imaging enables quantitative evaluation of articular cartilage. However, the potential of this technique for evaluation of subchondral bone has not been investigated in vivo. In this study, we address this issue in clinical arthroscopy of the human knee (n = 11) by determining quantitative ultrasound (9 MHz) reflection and backscattering parameters for cartilage and subchondral bone. Furthermore, in each knee, seven anatomical sites were graded using the International Cartilage Repair Society (ICRS) system based on (i) conventional arthroscopy and (ii) ultrasound images acquired in arthroscopy with a miniature transducer. Ultrasound enabled visualization of articular cartilage and subchondral bone. ICRS grades based on ultrasound images were higher (p < 0.05) than those based on conventional arthroscopy. The higher ultrasound-based ICRS grades were expected as ultrasound reveals additional information on, for example, the relative depth of the lesion. In line with previous literature, ultrasound reflection and scattering in cartilage varied significantly (p < 0.05) along the ICRS scale. However, no significant correlation between ultrasound parameters and structure or density of subchondral bone could be demonstrated. To conclude, arthroscopic ultrasound imaging had a significant effect on clinical grading of cartilage, and it was found to provide quantitative information on cartilage. The lack of correlation between the ultrasound parameters and bone properties may be related to lesser bone change or excessive attenuation in overlying cartilage and insufficient power of the applied miniature transducer. Copyright © 2014 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

The era of ultrasonography during laparoscopic cholecystectomy.

PubMed

Onders, Raymond P; Hallowell, Peter T

2005-03-01

The use of ultrasound cholangiography during cholecystectomy has been well described. This study was undertaken to assess the use of the umbilical port exclusively for ultrasound and to assess its employment on the use of fluoroscopy resources. In addition, we also looked at the increased use of ultrasound from 2000 to 2004. The use of imaging techniques during all cholecystectomies was analyzed from January 2000 to July 2001 for one surgeon and compared with that surgeon's present use from January 2004 to June 2004. Patient demographics, intraoperative finding, and postoperative results were reviewed. During the first study period, ultrasound was used in 29% of 189 laparoscopic cholecystectomies. During 2004, ultrasound was used in 77% of 66 laparoscopic cholecystectomies. Throughout both periods, fluoroscopy was only used during 6 laparoscopic common bile duct explorations (2.4% of all cases). There were no false-positive or -negative ultrasounds, and there were no bile duct injuries. As experience with ultrasound cholangiography increases, there is little indication for fluoroscopic cholangiography except for rare questions concerning anatomy and during therapeutic maneuvers for common bile duct stones.

Stability, Antioxidant Capacity and Degradation Kinetics of Pelargonidin-3-glucoside Exposed to Ultrasound Power at Low Temperature.

PubMed

Sun, Jianxia; Mei, Zhouxiong; Tang, Yajuan; Ding, Lijun; Jiang, Guichuan; Zhang, Chi; Sun, Aidong; Bai, Weibin

2016-08-24

As an alternative preservation method to thermal treatment, ultrasound is a novel non-thermal processing technology that can significantly avoid undesirable nutritional changes. However, recently literature indicated that anthocyanin degradation occurred when high amplitude ultrasound was applied to juice. This work mainly studied the effect of ultrasound on the stability and antioxidant capacity of pelargonidin-3-glucoside (Pg-3-glu) and the correlation between anthocyanin degradation and •OH generation in a simulated system. Results indicated that the spectral intensities of Pg-3-glu decreased with increasing ultrasound power (200-500 W) and treatment time (0-60 min). The degradation trend was consistent with first-order reaction kinetics (R² > 0.9100). Further study showed that there was a good linear correlation between Pg-3-glu degradation and •OH production (R² = 0.8790), which indicated the important role of •OH in the degradation of anthocyanin during ultrasound exposure. Moreover, a decrease in the antioxidant activity of solution(s) containing Pg-3-glu as evaluated by the DPPH and FRAP methods was observed after ultrasound treatment.

Augmentation of limb perfusion and reversal of tissue ischemia produced by ultrasound-mediated microbubble cavitation.

PubMed

Belcik, J Todd; Mott, Brian H; Xie, Aris; Zhao, Yan; Kim, Sajeevani; Lindner, Nathan J; Ammi, Azzdine; Linden, Joel M; Lindner, Jonathan R

2015-04-01

Ultrasound can increase tissue blood flow, in part, through the intravascular shear produced by oscillatory pressure fluctuations. We hypothesized that ultrasound-mediated increases in perfusion can be augmented by microbubble contrast agents that undergo ultrasound-mediated cavitation and sought to characterize the biological mediators. Contrast ultrasound perfusion imaging of hindlimb skeletal muscle and femoral artery diameter measurement were performed in nonischemic mice after unilateral 10-minute exposure to intermittent ultrasound alone (mechanical index, 0.6 or 1.3) or ultrasound with lipid microbubbles (2×10(8) IV). Studies were also performed after inhibiting shear- or pressure-dependent vasodilator pathways, and in mice with hindlimb ischemia. Ultrasound alone produced a 2-fold increase (P<0.05) in muscle perfusion regardless of ultrasound power. Ultrasound-mediated augmentation in flow was greater with microbubbles (3- and 10-fold higher than control for mechanical index 0.6 and 1.3, respectively; P<0.05), as was femoral artery dilation. Inhibition of endothelial nitric oxide synthase attenuated flow augmentation produced by ultrasound and microbubbles by 70% (P<0.01), whereas inhibition of adenosine-A2a receptors and epoxyeicosatrienoic acids had minimal effect. Limb nitric oxide production and muscle phospho-endothelial nitric oxide synthase increased in a stepwise fashion by ultrasound and ultrasound with microbubbles. In mice with unilateral hindlimb ischemia (40%-50% reduction in flow), ultrasound (mechanical index, 1.3) with microbubbles increased perfusion by 2-fold to a degree that was greater than the control nonischemic limb. Increases in muscle blood flow during high-power ultrasound are markedly amplified by the intravascular presence of microbubbles and can reverse tissue ischemia. These effects are most likely mediated by cavitation-related increases in shear and activation of endothelial nitric oxide synthase. © 2015 American Heart Association, Inc.

AUGMENTATION OF LIMB PERFUSION AND REVERSAL OF TISSUE ISCHEMIA PRODUCED BY ULTRASOUND-MEDIATED MICROBUBBLE CAVITATION

PubMed Central

Belcik, J. Todd; Mott, Brian H.; Xie, Aris; Zhao, Yan; Kim, Sajeevani; Lindner, Nathan J.; Ammi, Azzdine; Linden, Joel M.; Lindner, Jonathan R.

2015-01-01

Background Ultrasound can increase tissue blood flow in part through the intravascular shear produced by oscillatory pressure fluctuations. We hypothesized that ultrasound-mediated increases in perfusion can be augmented by microbubble contrast agents that undergo ultrasound-mediated cavitation, and sought to characterize the biologic mediators. Methods and Results Contrast ultrasound perfusion imaging of hindlimb skeletal muscle and femoral artery diameter measurement were performed in non-ischemic mice after unilateral 10 min exposure to intermittent ultrasound alone (mechanical index [MI] 0.6 or 1.3) or ultrasound with lipid microbubbles (2×108 I.V.). Studies were also performed after inhibiting shear- or pressure-dependent vasodilator pathways, and in mice with hindlimb ischemia. Ultrasound alone produced a 2-fold increase (p<0.05) in muscle perfusion regardless of ultrasound power. Ultrasound-mediated augmentation in flow was greater with microbubbles (3-fold and 10-fold higher than control for MI 0.6 and 1.3, respectively; p<0.05), as was femoral artery dilation. Inhibition of endothelial nitric oxide synthase (eNOS) attenuated flow augmentation produced by ultrasound and microbubbles by 70% (p<0.01), whereas inhibition of adenosine-A2a receptors and epoxyeicosatrienoic acids had minimal effect. Limb nitric oxide (NO) production and muscle phospho-eNOS increased in a stepwise fashion by ultrasound and ultrasound with microbubbles. In mice with unilateral hindlimb ischemia (40–50% reduction in flow), ultrasound (MI 1.3) with microbubbles increased perfusion by 2-fold to a degree that was greater than the control non-ischemic limb. Conclusions Increases in muscle blood flow during high-power ultrasound are markedly amplified by the intravascular presence of microbubbles and can reverse tissue ischemia. These effects are most likely mediated by cavitation-related increases in shear and activation of eNOS. PMID:25834183

Musculoskeletal ultrasound in rheumatology in Korea: targeted ultrasound initiative survey.

PubMed

Kang, Taeyoung; Wakefield, Richard J; Emery, Paul

2016-04-01

In collaboration with the Targeted Ultrasound Initiative (TUI), to conduct the first study in Korea to investigate current practices in ultrasound use among Korean rheumatologists. We translated the TUI Global Survey into Korean and added questions to better understand the specific challenges facing rheumatologists in Korea. To target as many rheumatologists in Korea as possible, we created an on-line version of this survey, which was conducted from March to April 2013. Rheumatologists are in charge of ultrasound in many Korean hospitals. Rheumatologists in hospitals and private clinics use ultrasound to examine between one and five patients daily; they use ultrasound for diagnosis more than monitoring and receive compensation of about US$30-50 per patient. There are marked differences in the rates of ultrasound usage between rheumatologists who work in private practice compared with tertiary hospitals. Korean rheumatologists not currently using ultrasound in their practice appear eager to do so. This survey provides important insights into the current status of ultrasound in rheumatology in Korea and highlights several priorities; specifically, greater provision of formal training, standardization of reporting and accrual of greater experience among ultrasound users. If these needs are addressed, all rheumatology departments in Korea are likely to use ultrasound or have access to it in the future. © 2014 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.

Ultrasonography for diagnosis, monitoring and treatment of tenosynovitis in patients with rheumatoid arthritis.

PubMed

Danielsen, Mads Ammitzbøll

2018-03-01

Rheumatod arthritis is a chronic systemic autoimmune disease, characterized by inflammation in joints and tendon sheaths, which frequently leads to permanent and serious disability due to joint destruction, but also tendon and ligament ruptures. Clinical management of rheumatoid arthritis has traditionally been supported by biochemical and radiographic findings. However, imaging modalities like ultrasound and magnetic resonance imaging (MRI) have improved the possibility for better management of rheumatoid arthritis patients, due to higher sensitivity and specificity for detecting ongoing inflammation, this thesis is focusing on tenosynovitis as recent studies have shown that inflammation in tendon sheaths, i.e. tenosynovitis, is a very common manifestation of rheumatoid arthritis and may often be mistaken for synovitis. Furthermore, presence of ultrasonographic tenosynovitis may predict clinical flare and erosive progression. 
The main aim of this PhD thesis was to further develop and validate ultrasound as a tool for diagnosis, monitoring and treatment of tenosynovitis. This was investigated in four studies: 
Study I: 3D Doppler Ultrasound findings in healthy wrist and finger tendon sheaths - Can feeding vessels lead to misinterpretation in Doppler-detected tenosynovitis? 
Study II: Image fusion of Ultrasound and MRI and B-flow evaluation of tenosynovitis - A pilot study on new imaging techniques in rheumatoid arthritis patients. 
Study III: Validity and sensitivity to change of the semi-quantitative Outcome Measures in Rheumatology Clinical Trials (OMERACT) ultrasound scoring system for tenosynovitis in patients with rheumatoid arthritis and for the quantitative scoring system, pixel index. 
Study IV: Intramuscular versus ultrasound guided intratenosynovial glucocorticoid injection for tenosynovitis in patients with rheumatoid arthritis - A randomised, double-blind, controlled study with ultrasound and clinical follow up at 4 and 12 weeks. 
From the studies presented in the PhD thesis the following was concluded:
 Doppler findings in or in close proximity to the tendon sheaths were common in wrists and fingers in healthy participants. These feeding vessels may be a source of misinterpretation, i.e .wrong diagnosis of a low degree of tenosynovitis, not only due to their presence but also because they may be interpreted as being inside the tendon sheath due to blooming and reverberations artefacts.
 Ultrasound and MRI had high agreement using image fusion for assessment of tenosynovitis when MRI partial volume artefacts were taken into account. In contrast, the agreement between B-flow and ultrasound was poor, since the quality of the b-flow images and the flow sensitivity were low.
 The OMERACT ultrasound scoring system for tenosynovitis had an excellent intra- and interreader agreement between trained investigators and a high ability to detect change over time, similarly, the quantitative tenosynovitis assessment by pixel index had a very good intrareader agreement and moderate to good interreader agreement, but only a moderate ability to detect change over time. The ultrasound scores had a high responsiveness, indicating that the OMERACT ultrasound scoring system was useful for diagnosing and monitoring tenosynovitis in rheumatoid arthritis patients in clinical trials and practice. For treatment of tenosynovitis in rheumatoid arthritis patients, remission (ultrasound tenosynovitis grey scale score ≤1 and Doppler score = 0) was achieved significantly more frequently in the ultrasound guided intratenosynovial glucocorticoid injection group than in the intramuscular glucocorticoid injection group, both at 4 and 12 week follow-ups. Furthermore, tenosynovitis responded significantly better clinically and by ultrasound assessment when treated with ultrasound guided intratenosynovial glucocorticoid injection com-pared to intramuscular glucocorticoid injection, both at 4 and 12 week follow-ups. Articles published in the Danish Medical Journal are “open access”. This means that the articles are distributed under the terms of the Creative Commons Attribution Non-commercial License, which permits any non-commercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited.

Towards enabling ultrasound guidance in cervical cancer high-dose-rate brachytherapy

NASA Astrophysics Data System (ADS)

Wong, Adrian; Sojoudia, Samira; Gaudet, Marc; Yap, Wan Wan; Chang, Silvia D.; Abolmaesumi, Purang; Aquino-Parsons, Christina; Moradi, Mehdi

2014-03-01

MRI and Computed Tomography (CT) are used in image-based solutions for guiding High Dose Rate (HDR) brachytherapy treatment of cervical cancer. MRI is costly and CT exposes the patients to ionizing radiation. Ultrasound, on the other hand, is affordable and safe. The long-term goal of our work is to enable the use of multiparametric ultrasound imaging in image-guided HDR for cervical cancer. In this paper, we report the development of enabling technology for ultrasound guidance and tissue typing. We report a system to obtain the 3D freehand transabdominal ultrasound RF signals and B-mode images of the uterus, and a method for registration of ultrasound to MRI. MRI and 3D ultrasound images of the female pelvis were registered by contouring the uterus in the two modalities, creating a surface model, followed by rigid and B-spline deformable registration. The resulting transformation was used to map the location of the tumor from the T2-weighted MRI to ultrasound images and to determine cancerous and normal areas in ultrasound. B-mode images show a contrast for cancer vs. normal tissue. Our study shows the potential and the challenges of ultrasound imaging in guiding cervical cancer treatments.

Ultrasound hepatic/renal ratio and hepatic attenuation rate for quantifying liver fat content.

PubMed

Zhang, Bo; Ding, Fang; Chen, Tian; Xia, Liang-Hua; Qian, Juan; Lv, Guo-Yi

2014-12-21

To establish and validate a simple quantitative assessment method for nonalcoholic fatty liver disease (NAFLD) based on a combination of the ultrasound hepatic/renal ratio and hepatic attenuation rate. A total of 170 subjects were enrolled in this study. All subjects were examined by ultrasound and (1)H-magnetic resonance spectroscopy ((1)H-MRS) on the same day. The ultrasound hepatic/renal echo-intensity ratio and ultrasound hepatic echo-intensity attenuation rate were obtained from ordinary ultrasound images using the MATLAB program. Correlation analysis revealed that the ultrasound hepatic/renal ratio and hepatic echo-intensity attenuation rate were significantly correlated with (1)H-MRS liver fat content (ultrasound hepatic/renal ratio: r = 0.952, P = 0.000; hepatic echo-intensity attenuation r = 0.850, P = 0.000). The equation for predicting liver fat content by ultrasound (quantitative ultrasound model) is: liver fat content (%) = 61.519 × ultrasound hepatic/renal ratio + 167.701 × hepatic echo-intensity attenuation rate -26.736. Spearman correlation analysis revealed that the liver fat content ratio of the quantitative ultrasound model was positively correlated with serum alanine aminotransferase, aspartate aminotransferase, and triglyceride, but negatively correlated with high density lipoprotein cholesterol. Receiver operating characteristic curve analysis revealed that the optimal point for diagnosing fatty liver was 9.15% in the quantitative ultrasound model. Furthermore, in the quantitative ultrasound model, fatty liver diagnostic sensitivity and specificity were 94.7% and 100.0%, respectively, showing that the quantitative ultrasound model was better than conventional ultrasound methods or the combined ultrasound hepatic/renal ratio and hepatic echo-intensity attenuation rate. If the (1)H-MRS liver fat content had a value < 15%, the sensitivity and specificity of the ultrasound quantitative model would be 81.4% and 100%, which still shows that using the model is better than the other methods. The quantitative ultrasound model is a simple, low-cost, and sensitive tool that can accurately assess hepatic fat content in clinical practice. It provides an easy and effective parameter for the early diagnosis of mild hepatic steatosis and evaluation of the efficacy of NAFLD treatment.

Sensitivity and specificity of diagnostic ultrasound in the diagnosis of phrenic neuropathy.

PubMed

Boon, Andrea J; Sekiguchi, Hiroshi; Harper, Caitlin J; Strommen, Jeffrey A; Ghahfarokhi, Leili S; Watson, James C; Sorenson, Eric J

2014-09-30

To determine the sensitivity and specificity of B-mode ultrasound in the diagnosis of neuromuscular diaphragmatic dysfunction, including phrenic neuropathy. A prospective study of patients with dyspnea referred to the EMG laboratory over a 2-year time frame for evaluation of neuromuscular respiratory failure who were recruited consecutively and examined with ultrasound for possible diaphragm dysfunction. Sonographic outcome measures were absolute thickness of the diaphragm and degree of increased thickness with maximal inspiration. The comparison standard for diagnosis of diaphragm dysfunction was the final clinical diagnosis of clinicians blinded to the diaphragm ultrasound results, but taking into account other diagnostic workup, including chest radiographs, fluoroscopy, phrenic nerve conduction studies, diaphragm EMG, and/or pulmonary function tests. Of 82 patients recruited over a 2-year period, 66 were enrolled in the study. Sixteen patients were excluded because of inconclusive or insufficient reference testing. One hemidiaphragm could not be adequately visualized; therefore, hemidiaphragm assessment was conducted in a total of 131 hemidiaphragms in 66 patients. Of the 82 abnormal hemidiaphragms, 76 had abnormal sonographic findings (atrophy or decreased contractility). Of the 49 normal hemidiaphragms, none had a false-positive ultrasound. Diaphragmatic ultrasound was 93% sensitive and 100% specific for the diagnosis of neuromuscular diaphragmatic dysfunction. B-mode ultrasound imaging of the diaphragm is a highly sensitive and specific tool for diagnosis of neuromuscular diaphragm dysfunction. This study provides Class II evidence that diaphragmatic ultrasound performed by well-trained individuals accurately identifies patients with neuromuscular diaphragmatic respiratory failure (sensitivity 93%; specificity 100%). © 2014 American Academy of Neurology.

Towards Dynamic Contrast Specific Ultrasound Tomography

NASA Astrophysics Data System (ADS)

Demi, Libertario; van Sloun, Ruud J. G.; Wijkstra, Hessel; Mischi, Massimo

2016-10-01

We report on the first study demonstrating the ability of a recently-developed, contrast-enhanced, ultrasound imaging method, referred to as cumulative phase delay imaging (CPDI), to image and quantify ultrasound contrast agent (UCA) kinetics. Unlike standard ultrasound tomography, which exploits changes in speed of sound and attenuation, CPDI is based on a marker specific to UCAs, thus enabling dynamic contrast-specific ultrasound tomography (DCS-UST). For breast imaging, DCS-UST will lead to a more practical, faster, and less operator-dependent imaging procedure compared to standard echo-contrast, while preserving accurate imaging of contrast kinetics. Moreover, a linear relation between CPD values and ultrasound second-harmonic intensity was measured (coefficient of determination = 0.87). DCS-UST can find clinical applications as a diagnostic method for breast cancer localization, adding important features to multi-parametric ultrasound tomography of the breast.

Towards Dynamic Contrast Specific Ultrasound Tomography.

PubMed

Demi, Libertario; Van Sloun, Ruud J G; Wijkstra, Hessel; Mischi, Massimo

2016-10-05

We report on the first study demonstrating the ability of a recently-developed, contrast-enhanced, ultrasound imaging method, referred to as cumulative phase delay imaging (CPDI), to image and quantify ultrasound contrast agent (UCA) kinetics. Unlike standard ultrasound tomography, which exploits changes in speed of sound and attenuation, CPDI is based on a marker specific to UCAs, thus enabling dynamic contrast-specific ultrasound tomography (DCS-UST). For breast imaging, DCS-UST will lead to a more practical, faster, and less operator-dependent imaging procedure compared to standard echo-contrast, while preserving accurate imaging of contrast kinetics. Moreover, a linear relation between CPD values and ultrasound second-harmonic intensity was measured (coefficient of determination = 0.87). DCS-UST can find clinical applications as a diagnostic method for breast cancer localization, adding important features to multi-parametric ultrasound tomography of the breast.

Towards Dynamic Contrast Specific Ultrasound Tomography

PubMed Central

Demi, Libertario; Van Sloun, Ruud J. G.; Wijkstra, Hessel; Mischi, Massimo

2016-01-01

We report on the first study demonstrating the ability of a recently-developed, contrast-enhanced, ultrasound imaging method, referred to as cumulative phase delay imaging (CPDI), to image and quantify ultrasound contrast agent (UCA) kinetics. Unlike standard ultrasound tomography, which exploits changes in speed of sound and attenuation, CPDI is based on a marker specific to UCAs, thus enabling dynamic contrast-specific ultrasound tomography (DCS-UST). For breast imaging, DCS-UST will lead to a more practical, faster, and less operator-dependent imaging procedure compared to standard echo-contrast, while preserving accurate imaging of contrast kinetics. Moreover, a linear relation between CPD values and ultrasound second-harmonic intensity was measured (coefficient of determination = 0.87). DCS-UST can find clinical applications as a diagnostic method for breast cancer localization, adding important features to multi-parametric ultrasound tomography of the breast. PMID:27703251

Ultrasound-enhanced localized chemotherapy of drug-sensitive and multidrug resistant tumors

NASA Astrophysics Data System (ADS)

Rapoport, Natalya Y.; Gao, Zhonggao; Kamaev, Pavel; Christensen, Douglas A.

2006-05-01

A new modality of targeted tumor chemotherapy is based on the drug encapsulation in polymeric nanoparticles followed by a localized release at the tumor site triggered by focused ultrasound. Effect of 1 MHz and 3 MHz unfocused ultrasound applied locally to the tumor on the Doxorubicin (DOX) biodistribution and tumor growth rates was measured for ovarian carcinoma tumors in nu/nu mice. The bioeffects of ultrasound were investigated on the systemic and cellular levels. Growth rates of A2780 ovarian carcinoma tumors were substantially reduced by combining micellar drug delivery with tumor irradiation. Ultrasound effect was not thermal as manifested by intratumoral temperature measurements during sonication. Biodistribution studies showed that ultrasound did not enhance micelle extravasation. Main mechanisms of the ultrasound-enhanced chemotherapy included (i) passive targeting of drug-loaded micelles to the tumor interstitium; (ii) ultrasound-triggered localized drug release from micelles in the tumor volume; (iii) enhanced micelle and drug diffusion through the tumor interstitium; and (iv) ultrasound-triggered cell membrane damage resulting in the enhanced micelle and drug uptake by tumor cells.

Studies on the foundation and development of diagnostic ultrasound

PubMed Central

Wagai, Toshio

2007-01-01

In recent years, various types of diagnostic imaging methods, such as CT, MRI, PET and Ultrasound, have been developed rapidly and become indispensable as clinical diagnostic tools. Among these imaging modalities, CT, MRI and PET all apply electromagnetic waves like radiation rays. In contrast, an ultrasound imaging method uses a completely different mechanical pressure wave: “sound”. Ultrasound has various features, including inaudible sound at very high frequencies, which allows its use in medical diagnoses. That is, ultrasound techniques can be applied in transmission, reflection and Doppler methods. Moreover, the sharp directivity of an ultrasound beam can also improve image resolution. Another big advantage of diagnostic ultrasound is that it does not harm the human body or cause any pain to patients. Given these various advantages, diagnostic ultrasound has recently been widely used in diagnosing cancer and cardiovascular disease and scanning fetuses (Fig. 1) as well as routine clinical examinations in hospitals. In this paper, I outline my almost 50-year history of diagnostic ultrasound research, particularly that performed at the early stage from 1950–56. PMID:24367150

Free radical generation induced by ultrasound in red wine and model wine: An EPR spin-trapping study.

PubMed

Zhang, Qing-An; Shen, Yuan; Fan, Xue-Hui; Martín, Juan Francisco García; Wang, Xi; Song, Yun

2015-11-01

Direct evidence for the formation of 1-hydroxylethyl radicals by ultrasound in red wine and air-saturated model wine is presented in this paper. Free radicals are thought to be the key intermediates in the ultrasound processing of wine, but their nature has not been established yet. Electron paramagnetic resonance (EPR) spin trapping with 5,5-dimethyl-l-pyrrolin N-oxide (DMPO) was used for the detection of hydroxyl free radicals and 1-hydroxylethyl free radicals. Spin adducts of hydroxyl free radicals were detected in DMPO aqueous solution after sonication while 1-hydroxylethyl free radical adducts were observed in ultrasound-processed red wine and model wine. The latter radical arose from ethanol oxidation via the hydroxyl radical generated by ultrasound in water, thus providing the first direct evidence of the formation of 1-hydroxylethyl free radical in red wine exposed to ultrasound. Finally, the effects of ultrasound frequency, ultrasound power, temperature and ultrasound exposure time were assessed on the intensity of 1-hydroxylethyl radical spin adducts in model wine. Copyright © 2015 Elsevier B.V. All rights reserved.

Performance of chest ultrasound in pediatric pneumonia.

PubMed

Claes, Anne-Sophie; Clapuyt, Philippe; Menten, Renaud; Michoux, Nicolas; Dumitriu, Dana

2017-03-01

The objective of this study was to evaluate the performance of ultrasound in detecting lung consolidation in children suspected of pneumonia, in comparison to the current gold standard, chest X-rays. From September 2013 to June 2014, a monocentric prospective study was performed on all children between 0 and 16 years-old, referred for chest X-ray for suspected pneumonia. Each child was examined by chest ultrasound by an examiner blinded to the chest X-ray. The presence or absence of areas of consolidation, their number and location were noted for each technique. The size of the consolidations identified only on ultrasound was compared with that of consolidations visible on both techniques. 143 children (mean age 3 years; limits between 8days and 14 years) were included. Ultrasound detected at least one area of consolidation in 44 out of 45 patients with positive X-rays. Of the 59 areas of consolidation on X-ray, ultrasound identified 54. In the 8 patients with negative X-ray, ultrasound revealed 17 areas of consolidation. The mean size of consolidations visible only on ultrasound was 9.4mm; for consolidations visible on both techniques the mean size was 26mm (p<0.0001). The sensitivity and specificity of ultrasound were calculated at 98% and 92%. PPV and NPV were 85% and 99%, respectively. Chest ultrasound is a fast, non-ionizing and feasible technique. With its high negative predictive value, it can replace X-rays in order to exclude lung consolidation in children, thus reducing radiation exposure in this population. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Point-of-care ultrasound leads to diagnostic shifts in patients with undifferentiated hypotension.

PubMed

Shokoohi, Hamid; Boniface, Keith S; Zaragoza, Michelle; Pourmand, Ali; Earls, James P

2017-12-01

To assess the impact of an ultrasound hypotension protocol in identifying life-threatening diagnoses that were missed in the initial evaluation of patients with hypotension and shock. A subset of cases from a previously published prospective study of hypotensive patients who presented at the Emergency Department in a single, academic tertiary care hospital is described. An ultrasound-trained emergency physician performed an ultrasound on each patient using a standardized hypotension protocol. In each case, the differential diagnosis and management plan was solicited from the treating physician immediately before and after the ultrasound. This is a case series of patients with missed diagnoses in whom ultrasound led to a dramatic shift in diagnosis and management by detecting life threatening pathologies. Following a published prospective study of the effect on an ultrasound protocol in 118 hypotensive patients, we identified a series of cases that ultrasound protocol unexpectedly determined serious life threatening diagnoses such as Takotsubo cardiomyopathy, pulmonary embolism, pericardial effusion with tamponade physiology, abdominal aortic aneurysm and perforated viscus resulting in proper diagnoses and management. These hypotensive patients had completely unsuspected but critical diagnoses explaining their hypotension, who in every case had their management altered to target the newly identified life-threatening condition. A hypotension protocol is an optimal use of ultrasound that exemplifies "right time, right place", and impacts decision-making at the bedside. In cases with undifferentiated hypotension, ultrasound is often the most readily available option to ensure that the most immediate life-threatening conditions are quickly identified and addressed in the order of their risk potential. Copyright © 2017 Elsevier Inc. All rights reserved.

Ultrasound definition of tendon damage in patients with rheumatoid arthritis. Results of a OMERACT consensus-based ultrasound score focussing on the diagnostic reliability.

PubMed

Bruyn, George A W; Hanova, Petra; Iagnocco, Annamaria; d'Agostino, Maria-Antonietta; Möller, Ingrid; Terslev, Lene; Backhaus, Marina; Balint, Peter V; Filippucci, Emilio; Baudoin, Paul; van Vugt, Richard; Pineda, Carlos; Wakefield, Richard; Garrido, Jesus; Pecha, Ondrej; Naredo, Esperanza

2014-11-01

To develop the first ultrasound scoring system of tendon damage in rheumatoid arthritis (RA) and assess its intraobserver and interobserver reliability. We conducted a Delphi study on ultrasound-defined tendon damage and ultrasound scoring system of tendon damage in RA among 35 international rheumatologists with experience in musculoskeletal ultrasound. Twelve patients with RA were included and assessed twice by 12 rheumatologists-sonographers. Ultrasound examination for tendon damage in B mode of five wrist extensor compartments (extensor carpi radialis brevis and longus; extensor pollicis longus; extensor digitorum communis; extensor digiti minimi; extensor carpi ulnaris) and one ankle tendon (tibialis posterior) was performed blindly, independently and bilaterally in each patient. Intraobserver and interobserver reliability were calculated by κ coefficients. A three-grade semiquantitative scoring system was agreed for scoring tendon damage in B mode. The mean intraobserver reliability for tendon damage scoring was excellent (κ value 0.91). The mean interobserver reliability assessment showed good κ values (κ value 0.75). The most reliable were the extensor digiti minimi, the extensor carpi ulnaris, and the tibialis posterior tendons. An ultrasound reference image atlas of tenosynovitis and tendon damage was also developed. Ultrasound is a reproducible tool for evaluating tendon damage in RA. This study strongly supports a new reliable ultrasound scoring system for tendon damage. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Contrast-Enhanced Ultrasound as a New Investigative Tool in Diagnostic Imaging of Muscle Injuries-A Pilot Study Evaluating Conventional Ultrasound, CEUS, and Findings in MRI.

PubMed

Hotfiel, Thilo; Heiss, Rafael; Swoboda, Bernd; Kellermann, Marion; Gelse, Kolja; Grim, Casper; Strobel, Deike; Wildner, Dane

2018-07-01

To emphasize the diagnostic value of contrast-enhanced ultrasound (CEUS) in the imaging of muscle injuries with different degrees of severity by comparing findings to established imaging modalities such as conventional ultrasound and magnetic resonance imaging (MRI). Case series. Institutional study. Conventional ultrasound and CEUS were performed in the Department of Internal Medicine. Magnetic resonance imaging was carried out in the Department of Radiology within the Magnetom Avanto 1.5T and Magnetom Skyra fit 3T (Siemens Healthineers, Erlangen, Germany) and in the Institution of Imaging Diagnostics and Therapy (Magnetom Avanto 1.5T; Siemens, Erlangen, Germany). Fifteen patients who underwent an acute muscle injury were recruited. The appearance and detectable size of muscle injuries were compared between each imaging modality. The injuries were assessed by 3 independent observers and blinded between imaging modalities. All 15 injuries were identified on MRI and CEUS, whereas 10 injuries showed abnormalities in conventional ultrasound. The determination and measurement revealed significant differences between conventional ultrasound and CEUS depending on injury severity. Contrast-enhanced ultrasound revealed an impairment of microcirculation in grade I lesions (corresponding to intramuscular edema observed in MRI), which was not detectable using conventional ultrasound. Our results indicate that performing CEUS seems to be a sensitive additional diagnostic modality in the early assessment of muscle injuries. Our results highlight the advantages of CEUS in the imaging of low-grade lesions when compared with conventional ultrasound, as this was the more accurate modality for identifying intramuscular edema.

An Examination of Ultrasound Measured Tissue Perfusion on Breast Cancer

DTIC Science & Technology

1998-12-01

is similar to those of the study by Ivey et al. [9] in which high intensity fields were used to produce cavitation bubbles for ultrasound contrast...ft * * AD AWARD NUMBER DAMD17-94-J-4144 TITLE: ^ Examination of Ultrasound Measured Tissue Perfusion on Breast Cancer...Examination of Ultrasound Measured Tissue Perfusion on Breast Cancer 3. REPORT TYPE AND DATES COVERED Final (1 Jun 94 - 30 Nov 98) 5. FUNDING

Real-time 3-dimensional contrast-enhanced ultrasound in detecting hemorrhage of blunt renal trauma.

PubMed

Xu, Rui-Xue; Li, Ye-Kuo; Li, Ting; Wang, Sha-Sha; Yuan, Gui-Zhong; Zhou, Qun-Fang; Zheng, Hai-Rong; Yan, Fei

2013-10-01

The objective of this study is to evaluate the diagnostic value of real-time 3-dimensional contrast-enhanced ultrasound in the hemorrhage of blunt renal trauma. Eighteen healthy New Zealand white rabbits were randomly divided into 3 groups. Blunt renal trauma was performed on each group by using minitype striker. Ultrasonography, color Doppler flow imaging, and contrast-enhanced 2-dimensional and real-time 3-dimensional ultrasound were applied before and after the strike. The time to shock and blood pressure were subjected to statistical analysis. Then, a comparative study of ultrasound and pathology was carried out. All the struck kidneys were traumatic. In the ultrasonography, free fluid was found under the renal capsule. In the color Doppler flow imaging, active hemorrhage was not identified. In 2-dimensional contrast-enhanced ultrasound, active hemorrhage of the damaged kidney was characterized. Real-time 3-dimensional contrast-enhanced ultrasound showed a real-time and stereoscopic ongoing bleeding of the injured kidney. The wider the hemorrhage area in 4-dimensional contrast-enhanced ultrasound was, the faster the blood pressure decreased. Real-time 3-dimensional contrast-enhanced ultrasound is a promising noninvasive tool for stereoscopically and vividly detecting ongoing hemorrhage of blunt renal trauma in real time. © 2013.

Pulmonary ultrasound elastography: a feasibility study with phantoms and ex-vivo tissue

NASA Astrophysics Data System (ADS)

Nguyen, Man Minh; Xie, Hua; Paluch, Kamila; Stanton, Douglas; Ramachandran, Bharat

2013-03-01

Elastography has become widely used for minimally invasive diagnosis in many tumors as seen with breast, liver and prostate. Among different modalities, ultrasound-based elastography stands out due to its advantages including being safe, real-time, and relatively low-cost. While lung cancer is the leading cause of cancer mortality among both men and women, the use of ultrasound elastography for lung cancer diagnosis has hardly been investigated due to the limitations of ultrasound in air. In this work, we investigate the use of static-compression based endobronchial ultrasound elastography by a 3D trans-oesophageal echocardiography (TEE) transducer for lung cancer diagnosis. A water-filled balloon was designed to 1) improve the visualization of endobronchial ultrasound and 2) to induce compression via pumping motion inside the trachea and bronchiole. In a phantom study, we have successfully generated strain images indicating the stiffness difference between the gelatin background and agar inclusion. A similar strain ratio was confirmed with Philips ultrasound strain-based elastography product. For ex-vivo porcine lung study, different tissue ablation methods including chemical injection, Radio Frequency (RF) ablation, and direct heating were implemented to achieve tumor-mimicking tissue. Stiff ablated lung tissues were obtained and detected with our proposed method. These results suggest the feasibility of pulmonary elastography to differentiate stiff tumor tissue from normal tissue.

Comparison of Diagnostic Performance of Semi-Quantitative Knee Ultrasound and Knee Radiography with MRI: Oulu Knee Osteoarthritis Study.

PubMed

Podlipská, Jana; Guermazi, Ali; Lehenkari, Petri; Niinimäki, Jaakko; Roemer, Frank W; Arokoski, Jari P; Kaukinen, Päivi; Liukkonen, Esa; Lammentausta, Eveliina; Nieminen, Miika T; Tervonen, Osmo; Koski, Juhani M; Saarakkala, Simo

2016-03-01

Osteoarthritis (OA) is a common degenerative musculoskeletal disease highly prevalent in aging societies worldwide. Traditionally, knee OA is diagnosed using conventional radiography. However, structural changes of articular cartilage or menisci cannot be directly evaluated using this method. On the other hand, ultrasound is a promising tool able to provide direct information on soft tissue degeneration. The aim of our study was to systematically determine the site-specific diagnostic performance of semi-quantitative ultrasound grading of knee femoral articular cartilage, osteophytes and meniscal extrusion, and of radiographic assessment of joint space narrowing and osteophytes, using MRI as a reference standard. Eighty asymptomatic and 79 symptomatic subjects with mean age of 57.7 years were included in the study. Ultrasound performed best in the assessment of femoral medial and lateral osteophytes, and medial meniscal extrusion. In comparison to radiography, ultrasound performed better or at least equally well in identification of tibio-femoral osteophytes, medial meniscal extrusion and medial femoral cartilage morphological degeneration. Ultrasound provides relevant additional diagnostic information on tissue-specific morphological changes not depicted by conventional radiography. Consequently, the use of ultrasound as a complementary imaging tool along with radiography may enable more accurate and cost-effective diagnostics of knee osteoarthritis at the primary healthcare level.

Quality properties of pre- and post-rigor beef muscle after interventions with high frequency ultrasound.

PubMed

Sikes, Anita L; Mawson, Raymond; Stark, Janet; Warner, Robyn

2014-11-01

The delivery of a consistent quality product to the consumer is vitally important for the food industry. The aim of this study was to investigate the potential for using high frequency ultrasound applied to pre- and post-rigor beef muscle on the metabolism and subsequent quality. High frequency ultrasound (600kHz at 48kPa and 65kPa acoustic pressure) applied to post-rigor beef striploin steaks resulted in no significant effect on the texture (peak force value) of cooked steaks as measured by a Tenderometer. There was no added benefit of ultrasound treatment above that of the normal ageing process after ageing of the steaks for 7days at 4°C. Ultrasound treatment of post-rigor beef steaks resulted in a darkening of fresh steaks but after ageing for 7days at 4°C, the ultrasound-treated steaks were similar in colour to that of the aged, untreated steaks. High frequency ultrasound (2MHz at 48kPa acoustic pressure) applied to pre-rigor beef neck muscle had no effect on the pH, but the calculated exhaustion factor suggested that there was some effect on metabolism and actin-myosin interaction. However, the resultant texture of cooked, ultrasound-treated muscle was lower in tenderness compared to the control sample. After ageing for 3weeks at 0°C, the ultrasound-treated samples had the same peak force value as the control. High frequency ultrasound had no significant effect on the colour parameters of pre-rigor beef neck muscle. This proof-of-concept study showed no effect of ultrasound on quality but did indicate that the application of high frequency ultrasound to pre-rigor beef muscle shows potential for modifying ATP turnover and further investigation is warranted. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

Microbubble and ultrasound radioenhancement of bladder cancer

PubMed Central

Tran, W T; Iradji, S; Sofroni, E; Giles, A; Eddy, D; Czarnota, G J

2012-01-01

Background: Tumour vasculature is an important component of tumour growth and survival. Recent evidence indicates tumour vasculature also has an important role in tumour radiation response. In this study, we investigated ultrasound and microbubbles to enhance the effects of radiation. Methods: Human bladder cancer HT-1376 xenografts in severe combined immuno-deficient mice were used. Treatments consisted of no, low and high concentrations of microbubbles and radiation doses of 0, 2 and 8 Gy in short-term and longitudinal studies. Acute response was assessed 24 h after treatment and longitudinal studies monitored tumour response weekly up to 28 days using power Doppler ultrasound imaging for a total of 9 conditions (n=90 animals). Results: Quantitative analysis of ultrasound data revealed reduced blood flow with ultrasound-microbubble treatments alone and further when combined with radiation. Tumours treated with microbubbles and radiation revealed enhanced cell death, vascular normalisation and areas of fibrosis. Longitudinal data demonstrated a reduced normalised vascular index and increased tumour cell death in both low and high microbubble concentrations with radiation. Conclusion: Our study demonstrated that ultrasound-mediated microbubble exposure can enhance radiation effects in tumours, and can lead to enhanced tumour cell death. PMID:22790798

The reliability and validity of ultrasound to quantify muscles in older adults: a systematic review

PubMed Central

Scafoglieri, Aldo; Jager‐Wittenaar, Harriët; Hobbelen, Johannes S.M.; van der Schans, Cees P.

2017-01-01

Abstract This review evaluates the reliability and validity of ultrasound to quantify muscles in older adults. The databases PubMed, Cochrane, and Cumulative Index to Nursing and Allied Health Literature were systematically searched for studies. In 17 studies, the reliability (n = 13) and validity (n = 8) of ultrasound to quantify muscles in community‐dwelling older adults (≥60 years) or a clinical population were evaluated. Four out of 13 reliability studies investigated both intra‐rater and inter‐rater reliability. Intraclass correlation coefficient (ICC) scores for reliability ranged from −0.26 to 1.00. The highest ICC scores were found for the vastus lateralis, rectus femoris, upper arm anterior, and the trunk (ICC = 0.72 to 1.000). All included validity studies found ICC scores ranging from 0.92 to 0.999. Two studies describing the validity of ultrasound to predict lean body mass showed good validity as compared with dual‐energy X‐ray absorptiometry (r 2 = 0.92 to 0.96). This systematic review shows that ultrasound is a reliable and valid tool for the assessment of muscle size in older adults. More high‐quality research is required to confirm these findings in both clinical and healthy populations. Furthermore, ultrasound assessment of small muscles needs further evaluation. Ultrasound to predict lean body mass is feasible; however, future research is required to validate prediction equations in older adults with varying function and health. PMID:28703496

Incremental clinical value of ultrasound in men with mammographically confirmed gynecomastia.

PubMed

Chen, Po-Hao; Slanetz, Priscilla J

2014-01-01

To determine whether ultrasound is of any value in male patients presenting with focal symptoms who have classic features of gynecomastia but no concerning findings on mammography. Over a 3-year period, all male patients who underwent mammographic evaluation were identified in this retrospective study. Patients with a mammographic diagnosis of gynecomastia and subsequent breast ultrasound at a large tertiary academic medical center comprised the study cohort. Men whose ultrasound diagnosis differed from the initial mammographic evaluation were analyzed for both additional benign findings as well as findings that warranted biopsy. A total of 353 mammograms were obtained from 327 unique patients (ages 18-95, mean 51 years). Of all mammographic examinations, gynecomastia was the sole finding in 73% (259). In those 259 studies, 85% were further evaluated with ultrasound, in which 6 (2.7%) showed additional benign findings, and 4 (1.8%) showed suspicious findings for which biopsy was recommended. No malignancies were detected in those patients. Furthermore, no malignancies were detected in patients whose mammogram revealed only normal fatty parenchyma or only gynecomastia. In all cases of cancer, mammography revealed visible masses. Judicious use of breast ultrasound in men improves outcome. Our data suggest that targeted ultrasound is of limited value in symptomatic male patients where mammography is negative or reveals only gynecomastia and leads to unnecessary benign biopsies in these patients. When mammography reveals concerning findings, ultrasound adds positively to clinical management. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Time course of VMN lesion effects on lordosis and proceptive behavior in female hamsters.

PubMed

Floody, Owen R

2002-06-01

Previous studies suggest that ultrasound production by female hamsters is better able than other reproductive behaviors to recover from an initial drop caused by damage to the ventromedial hypothalamus (VMN). At the same time, few studies have examined the time course of such lesion effects. To remedy this, female hamsters were observed before and after control operations or VMN lesions. The behaviors considered were ultrasound production, lordosis, approach, and vaginal marking. Ultrasound production, lordosis, and approach were affected by lesions, permitting the description of the time course of each of these effects. Only ultrasound rates showed evidence of recovery, which culminated in rates significantly above those observed preoperatively in the same animals. This suggests that ultrasound production is unusual in its response to VMN damage and that the underlying mechanism could be of interest in studies of the processes that determine recovery from brain damage. (c) 2002 Elsevier Science (USA).

The utility of ultrasound in patients with melanoma.

PubMed

Uren, Roger F; Sanki, Amira; Thompson, John F

2007-11-01

The highest quality gray-scale ultrasound images are obtained with high-frequency transducers; however, such high frequencies do not penetrate more than a few centimeters into body tissue. Fortunately, in patients with melanoma, the structures of interest are close to the skin surface, making them ideal targets for examination with high-resolution ultrasound. These include primary cutaneous melanomas, uveal melanomas and the regional lymph nodes draining the skin that lie in the axilla, groin, neck and other locations. Although ultrasound study of primary melanomas arising in the skin and eye has provided some insights, a major role for ultrasound has evolved recently, to provide early detection of metastatic melanoma in regional lymph nodes. Ultrasound is clearly superior to clinical palpation of the nodes during follow-up and, when combined with guided fine-needle biopsy, allows the earliest possible surgical intervention for regional nodal metastases. In the future the use of ultrasound contrast agents may improve the sensitivity of ultrasound in the detection of very small metastatic deposits.

Cost-effectiveness of focused ultrasound, radiosurgery, and DBS for essential tremor.

PubMed

Ravikumar, Vinod K; Parker, Jonathon J; Hornbeck, Traci S; Santini, Veronica E; Pauly, Kim Butts; Wintermark, Max; Ghanouni, Pejman; Stein, Sherman C; Halpern, Casey H

2017-08-01

Essential tremor remains a very common yet medically refractory condition. A recent phase 3 study demonstrated that magnetic resonance-guided focused ultrasound thalamotomy significantly improved upper limb tremor. The objectives of this study were to assess this novel therapy's cost-effectiveness compared with existing procedural options. Literature searches of magnetic resonance-guided focused ultrasound thalamotomy, DBS, and stereotactic radiosurgery for essential tremor were performed. Pre- and postoperative tremor-related disability scores were collected from 32 studies involving 83 magnetic resonance-guided focused ultrasound thalamotomies, 615 DBSs, and 260 stereotactic radiosurgery cases. Utility, defined as quality of life and derived from percent change in functional disability, was calculated; Medicare reimbursement was employed as a proxy for societal cost. Medicare reimbursement rates are not established for magnetic resonance-guided focused ultrasound thalamotomy for essential tremor; therefore, reimbursements were estimated to be approximately equivalent to stereotactic radiosurgery to assess a cost threshold. A decision analysis model was constructed to examine the most cost-effective option for essential tremor, implementing meta-analytic techniques. Magnetic resonance-guided focused ultrasound thalamotomy resulted in significantly higher utility scores compared with DBS (P < 0.001) or stereotactic radiosurgery (P < 0.001). Projected costs of magnetic resonance-guided focused ultrasound thalamotomy were significantly less than DBS (P < 0.001), but not significantly different from radiosurgery. Magnetic resonance-guided focused ultrasound thalamotomy is cost-effective for tremor compared with DBS and stereotactic radiosurgery and more effective than both. Even if longer follow-up finds changes in effectiveness or costs, focused ultrasound thalamotomy will likely remain competitive with both alternatives. © 2017 International Parkinson and Movement Disorder Society. © 2017 International Parkinson and Movement Disorder Society.

Descriptive Cadaveric Study Comparing the Accuracy of Ultrasound Versus Fluoroscopic Guidance for First Sacral Transforaminal Injections: A Comparison Study.

PubMed

Thompson, Bradley F; Pingree, Matthew J; Qu, Wenchun; Murthy, Naveen S; Lachman, Nirusha; Hurdle, Mark Friedrich

2018-04-01

Ultrasound is rarely used for guiding lumbosacral epidural steroid injections due to its technical limitations. For example, sonographic imaging lacks the ability to confirm epidural spread and identify vascular uptake. The perceived risk that these limitations pose to human subjects has precluded any large scale clinical trials to date. To compare the accuracy of ultrasound versus fluoroscopic guidance for first sacral transforaminal epidural injections. Cadaveric comparative study using dichotomous outcomes. A fluoroscopy suite and anatomic laboratory at an academic medical center. Four unembalmed adult human cadavers with no history of spinal surgery. Eight sites were injected twice by one interventionalist, using fluoroscopic and ultrasound guidance. In the fluoroscopy arm, contrast spread was assessed using computed tomography. In the ultrasound arm, latex spread was assessed using gross anatomic dissection. Any visible evidence of epidural spread constituted a positive result. Comparison of the success of obtaining epidural contrast flow was the primary outcome measure. Secondary outcome measures included average duration, rate of intravascular uptake, and quantity of intravascular uptake. All injections performed in both the ultrasound arm and the fluoroscopy arm had positive epidural spread. The average duration was 3.03 minutes with fluoroscopy and 4.76 minutes with ultrasound. The rate of intravascular uptake was 37.5% with fluoroscopy and 50% with ultrasound. Within the ultrasound arm, greater intravascular spread and duration variability were recorded. Although ultrasonography can provide reliable image guidance for cannulating the first sacral foramen in cadavers, it would have limited clinical utility due to its inability to visualize relevant neurovascular structures deep to the osseus roof and exclude intravascular uptake. IV. Copyright © 2018 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

Non-ionizing real-time ultrasonography in implant and oral surgery: A feasibility study.

PubMed

Chan, Hsun-Liang; Wang, Hom-Lay; Fowlkes, Jeffery Brian; Giannobile, William V; Kripfgans, Oliver D

2017-03-01

Ultrasound imaging has potential to complement radiographic imaging modalities in implant and oral surgery given that it is non-ionizing and provides instantaneous images of anatomical structures. For application in oral and dental imaging, its qualities are dependent on its ability to accurately capture these complex structures. Therefore, the aim of this feasibility study was to investigate ultrasound to image soft tissue, hard tissue surface topography and specific vital structures. A clinical ultrasound scanner, paired with two 14-MHz transducers of different sizes (one for extraoral and the other for intraoral scans), was used to scan the following structures on a fresh cadaver: (i) the facial bone surface and soft tissue of maxillary anterior teeth, (ii) the greater palatine foramen; (iii) the mental foramen and (iv) the lingual nerve. Multiple measurements relevant to these structures were made on the ultrasound images and compared to those on cone-beam computed tomography (CBCT) scans and/or direct measurements. Ultrasound imaging could delineate hard tissue surfaces, including enamel, root dentin and bone as well as soft tissue with high resolution (110 μm wavelength). The greater palatine foramen, mental foramen and lingual nerve were clearly shown in ultrasound images. Merging ultrasound and CBCT images demonstrated overall spatial accuracy of ultrasound images, which was corroborated by data gathered from direct measurements. For the first time, this study provides proof-of-concept evidence that ultrasound can be a real-time and non-invasive alternative for the evaluation of oral and dental anatomical structures relevant for implant and oral surgery. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

VEGFR2-Targeted Ultrasound Imaging Agent Enhances the Detection of Ovarian Tumors at Early Stage in Laying Hens, a Preclinical Model of Spontaneous Ovarian Cancer.

PubMed

Barua, Animesh; Yellapa, Aparna; Bahr, Janice M; Machado, Sergio A; Bitterman, Pincas; Basu, Sanjib; Sharma, Sameer; Abramowicz, Jacques S

2015-07-01

Tumor-associated neoangiogenesis (TAN) is an early event in ovarian cancer (OVCA) development. Increased expression of vascular endothelial growth factor receptor 2 (VEGFR2) by TAN vessels presents a potential target for early detection by ultrasound imaging. The goal of this study was to examine the suitability of VEGFR2-targeted ultrasound contrast agents in detecting spontaneous OVCA in laying hens. Effects of VEGFR2-targeted contrast agents in enhancing the intensity of ultrasound imaging from spontaneous ovarian tumors in hens were examined in a cross-sectional study. Enhancement in the intensity of ultrasound imaging was determined before and after injection of VEGFR2-targeted contrast agents. All ultrasound images were digitally stored and analyzed off-line. Following scanning, ovarian tissues were collected and processed for histology and detection of VEGFR2-expressing microvessels. Enhancement in visualization of ovarian morphology was detected by gray-scale imaging following injection of VEGFR2-targeted contrast agents. Compared with pre-contrast, contrast imaging enhanced the intensities of ultrasound imaging significantly (p < 0.0001) irrespective of the pathological status of ovaries. In contrast to normal hens, the intensity of ultrasound imaging was significantly (p < 0.0001) higher in hens with early stage OVCA and increased further in hens with late stage OVCA. Higher intensities of ultrasound imaging in hens with OVCA were positively correlated with increased (p < 0.0001) frequencies of VEGFR2-expressing microvessels. The results of this study suggest that VEGFR2-targeted contrast agents enhance the visualization of spontaneous ovarian tumors in hens at early and late stages of OVCA. The laying hen may be a suitable model to test new imaging agents and develop targeted therapeutics. © The Author(s) 2014.

Teaching the internist to see: effectiveness of a 1-day workshop in bedside ultrasound for internal medicine residents.

PubMed

Clay, Ryan D; Lee, Elizabeth C; Kurtzman, Marc F; Dversdal, Renee K

2016-12-01

A growing body of evidence supports the use of bedside ultrasound for core Internal Medicine procedures and increasingly as augmentation of the physical exam. The literature also supports that trainees, both medical students and residents, can acquire these skills. However, there is no consensus on training approach. To implement and study the effectiveness of a high-yield and expedited curriculum to train internal medicine interns to use bedside ultrasound for physical examination and procedures. The study was conducted at a metropolitan, academic medical center and included 33 Internal Medicine interns. This was a prospective cohort study of a new educational intervention consisting of a single-day intensive bedside ultrasound workshop followed by two optional hour-long workshops later in the year. The investigation was conducted at Oregon Health & Science University in Portland, Oregon. The intensive day consisted of alternating didactic sessions with small group hands-on ultrasound practice sessions and ultrasound simulations. A 30-question assessment was used to assess ultrasound interpretation knowledge prior to, immediately post, and 6 months post intervention. Thirty-three interns served as their own historical controls. Assessment performance significantly increased after the intervention from a mean pre-test score of 18.3 (60.9 % correct) to a mean post-test score 25.5 (85.0 % correct), P value of <0.0001. This performance remained significantly better at 6 months with a mean score of 23.8 (79.3 % correct), P value <0.0001. There was significant knowledge attrition compared to the immediate post-assessment, P value 0.0099. A single-day ultrasound training session followed by two optional noon conference sessions yielded significantly improved ultrasound interpretation skills in internal medicine interns.

Assessment of pelvic floor muscle contraction with palpation, perineometry and transperineal ultrasound: a cross-sectional study.

PubMed

Volløyhaug, I; Mørkved, S; Salvesen, Ø; Salvesen, K Å

2016-06-01

To study the correlation between palpation, perineometry and transperineal ultrasound for assessment of pelvic floor muscle contraction and to define a contraction scale for ultrasound measurements. This was a cross-sectional study of 608 women examined with palpation of pelvic floor muscle contraction, using the Modified Oxford Scale, and measurement of the vaginal squeeze pressure with a vaginal balloon connected to a fiber-optic microtip transducer (perineometry). Transperineal ultrasound was used for measurements of levator hiatal area and anteroposterior (AP) diameter in the plane of minimal hiatal dimensions, at rest and on contraction. The pelvic floor muscle contraction was expressed as the percentage difference between values at rest and on contraction. Spearman's rank was used to test for correlation between the different methods of assessment. Significant correlations were found between all assessment methods (P < 0.001). Palpation correlated with perineometry (rs = 0.74) and with proportional change in hiatal area (rs = 0.67) and AP diameter (rs = 0.69) on ultrasound. Perineometry correlated with proportional change in hiatal area (rs = 0.60) and AP diameter (rs = 0.66) on ultrasound. We defined a contraction scale based on the proportional change in AP diameter. In this population, a change in AP diameter of < 7% corresponded to absence of contractions, 7-18% corresponded to weak contractions, 18-35% corresponded to normal contractions and > 35% corresponded to strong contractions. We found moderate to strong correlation between ultrasound measurements, palpation and perineometry for assessing pelvic floor muscle contraction. The proportional change in levator hiatal AP diameter was the ultrasound measurement with strongest correlation to palpation and perineometry and formed the basis for the contraction scale for ultrasound measurements. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Implementation of real-time ultrasound in a thoracic surgery practice.

PubMed

Coonar, Aman S; Hughes, Jacqueline A; Walker, Susan; dePerrot, Marc; Waddell, Thomas K; Pierre, Andrew F; Darling, Gail E; Johnston, Michael R; Keshavjee, Shaf

2009-05-01

The purpose of this study was to implement real-time transthoracic ultrasound in a thoracic surgery and lung transplant practice. Ultrasound units that are light, small, robust, and portable are now available. Obstacles to use include demarcation issues between specialties, training, and a perception that basic ultrasound may be difficult to use. The experience of implementing this is described. After a training period, 62 studies were performed in 4 months. Patients and clinicians gave positive feedback. The learning time was short, and with ultrasonic guidance, all interventional procedures were successful at the first attempt, without any complications. Basic transthoracic ultrasound was found to be easy to learn and use by thoracic surgeons, fellows, and specialist nurses. Patients were appreciative. Real-time use may have genuine advantages to patient care.

Bedside Ultrasound in the Emergency Department to Detect Hydronephrosis for the Evaluation of Suspected Ureteric Colic.

PubMed

Shrestha, R; Shakya, R M; Khan A, A

2016-01-01

Background Renal colic is a common emergency department presentation. Hydronephrosis is indirect sign of urinary obstruction which may be due to obstructing ureteric calculus and can be detected easily by bedside ultrasound with minimal training. Objective To compare the accuracy of detection of hydronephrosis performed by the emergency physician with that of radiologist's in suspected renal colic cases. Method This was a prospective observational study performed over a period of 6 months. Patients >8 years with provisional diagnosis of renal colic with both the bedside ultrasound and the formal ultrasound performed were included. Presence of hydronephrosis in both ultrasounds and size and location of ureteric stone if present in formal ultrasound was recorded. The accuracy of the emergency physician detection of hydronephrosis was determined using the scan reported by the radiologists as the "gold standard" as computed tomography was unavailable. Statistical analysis was executed using SPSS 17.0. Result Among the 111 included patients, 56.7% had ureteric stone detected in formal ultrasound. The overall sensitivity, specificity, positive predictive value and negative predictive value of bedside ultrasound performed by emergency physician for detection of hydronephrosis with that of formal ultrasound performed by radiologist was 90.8%., 78.3%, 85.5% and 85.7% respectively. Bedside ultrasound and formal ultrasound both detected hydronephrosis more often in patients with larger stones and the difference was statistically significant (p=.000). Conclusion Bedside ultrasound can be potentially used as an important tool in detecting clinically significant hydronephrosis in emergency to evaluate suspected ureteric colic. Focused training in ultrasound could greatly improve the emergency management of these patients.

[Study on assistant cleaning of ultrasound for the ultrafiltration membrane].

PubMed

Zhang, Guojun; Liu, Zhongzhou

2003-11-01

The effects of ultrasounds with different frequency on membrane performance were investigated in this paper. The experimental results show that there were nearly no effects of 20 W ultrasound on membrane retention coefficient, but it decreased seriously when the ultrasound power was above 30 W. On the basis of these results, low frequency ultrasound (20 W) was introduced to assist the chemical cleaning in the ultrafiltration process of wastewater from bank note printing works. The cleaning time could be shortened from 20-30 min to 5 min by the ultra-liberation and ultra-blend effects of ultrasound, therefore, the cleaning efficiency was highly improved. However, the fouling substances could not be cleaned entirely in the simple physical cleaning process by SEM analysis.

Updates on ultrasound research in implant dentistry: a systematic review of potential clinical indications.

PubMed

Bhaskar, Vaishnavi; Chan, Hsun-Liang; MacEachern, Mark; Kripfgans, Oliver D

2018-05-23

Ultrasonography has shown promising diagnostic value in dental implant imaging research; however, exactly how ultrasound was used and at what stage of implant therapy it can be applied has not been systematically evaluated. Therefore, the aim of this review is to investigate potential indications of ultrasound use in the three implant treatment phases, namely planning, intraoperative and postoperative phase. Eligible manuscripts were searched in major databases with a combination of key words related to the use of ultrasound imaging in implant therapy. An initial search yielded 414 articles, after further review, 28 articles were finally included for this systematic review. Ultrasound was found valuable, though at various development stages, for evaluating (1) soft tissues, (2) hard tissues (3) vital structures and (4) implant stability. B-mode, the main function to image anatomical structures of interest, has been evaluated in pre-clinical and clinical studies. Quantitative ultrasound parameters, e.g. sound speed and amplitude, are being developed to evaluate implant-bone stability, mainly in simulation and pre-clinical studies. Ultrasound could be potentially useful in all 3 treatment phases. In the planning phase, ultrasound could evaluate vital structures, tissue biotype, ridge width/density, and cortical bone thickness. During surgery, it can provide feedback by identifying vital structures and bone boundary. At follow-up visits, it could evaluate marginal bone level and implant stability. Understanding the current status of ultrasound imaging research for implant therapy would be extremely beneficial for accelerating translational research and its use in dental clinics.

Stably engineered nanobubbles and ultrasound - An effective platform for enhanced macromolecular delivery to representative cells of the retina.

PubMed

Thakur, Sachin S; Ward, Micheal S; Popat, Amirali; Flemming, Nicole B; Parat, Marie-Odile; Barnett, Nigel L; Parekh, Harendra S

2017-01-01

Herein we showcase the potential of ultrasound-responsive nanobubbles in enhancing macromolecular permeation through layers of the retina, ultimately leading to significant and direct intracellular delivery; this being effectively demonstrated across three relevant and distinct retinal cell lines. Stably engineered nanobubbles of a highly homogenous and echogenic nature were fully characterised using dynamic light scattering, B-scan ultrasound and transmission electron microscopy (TEM). The nanobubbles appeared as spherical liposome-like structures under TEM, accompanied by an opaque luminal core and darkened corona around their periphery, with both features indicative of efficient gas entrapment and adsorption, respectively. A nanobubble +/- ultrasound sweeping study was conducted next, which determined the maximum tolerated dose for each cell line. Detection of underlying cellular stress was verified using the biomarker heat shock protein 70, measured before and after treatment with optimised ultrasound. Next, with safety to nanobubbles and optimised ultrasound demonstrated, each human or mouse-derived cell population was incubated with biotinylated rabbit-IgG in the presence and absence of ultrasound +/- nanobubbles. Intracellular delivery of antibody in each cell type was then quantified using Cy3-streptavidin. Nanobubbles and optimised ultrasound were found to be negligibly toxic across all cell lines tested. Macromolecular internalisation was achieved to significant, yet varying degrees in all three cell lines. The results of this study pave the way towards better understanding mechanisms underlying cellular responsiveness to ultrasound-triggered drug delivery in future ex vivo and in vivo models of the posterior eye.

Stably engineered nanobubbles and ultrasound - An effective platform for enhanced macromolecular delivery to representative cells of the retina

PubMed Central

Thakur, Sachin S.; Ward, Micheal S.; Popat, Amirali; Flemming, Nicole B.; Parat, Marie-Odile; Barnett, Nigel L.

2017-01-01

Herein we showcase the potential of ultrasound-responsive nanobubbles in enhancing macromolecular permeation through layers of the retina, ultimately leading to significant and direct intracellular delivery; this being effectively demonstrated across three relevant and distinct retinal cell lines. Stably engineered nanobubbles of a highly homogenous and echogenic nature were fully characterised using dynamic light scattering, B-scan ultrasound and transmission electron microscopy (TEM). The nanobubbles appeared as spherical liposome-like structures under TEM, accompanied by an opaque luminal core and darkened corona around their periphery, with both features indicative of efficient gas entrapment and adsorption, respectively. A nanobubble +/- ultrasound sweeping study was conducted next, which determined the maximum tolerated dose for each cell line. Detection of underlying cellular stress was verified using the biomarker heat shock protein 70, measured before and after treatment with optimised ultrasound. Next, with safety to nanobubbles and optimised ultrasound demonstrated, each human or mouse-derived cell population was incubated with biotinylated rabbit-IgG in the presence and absence of ultrasound +/- nanobubbles. Intracellular delivery of antibody in each cell type was then quantified using Cy3-streptavidin. Nanobubbles and optimised ultrasound were found to be negligibly toxic across all cell lines tested. Macromolecular internalisation was achieved to significant, yet varying degrees in all three cell lines. The results of this study pave the way towards better understanding mechanisms underlying cellular responsiveness to ultrasound-triggered drug delivery in future ex vivo and in vivo models of the posterior eye. PMID:28542473

Synergistic effect of ultrasound and PEI on DNA transfection in vitro

PubMed Central

Deshpande, Mangesh C.; Prausnitz, Mark R.

2007-01-01

Ultrasound and poly(ethylenimine) (PEI) have each separately been shown to increase DNA transfection efficiency. This study tested the hypothesis that the combination of ultrasound and PEI can have a synergistic effect to increase DNA transfection. This in vitro study assessed transfection efficiency of two different DNA plasmids encoding green fluorescent protein and firefly luciferase in two different cells types, a primary culture of human aortic smooth muscle cells and an immortal line of human prostrate cancer cells. We found that ultrasound sonication increased transfection up to 18-fold, DNA complexation with PEI increased transfection up to 90-fold, and the combination of ultrasound and PEI synergistically increased transfection up to 200-fold, which resulted in reporter gene expression by 34% of cells. Kinetic measurements found that the effects of ultrasound alone acted quickly, whereas increased transfection by PEI either alone or in combination with ultrasound strongly benefited from a 4-h incubation with the DNA plasmid after sonication. Although serum reduced absolute expression levels, it did not affect the relative increase in transfection when ultrasound was added to PEI enhancement. Flow cytometry measurements showed that sonication increased intracellular uptake of labelled DNA complexed to PEI by 55% relative to PEI complexation alone. Electrophoresis assay showed no damage to DNA or PEI-DNA complexes after sonication. Overall, these results suggest that the combination of ultrasound and PEI can have a synergistic effect to increase DNA transfection. PMID:17258835

Ultrasound phonophoresis of panax notoginseng improves the strength of repairing ligament: a rat model.

PubMed

Ng, Gabriel Y F; Wong, Richard Y F

2008-12-01

This study examined the phonophoretic effect of a therapeutic ultrasound coupled with a Panax notoginseng (PN) gel and compared it with a therapeutic ultrasound alone for medial collateral ligament repair in rats. Twenty mature male Sprague-Dawley rats receiving surgical transection to the left medial collateral ligament (MCL) were divided randomly into three groups: ultrasound (US, n = 7), ultrasound with PN coupling gel (PNUS, n = 7) and control (n = 6). The treatments started on day 3 after surgery for six days per week over a two-week period. The US group received 4 min of pulsed ultrasound (1 MHz) at the intensity of 0.5W/cm(2) with a normal ultrasonic coupling gel. The PNUS group received the same ultrasound treatment, but with a coupling gel that contained PN extract. The control group received a placebo ultrasound treatment similar to the other two groups. On day 17, the ligaments were mechanically tested for load-relaxation, stiffness and ultimate tensile strength (UTS). Values of the left side were normalized against that of the right side of each animal for analysis. Results revealed significantly higher normalized stiffness (p = 0.009) and UTS (p = 0.022) in the PNUS group than the other two groups, but insignificant difference in load-relaxation among all groups. This study reveals a positive ultrasonic phonophoretic effect of Panax notoginseng extract for improving the strength of ligament repair than ultrasound therapy alone.

Solubilization of bovine gelatin using power ultrasound: gelation without heating.

PubMed

Farahnaky, Asgar; Zendeboodi, Fatemeh; Azizi, Rezvan; Mesbahi, Gholamreza; Majzoobi, Mahsa

2017-04-01

The aim of this study was to investigate the efficacy of power ultrasound without using any heating stage in solubilizeing gelatin dispersions, and to characterize the mechanical and microstructural properties of the resulting gels using texture analysis and scanning electron microscopy, respectively. Usually to prepare a gel from gelatin, a primary heating stage of at about 40C or above is required to solubilize gelatin macromolecules. In this study solubilizing gelatin dispersions using power ultrasound without any heating was successfully performed. For solubilising gelatin, an ultrasound equipment with a frequency of 20 kHz, amplitude of 100% and power range of 50-150 W was used. Aqueous gelatin dispersions (4% w/v) were subjected to ultrasound for different times (40-240 s) at a constant temperature of 13C. Applying ultrasound to gelatin dispersions caused increases in water absorption and water solubility of the hydrocolloid. The textural parameters of the resulting gelatin gels, increased with increasing time and power of ultrasound. Moreover, a generalized Maxwell model with three elements was used for calculating relaxation times of the gels. The microstructural observations by SEM showed that the structural cohesiveness of the gels increased by increasing ultrasonication time. Ultrasound-assisted solubilization of gelatin can have emerging implications for industrial uses in pharmaceuticals, food and non-food systems. Usually to prepare a gel from gelatin, a primary heating stage of at about 40C or above is required to solubilize gelatin macromolecules. Therefore, the use of gelatin as a hydrocolloid in food processings or pharmaceutical formulations which lack a heating step has been a technological and practical challenge. In this study solubilizing gelatin dispersions using power ultrasound without any heating was successfully performed. Ultrasound-assisted solubilisation of gelatin can have emerging implications for industrial uses in pharmaceuticals, food, and non-food systems, for example, to conserve heat sensitive compounds. © 2016 Wiley Periodicals, Inc.

Using Ultrasound to Enhance Medical Students' Femoral Vascular Physical Examination Skills.

PubMed

Ahn, Justin S; French, Andrew J; Thiessen, Molly E W; Browne, Vaughn; Deutchman, Mark; Guiton, Gretchen; Madigosky, Wendy; Kendall, John L

2015-10-01

To determine whether the addition of ultrasound to traditional physical examination instruction improves junior medical students' abilities to locate the femoral pulse. Initially, 150 second-year medical students were taught the femoral pulse examination using traditional bedside teaching on standardized patients and online didactic videos. Students were then randomized into 2 groups: group 1 received ultrasound training first and then completed the standardized examination; and group 2 performed the standardized examination first and then received ultrasound training. On the standardized patients, the femoral artery was marked with invisible ink before the sessions using ultrasound. Compared to these markers, students were then evaluated on the accuracy of femoral artery pulse palpation and the estimated location of the femoral vein. All students completed a self-assessment survey after the ultrasound sessions. Ultrasound training improved the students' ability to palpate the femoral pulse (P= .02). However, ultrasound did not facilitate correct estimation of the femoral vein's anatomic location (P = .09). Confidence levels in localizing the femoral artery and vein were equal between groups at baseline, and both increased after the ultrasound sessions. The addition of ultrasound teaching to traditional physical examination instruction enhanced medical student competency and confidence with the femoral vascular examination. However, understanding of anatomy may require emphasis on precourse didactic material, but further study is required. © 2015 by the American Institute of Ultrasound in Medicine.

Study on text mining algorithm for ultrasound examination of chronic liver diseases based on spectral clustering

NASA Astrophysics Data System (ADS)

Chang, Bingguo; Chen, Xiaofei

2018-05-01

Ultrasonography is an important examination for the diagnosis of chronic liver disease. The doctor gives the liver indicators and suggests the patient's condition according to the description of ultrasound report. With the rapid increase in the amount of data of ultrasound report, the workload of professional physician to manually distinguish ultrasound results significantly increases. In this paper, we use the spectral clustering method to cluster analysis of the description of the ultrasound report, and automatically generate the ultrasonic diagnostic diagnosis by machine learning. 110 groups ultrasound examination report of chronic liver disease were selected as test samples in this experiment, and the results were validated by spectral clustering and compared with k-means clustering algorithm. The results show that the accuracy of spectral clustering is 92.73%, which is higher than that of k-means clustering algorithm, which provides a powerful ultrasound-assisted diagnosis for patients with chronic liver disease.

Therapeutic ultrasound as a potential male contraceptive: power, frequency and temperature required to deplete rat testes of meiotic cells and epididymides of sperm determined using a commercially available system.

PubMed

Tsuruta, James K; Dayton, Paul A; Gallippi, Caterina M; O'Rand, Michael G; Streicker, Michael A; Gessner, Ryan C; Gregory, Thomas S; Silva, Erick J R; Hamil, Katherine G; Moser, Glenda J; Sokal, David C

2012-01-30

Studies published in the 1970s by Mostafa S. Fahim and colleagues showed that a short treatment with ultrasound caused the depletion of germ cells and infertility. The goal of the current study was to determine if a commercially available therapeutic ultrasound generator and transducer could be used as the basis for a male contraceptive. Sprague-Dawley rats were anesthetized and their testes were treated with 1 MHz or 3 MHz ultrasound while varying power, duration and temperature of treatment. We found that 3 MHz ultrasound delivered with 2.2 Watt per square cm power for fifteen minutes was necessary to deplete spermatocytes and spermatids from the testis and that this treatment significantly reduced epididymal sperm reserves. 3 MHz ultrasound treatment reduced total epididymal sperm count 10-fold lower than the wet-heat control and decreased motile sperm counts 1,000-fold lower than wet-heat alone. The current treatment regimen provided nominally more energy to the treatment chamber than Fahim's originally reported conditions of 1 MHz ultrasound delivered at 1 Watt per square cm for ten minutes. However, the true spatial average intensity, effective radiating area and power output of the transducers used by Fahim were not reported, making a direct comparison impossible. We found that germ cell depletion was most uniform and effective when we rotated the therapeutic transducer to mitigate non-uniformity of the beam field. The lowest sperm count was achieved when the coupling medium (3% saline) was held at 37 degrees C and two consecutive 15-minute treatments of 3 MHz ultrasound at 2.2 Watt per square cm were separated by 2 days. The non-invasive nature of ultrasound and its efficacy in reducing sperm count make therapeutic ultrasound a promising candidate for a male contraceptive. However, further studies must be conducted to confirm its efficacy in providing a contraceptive effect, to test the result of repeated use, to verify that the contraceptive effect is reversible and to demonstrate that there are no detrimental, long-term effects from using ultrasound as a method of male contraception.

Ultrasound pretreatment for enhanced biogas production from olive mill wastewater.

PubMed

Oz, Nilgun Ayman; Uzun, Alev Cagla

2015-01-01

This study investigates applicability of low frequency ultrasound technology to olive mill wastewaters (OMWs) as a pretreatment step prior to anaerobic batch reactors to improve biogas production and methane yield. OMWs originating from three phase processes are characterized with high organic content and complex nature. The treatment of the wastewater is problematic and alternative treatment options should be investigated. In the first part of the study, OMW samples were subjected to ultrasound at a frequency of 20kHz with applied powers varying between 50 and 100W under temperature controlled conditions for different time periods in order to determine the most effective sonication conditions. The level of organic matter solubilization at ultrasound experiments was assessed by calculating the ratio of soluble chemical oxygen demand/total chemical oxygen demand (SCOD/TCOD). The results revealed that the optimum ultrasonic condition for diluted OMW is 20kHz, 0.4W/mL for 10min. The application of ultrasound to OMW increased SCOD/TCOD ratio from 0.59 to 0.79. Statistical analysis (Friedman's tests) show that ultrasound was significantly effective on diluted OMW (p<0.05) in terms of SCOD parameter, but not for raw OMW (p>0.05). For raw OMW, this increase has been found to be limited due to high concentration of suspended solids (SS). In the second part of the study, biogas and methane production rates of anaerobic batch reactor fed with the ultrasound pretreated OMW samples were compared with the results of control reactor fed with untreated OMW in order to determine the effect of sonication. A nonparametric statistical procedure, Mann-Whitney U test, was used to compare biogas and methane production from anaerobic batch reactors for control and ultrasound pretreated samples. Results showed that application of low frequency ultrasound to OMW significantly improved both biogas and methane production in anaerobic batch reactor fed with the wastewater (p<0.05). Anaerobic batch reactor fed with ultrasound pretreated diluted OMW produced approximately 20% more biogas and methane compared with the untreated one (control reactor). The overall results indicated that low frequency ultrasound pretreatment increased soluble COD in OMW and subsequently biogas production. Copyright © 2014 Elsevier B.V. All rights reserved.

Bedside ultrasonography (US), Echoscopy and US point of care as a new kind of stethoscope for Internal Medicine Departments: the training program of the Italian Internal Medicine Society (SIMI).

PubMed

Arienti, Vincenzo; Di Giulio, Rosella; Cogliati, Chiara; Accogli, Esterita; Aluigi, Leonardo; Corazza, Gino Roberto

2014-10-01

In recent years, thanks to the development of miniaturized ultrasound devices, comparable to personal computers, tablets and even to smart phones, we have seen an increasing use of bedside ultrasound in internal medicine departments as a novel kind of ultrasound stethoscope. The clinical ultrasound-assisted approach has proved to be particularly useful in assessing patients with nodules of the neck, dyspnoea, abdominal pain, and with limb edema. In several cases, it has allowed a simple, rapid and precise diagnosis. Since 2005, the Italian Society of Internal Medicine and its Ultrasound Study Group has been holding a Summer School and training courses in ultrasound for residents in internal medicine. A national network of schools in bedside ultrasound was then organized for internal medicine specialists who want to learn this technique. Because bedside ultrasound is a user-dependent diagnostic method, it is important to define the limits and advantages of different new ultrasound devices, to classify them (i.e. Echoscopy and Point of Care Ultrasound), to establish appropriate different levels of competence and to ensure their specific training. In this review, we describe the point of view of the Italian Internal Medicine Society on these topics.

An orthopedist's guide to shoulder ultrasound: a systematic review of examination protocols.

PubMed

Amoo-Achampong, Kelms; Nwachukwu, Benedict U; McCormick, Frank

2016-11-01

The utilization of musculoskeletal ultrasound has expanded within the setting of the orthopedic clinic as a cost-effective, point-of-care diagnostic tool for shoulder pathology. In experienced hands, ultrasound exhibits capabilities equivalent to that of magnetic resonance imaging in the diagnosis of many shoulder diseases including full-thickness and partial-thickness rotator cuff tears. Although similarly effective in identifying additional shoulder disease processes, major obstacles to its widespread use include user dependence and intrinsic limitation to extra-articular diagnosis. The purpose of this review is to present a step-by-step guide of how to perform a comprehensive shoulder examination and to discuss the appropriate use, economic benefit and implementation of ultrasound within the clinic. A systematic search (June 2016) of PubMed, Scopus, and EMBASE databases was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for literature presenting shoulder ultrasound examination protocols. Included studies were peer-reviewed articles or academic society endorsed protocols presenting comprehensive sonographic examinations of the adult shoulder. Papers with limited or single structure examination descriptions, non-English language, and publication dates before 1980 were excluded. Final papers meeting criteria were secondarily screened for publication after 2005 to reflect the current state of ultrasound imaging. The search yielded 1,725 unique articles with 17 studies meeting final selection criteria. Information from identified studies was summarized to formulate a 4-part shoulder examination protocol, including steps most pertinent to orthopedic in-office diagnoses. In agreement with previous studies, the inexperienced orthopedic surgeon can be quickly trained to expert level proficiency in shoulder ultrasound diagnosis. Using an established protocol, a comprehensive, yet effective shoulder ultrasound examination can be performed within ten minutes. Further, ultrasound provides opportunity to off-set costs through the engagement of revenue generating activity for the orthopedic practice.

Enhancing mung bean hydration using the ultrasound technology: description of mechanisms and impact on its germination and main components

NASA Astrophysics Data System (ADS)

Miano, Alberto Claudio; Pereira, Jessica Da Costa; Castanha, Nanci; Júnior, Manoel Divino Da Matta; Augusto, Pedro Esteves Duarte

2016-12-01

The ultrasound technology was successfully used to improve the mass transfer processes on food. However, the study of this technology on the grain hydration and on its main components properties was still not appropriately described. This work studied the application of the ultrasound technology on the hydration process of mung beans (Vigna radiata). This grain showed sigmoidal hydration behavior with a specific water entrance pathway. The ultrasound reduced ~25% of the hydration process time. In addition, this technology caused acceleration of the seed germination - and some hypothesis for this enhancement were proposed. Moreover, it was demonstrated that the ultrasound did not change both structure and pasting properties of the bean starch. Finally, the flour rheological properties proved that the ultrasound increased its apparent viscosity, and as the starch was not modified, this alteration was attributed to the proteins. All these results are very desirable for industry since the ultrasound technology improves the hydration process without altering the starch properties, accelerates the germination process (that is important for the malting and sprouting process) and increases the flour apparent viscosity, which is desirable to produce bean-based products that need higher consistency.

The validity of ultrasound estimation of muscle volumes.

PubMed

Infantolino, Benjamin W; Gales, Daniel J; Winter, Samantha L; Challis, John H

2007-08-01

The purpose of this study was to validate ultrasound muscle volume estimation in vivo. To examine validity, vastus lateralis ultrasound images were collected from cadavers before muscle dissection; after dissection, the volumes were determined by hydrostatic weighing. Seven thighs from cadaver specimens were scanned using a 7.5-MHz ultrasound probe (SSD-1000, Aloka, Japan). The perimeter of the vastus lateralis was identified in the ultrasound images and manually digitized. Volumes were then estimated using the Cavalieri principle, by measuring the image areas of sets of parallel two-dimensional slices through the muscles. The muscles were then dissected from the cadavers, and muscle volume was determined via hydrostatic weighing. There was no statistically significant difference between the ultrasound estimation of muscle volume and that estimated using hydrostatic weighing (p > 0.05). The mean percentage error between the two volume estimates was 0.4% +/- 6.9. Three operators all performed four digitizations of all images from one randomly selected muscle; there was no statistical difference between operators or trials and the intraclass correlation was high (>0.8). The results of this study indicate that ultrasound is an accurate method for estimating muscle volumes in vivo.

Mixed reality ultrasound guidance system: a case study in system development and a cautionary tale.

PubMed

Ameri, Golafsoun; Baxter, John S H; Bainbridge, Daniel; Peters, Terry M; Chen, Elvis C S

2018-04-01

Real-time ultrasound has become a crucial aspect of several image-guided interventions. One of the main constraints of such an approach is the difficulty in interpretability of the limited field of view of the image, a problem that has recently been addressed using mixed reality, such as augmented reality and augmented virtuality. The growing popularity and maturity of mixed reality has led to a series of informal guidelines to direct development of new systems and to facilitate regulatory approval. However, the goals of mixed reality image guidance systems and the guidelines for their development have not been thoroughly discussed. The purpose of this paper is to identify and critically examine development guidelines in the context of a mixed reality ultrasound guidance system through a case study. A mixed reality ultrasound guidance system tailored to central line insertions was developed in close collaboration with an expert user. This system outperformed ultrasound-only guidance in a novice user study and has obtained clearance for clinical use in humans. A phantom study with 25 experienced physicians was carried out to compare the performance of the mixed reality ultrasound system against conventional ultrasound-only guidance. Despite the previous promising results, there was no statistically significant difference between the two systems. Guidelines for developing mixed reality image guidance systems cannot be applied indiscriminately. Each design decision, no matter how well justified, should be the subject of scientific and technical investigation. Iterative and small-scale evaluation can readily unearth issues and previously unknown or implicit system requirements. We recommend a wary eye in development of mixed reality ultrasound image guidance systems emphasizing small-scale iterative evaluation alongside system development. Ultimately, we recommend that the image-guided intervention community furthers and deepens this discussion into best practices in developing image-guided interventions.

Toward a real-time system for temporal enhanced ultrasound-guided prostate biopsy.

PubMed

Azizi, Shekoofeh; Van Woudenberg, Nathan; Sojoudi, Samira; Li, Ming; Xu, Sheng; Abu Anas, Emran M; Yan, Pingkun; Tahmasebi, Amir; Kwak, Jin Tae; Turkbey, Baris; Choyke, Peter; Pinto, Peter; Wood, Bradford; Mousavi, Parvin; Abolmaesumi, Purang

2018-03-27

We have previously proposed temporal enhanced ultrasound (TeUS) as a new paradigm for tissue characterization. TeUS is based on analyzing a sequence of ultrasound data with deep learning and has been demonstrated to be successful for detection of cancer in ultrasound-guided prostate biopsy. Our aim is to enable the dissemination of this technology to the community for large-scale clinical validation. In this paper, we present a unified software framework demonstrating near-real-time analysis of ultrasound data stream using a deep learning solution. The system integrates ultrasound imaging hardware, visualization and a deep learning back-end to build an accessible, flexible and robust platform. A client-server approach is used in order to run computationally expensive algorithms in parallel. We demonstrate the efficacy of the framework using two applications as case studies. First, we show that prostate cancer detection using near-real-time analysis of RF and B-mode TeUS data and deep learning is feasible. Second, we present real-time segmentation of ultrasound prostate data using an integrated deep learning solution. The system is evaluated for cancer detection accuracy on ultrasound data obtained from a large clinical study with 255 biopsy cores from 157 subjects. It is further assessed with an independent dataset with 21 biopsy targets from six subjects. In the first study, we achieve area under the curve, sensitivity, specificity and accuracy of 0.94, 0.77, 0.94 and 0.92, respectively, for the detection of prostate cancer. In the second study, we achieve an AUC of 0.85. Our results suggest that TeUS-guided biopsy can be potentially effective for the detection of prostate cancer.

A motorized ultrasound system for MRI-ultrasound fusion guided prostatectomy

NASA Astrophysics Data System (ADS)

Seifabadi, Reza; Xu, Sheng; Pinto, Peter; Wood, Bradford J.

2016-03-01

Purpose: This study presents MoTRUS, a motorized transrectal ultrasound system, to enable remote navigation of a transrectal ultrasound (TRUS) probe during da Vinci assisted prostatectomy. MoTRUS not only provides a stable platform to the ultrasound probe, but also allows the physician to navigate it remotely while sitting on the da Vinci console. This study also presents phantom feasibility study with the goal being intraoperative MRI-US image fusion capability to bring preoperative MR images to the operating room for the best visualization of the gland, boundaries, nerves, etc. Method: A two degree-of-freedom probe holder is developed to insert and rotate a bi-plane transrectal ultrasound transducer. A custom joystick is made to enable remote navigation of MoTRUS. Safety features have been considered to avoid inadvertent risks (if any) to the patient. Custom design software has been developed to fuse pre-operative MR images to intraoperative ultrasound images acquired by MoTRUS. Results: Remote TRUS probe navigation was evaluated on a patient after taking required consents during prostatectomy using MoTRUS. It took 10 min to setup the system in OR. MoTRUS provided similar capability in addition to remote navigation and stable imaging. No complications were observed. Image fusion was evaluated on a commercial prostate phantom. Electromagnetic tracking was used for the fusion. Conclusions: Motorized navigation of the TRUS probe during prostatectomy is safe and feasible. Remote navigation provides physician with a more precise and easier control of the ultrasound image while removing the burden of manual manipulation of the probe. Image fusion improved visualization of the prostate and boundaries in a phantom study.

Clinical use of ultrasonography associated with color Doppler in the diagnosis and follow-up of acute pyelonephritis.

PubMed

Dell'Atti, Lucio; Borea, Pier Andrea; Ughi, Gianni; Russo, Gian Rosario

2010-12-01

The purpose of this study is to evaluate the current role of the Ultrasound associated with the color-Doppler in the diagnosis of acute pyelonephritis (APN) and to compare ultrasound images with CT images in order to reduce the amount radiation absorbe without significant loss of diagnostic efficacy, since this disease in most cases affects young adults. We studied 38 patients (aged 17-65 years) who presented from September 2007 to March 2010 to the emergency department with suspected diagnosis of APN. All patients underwent first to an ultrasound study, then to abdominal CT. Renal, perirenal and extrarenal tomographic findings usually associated with acute pyelonephritis were analyzed, in an attempt to identify what are the differences with respect to the images obtained with an ultrasound study. All patients then performed ultrasonography and/or abdominal CT evaluation one month later, 25 patients repeated both examinations, while the other 13 repeated only ultrasound. In 38 subjects with suspected APN, CT assessed the presence in 79% and in 21% the absence of the disease. Ultrasonography in 68% of cases diagnosed APN, by an increase in kidney size related to the presence of hypoechoic areas associated to edema, blurred margins and reduction of the color-Doppler vascularity. Ultrasound associated with the use of color-Doppler revealed a sensibility of 76% and specificity of 75%. Color and power-Doppler have better diagnostic accuracy than basic gray scale ultrasound, in the diagnosis of focal pyelonephritis. Therefore the combined use of ultrasound and color-Doppler can obtain useful information about the diagnosis and follow-up of the disease, with an improvement in terms of cost, without significantly altering the diagnostic efficacy and reducing the amount of radiation absorbed.

Progression of ultrasound findings of fetal syphilis after maternal treatment.

PubMed

Rac, Martha W F; Bryant, Stefanie N; McIntire, Donald D; Cantey, Joseph B; Twickler, Diane M; Wendel, George D; Sheffield, Jeanne S

2014-10-01

The purpose of this study was to evaluate ultrasound findings of fetal syphilis and to describe their progression after maternal treatment. This was a retrospective cohort study from September 1981 to June 2011 of seropositive women after 18 weeks of gestation who had an ultrasound before treatment to evaluate for fetal syphilis. Only those women who received treatment after the initial ultrasound scan, but before delivery, were included. If the initial ultrasound scan was abnormal, serial sonography was performed until resolution of the abnormality or delivery. Patient demographics, ultrasound findings, stage of syphilis, delivery, and infant outcomes were recorded. Standard statistical analyses were performed. Kaplan-Meier estimates were constructed to estimate time to resolution. Two hundred thirty-five women met the inclusion criteria; 73 of them (30%) had evidence of fetal syphilis on initial ultrasound scan. Abnormalities included hepatomegaly (79%), placentomegaly (27%), polyhydramnios (12%), ascites (10%) and abnormal middle cerebral arterial Doppler assessment (33%). After treatment, middle cerebral arterial Doppler assessment abnormalities, ascites, and polyhydramnios resolved first, followed by placentomegaly and finally hepatomegaly. Infant outcomes were available for 173 deliveries; of these, 32 infants (18%) were diagnosed with congenital syphilis. Congenital syphilis was more common when antenatal ultrasound abnormalities were present (39% vs 12%; P < .001). Infant examination findings at delivery were similar between women with and without an abnormal pretreatment ultrasound scan. However, in those infants with congenital syphilis, hepatomegaly was the most frequent abnormality found, regardless of antenatal ultrasound findings. Sonographic signs of fetal syphilis confer a higher risk of congenital syphilis at delivery for all maternal stages. Hepatomegaly develops early and resolves last after antepartum treatment. Copyright © 2014 Elsevier Inc. All rights reserved.

Auscultation versus Point-of-care Ultrasound to Determine Endotracheal versus Bronchial Intubation: A Diagnostic Accuracy Study.

PubMed

Ramsingh, Davinder; Frank, Ethan; Haughton, Robert; Schilling, John; Gimenez, Kimberly M; Banh, Esther; Rinehart, Joseph; Cannesson, Maxime

2016-05-01

Unrecognized malposition of the endotracheal tube (ETT) can lead to severe complications in patients under general anesthesia. The focus of this double-blinded randomized study was to assess the accuracy of point-of-care ultrasound in verifying the correct position of the ETT and to compare it with the accuracy of auscultation. Forty-two adult patients requiring general anesthesia with ETT were consented. Patients were randomized to right main bronchus, left main bronchus, or tracheal intubation. After randomization, the ETT was placed via fiber-optic visualization. Next, the location of the ETT was assessed using auscultation by a separate blinded anesthesiologist, followed by an ultrasound performed by a third blinded anesthesiologist. Ultrasound examination included assessment of tracheal dilation via cuff inflation with air and evaluation of pleural lung sliding. Statistical analysis included sensitivity, specificity, positive predictive value, negative predictive value, and interobserver agreement for the ultrasound examination (95% CI). In differentiating tracheal versus bronchial intubations, auscultation showed a sensitivity of 66% (0.39 to 0.87) and a specificity of 59% (0.39 to 0.77), whereas ultrasound showed a sensitivity of 93% (0.66 to 0.99) and specificity of 96% (0.79 to 1). Identification of tracheal versus bronchial intubation was 62% (26 of 42) in the auscultation group and 95% (40 of 42) in the ultrasound group (P = 0.0005) (CI for difference, 0.15 to 0.52), and the McNemar comparison showed statistically significant improvement with ultrasound (P < 0.0001). Interobserver agreement of ultrasound findings was 100%. Assessment of trachea and pleura via point-of-care ultrasound is superior to auscultation in determining the location of ETT.

Endovascular ultrasound for renal sympathetic denervation in patients with therapy-resistant hypertension not responding to radiofrequency renal sympathetic denervation.

PubMed

Stiermaier, Thomas; Okon, Thomas; Fengler, Karl; Mueller, Ulrike; Hoellriegel, Robert; Schuler, Gerhard; Desch, Steffen; Lurz, Philipp

2016-06-12

Recent studies have reported a considerable number of non-responders after renal sympathetic de-nervation (RSD) with radiofrequency technology. Here we report our results of repeat RSD using ultrasound in these patients. A cohort study was performed in patients who underwent ultrasound RSD after non-response to RSD with radiofrequency. Non-response was defined as mean daytime systolic blood pressure ≥140 mmHg and/or a reduction of ≤10 mmHg in ambulatory blood pressure measurement (ABPM) ≥6 months after radiofrequency denervation. ABPM was recorded at baseline, post radiofrequency RSD as well as at three and six months post ultrasound RSD. A total of 24 non-responders underwent retreatment with the ultrasound device at a mean 15.3±8.2 months after radiofrequency RSD. Ultrasound RSD was performed successfully in all patients without severe adverse events. Mean daytime systolic blood pressure changed from 161.7±14.6 mmHg at baseline to 158.5±9.5 mmHg post radiofrequency RSD and to 150.5±10.4 mmHg and 151.6±11.0 mmHg at three and six months, respectively, post ultrasound RSD (p<0.01 with repeated measures analysis of variance). The main results of post hoc testing were as follows: baseline versus post radiofrequency RSD, p=0.83; baseline versus three months post ultrasound RSD, p=0.01; and baseline versus six months post ultrasound RSD, p=0.04. Ultrasound RSD appears to be safe and an effective therapeutic approach in patients not responding to previous RSD with radiofrequency technology.

Ultrasound in Speech Therapy with Adolescents and Adults

ERIC Educational Resources Information Center

Bernhardt, Barbara; Gick, Bryan; Bacsfalvi, Penelope; Adler-Bock, Marcy

2005-01-01

The present paper comprises an overview of techniques using ultrasound in speech (re)habilitation. Ultrasound treatment techniques have been developed for English lingual stops, vowels, sibilants, and liquids. These techniques come from a series of small "n" studies with adolescents and adults with severe hearing impairment, residual…

The Effects of Ultrasound on Biological Systems: Site

NASA Astrophysics Data System (ADS)

El-Karmi, Anan M.

Earlier studies (Dinno et al., Ultrasound Med. Biol. 15:461 -470; 1989) demonstrated that ultrasound at therapeutic intensities causes large increases in total conductance (G_{rm t}) of frog skin. These changes were attributed to non-thermal mechanisms, primarily, cavitation. In this study, the site(s) and mechanism(s) of action of ultrasound for the increase in G_{rm t} were examined. The reversible changes in G_{rm t } and sodium current were monitored in real time as a function of ultrasound exposure. Amiloride, a sodium channel blocker, was used to differentiate between cellular (G_{rm c}) and paracellular (G_{rm s}) pathways in the presence and absence of ultrasound. No significant changes were detected in G_ {rm c}. However, changes in G _{rm s} were significant. These results demonstrate that most of the increase in G _{rm t} due to ultrasound is taking place in the paracellular pathways. Sodium channels were not significantly affected by ultrasound. Thus, the changes in G_{rm c} are not specific. The effects of ultrasound were examined in the presence of radical scavengers and antioxidants. The increase in G_{rm t} due to ultrasound was significantly minimized in the presence of cystamine, cysteamine, and sodium ascorbate. This demonstrates that free radicals and other reactive species generated by cavitation are causing the increase in G_ {rm t}, possibly by acting from inside the cells. Radical scavengers and antioxidants are providing protection from oxidative damage but are not involved in the recovery of G_{ rm t} towards steady state values after sonication. The role of Ca^{2+} in the effects of ultrasound was examined since many of the cellular reactions involved in tissue recovery are dependent on the intracellular availability of free Ca^{2+}. The percentage increase in G_{rm t} in the presence of Ca^{2+} was larger than in its absence (140% vs. 27%). The time constant for G_{rm t} to return to steady state was longer in calcium-free solutions (122 vs. 18 minutes). This demonstrates that the biological effects of ultrasound are influenced by Ca^ {2+}. The larger increases in G _{rm t} and the time constants confirm other studies addressing the role of Ca ^{2+} in potentiating lipid peroxidation by free radicals, and the role of calcium ions in the formation of tight junctions.

Ultrasound for Distal Forearm Fracture: A Systematic Review and Diagnostic Meta-Analysis

PubMed Central

Douma-den Hamer, Djoke; Blanker, Marco H.; Edens, Mireille A.; Buijteweg, Lonneke N.; Boomsma, Martijn F.; van Helden, Sven H.; Mauritz, Gert-Jan

2016-01-01

Study Objective To determine the diagnostic accuracy of ultrasound for detecting distal forearm fractures. Methods A systematic review and diagnostic meta-analysis was performed according to the PRISMA statement. We searched MEDLINE, Web of Science and the Cochrane Library from inception to September 2015. All prospective studies of the diagnostic accuracy of ultrasound versus radiography as the reference standard were included. We excluded studies with a retrospective design and those with evidence of verification bias. We assessed the methodological quality of the included studies with the QUADAS-2 tool. We performed a meta-analysis of studies evaluating ultrasound to calculate the pooled sensitivity and specificity with 95% confidence intervals (CI95%) using a bivariate model with random effects. Subgroup and sensitivity analysis were used to examine the effect of methodological differences and other study characteristics. Results Out of 867 publications we included 16 studies with 1,204 patients and 641 fractures. The pooled test characteristics for ultrasound were: sensitivity 97% (CI95% 93–99%), specificity 95% (CI95% 89–98%), positive likelihood ratio (LR) 20.0 (8.5–47.2) and negative LR 0.03 (0.01–0.08). The corresponding pooled diagnostic odds ratio (DOR) was 667 (142–3,133). Apparent differences were shown for method of viewing, with the 6-view method showing higher specificity, positive LR, and DOR, compared to the 4-view method. Conclusion The present meta-analysis showed that ultrasound has a high accuracy for the diagnosis of distal forearm fractures in children when used by proper viewing method. Based on this, ultrasound should be considered a reliable alternative, which has the advantages of being radiation free. PMID:27196439

Ultrasound Metrology in Mexico: a round robin test for medical diagnostics

NASA Astrophysics Data System (ADS)

Amezola Luna, R.; López Sánchez, A. L.; Elías Juárez, A. A.

2011-02-01

This paper presents preliminary statistical results from an on-going imaging medical ultrasound study, of particular relevance for gynecology and obstetrics areas. Its scope is twofold, firstly to compile the medical ultrasound infrastructure available in cities of Queretaro-Mexico, and second to promote the use of traceable measurement standards as a key aspect to assure quality of ultrasound examinations performed by medical specialists. The experimental methodology is based on a round robin test using an ultrasound phantom for medical imaging. The physician, using its own ultrasound machine, couplant and facilities, measures the size and depth of a set of pre-defined reflecting and absorbing targets of the reference phantom, which simulate human illnesses. Measurements performed give the medical specialist an objective feedback regarding some performance characteristics of their ultrasound examination systems, such as measurement system accuracy, dead zone, axial resolution, depth of penetration and anechoic targets detection. By the end of March 2010, 66 entities with medical ultrasound facilities, from both public and private institutions, have performed measurements. A network of medical ultrasound calibration laboratories in Mexico, with traceability to The International System of Units via national measurement standards, may indeed contribute to reduce measurement deviations and thus attain better diagnostics.

Implementation of a 4-Year Point-of-Care Ultrasound Curriculum in a Liaison Committee on Medical Education-Accredited US Medical School.

PubMed

Wilson, Sean P; Mefford, Jason M; Lahham, Shadi; Lotfipour, Shahram; Subeh, Mohammad; Maldonado, Gracie; Spann, Sophie; Fox, John C

2017-02-01

The established benefits of point-of-care ultrasound have given rise to multiple new and innovative curriculums to incorporate ultrasound teaching into medical education. This study sought to measure the educational success of a comprehensive and integrated 4-year point-of-care ultrasound curriculum. We integrated a curriculum consisting of traditional didactics combined with asynchronous learning modules and hands-on practice on live models with skilled sonographers into all 4 years of education at a Liaison Committee on Medical Education-accredited US Medical School. Each graduating student was administered an exit examination with 48 questions that corresponded to ultrasound milestones. Ninety-five percent (n = 84) of fourth-year medical students completed the exit examination. The mean score was 79.5% (SD, 10.2%), with mean scores on the ultrasound physics and anatomy subsections being 77.1% (SD, 11.0%) and 85.9% (SD, 21.0%), respectively. A comprehensive 4-year point-of-care ultrasound curriculum integrated into medical school may successfully equip graduating medical students with a fundamental understanding of ultrasound physics, anatomy, and disease recognition. © 2016 by the American Institute of Ultrasound in Medicine.

The ultrasound-assisted aqueous extraction of rice bran oil.

PubMed

Khoei, Maryam; Chekin, Fereshteh

2016-03-01

In this work, aqueous extraction of rice bran oil was done without and with ultrasound pretreatment. Key factors controlling the extraction and optimal operating conditions were identified. The highest extraction efficiency was found at pH=12, temperature of 45°C, agitation speed of 800rpm and agitation time of 15min, ultrasound treatment time of 70min and ultrasound treatment temperature of 25°C. Moreover, extraction yields were compared to ultrasound-assisted aqueous extraction and Soxhlet extraction. The results showed that the yield of rice bran oil at ultrasound-assisted aqueous extraction was close to the yield of oil extracted by hexane Soxhlet extraction. This result implied that the yield of rice bran oil was significantly influenced by ultrasound. With regard to quality, the oil extracted by ultrasound-assisted aqueous process had a lower content of free fatty acid and lower color imparting components than the hexane-extracted oil. Also, effect of parboiling of paddy on hexane and ultrasound-assisted aqueous extraction was studied. Both extraction methods gives higher percentage of oil from par boiled rice bran compared with raw rice bran. This may be due to the fact that parboiling releases the oil. Copyright © 2015 Elsevier Ltd. All rights reserved.

Measuring Femoral Torsion In Vivo Using Freehand 3-D Ultrasound Imaging.

PubMed

Passmore, Elyse; Pandy, Marcus G; Graham, H Kerr; Sangeux, Morgan

2016-02-01

Despite variation in bone geometry, muscle and joint function is often investigated using generic musculoskeletal models. Patient-specific bone geometry can be obtained from computerised tomography, which involves ionising radiation, or magnetic resonance imaging (MRI), which is costly and time consuming. Freehand 3-D ultrasound provides an alternative to obtain bony geometry. The purpose of this study was to determine the accuracy and repeatability of 3-D ultrasound in measuring femoral torsion. Measurements of femoral torsion were performed on 10 healthy adults using MRI and 3-D ultrasound. Measurements of femoral torsion from 3-D ultrasound were, on average, smaller than those from MRI (mean difference = 1.8°; 95% confidence interval: -3.9°, 7.5°). MRI and 3-D ultrasound had Bland and Altman repeatability coefficients of 3.1° and 3.7°, respectively. Accurate measurements of femoral torsion were obtained with 3-D ultrasound offering the potential to acquire patient-specific bone geometry for musculoskeletal modelling. Three-dimensional ultrasound is non-invasive and relatively inexpensive and can be integrated into gait analysis. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Needle tip visibility in 3D ultrasound images

NASA Astrophysics Data System (ADS)

Arif, Muhammad; Moelker, Adriaan; van Walsum, Theo

2017-03-01

Needle visibility is of crucial importance for ultrasound guided interventional procedures. However, several factors, such as shadowing by bone or gas and tissue echogenic properties similar to needles, may compromise needle visibility. Additionally, small angle between the ultrasound beam and the needle, as well as small gauged needles may reduce visibility. Variety in needle tips design may also affect needle visibility. Whereas several studies have investigated needle visibility in 2D ultrasound imaging, no data is available for 3D ultrasound imaging, a modality that has great potential for image guidance interventions1. In this study, we evaluated needle visibility using a 3D ultrasound transducer. We examined different needles in a tissue mimicking liver phantom at three angles (200, 550 and 900) and quantify their visibility. The liver phantom was made by 5% polyvinyl alcohol solution containing 1% Silica gel particles to act as ultrasound scattering particles. We used four needles; two biopsy needles (Quick core 14G and 18G), one Ablation needle (Radiofrequency Ablation 17G), and Initial puncture needle (IP needle 17G). The needle visibility was quantified by calculating contrast to noise ratio. The results showed that the visibility for all needles were almost similar at large angles. However the difference in visibility at lower angles is more prominent. Furthermore, the visibility increases with the increase in angle of ultrasound beam with needles.

Potential mechanism in sonodynamic therapy and focused ultrasound induced apoptosis in sarcoma 180 cells in vitro.

PubMed

Tang, Wei; Liu, Quanhong; Wang, Xiaobing; Wang, Pan; Zhang, Jing; Cao, Bing

2009-12-01

Sonodynamic therapy employs a combination of ultrasound and a sonosensitizer to enhance the cytotoxic effect of ultrasound and promote apoptosis. However, the mechanism underlying the synergistic effect of ultrasound and hematoporphyrin is still unclear. In this study, we investigated mechanism of the induction of apoptosis by sonodynamic therapy in Sarcoma 180 cells. The cell suspension was treated by 1.75-MHz focused continuous ultrasound at an acoustic power (I(SATA)) of 1.4+/-0.07 W/cm(2) for 3 min in the absence or presence of 20 microg/ml hematoporphyrin. The proportion of apoptotic cells was determined by flow cytometry. We then analyzed the reactive oxygen species generation and localization by confocal microscopy. Western blotting and reverse transcriptase-polymerase chain reaction were used to analyze the expression of caspase-8, caspase-9, poly(ADP)-ribose polymerase, and nuclear factor-kappaB. The findings of our study indicate that ultrasound treatment induced the activation of nuclear factor-kappaB as an early stress response. When cells were pretreated with hematoporphyrin, the initial response to the therapy was the formation of (1)O(2) in the mitochondria. Our results primarily demonstrate that the mechanisms of induction of apoptosis by ultrasound and hematoporphyrin-sonodynamic therapies are very different. Our findings can provide a basis for explaining the synergistic effect of ultrasound and hematoporphyrin.

Cognitive load imposed by ultrasound-facilitated teaching does not adversely affect gross anatomy learning outcomes.

PubMed

Jamniczky, Heather A; Cotton, Darrel; Paget, Michael; Ramji, Qahir; Lenz, Ryan; McLaughlin, Kevin; Coderre, Sylvain; Ma, Irene W Y

2017-03-01

Ultrasonography is increasingly used in medical education, but its impact on learning outcomes is unclear. Adding ultrasound may facilitate learning, but may also potentially overwhelm novice learners. Based upon the framework of cognitive load theory, this study seeks to evaluate the relationship between cognitive load associated with using ultrasound and learning outcomes. The use of ultrasound was hypothesized to facilitate learning in anatomy for 161 novice first-year medical students. Using linear regression analyses, the relationship between reported cognitive load on using ultrasound and learning outcomes as measured by anatomy laboratory examination scores four weeks after ultrasound-guided anatomy training was evaluated in consenting students. Second anatomy examination scores of students who were taught anatomy with ultrasound were compared with historical controls (those not taught with ultrasound). Ultrasound's perceived utility for learning was measured on a five-point scale. Cognitive load on using ultrasound was measured on a nine-point scale. Primary outcome was the laboratory examination score (60 questions). Learners found ultrasound useful for learning. Weighted factor score on "image interpretation" was negatively, but insignificantly, associated with examination scores [F (1,135) = 0.28, beta = -0.22; P = 0.61]. Weighted factor score on "basic knobology" was positively and insignificantly associated with scores; [F (1,138) = 0.27, beta = 0.42; P = 0.60]. Cohorts exposed to ultrasound had significantly higher scores than historical controls (82.4% ± SD 8.6% vs. 78.8% ± 8.5%, Cohen's d = 0.41, P < 0.001). Using ultrasound to teach anatomy does not negatively impact learning and may improve learning outcomes. Anat Sci Educ 10: 144-151. © 2016 American Association of Anatomists. © 2016 American Association of Anatomists.

Ultrasound versus liver function tests for diagnosis of common bile duct stones.

PubMed

Gurusamy, Kurinchi Selvan; Giljaca, Vanja; Takwoingi, Yemisi; Higgie, David; Poropat, Goran; Štimac, Davor; Davidson, Brian R

2015-02-26

Ultrasound and liver function tests (serum bilirubin and serum alkaline phosphatase) are used as screening tests for the diagnosis of common bile duct stones in people suspected of having common bile duct stones. There has been no systematic review of the diagnostic accuracy of ultrasound and liver function tests. To determine and compare the accuracy of ultrasound versus liver function tests for the diagnosis of common bile duct stones. We searched MEDLINE, EMBASE, Science Citation Index Expanded, BIOSIS, and Clinicaltrials.gov to September 2012. We searched the references of included studies to identify further studies and systematic reviews identified from various databases (Database of Abstracts of Reviews of Effects, Health Technology Assessment, Medion, and ARIF (Aggressive Research Intelligence Facility)). We did not restrict studies based on language or publication status, or whether data were collected prospectively or retrospectively. We included studies that provided the number of true positives, false positives, false negatives, and true negatives for ultrasound, serum bilirubin, or serum alkaline phosphatase. We only accepted studies that confirmed the presence of common bile duct stones by extraction of the stones (irrespective of whether this was done by surgical or endoscopic methods) for a positive test result, and absence of common bile duct stones by surgical or endoscopic negative exploration of the common bile duct, or symptom-free follow-up for at least six months for a negative test result as the reference standard in people suspected of having common bile duct stones. We included participants with or without prior diagnosis of cholelithiasis; with or without symptoms and complications of common bile duct stones, with or without prior treatment for common bile duct stones; and before or after cholecystectomy. At least two authors screened abstracts and selected studies for inclusion independently. Two authors independently collected data from each study. Where meta-analysis was possible, we used the bivariate model to summarise sensitivity and specificity. Five studies including 523 participants reported the diagnostic accuracy of ultrasound. One studies (262 participants) compared the accuracy of ultrasound, serum bilirubin and serum alkaline phosphatase in the same participants. All the studies included people with symptoms. One study included only participants without previous cholecystectomy but this information was not available from the remaining studies. All the studies were of poor methodological quality. The sensitivities for ultrasound ranged from 0.32 to 1.00, and the specificities ranged from 0.77 to 0.97. The summary sensitivity was 0.73 (95% CI 0.44 to 0.90) and the specificity was 0.91 (95% CI 0.84 to 0.95). At the median pre-test probability of common bile duct stones of 0.408, the post-test probability (95% CI) associated with positive ultrasound tests was 0.85 (95% CI 0.75 to 0.91), and negative ultrasound tests was 0.17 (95% CI 0.08 to 0.33).The single study of liver function tests reported diagnostic accuracy at two cut-offs for bilirubin (greater than 22.23 μmol/L and greater than twice the normal limit) and two cut-offs for alkaline phosphatase (greater than 125 IU/L and greater than twice the normal limit). This study also assessed ultrasound and reported higher sensitivities for bilirubin and alkaline phosphatase at both cut-offs but the specificities of the markers were higher at only the greater than twice the normal limit cut-off. The sensitivity for ultrasound was 0.32 (95% CI 0.15 to 0.54), bilirubin (cut-off greater than 22.23 μmol/L) was 0.84 (95% CI 0.64 to 0.95), and alkaline phosphatase (cut-off greater than 125 IU/L) was 0.92 (95% CI 0.74 to 0.99). The specificity for ultrasound was 0.95 (95% CI 0.91 to 0.97), bilirubin (cut-off greater than 22.23 μmol/L) was 0.91 (95% CI 0.86 to 0.94), and alkaline phosphatase (cut-off greater than 125 IU/L) was 0.79 (95% CI 0.74 to 0.84). No study reported the diagnostic accuracy of a combination of bilirubin and alkaline phosphatase, or combinations with ultrasound. Many people may have common bile duct stones in spite of having a negative ultrasound or liver function test. Such people may have to be re-tested with other modalities if the clinical suspicion of common bile duct stones is very high because of their symptoms. False-positive results are also possible and further non-invasive testing is recommended to confirm common bile duct stones to avoid the risks of invasive testing.It should be noted that these results were based on few studies of poor methodological quality and the results for ultrasound varied considerably between studies. Therefore, the results should be interpreted with caution. Further studies of high methodological quality are necessary to determine the diagnostic accuracy of ultrasound and liver function tests.

Ultrasound-enhanced delivery of antibiotics and anti-inflammatory drugs into the eye.

PubMed

Nabili, Marjan; Patel, Hetal; Mahesh, Sankaranarayana P; Liu, Ji; Geist, Craig; Zderic, Vesna

2013-04-01

Delivery of sufficient amounts of therapeutic drugs into the eye is often a challenging task. In this study, ultrasound application (frequencies of 400 KHz to 1 MHz, intensities of 0.3-1.0 W/cm(2) and exposure duration of 5 min) was investigated to overcome the barrier properties of cornea, which is a typical route for topical administration of ophthalmic drugs. Permeability of ophthalmic drugs, tobramycin and dexamethasone and sodium fluorescein, a drug-mimicking compound, was studied in ultrasound- and sham-treated rabbit corneas in vitro using a standard diffusion cell setup. Light microscopy observations were used to determine ultrasound-induced structural changes in the cornea. For tobramycin, an increase in permeability for ultrasound- and sham-treated corneas was not statistically significant. Increase of 46%-126% and 32%-109% in corneal permeability was observed for sodium fluorescein and dexamethasone, respectively, with statistical significance (p < 0.05) achieved at all treatment parameter combinations (compared with sham treatments) except for 1-MHz ultrasound applications for dexamethasone experiments. This permeability increase was highest at 400 kHz and appeared to be higher at higher intensities applied. Histologic analysis showed structural changes that were limited to epithelial layers of cornea. In summary, ultrasound application provided enhancement of drug delivery, increasing the permeability of the cornea for the anti-inflammatory ocular drug dexamethasone. Future investigations are needed to determine the effectiveness and safety of this application in in vivo long-term survival studies. Copyright © 2013 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

[Applicability of 3/4D transperineal ultrasound for the diagnosis of anal sphincter injury during the immediate pospartum].

PubMed

García-Mejido, José Antonio; Gutiérrez Palomino, Laura; Fernández Palacín, Ana; Sainz-Bueno, José Antonio

The most common cause of anal sphincter injuries in women is vaginal birth. Endo-anal ultrasound is currently used for the diagnosis of anal sphincter defect. However, due to the inconvenience caused, it is not an applicable technique during the immediate post-partum. The aim of this study was to determine whether transperineal ultrasound in 3/4D is a useful diagnostic method for the assessment of anal sphincter during the immediate post-partum. A prospective study was conducted on the vaginal deliveries performed between September 2012 and June 2013 in the Valme University Hospital (Seville). Obstetric and foetal parameters that could influence the onset of perineal tears were studied. The patients underwent a transperineal 3/4D ultrasound and a multislice study (48hours after birth). The study included 146 puerperal women. The sphincter complex was assessed in all of them during the immediate post-partum. External anal injuries were observed in 10.3% of the cases. In 8.2% of cases, the primary suture of the external anal sphincter was detected during ultrasound examination, and 2.1% of asymptomatic lesions were diagnosed only with post-partum ultrasound. None of the patients reported discomfort or pain. The 3-dimensional transperineal ultrasound is helpful in determining the primary repair of the anal sphincter during the immediate post-partum, with no discomfort for patients, as well as for establishing those early sphincter injuries that go unnoticed during vaginal delivery. Copyright © 2015 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.

Basic study on apoptosis induction into cancer cells U-937 and EL-4 by ultrasound exposure.

PubMed

Takeuchi, Shinichi; Udagawa, Yoshiko; Oku, Yumiko; Fujii, Takuma; Nishimura, Hiroyuki; Kawashima, Norimichi

2006-12-22

Recently, the low invasive cancer treatments with small aftereffects have been considered. We are studying on the suppression methods of cancer cell proliferation with ultrasound. Cancer cells of mouse T lymphoma (EL-4) have been used in our study. The human histitocytic lymphoma cells (U-937) was used in this time. The cancer cells were cultured in a culture medium of RPMI1640. The standing wave acoustic field was formed in a water tank of our ultrasound exposure system by a vibrating plate driven with a Langevine type transducer. The U-937 and EL-4 were exposed to ultrasound in the acoustic field with spatial average acoustic intensity of 350 mW/cm(2) at 150 kHz. The viable rate of EL-4 decreased with the lapse of culture time after ultrasound exposure. U-937 did not show the remarkable decrease tendency. The proliferation of U-937 which exposed to ultrasound with 700 mW/cm(2) was suppressed. It can be thought that apoptosis was induced in the cancer cells in this condition. We observed the morphological change on the U-937 exposed to ultrasound with this condition. The morphological changes by apoptosis like the shrink of cells, formation of apoptotic bodies etc. can be observed with an optical microscope and a phase contrast microscope.

Effect of anisotropy on stress-induced electrical potentials in bovine bone using ultrasound irradiation

NASA Astrophysics Data System (ADS)

Matsukawa, S.; Makino, T.; Mori, S.; Koyama, D.; Takayanagi, S.; Mizuno, K.; Yanagitani, T.; Matsukawa, M.

2017-04-01

The bone fracture healing mechanism of the low-intensity pulsed ultrasound technique is not yet clearly understood. In our previous study, the electrical potentials induced in bone were successfully measured by focusing on piezoelectricity in the MHz range. Bone is composed of collagen and hydroxyapatite and has strong anisotropy. The purpose of this study is to investigate the effects of bone anisotropy on the electrical potentials induced by ultrasound irradiation. For this study, ultrasound bone transducers were fabricated using cortical bovine bone plates as piezoelectric devices. An ultrasound of 7.4 kPapeak-peak (i.e., the peak-to-peak pressure value) was used to irradiate the side surface of each bone plate. Electrical potentials induced in the bone plate were then measured by varying the wave propagation direction in the plate. The peak-to-peak values of these ultrasonically induced electrical potentials were found to vary with changes in the ultrasound propagation direction in the bone sample. The potential was maximized at an inclination of approximately 45° to the bone axis but was minimized around the three orthogonal directions. These maxima and minima ranged from 28 to 33 μVpeak-peak and from 5 to 12 μVpeak-peak, respectively. Additionally, our ultrasound results indicated a change in polarity due to bone anisotropy in the MHz range.

Comparison of Metallic Foreign-Body Removal between Dynamic Ultrasound and Static Radiography in a Pigs' Feet Model

PubMed Central

Manson, William C; Ryan, James G; Ladner, Heidi; Gupta, Sanjey

2011-01-01

Introduction We compared the immediate cosmetic outcome of metallic foreign-body removal by emergency medicine (EM) residents with ultrasound guidance and conventional radiography. Methods This single-blinded, randomized, crossover study evaluated the ability of EM residents to remove metallic pins embedded in pigs' feet. Before the experiment, we embedded 1.5-cm metallic pins into numbered pigs' feet. We randomly assigned 14 EM residents to use either ultrasound or radiography to help remove the foreign body. Residents had minimal ultrasound experience. After a brief lecture, we provided residents with a scalpel, laceration kit, a bedside portable ultrasound machine, nipple markers, paper clips, a dedicated radiograph technician, and radiograph machine 20 feet away. After removal, 3 board-certified emergency physicians, who were blinded to the study group, evaluated the soft-tissue model by using a standardized form. They recorded incision length and cosmetic appearance on the Visual Analog Scale. Results In total, 28 foreign bodies were removed. No significant difference in the time of removal (P = 0.12), cosmetic appearance (P = 0.96), or incision length (P = 0.76) was found. Conclusion This study showed no difference between bedside ultrasound and radiography in assisting EM residents with metallic foreign-body removal from soft tissue. No significant difference was found in removal time or cosmetic outcome when comparing ultrasound with radiography. PMID:22224139

[Detection of small for gestational age fetuses during third trimester ultrasound. A monocentric observational study].

PubMed

Peyronnet, V; Kayem, G; Mandelbrot, L; Sibiude, J

2016-09-01

Fetus small for gestational age (SGA) screening rate is evaluated around 21,7 % in France. Recommendations were developed to improve the efficiency of ultrasound conducted in the third trimester (T3), because neonatal consequences can be significant. This study aims to evaluate screening of SGA during T3 ultrasound and to describe causes for failure and differences with the recommendations of CNGOF. All children born between 2011 and 2012 with a birth weight below the 3rd percentile were included in this observational, retrospective, monocentric study. We noted that the diagnosis of SGA was placed on file. Then, as recommended by the CNGOF, we calculated estimated fetal weight (EFW) with Hadlock 3 and Hadlock 4, and the corresponding percentiles, using the biometrics from the ultrasound report. We thus could evaluate a new screening rate with SGA fetus identified through this technique. A total of 142 patients were included. By calculating correctly all EFW and checking abdominal circumference percentiles, the screening rate of SGA fetuses with T3 ultrasound increased from 40 % to 50 % and the overall screening rate (clinical and ultrasound) from 54 % to 66 %. By following the recommendations we found a real improvement in fetal SGA screening rates to T3 ultrasound with a potential benefit for their care. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Endoscopic Ultrasound Elastography: Current Clinical Use in Pancreas.

PubMed

Mondal, Utpal; Henkes, Nichole; Patel, Sandeep; Rosenkranz, Laura

2016-08-01

Elastography is a newer technique for the assessment of tissue elasticity using ultrasound. Cancerous tissue is known to be stiffer (hence, less elastic) than corresponding healthy tissue, and as a result, could be identified in an elasticity-based imaging. Ultrasound elastography has been used in the breast, thyroid, and cervix to differentiate malignant from benign neoplasms and to guide or avoid unnecessary biopsies. In the liver, elastography has enabled a noninvasive and reliable estimate of fibrosis. Endoscopic ultrasound has become a robust diagnostic and therapeutic tool for the management of pancreatic diseases. The addition of elastography to endoscopic ultrasound enabled further characterization of pancreas lesions, and several European and Asian studies have reported encouraging results. The current clinical role of endoscopic ultrasound elastography in the management of pancreas disorders and related literature are reviewed.

Investigation of the effect of power ultrasound on the nucleation of water during freezing of agar gel samples in tubing vials.

PubMed

Kiani, Hossein; Sun, Da-Wen; Delgado, Adriana; Zhang, Zhihang

2012-05-01

Nucleation, as an important stage of freezing process, can be induced by the irradiation of power ultrasound. In this study, the effect of irradiation temperature (-2 °C, -3 °C, -4 °C and -5 °C), irradiation duration (0s, 1s, 3s, 5s, 10s or 15s) and ultrasound intensity (0.07 W cm(-2), 0.14 W cm(-2), 0.25 W cm(-2), 0.35 W cm(-2) and 0.42 W cm(-2)) on the dynamic nucleation of ice in agar gel samples was studied. The samples were frozen in an ethylene glycol-water mixture (-20 °C) in an ultrasonic bath system after putting them into tubing vials. Results indicated that ultrasound irradiation is able to initiate nucleation at different supercooled temperatures (from -5 °C to -2 °C) in agar gel if optimum intensity and duration of ultrasound were chosen. Evaluation of the effect of 0.25 W cm(-2) ultrasound intensity and different durations of ultrasound application on agar gels showed that 1s was not long enough to induce nucleation, 3s induced the nucleation repeatedly but longer irradiation durations resulted in the generation of heat and therefore nucleation was postponed. Investigation of the effect of ultrasound intensity revealed that higher intensities of ultrasound were effective when a shorter period of irradiation was used, while lower intensities only resulted in nucleation when a longer irradiation time was applied. In addition to this, higher intensities were not effective at longer irradiation times due to the heat generated in the samples by the heating effect of ultrasound. In conclusion, the use of ultrasound as a means to control the crystallization process offers promising application in freezing of solid foods, however, optimum conditions should be selected. Copyright © 2011 Elsevier B.V. All rights reserved.

Ultrasound imaging to tailor the treatment of acute shoulder pain: a randomised controlled trial in general practice.

PubMed

Ottenheijm, Ramon P G; Cals, Jochen W L; Winkens, Bjorn; Weijers, René E; de Bie, Rob A; Dinant, Geert-Jan

2016-11-21

To determine the clinical effectiveness of ultrasound tailored treatment in patients with acute subacromial disorders. Pragmatic randomised controlled trial. Dutch general practice. Patients aged 18-65 years with acute (duration <3 months) unilateral shoulder pain and no previous treatment, in whom the general practitioner suspected a subacromial disorder was enrolled. All patients underwent ultrasound imaging of the affected shoulder. Patients who were still symptomatic after a qualification period of 2 weeks with standard treatment were randomised to treatment tailored to ultrasound diagnosis (disclosure of the ultrasound diagnosis) or usual care (non-disclosure of the ultrasound diagnosis). Patient-perceived recovery using the Global Perceived Effect questionnaire at 1 year. 129 patients were included. 18 patients recovered during the 2-week qualification period, resulting in 111 randomised patients; 56 were allocated to ultrasound tailored treatment and 55 to usual care. After 1 year, no statistically significant differences in recovery were found between the ultrasound tailored treatment group (72.5% (37/51)) and the usual care group (60% (30/50), OR 2.24 (95% CI 0.72 to 6.89; p=0.16)). Also, healthcare use was similar. This study has shown no clinically significant difference in the primary outcome measure between the ultrasound tailored treatment and usual care groups. Furthermore, there was no overall difference in healthcare resources used between groups. Although no formal cost data are included, one can only assume that the ultrasound examinations are additional costs for the intervention group, which cannot be justified in routine practice based on this trial. Based on this study, no change in current pragmatic guidelines to incorporate early ultrasound imaging can be recommended. NTR2403; Results. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Development of the Fetal Vermis: New Biometry Reference Data and Comparison of 3 Diagnostic Modalities-3D Ultrasound, 2D Ultrasound, and MR Imaging.

PubMed

Katorza, E; Bertucci, E; Perlman, S; Taschini, S; Ber, R; Gilboa, Y; Mazza, V; Achiron, R

2016-07-01

Normal biometry of the fetal posterior fossa rules out most major anomalies of the cerebellum and vermis. Our aim was to provide new reference data of the fetal vermis in 4 biometric parameters by using 3 imaging modalities, 2D ultrasound, 3D ultrasound, and MR imaging, and to assess the relation among these modalities. A retrospective study was conducted between June 2011 and June 2013. Three different imaging modalities were used to measure vermis biometry: 2D ultrasound, 3D ultrasound, and MR imaging. The vermian parameters evaluated were the maximum superoinferior diameter, maximum anteroposterior diameter, the perimeter, and the surface area. Statistical analysis was performed to calculate centiles for gestational age and to assess the agreement among the 3 imaging modalities. The number of fetuses in the study group was 193, 172, and 151 for 2D ultrasound, 3D ultrasound, and MR imaging, respectively. The mean and median gestational ages were 29.1 weeks, 29.5 weeks (range, 21-35 weeks); 28.2 weeks, 29.05 weeks (range, 21-35 weeks); and 32.1 weeks, 32.6 weeks (range, 27-35 weeks) for 2D ultrasound, 3D ultrasound, and MR imaging, respectively. In all 3 modalities, the biometric measurements of the vermis have shown a linear growth with gestational age. For all 4 biometric parameters, the lowest results were those measured by MR imaging, while the highest results were measured by 3D ultrasound. The inter- and intraobserver agreement was excellent for all measures and all imaging modalities. Limits of agreement were considered acceptable for clinical purposes for all parameters, with excellent or substantial agreement defined by the intraclass correlation coefficient. Imaging technique-specific reference data should be used for the assessment of the fetal vermis in pregnancy. © 2016 by American Journal of Neuroradiology.

Accuracy of integrated total pelvic floor ultrasound compared to defaecatory MRI in females with pelvic floor defaecatory dysfunction

PubMed Central

Pilkington, Sophie A; Grierson, Catherine; Rutherford, Elizabeth; Schizas, Alexis M P; Nugent, Karen P; Williams, Andrew B

2016-01-01

Objective: Defaecatory MRI allows multicompartmental assessment of defaecatory dysfunction but is often inaccessible. Integrated total pelvic floor ultrasound (transperineal, transvaginal, endoanal) may provide a cheap, portable alternative. The accuracy of total pelvic floor ultrasound for anatomical abnormalities when compared with defaecatory MRI was assessed. Methods: The dynamic images from 68 females who had undergone integrated total pelvic floor ultrasound and defaecatory MRI between 2009 and 2015 were blindly reviewed. The following were recorded: rectocoele, enterocoele, intussusception and cystocoele. Results: There were 26 rectocoeles on MRI (49 rectocoeles on ultrasound), 24 rectocoeles with intussusception on MRI (19 rectocoeles on ultrasound), 23 enterocoeles on MRI (24 enterocoeles on ultrasound) and 49 cystocoeles on MRI (35 cystocoeles on ultrasound). Sensitivity and specificity of total pelvic floor ultrasound were 81% and 33% for rectocoele, 60% and 91% for intussusception, 65% and 80% for enterocoele and 65% and 84% for cystocoele when compared with defaecatory MRI. This gave a negative-predictive value and positive-predictive value of 74% and 43% for rectocoele, 80% and 79% for intussusception, 82% and 63% for enterocoele and 48% and 91% for cystocoele. Conclusion: Integrated total pelvic floor ultrasound may serve as a screening tool for pelvic floor defaecatory dysfunction; when normal, defaecatory MRI can be avoided, as rectocoele, intussusception and enterocoele are unlikely to be present. Advances in knowledge: This is the first study to compare integrated total pelvic floor ultrasound with defaecatory MRI. The results support the use of integrated total pelvic floor ultrasound as a screening tool for defaecatory dysfunction. PMID:27730818

Clinical responses to focused ultrasound applied to women with vulval intraepithelial neoplasia.

PubMed

Jia, Ying; Wu, Jin; Xu, Man; Tang, Liangdan; Li, Chengzhi; Luo, Ming; Lou, Meng

2014-11-01

Focused ultrasound waves penetrate superficial tissues and are aimed toward the target tissues at specific depths to exert their biological effects. Focused ultrasound has been applied for a number of clinical indications, including vulval dystrophies and low-grade vulval disease. This study aimed to assess the efficacy and safety of focused ultrasound treatment of high-grade vulval intraepithelial neoplasia (VIN). Eighteen women with high-grade VIN were recruited and treated with focused ultrasound. During each posttreatment follow-up, the safety of, side effects of, and clinical responses to focused ultrasound were evaluated by a standardized protocol, including symptoms, clinical appearance, and histologic findings. All patients completed the designed follow-ups. In most cases, superficial mild to moderate swelling and blisters were seen in the focused ultrasound-treated skin but not in adjacent normal skin. Of the 18 patients, 16 showed complete histologic regression and resolution of symptoms 6 months after treatment. Of the other 2 patients, 1 showed complete regression after a second focused ultrasound treatment. The other patient did not respond to the focused ultrasound treatment and underwent a partial vulvectomy 6 months after treatment. None of the patients developed invasive carcinoma of the vulva during the follow-up period. One patient had local pruritus that was not alleviated by anti-inflammatory medication and local care. The complete responses observed in women with high-grade VIN treated by focused ultrasound, together with the preservation of adjacent normal tissue, suggest that focused ultrasound may be considered for treatment of high-grade VIN. © 2014 by the American Institute of Ultrasound in Medicine.

Ultrasound imaging of the anal sphincter complex: a review

PubMed Central

Abdool, Z; Sultan, A H; Thakar, R

2012-01-01

Endoanal ultrasound is now regarded as the gold standard for evaluating anal sphincter pathology in the investigation of anal incontinence. The advent of three-dimensional ultrasound has further improved our understanding of the two-dimensional technique. Endoanal ultrasound requires specialised equipment and its relative invasiveness has prompted clinicians to explore alternative imaging techniques. Transvaginal and transperineal ultrasound have been recently evaluated as alternative imaging modalities. However, the need for technique standardisation, validation and reporting is of paramount importance. We conducted a MEDLINE search (1950 to February 2010) and critically reviewed studies using the three imaging techniques in evaluating anal sphincter integrity. PMID:22374273

Three-dimensional assessment of scoliosis based on ultrasound data

NASA Astrophysics Data System (ADS)

Zhang, Junhua; Li, Hongjian; Yu, Bo

2015-12-01

In this study, an approach was proposed to assess the 3D scoliotic deformity based on ultrasound data. The 3D spine model was reconstructed by using a freehand 3D ultrasound imaging system. The geometric torsion was then calculated from the reconstructed spine model. A thoracic spine phantom set at a given pose was used in the experiment. The geometric torsion of the spine phantom calculated from the freehand ultrasound imaging system was 0.041 mm-1 which was close to that calculated from the biplanar radiographs (0.025 mm-1). Therefore, ultrasound is a promising technique for the 3D assessment of scoliosis.

Investigation of optimal method for inducing harmonic motion in tissue using a linear ultrasound phased array--a simulation study.

PubMed

Heikkilä, Janne; Hynynen, Kullervo

2006-04-01

Many noninvasive ultrasound techniques have been developed to explore mechanical properties of soft tissues. One of these methods, Localized Harmonic Motion Imaging (LHMI), has been proposed to be used for ultrasound surgery monitoring. In LHMI, dynamic ultrasound radiation-force stimulation induces displacements in a target that can be measured using pulse-echo imaging and used to estimate the elastic properties of the target. In this initial, simulation study, the use of a one-dimensional phased array is explored for the induction of the tissue motion. The study compares three different dual-frequency and amplitude-modulated single-frequency methods for the inducing tissue motion. Simulations were computed in a homogeneous soft-tissue volume. The Rayleigh integral was used in the simulations of the ultrasound fields and the tissue displacements were computed using a finite-element method (FEM). The simulations showed that amplitude-modulated sonication using a single frequency produced the largest vibration amplitude of the target tissue. These simulations demonstrate that the properties of the tissue motion are highly dependent on the sonication method and that it is important to consider the full three-dimensional distribution of the ultrasound field for controlling the induction of tissue motion.

Plantar fasciitis (fasciosis) treatment outcome study: plantar fascia thickness measured by ultrasound and correlated with patient self-reported improvement.

PubMed

Fabrikant, Jerry M; Park, Tae Soon

2011-06-01

Ultrasound, well recognized as an effective diagnostic tool, reveals a thickening of the plantar fascia in patients with plantar fasciitis/fasciosis disease. The authors hypothesized that ultrasound would also reveal a decrease in the plantar fascia thickness for patients undergoing treatment for the disease, a hypothesis that, heretofore, had been only tested on a limited number of subjects. They conducted a more statistically significant study that found that clinical treatment with injection and biomechanical correction does indeed diminish plantar fascia thickness as shown on ultrasound. The study also revealed that patients experience the most heightened plantar fascia tenderness toward the end of the day, and improvement in their symptomatic complaints were associated with a reduction in plantar fascia thickness. As a result, the authors conclude that office-based ultrasound can help diagnose and confirm plantar fasciitis/fasciosis through the measurement of the plantar fascia thickness. Because of the advantages of ultrasound--that it is non-invasive with greater patient acceptance, cost effective and radiation-free--the imaging tool should be considered and implemented early in the diagnosis and treatment of plantar fasciitis/fasciosis. Copyright © 2011 Elsevier Ltd. All rights reserved.

Optimization of ultrasound-assisted extraction of pectinase enzyme from guava (Psidium guajava) peel: Enzyme recovery, specific activity, temperature, and storage stability.

PubMed

Amid, Mehrnoush; Murshid, Fara Syazana; Manap, Mohd Yazid; Islam Sarker, Zaidul

2016-01-01

This study aimed to investigate the effects of the ultrasound-assisted extraction conditions on the yield, specific activity, temperature, and storage stability of the pectinase enzyme from guava peel. The ultrasound variables studied were sonication time (10-30 min), ultrasound temperature (30-50 °C), pH (2.0-8.0), and solvent-to-sample ratio (2:1 mL/g to 6:1 mL/g). The main goal was to optimize the ultrasound-assisted extraction conditions to maximize the recovery of pectinase from guava peel with the most desirable enzyme-specific activity and stability. Under the optimum conditions, a high yield (96.2%), good specific activity (18.2 U/mg), temperature stability (88.3%), and storage stability (90.3%) of the extracted enzyme were achieved. The optimal conditions were 20 min sonication time, 40 °C temperature, at pH 5.0, using a 4:1 mL/g solvent-to-sample ratio. The study demonstrated that optimization of ultrasound-assisted process conditions for the enzyme extraction could improve the enzymatic characteristics and yield of the enzyme.

Validity of gestational age estimates by last menstrual period and neonatal examination compared to ultrasound in Vietnam.

PubMed

Deputy, Nicholas P; Nguyen, Phuong H; Pham, Hoa; Nguyen, Son; Neufeld, Lynnette; Martorell, Reynaldo; Ramakrishnan, Usha

2017-01-11

Accurate estimation of gestational age is important for both clinical and public health purposes. Estimates of gestational age using fetal ultrasound measurements are considered most accurate but are frequently unavailable in low- and middle-income countries. The objective of this study was to assess the validity of last menstrual period and Farr neonatal examination estimates of gestational age, compared to ultrasound estimates, in a large cohort of women in Vietnam. Data for this analysis come from a randomized, placebo-controlled micronutrient supplementation trial in Vietnam. We analyzed 912 women with ultrasound and prospectively-collected last menstrual period estimates of gestational age and 685 women with ultrasound and Farr estimates of gestational age. We used the Wilcoxon signed rank sum test to assess differences in gestational age estimated by last menstrual period or Farr examination compared to ultrasound and computed the intraclass correlation coefficient (ICC) and concordance correlation coefficient (CCC) to quantify agreement between methods. We computed the Kappa coefficient (κ) to quantify agreement in preterm, term and post-term classification. The median gestational age estimated by ultrasound was 273.9 days. Gestational age was slightly overestimated by last menstrual period (median 276.0 days, P < 0.001) and more greatly overestimated by Farr examination (median 286.7 days, P < 0.001). Gestational age estimates by last menstrual period and ultrasound were moderately correlated (ICC = 0.78) and concordant (CCC = 0.63), whereas gestational age estimates by Farr examination and ultrasound were weakly correlated (ICC = 0.26) and concordant (CCC = 0.05). Last menstrual period and ultrasound estimates of gestational age were within ± 14 days for 88.4% of women; Farr and ultrasound estimates were within ± 14 days for 55.8% of women. Last menstrual period and ultrasound estimates of gestational age had higher agreement in term classification (κ = 0.41) than Farr and ultrasound (κ = 0.05). In this study of women in Vietnam, we found last menstrual period provided a more accurate estimate of gestational age than the Farr examination when compared to ultrasound. These findings provide useful information about the utility and accuracy of different methods to estimate gestational age and suggest last menstrual period may be preferred over Farr examination in settings where ultrasound is unavailable. The trial was registered at ClinicalTrials.Gov as NCT01665378 on August 13, 2012.

Evaluating the extent of cell death in 3D high frequency ultrasound by registration with whole-mount tumor histopathology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vlad, Roxana M.; Kolios, Michael C.; Moseley, Joanne L.

Purpose: High frequency ultrasound imaging, 10-30 MHz, has the capability to assess tumor response to radiotherapy in mouse tumors as early as 24 h after treatment administration. The advantage of this technique is that the image contrast is generated by changes in the physical properties of dying cells. Therefore, a subject can be imaged before and multiple times during the treatment without the requirement of injecting specialized contrast agents. This study is motivated by a need to provide metrics of comparison between the volume and localization of cell death, assessed from histology, with the volume and localization of cell deathmore » surrogate, assessed as regions with increased echogeneity from ultrasound images. Methods: The mice were exposed to radiation doses of 2, 4, and 8 Gy. Ultrasound images were collected from each tumor before and 24 h after exposure to radiation using a broadband 25 MHz center frequency transducer. After radiotherapy, tumors exhibited hyperechoic regions in ultrasound images that corresponded to areas of cell death in histology. The ultrasound and histological images were rigidly registered. The tumors and regions of cell death were manually outlined on histological images. Similarly, the tumors and hyperechoic regions were outlined on the ultrasound images. Each set of contours was converted to a volumetric mesh in order to compare the volumes and the localization of cell death in histological and ultrasound images. Results: A shrinkage factor of 17{+-}2% was calculated from the difference in the tumor volumes evaluated from histological and ultrasound images. This was used to correct the tumor and cell death volumes assessed from histology. After this correction, the average absolute difference between the volume of cell death assessed from ultrasound and histological images was 11{+-}14% and the volume overlap was 70{+-}12%. Conclusions: The method provided metrics of comparison between the volume of cell death assessed from histology and that assessed from ultrasound images. It was applied here to evaluate the capability of ultrasound imaging to assess early tumor response to radiotherapy in mouse tumors. Similarly, it can be applied in the future to evaluate the capability of ultrasound imaging to assess early tumor response to other modalities of cancer treatment. The study contributes to an understanding of the capabilities and limitation of ultrasound imaging at noninvasively detecting cell death. This provides a foundation for future developments regarding the use of ultrasound in preclinical and clinical applications to adapt treatments based on tumor response to cancer therapy.« less

Discriminant validity study of Achilles enthesis ultrasound.

PubMed

Expósito Molinero, María Rosa; de Miguel Mendieta, Eugenio

2016-01-01

We want to know if the ultrasound examination of the Achilles tendon in spondyloarthritis is different compared to other rheumatic diseases. We studied 97 patients divided into five groups: rheumatoid arthritis, spondyloarthritis, gout, chondrocalcinosis and osteoarthritis, exploring six elementary lesions in 194 Achilles entheses examined. In our study the total index ultrasonographic Achilles is higher in spondyloarthritis with significant differences. The worst elementary spondyloarthritis lesions for discriminations against other pathologies were calcification. This study aims to demonstrate the discriminant validity of Achilles enthesitis observed by ultrasound in spondyloarthritis compared with other rheumatic diseases that may also have ultrasound abnormalities such enthesis level. Copyright © 2015 Elsevier España, S.L.U. and Sociedad Española de Reumatología y Colegio Mexicano de Reumatología. All rights reserved.

[Ultrasound-guided peripheral catheterization].

PubMed

Salleras-Duran, Laia; Fuentes-Pumarola, Concepció

2016-01-01

Peripheral catheterization is a technique that can be difficult in some patients. Some studies have recently described the use of ultrasound to guide the venous catheterization. To describe the success rate, time required, complications of ultrasound-guided peripheral venous catheterization. and patients and professionals satisfaction The search was performed in databases (Medline-PubMed, Cochrane Library, CINAHL and Cuiden Plus) for studies published about ultrasound-guided peripheral venous catheterization performed on patients that provided results on the success of the technique, complications, time used, patient satisfaction and the type of professional who performed the technique. A total of 21 studies were included. Most of them get a higher success rate 80% in the catheterization ecoguide and time it is not higher than the traditional technique. The Technical complications analyzed were arterial puncture rates and lower nerve 10%. In all studies measuring and comparing patient satisfaction in the art ecoguide is greater. Various professional groups perform the technique. The use of ultrasound for peripheral pipes has a high success rate, complications are rare and the time used is similar to that of the traditional technique. The technique of inserting catheters through ultrasound may be learned by any professional group performing venipuncture. Finally, it gets underscores the high patient satisfaction with the use of this technique. Copyright © 2015 Elsevier España, S.L.U. All rights reserved.

Point-of-care lung ultrasound in children with community acquired pneumonia.

PubMed

Yilmaz, Hayri Levent; Özkaya, Ahmet Kağan; Sarı Gökay, Sinem; Tolu Kendir, Özlem; Şenol, Hande

2017-07-01

To present lung ultrasound findings in children assessed with suspected pneumonia in the emergency department and to show the benefit of lung ultrasound in diagnosing pneumonia in comparison with chest X-rays. This observational prospective study was performed in the pediatric emergency department of a single center. Point of care lung ultrasound was performed on each child by an independent sonographer blinded to the patient's clinical and chest X-ray findings. Community acquired pneumonia was established as a final diagnosis by two clinicians based on the recommendations in the British Thoracic Society guideline. One hundred sixty children with a mean age of 3.3±4years and a median age of 1.4years (min-max 0.08-17.5years) were investigated. Final diagnosis in 149 children was community-acquired pneumonia. Lung ultrasound findings were compatible with pneumonia in 142 (95.3%) of these 149 children, while chest X-ray findings were compatible with pneumonia in 132 (88.5%). Pneumonia was confirmed with lung ultrasound in 15 of the 17 patients (11.4%) not evaluated as compatible with pneumonia at chest X-ray. While pneumonia could not be confirmed with lung ultrasound in seven (4.6%) patients, findings compatible with pneumonia were not determined at chest X-ray in two of these patients. When lung ultrasound and chest X-ray were compared as diagnostic tools, a significant difference was observed between them (p=0.041). This study shows that lung ultrasound is at least as useful as chest X-ray in diagnosing children with community-acquired pneumonia. Copyright © 2017 Elsevier Inc. All rights reserved.

Ultrasound of the small joints of the hands and feet: current status

PubMed Central

2007-01-01

The aim of this article was to review the current status of ultrasound imaging of patients with rheumatological disorders of the hands and feet. Ultrasound machines with high-resolution surface probes are readily available in most radiology departments and can be used to address important clinical questions posed by the rheumatologist and sports and rehabilitation physician. There is increasing evidence that ultrasound detects synovitis that is silent to clinical examination. Detection and classification of synovitis and the early detection of bone erosions are important in clinical decision making. Ultrasound has many advantages over other imaging techniques with which it is compared, particularly magnetic resonance. The ability to carry out a rapid assessment of many widely spaced joints, coupled with clinical correlation, the ability to move and stress musculoskeletal structures and the use of ultrasound to guide therapy accurately are principal amongst these. The use of colour flow Doppler studies provides a measure of neovascularisation within the synovial lining of joints and tendons, and within tendons themselves, that is not available with other imaging techniques. Disadvantages compared to MRI include small field of view, poor image presentation, and difficulty in demonstrating cartilage and deep joints in their entirety. Contrast-enhanced magnetic resonance provides a better measure of capillary permeability and extracellular fluid than does ultrasound. The ability to image simultaneously multiple small joints in the hands and feet and their enhancement characteristics cannot be matched with ultrasound, though future developments in 3-D ultrasound may narrow this gap. Magnetic resonance provides a more uniform and reproducible image for long-term follow-up studies. PMID:17712556

Effect of pulsed ultrasound in combination with gentamicin on bacterial viability in biofilms on bone cements in vivo.

PubMed

Ensing, G T; Roeder, B L; Nelson, J L; van Horn, J R; van der Mei, H C; Busscher, H J; Pitt, W G

2005-01-01

The aim of this study is to investigate whether pulsed ultrasound (US) in combination with gentamicin yields a decreased viability of bacteria in biofilms on bone cements in vivo. Bacterial survival on bone cement in the presence and absence of ultrasound was compared in a rabbit model. Two bone cement samples with an Escherichia coli ATCC 10798 biofilm were implanted in a total of nine rabbits. In two groups bone cement discs loaded with gentamicin, freshly prepared and aged were used, and in one group unloaded bone cement discs in combination with systemically administered gentamicin. Pulsed ultrasound with a frequency of 28.48 kHz and a maximum acoustic intensity of 500 mW cm(-2) was applied continuously from 24 h till 72 h postsurgery on one of the two implanted discs. After euthanization and removal of the bacteria from the discs, the number of viable bacteria were quantified and skin samples were analysed for histopathological examination. Application of ultrasound, combined with gentamicin, reduced the viability of the biofilms in all three groups varying between 58 and 69% compared with the negative control. Histopathological examinations showed no skin lesions. Ultrasound resulted in a tendency of improved efficacy of gentamicin, either applied locally or systemically. Usage of ultrasound in this model proved to be safe. This study implies that ultrasound could improve the prevention of infection immediately after surgery, especially because the biomaterials, gentamicin and ultrasound used in this model are all in clinical usage, but not yet combined in clinical practice.

Intensive point-of-care ultrasound training with long-term follow-up in a cohort of Rwandan physicians.

PubMed

Henwood, Patricia C; Mackenzie, David C; Rempell, Joshua S; Douglass, Emily; Dukundane, Damas; Liteplo, Andrew S; Leo, Megan M; Murray, Alice F; Vaillancourt, Samuel; Dean, Anthony J; Lewiss, Resa E; Rulisa, Stephen; Krebs, Elizabeth; Raja Rao, A K; Rudakemwa, Emmanuel; Rusanganwa, Vincent; Kyanmanywa, Patrick; Noble, Vicki E

2016-12-01

We delivered a point-of-care ultrasound training programme in a resource-limited setting in Rwanda, and sought to determine participants' knowledge and skill retention. We also measured trainees' assessment of the usefulness of ultrasound in clinical practice. This was a prospective cohort study of 17 Rwandan physicians participating in a point-of-care ultrasound training programme. The follow-up period was 1 year. Participants completed a 10-day ultrasound course, with follow-up training delivered over the subsequent 12 months. Trainee knowledge acquisition and skill retention were assessed via observed structured clinical examinations (OSCEs) administered at six points during the study, and an image-based assessment completed at three points. Trainees reported minimal structured ultrasound education and little confidence using point-of-care ultrasound before the training. Mean scores on the image-based assessment increased from 36.9% (95% CI 32-41.8%) before the initial 10-day training to 74.3% afterwards (95% CI 69.4-79.2; P < 0.001). The mean score on the initial OSCE after the introductory course was 81.7% (95% CI 78-85.4%). The mean OSCE performance at each subsequent evaluation was at least 75%, and the mean OSCE score at the 58-week follow up was 84.9% (95% CI 80.9-88.9%). Physicians providing acute care in a resource-limited setting demonstrated sustained improvement in their ultrasound knowledge and skill 1 year after completing a clinical ultrasound training programme. They also reported improvements in their ability to provide patient care and in job satisfaction. © 2016 John Wiley & Sons Ltd.

Portable bladder ultrasound: an evidence-based analysis.

PubMed

2006-01-01

The aim of this review was to assess the clinical utility of portable bladder ultrasound. TARGET POPULATION AND CONDITION Data from the National Population Health Survey indicate prevalence rates of urinary incontinence are 2.5% in women and 1.4 % in men in the general population. Prevalence of urinary incontinence is higher in women than men and prevalence increases with age. Identified risk factors for urinary incontinence include female gender, increasing age, urinary tract infections (UTI), poor mobility, dementia, smoking, obesity, consuming alcohol and caffeine beverages, physical activity, pregnancy, childbirth, forceps and vacuum-assisted births, episiotomy, abdominal resection for colorectal cancer, and hormone replacement therapy. For the purposes of this review, incontinence populations will be stratified into the following; the elderly, urology patients, postoperative patients, rehabilitation settings, and neurogenic bladder populations. Urinary incontinence is defined as any involuntary leakage of urine. Incontinence can be classified into diagnostic clinical types that are useful in planning evaluation and treatment. The major types of incontinence are stress (physical exertion), urge (overactive bladder), mixed (combined urge and stress urinary incontinence), reflex (neurological impairment of the central nervous system), overflow (leakage due to full bladder), continuous (urinary tract abnormalities), congenital incontinence, and transient incontinence (temporary incontinence). Postvoid residual (PVR) urine volume, which is the amount of urine in the bladder immediately after urination, represents an important component in continence assessment and bladder management to provide quantitative feedback to the patient and continence care team regarding the effectiveness of the voiding technique. Although there is no standardized definition of normal PVR urine volume, measurements greater than 100 mL to 150 mL are considered an indication for urinary retention, requiring intermittent catheterization, whereas a PVR urine volume of 100 mL to 150 mL or less is generally considered an acceptable result of bladder training. Urinary retention has been associated with poor outcomes including UTI, bladder overdistension, and higher hospital mortality rates. The standard method of determining PVR urine volumes is intermittent catheterization, which is associated with increased risk of UTI, urethral trauma and discomfort. Portable bladder ultrasound products are transportable ultrasound devices that use automated technology to register bladder volume digitally, including PVR volume, and provide three-dimensional images of the bladder. The main clinical use of portable bladder ultrasound is as a diagnostic aid. Health care professionals (primarily nurses) administer the device to measure PVR volume and prevent unnecessary catheterization. An adjunctive use of the bladder ultrasound device is to visualize the placement and removal of catheters. Also, portable bladder ultrasound products may improve the diagnosis and differentiation of urological problems and their management and treatment, including the establishment of voiding schedules, study of bladder biofeedback, fewer UTIs, and monitoring of potential urinary incontinence after surgery or trauma. To determine the effectiveness and clinical utility of portable bladder ultrasound as reported in the published literature, the Medical Advisory Secretariat used its standard search strategy to retrieve international health technology assessments and English-language journal articles from selected databases. Nonsystematic reviews, nonhuman studies, case reports, letters, editorials, and comments were excluded. Of the 4 included studies that examined the clinical utility of portable bladder ultrasound in the elderly population, all found the device to be acceptable. One study reported that the device underestimated catheterized bladder volume In patients with urology problems, 2 of the 3 studies concerning portable bladder ultrasound found the device acceptable to use. However, one study did not find the device as accurate for small PVR volume as for catheterization and another found that the device overestimated catheterized bladder volume. In the remaining study, the authors reported that when the device's hand-held ultrasound transducers (scanheads) were aimed improperly, bladders were missed, or lateral borders of bladders were missed resulting in partial bladder volume measurements and underestimation of PVR measurements. They concluded that caution should be used in interpreting PVR volume measured by portable bladder ultrasound machines and that catheterization may be the preferred assessment modality if an accurate PVR measurement is necessary. All 3 studies with post-operative populations found portable bladder ultrasound use to be reasonably acceptable. Two studies reported that the device overestimated catheter-derived bladder volumes, one by 7% and the other by 21 mL. The third study reported the opposite, that the device underestimated catheter bladder volume by 39 mL but that the results remained acceptable In rehabilitation settings, 2 studies found portable bladder ultrasound to underestimate catheter-derived bladder volumes; yet, both authors concluded that the mean errors were within acceptable limits. In patients with neurogenic bladder problems, 2 studies found portable bladder ultrasound to be an acceptable alternative to catheterization despite the fact that it was not as accurate as catheterization for obtaining bladder volumes. Lastly, examinations concerning avoidance of negative health outcomes showed that, after use of the portable bladder ultrasound, unnecessary catheterizations and UTIs were decreased. Unnecessary catheterizations avoided ranged from 16% to 47% in the selected articles. Reductions in UTI ranged from 38% to 72%. In sum, all but one study advocated the use of portable bladder ultrasound as an alternative to catheterization. An economic analysis estimating the budget-impact of BladderScan in complex continuing care facilities was completed. The analysis results indicated a $192,499 (Cdn) cost-savings per year per facility and a cost-savings of $2,887,485 (Cdn) for all 15 CCC facilities. No economic analysis was completed for long-term care and acute care facilities due to lack of data. Rapid diffusion of portable bladder ultrasound technology is expected. Recently, the IC5 project on improving continence care in Ontario's complex continuing care centres piloted portable bladder ultrasound at 12 sites. Preliminary results were promising. Many physicians and health care facilities already have portable bladder ultrasound devices. However, portable bladder ultrasound devices for PVR measurement are not in use at most health care facilities in Ontario and Canada. The Verathon Corporation (Bothell, Wisconsin, United States), which patents BladderScan, is the sole licensed manufacturer of the portable bladder ultrasound in Canada. Field monopoly may influence the rising costs of portable bladder ultrasound, particularly when faced with rapid expansion of the technology. Several thousand residents of Ontario would benefit from portable bladder ultrasound. The number of residents of Ontario that would benefit from the technology is difficult to quantify, because the incidence and prevalence of incontinence are grossly under-reported. However, long-term care and complex continuing care institutions would benefit greatly from portable bladder ultrasound, as would numerous rehabilitation units, postsurgical care units, and urology clinics. The cost of the portable bladder ultrasound devices ranges from $17,698.90 to $19,565.95 (Cdn) (total purchase price per unit as quoted by the manufacturer). Additional training packages, batteries and battery chargers, software, gel pads, and yearly warranties are additional costs. Studies indicate that portable bladder ultrasound is a cost-effective technology, because it avoids costs associated with catheterization equipment, saves nursing time, and reduces catheter-related complications and UTIs. The use of portable bladder ultrasound device will affect the patient directly in terms of health outcomes. Its use avoids the trauma related to the urinary tract that catheterization inflicts, and does not result in UTIs. In addition, patients prefer it, because it preserves dignity and reduces discomfort.

Portable Bladder Ultrasound

PubMed Central

2006-01-01

Executive Summary Objective The aim of this review was to assess the clinical utility of portable bladder ultrasound. Clinical Need: Target Population and Condition Data from the National Population Health Survey indicate prevalence rates of urinary incontinence are 2.5% in women and 1.4 % in men in the general population. Prevalence of urinary incontinence is higher in women than men and prevalence increases with age. Identified risk factors for urinary incontinence include female gender, increasing age, urinary tract infections (UTI), poor mobility, dementia, smoking, obesity, consuming alcohol and caffeine beverages, physical activity, pregnancy, childbirth, forceps and vacuum-assisted births, episiotomy, abdominal resection for colorectal cancer, and hormone replacement therapy. For the purposes of this review, incontinence populations will be stratified into the following; the elderly, urology patients, postoperative patients, rehabilitation settings, and neurogenic bladder populations. Urinary incontinence is defined as any involuntary leakage of urine. Incontinence can be classified into diagnostic clinical types that are useful in planning evaluation and treatment. The major types of incontinence are stress (physical exertion), urge (overactive bladder), mixed (combined urge and stress urinary incontinence), reflex (neurological impairment of the central nervous system), overflow (leakage due to full bladder), continuous (urinary tract abnormalities), congenital incontinence, and transient incontinence (temporary incontinence). Postvoid residual (PVR) urine volume, which is the amount of urine in the bladder immediately after urination, represents an important component in continence assessment and bladder management to provide quantitative feedback to the patient and continence care team regarding the effectiveness of the voiding technique. Although there is no standardized definition of normal PVR urine volume, measurements greater than 100 mL to 150 mL are considered an indication for urinary retention, requiring intermittent catheterization, whereas a PVR urine volume of 100 mL to 150 mL or less is generally considered an acceptable result of bladder training. Urinary retention has been associated with poor outcomes including UTI, bladder overdistension, and higher hospital mortality rates. The standard method of determining PVR urine volumes is intermittent catheterization, which is associated with increased risk of UTI, urethral trauma and discomfort. The Technology Being Reviewed Portable bladder ultrasound products are transportable ultrasound devices that use automated technology to register bladder volume digitally, including PVR volume, and provide three-dimensional images of the bladder. The main clinical use of portable bladder ultrasound is as a diagnostic aid. Health care professionals (primarily nurses) administer the device to measure PVR volume and prevent unnecessary catheterization. An adjunctive use of the bladder ultrasound device is to visualize the placement and removal of catheters. Also, portable bladder ultrasound products may improve the diagnosis and differentiation of urological problems and their management and treatment, including the establishment of voiding schedules, study of bladder biofeedback, fewer UTIs, and monitoring of potential urinary incontinence after surgery or trauma. Review Strategy To determine the effectiveness and clinical utility of portable bladder ultrasound as reported in the published literature, the Medical Advisory Secretariat used its standard search strategy to retrieve international health technology assessments and English-language journal articles from selected databases. Nonsystematic reviews, nonhuman studies, case reports, letters, editorials, and comments were excluded. Summary of Findings Of the 4 included studies that examined the clinical utility of portable bladder ultrasound in the elderly population, all found the device to be acceptable. One study reported that the device underestimated catheterized bladder volume In patients with urology problems, 2 of the 3 studies concerning portable bladder ultrasound found the device acceptable to use. However, one study did not find the device as accurate for small PVR volume as for catheterization and another found that the device overestimated catheterized bladder volume. In the remaining study, the authors reported that when the device’s hand-held ultrasound transducers (scanheads) were aimed improperly, bladders were missed, or lateral borders of bladders were missed resulting in partial bladder volume measurements and underestimation of PVR measurements. They concluded that caution should be used in interpreting PVR volume measured by portable bladder ultrasound machines and that catheterization may be the preferred assessment modality if an accurate PVR measurement is necessary. All 3 studies with post-operative populations found portable bladder ultrasound use to be reasonably acceptable. Two studies reported that the device overestimated catheter-derived bladder volumes, one by 7% and the other by 21 mL. The third study reported the opposite, that the device underestimated catheter bladder volume by 39 mL but that the results remained acceptable In rehabilitation settings, 2 studies found portable bladder ultrasound to underestimate catheter-derived bladder volumes; yet, both authors concluded that the mean errors were within acceptable limits. In patients with neurogenic bladder problems, 2 studies found portable bladder ultrasound to be an acceptable alternative to catheterization despite the fact that it was not as accurate as catheterization for obtaining bladder volumes. Lastly, examinations concerning avoidance of negative health outcomes showed that, after use of the portable bladder ultrasound, unnecessary catheterizations and UTIs were decreased. Unnecessary catheterizations avoided ranged from 16% to 47% in the selected articles. Reductions in UTI ranged from 38% to 72%. In sum, all but one study advocated the use of portable bladder ultrasound as an alternative to catheterization. Economic Analysis An economic analysis estimating the budget-impact of BladderScan in complex continuing care facilities was completed. The analysis results indicated a $192,499 (Cdn) cost-savings per year per facility and a cost-savings of $2,887,485 (Cdn) for all 15 CCC facilities. No economic analysis was completed for long-term care and acute care facilities due to lack of data. Considerations for Policy Development Rapid diffusion of portable bladder ultrasound technology is expected. Recently, the IC5 project on improving continence care in Ontario’s complex continuing care centres piloted portable bladder ultrasound at 12 sites. Preliminary results were promising. Many physicians and health care facilities already have portable bladder ultrasound devices. However, portable bladder ultrasound devices for PVR measurement are not in use at most health care facilities in Ontario and Canada. The Verathon Corporation (Bothell, Wisconsin, United States), which patents BladderScan, is the sole licensed manufacturer of the portable bladder ultrasound in Canada. Field monopoly may influence the rising costs of portable bladder ultrasound, particularly when faced with rapid expansion of the technology. Several thousand residents of Ontario would benefit from portable bladder ultrasound. The number of residents of Ontario that would benefit from the technology is difficult to quantify, because the incidence and prevalence of incontinence are grossly under-reported. However, long-term care and complex continuing care institutions would benefit greatly from portable bladder ultrasound, as would numerous rehabilitation units, postsurgical care units, and urology clinics. The cost of the portable bladder ultrasound devices ranges from $17,698.90 to $19,565.95 (Cdn) (total purchase price per unit as quoted by the manufacturer). Additional training packages, batteries and battery chargers, software, gel pads, and yearly warranties are additional costs. Studies indicate that portable bladder ultrasound is a cost-effective technology, because it avoids costs associated with catheterization equipment, saves nursing time, and reduces catheter-related complications and UTIs. The use of portable bladder ultrasound device will affect the patient directly in terms of health outcomes. Its use avoids the trauma related to the urinary tract that catheterization inflicts, and does not result in UTIs. In addition, patients prefer it, because it preserves dignity and reduces discomfort. PMID:23074481

Adding New Tools to the Black Bag—Introduction of Ultrasound into the Physical Diagnosis Course

PubMed Central

Amponsah, David; Yang, James; Mendez, Jennifer; Bridge, Patrick; Hays, Gregory; Baliga, Sudhir; Crist, Karen; Brennan, Simone; Jackson, Matt; Dulchavsky, Scott

2010-01-01

INTRODUCTION Ultrasound, a versatile diagnostic modality that permits real-time visualization at the patient’s bedside, can be used as an adjunct in teaching physical diagnosis (PD). Aims: (1) to study the feasibility of incorporating ultrasound into PD courses and (2) determine whether learners can demonstrate image recognition and acquisition skills. PROGRAM DESCRIPTION Three hundred seven second-year medical students were introduced to cardiovascular and abdominal ultrasound scanning after training in the physical examination. This consisted of a demonstration of the ultrasound examination, followed by practice on standardized patients (SPs). Pre-post tests were administered to evaluate students’ knowledge and understanding of ultrasound. Students performed an ultrasound examination during the PD final examination. PROGRAM EVALUATION Pre-post test data revealed significant improvements in image recognition. On the final exam, the highest scores (98.4%) were obtained for the internal jugular vein and lowest scores (74.6%) on the Focused Assessment with Sonography for Trauma images. Eighty-nine percent of students’ surveyed felt ultrasound was a valuable tool for physicians. DISCUSSION An introductory ultrasound course is effective in improving medical students' acquisition and recognition of basic cardiovascular and abdominal ultrasound images. This innovative program demonstrates the feasibility of incorporating portable ultrasound as a learning tool during medical school. Electronic supplementary material The online version of this article (doi:10.1007/s11606-010-1451-5) contains supplementary material, which is available to authorized users. PMID:20697974

‘Women think pregnancy management means obstetric ultrasound’: Vietnamese obstetricians’ views on the use of ultrasound during pregnancy

PubMed Central

Edvardsson, Kristina; Graner, Sophie; Thi, Lan Pham; Åhman, Annika; Small, Rhonda; Lalos, Ann; Mogren, Ingrid

2015-01-01

Objective To explore Vietnamese obstetricians’ experiences and views on the role of obstetric ultrasound in clinical management of complicated pregnancy and in situations where maternal and fetal health interests conflict. Design Seventeen obstetricians in northern Vietnam were interviewed as part of the CROss-Country Ultrasound Study (CROCUS) project in 2013. Data were analysed using qualitative content analysis. Results The participants described ultrasound as a central tool in prenatal care, although they called for increased training and resources to prevent inappropriate management. A prevailing overuse driven by women's request and increased commercialisation was described. Other clinical examinations were seen as being disregarded by women in favour of ultrasound, resulting in missed opportunities for identifying potential pregnancy complications. The use of ultrasound for sex selection purposes raised concern among participants. Visualisation of human features or heartbeat during ultrasound was commonly described as the point where the fetus became regarded as a ‘person’. Women were said to prioritise fetal health interests over their own health, particularly if a woman had difficulties becoming pregnant or had undergone assisted fertilisation. The woman's husband and his family were described as having an important role in decision-making in situations of maternal and fetal health conflicts. Conclusions This study provides insight into issues surrounding ultrasound use in contemporary Vietnam, some of which may be specific to this low-income context. It is clear that ultrasound has become a central tool in prenatal care in Vietnam and that it has also been embraced by women. However, there seems to be a need to balance women's demands for obstetric ultrasound with better recognition of the valuable contribution to be made by the full range of clinical examinations in pregnancy, along with a more strategic allocation of resources, that is, use of obstetric ultrasound based on clinical indications. Better regulation of private obstetric practice also appears to be needed. While the root causes of sex selection need to be addressed at societal level, efforts are also required more immediately to find ways to combat the inappropriate use of ultrasound for the purpose of sex selection. PMID:26519131

Which imaging modality is most effective for identifying pseudotumours in metal-on-metal hip resurfacings requiring revision: ultrasound or MARS-MRI or both?

PubMed

Matharu, G S; Mansour, R; Dada, O; Ostlere, S; Pandit, H G; Murray, D W

2016-01-01

The aims of this study were to compare the diagnostic test characteristics of ultrasound alone, metal artefact reduction sequence MRI (MARS-MRI) alone, and ultrasound combined with MARS-MRI for identifying intra-operative pseudotumours in metal-on-metal hip resurfacing (MoMHR) patients undergoing revision surgery. This retrospective diagnostic accuracy study involved 39 patients (40 MoMHRs). The time between imaging modalities was a mean of 14.6 days (0 to 90), with imaging performed at a mean of 5.3 months (0.06 to 12) before revision. The prevalence of intra-operative pseudotumours was 82.5% (n = 33). Agreement with the intra-operative findings was 82.5% (n = 33) for ultrasound alone, 87.5% (n = 35) for MARS-MRI alone, and 92.5% (n = 37) for ultrasound and MARS-MRI combined. The diagnostic characteristics for ultrasound alone and MARS-MRI alone reached similar sensitivities (90.9% vs 93.9%) and positive predictive values (PPVs; 88.2% vs 91.2%), but higher specificities (57.1% vs 42.9%) and negative predictive values (NPVs; 66.7% vs 50.0%) were achieved with MARS-MRI. Ultrasound and MARS-MRI combined produced 100% sensitivity and 100% NPV, whilst maintaining both specificity (57.1%) and PPV (91.7%). For the identification of a pseudotumour, which was confirmed at revision surgery, agreement was substantial for ultrasound and MARS-MRI combined (κ = 0.69), moderate for MARS-MRI alone (κ = 0.54), and fair for ultrasound alone (κ = 0.36). These findings suggest that ultrasound and/or MARS-MRI have a role when assessing patients with a MoMHR, with the choice dependent on local financial constraints and the availability of ultrasound expertise. However in patients with a MoMHR who require revision, combined imaging was most effective. Combined imaging with ultrasound and MARS-MRI always identified intra-operative pseudotumours if present. Furthermore, if neither imaging modality showed a pseudotumour, one was not found intra-operatively. ©2016 The British Editorial Society of Bone & Joint Surgery.

Investigation of Post-mortem Tissue Effects Using Long-time Decorrelation Ultrasound

NASA Astrophysics Data System (ADS)

Csány, Gergely; Balogh, Lajos; Gyöngy, Miklós

Decorrelation ultrasound is being increasingly used to investigate long-term biological phenomena. In the current work, ultrasound image sequences of mice who did not survive anesthesia (in a separate investigation) were analyzed and post-mortem tissue effects were observed via decorrelation calculation. A method was developed to obtain a quantitative parameter characterizing the rate of decorrelation. The results show that ultrasound decorrelation imaging is an effective method of observing post-mortem tissue effects and point to further studies elucidating the mechanism behind these effects.

An Experimental Model Using Cultured Cardiac Myocytes for a Study of the Generation of Premature Ventricular Contractions Under Ultrasound Exposure

NASA Astrophysics Data System (ADS)

Kudo, Nobuki; Yamamoto, Masaya

2011-09-01

It is known that use of a contrast agents in echocardiography increases the probability of generation of premature ventricular contractions (PVCs). As a basic study to elucidate the mechanisms and to reduce adverse effects, the generation of PVCs was investigated using cultured cardiac myocytes instead of the intact heart in vivo. Cardiac myocytes were isolated from neonatal rats and cultured on a cover slip. The myocyte sample was exposed to pulsed ultrasound with microbubbles adjacent to the myocytes, and generation of PVCs was examined with ultrasound exposure at various delay times after onset of myocyte contraction. The experimental results showed that generation of PVCs had a stable threshold delay time and that PVCs were generated only when myocytes were exposed to ultrasound with delay times longer than the threshold. The results indicate that the model used in this study is useful for revealing the mechanisms by which PVCs are induced by ultrasound exposure.

Ultrasound assessment of lung consolidation and reaeration after pleural effusion drainage in patients with Acute Respiratory Distress Syndrome: a pilot study.

PubMed

Chinardet, B; Brisson, H; Arbelot, C; Langeron, O; Rouby, J J; Lu, Q

2016-01-01

The aim of the pilot study was to assess by ultrasound changes in dimensions of lung consolidation and reaeration after drainage of large pleural effusion in patients with acute respiratory distress syndrome (ARDS). Lung ultrasound and blood gas were performed before, 2 hours (H2) and 24 hours (H24) after drainage of pleural effusion. Lung ultrasound aeration score was calculated. Cephalocaudal dimension and diaphragmatic transversal area of lung consolidation were measured. Ten patients were studied. Median volume of drained effusion was 675 ml at H2 and 895 at H24. Two hours after drainage, dimension of cephalocaudal consolidation and diaphragmatic transversal area decreased significantly. Lung reaeration after drainage occurred mainly in latero-inferior and postero-superior regions. PaO2/FiO2 increased significantly at H24. Ultrasound is a useful method to assess lung consolidation after pleural effusion drainage. Drainage of pleural effusion may lead to a decrease of lung consolidation and improvement of lung reaeration.

Ultrasound elastographic techniques in focal liver lesions

PubMed Central

Conti, Clara Benedetta; Cavalcoli, Federica; Fraquelli, Mirella; Conte, Dario; Massironi, Sara

2016-01-01

Elastographic techniques are new ultrasound-based imaging techniques developed to estimate tissue deformability/stiffness. Several ultrasound elastographic approaches have been developed, such as static elastography, transient elastography and acoustic radiation force imaging methods, which include point shear wave and shear wave imaging elastography. The application of these methods in clinical practice aims at estimating the mechanical tissues properties. One of the main settings for the application of these tools has been liver stiffness assessment in chronic liver disease, which has been studied mainly using transient elastography. Another field of application for these techniques is the assessment of focal lesions, detected by ultrasound in organs such as pancreas, prostate, breast, thyroid, lymph nodes. Considering the frequency and importance of the detection of focal liver lesions through routine ultrasound, some studies have also aimed to assess the role that elestography can play in studying the stiffness of different types of liver lesions, in order to predict their nature and thus offer valuable non-invasive methods for the diagnosis of liver masses. PMID:26973405

Ultrasound elastographic techniques in focal liver lesions.

PubMed

Conti, Clara Benedetta; Cavalcoli, Federica; Fraquelli, Mirella; Conte, Dario; Massironi, Sara

2016-03-07

Elastographic techniques are new ultrasound-based imaging techniques developed to estimate tissue deformability/stiffness. Several ultrasound elastographic approaches have been developed, such as static elastography, transient elastography and acoustic radiation force imaging methods, which include point shear wave and shear wave imaging elastography. The application of these methods in clinical practice aims at estimating the mechanical tissues properties. One of the main settings for the application of these tools has been liver stiffness assessment in chronic liver disease, which has been studied mainly using transient elastography. Another field of application for these techniques is the assessment of focal lesions, detected by ultrasound in organs such as pancreas, prostate, breast, thyroid, lymph nodes. Considering the frequency and importance of the detection of focal liver lesions through routine ultrasound, some studies have also aimed to assess the role that elestography can play in studying the stiffness of different types of liver lesions, in order to predict their nature and thus offer valuable non-invasive methods for the diagnosis of liver masses.

[Ultrasound in complex of radiological studies in diagnosis of ankle joint medial aspect pathologies].

PubMed

Gurgenidze, T; Mizandari, M

2011-10-01

The aim of the research is to study sonosemiotics of ankle joint pathology by means of ultrasound in order to optimize the diagnostic process and improve the treatment. 130 patients (age ranges from 5 to 70 years) underwent the radiological study of ankle joint medial aspect. Pathology types: degenerative-dystrophic diseases - 39 (30%), inflammatory pathology - 21 (16.2%), traumatic injuries - 20 (15.2%), vascular pathologies - 26 (20%), neurogenic problems -7 (5.4%), soft tissue neoplasms - 5 (3.8%), congenital anomalies - 7 (5.4%) and vertebral pathology - 5 (4.0%). The diagnostic studies include: a) Ultrasound, performed on digital ultrasound system using high frequency (7.5-12.0 MHz) linear probe with Doppler capability (all patients); b) X-Ray filming in antero-posterior and lateral projections (6 patients- 4.5%); c) MRI - T1 and T2 weighted images in saggital and transverse planes 10 patients (10.0%) and d) CT - 2 patients (1.5%); To 2 (1.5%) patient biopsy has been performed. This study showed that ultrasound was successful in ankle joint medial aspect pathology diagnosis in 108 cases (84.0%); It was ineffective in osseous pathology definition. In final diagnosis of impingment syndrom MRI was required in 4 (3.6%) cases. It is concluded that ultrasound should be used as a Gold Standard in diagnosis of localized pain and swelling in the ankle joint.

Ultrasound for diagnosing radiographically occult scaphoid fracture.

PubMed

Kwee, Robert M; Kwee, Thomas C

2018-04-04

To systematically review the literature on the performance of ultrasound in diagnosing radiographically occult scaphoid fracture. A systematic search was performed in the MEDLINE and Embase databases. Original studies investigating the performance of ultrasound in diagnosing radiographically occult scaphoid fracture in more than 10 patients were eligible for inclusion. Studies that included both radiographically apparent and occult scaphoid fractures (at initial radiography) were only included if independent data on radiographically occult fractures were reported. Methodological quality of the studies included was assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool. Accuracy data were extracted. Sensitivity and specificity were pooled with a bivariate random-effects model. The inclusion criteria were met by 7 studies; total sample size comprised 314 patients. All studies, except 1, included cortical disruption of the scaphoid in their diagnostic criteria. The sensitivity and specificity of ultrasound in diagnosing radiographically occult scaphoid fracture ranged from 77.8% to 100% and from 71.4% to 100% respectively, with pooled estimates of 85.6% (95% CI: 73.9%, 92.6%) and 83.3% % (95% CI: 72.0%, 90.6%) respectively. Exclusion of two studies with a high risk of bias in any QUADAS-2 domain did not affect the pooled results. Ultrasound can diagnose radiographically occult scaphoid fracture with a fairly high degree of accuracy. Because of its relatively low costs and fairly high sensitivity, ultrasound seems more cost-effective than empiric cast immobilization and may be used when CT and MRI are not readily available.

Ultrasound guidance for internal jugular vein cannulation: Continuing Professional Development.

PubMed

Ayoub, Christian; Lavallée, Catherine; Denault, André

2010-05-01

The objective of this continuing professional development module is to describe the role of ultrasound for central venous catheterization and to specify its benefits and limitations. Although ultrasound techniques are useful for all central venous access sites, the focus of this module is on the internal jugular vein approach. In recent years, several studies were published on the benefits of ultrasound use for central venous catheterization. This technique has evolved rapidly due to improvements in the equipment and technology available. Ultrasound helps to detect the anatomical variants of the internal jugular vein. The typical anterolateral position of the internal jugular vein with respect to the carotid is found in only 9-92% of cases. Ultrasound guidance reduces the rate of mechanical, infectious, and thrombotic complications by 57%, and it also reduces the failure rate by 86%. Cost-benefit analyses show that the cost of ultrasound equipment is compensated by the decrease in the expenses associated with the treatment of complications. In this article, we will review the history of ultrasound guidance as well as the reasons that account for its superiority over the classical anatomical landmark technique. We will describe the equipment needed for central venous catheterization as well as the various methods to visualize with ultrasound. To improve patient safety, we recommend the use of ultrasound for central venous catheterization using the internal jugular approach.

Remote just-in-time telementored trauma ultrasound: a double-factorial randomized controlled trial examining fluid detection and remote knobology control through an ultrasound graphic user interface display.

PubMed

Kirkpatrick, Andrew W; McKee, Ian; McKee, Jessica L; Ma, Irene; McBeth, Paul B; Roberts, Derek J; Wurster, Charles L; Parfitt, Robbie; Ball, Chad G; Oberg, Scott; Sevcik, William; Hamilton, Douglas R

2016-05-01

Remote-telementored ultrasound involves novice examiners being remotely guided by experts using informatic-technologies. However, requiring a novice to perform ultrasound is a cognitively demanding task exacerbated by unfamiliarity with ultrasound-machine controls. We incorporated a randomized evaluation of using remote control of the ultrasound functionality (knobology) within a study in which the images generated by distant naive examiners were viewed on an ultrasound graphic user interface (GUI) display viewed on laptop computers by mentors in different cities. Fire-fighters in Edmonton (101) were remotely mentored from Calgary (n = 65), Nanaimo (n = 19), and Memphis (n = 17) to examine an ultrasound phantom randomized to contain free fluid or not. Remote mentors (2 surgeons, 1 internist, and 1 ED physician) were randomly assigned to use GUI knobology control during mentoring (GUIK+/GUIK-). Remote-telementored ultrasound was feasible in all cases. Overall accuracy for fluid detection was 97% (confidence interval = 91 to 99%) with 3 false negatives (FNs). Positive/negative likelihood ratios were infinity/0.0625. One FN occurred with the GUIK+ and 2 without (GUIK-). There were no statistical test performance differences in either group (GUIK+ and GUIK-). Ultrasound-naive 1st responders can be remotely mentored with high accuracy, although providing basic remote control of the knobology did not affect outcomes. Copyright © 2016 Elsevier Inc. All rights reserved.

Nonthermal effects of therapeutic ultrasound: the frequency resonance hypothesis.

PubMed

Johns, Lennart D

2002-07-01

To present the frequency resonance hypothesis, a possible mechanical mechanism by which treatment with non-thermal levels of ultrasound stimulates therapeutic effects. The review encompasses a 4-decade history but focuses on recent reports describing the effects of nonthermal therapeutic levels of ultrasound at the cellular and molecular levels. A search of MEDLINE from 1965 through 2000 using the terms ultrasound and therapeutic ultrasound. The literature provides a number of examples in which exposure of cells to therapeutic ultrasound under nonthermal conditions modified cellular functions. Nonthermal levels of ultrasound are reported to modulate membrane properties, alter cellular proliferation, and produce increases in proteins associated with inflammation and injury repair. Combined, these data suggest that nonthermal effects of therapeutic ultrasound can modify the inflammatory response. The concept of the absorption of ultrasonic energy by enzymatic proteins leading to changes in the enzymes activity is not novel. However, recent reports demonstrating that ultrasound affects enzyme activity and possibly gene regulation provide sufficient data to present a probable molecular mechanism of ultrasound's nonthermal therapeutic action. The frequency resonance hypothesis describes 2 possible biological mechanisms that may alter protein function as a result of the absorption of ultrasonic energy. First, absorption of mechanical energy by a protein may produce a transient conformational shift (modifying the 3-dimensional structure) and alter the protein's functional activity. Second, the resonance or shearing properties of the wave (or both) may dissociate a multimolecular complex, thereby disrupting the complex's function. This review focuses on recent studies that have reported cellular and molecular effects of therapeutic ultrasound and presents a mechanical mechanism that may lead to a better understanding of how the nonthermal effects of ultrasound may be therapeutic. Moreover, a better understanding of ultrasound's mechanical mechanism could lead to a better understanding of how and when ultrasound should be employed as a therapeutic modality.

Development of the ultrasonography learning model for undergraduate medical students: A case study of the Faculty of Medicine, Burapha University.

PubMed

Limchareon, Sornsupha; Asawaworarit, Nattawat; Klinwichit, Wethaka; Dinchuthai, Pakaphun

2016-08-01

Ultrasound technology is generally considered to be reliable and widely used by physicians today. Therefore, given the efficacy and popularity of the technology, the need for quality ultrasound education is evident. Ultrasound training for undergraduate medical students has been increasingly incorporated into school curriculums, but the teaching methods can vary significantly among medical schools. Among many different choices, one effective teaching model was proposed which added hands-on ultrasound experience on live patients that was supervised by radiologists in the last clinical year. A 2-week radiology elective course was offered for 6(th)-year medical students at Burapha University Hospital, Chonburi, Thailand in the academic year 2014. Fourteen medical students participated in the elective course. Additionally, students who chose radiology as their elective were provided an ultrasound experience on live patients in real-life clinical settings. All 6(th)-year medical students then completed a 25-ultrasound image quiz, and completed a questionnaire at the end of the academic year. The ultrasound test scores were compared between the elective and nonelective students. The students' background characteristics were determined by a grade point average and the ultrasound experience was determined by the number of scans. These were collected, and analyzed to establish their relationship with the ultrasound test scores. The students' opinions were also surveyed. Fourteen medical students participated in the elective course. The ultrasound test scores in the elective group were significantly higher than those in the nonelective group (p=0.013). The students' background characteristics and ultrasound experience had no significant relationship with the ultrasound test scores. By adding hands-on ultrasound experience using live patients proctored by radiologists for final year medical students, in the space of 2 weeks, an effective ultrasound learning model for undergraduate medical students can be provided. This model should be considered in the curricular design. Copyright © 2016. Published by Elsevier Taiwan LLC.

The efficacy, safety, effectiveness, and cost-effectiveness of ultrasound and shock wave therapies for low back pain: a systematic review.

PubMed

Seco, Jesús; Kovacs, Francisco M; Urrutia, Gerard

2011-10-01

Shock wave and especially ultrasound are commonly used to treat low back pain (LBP) in routine practice. To assess the evidence on the efficacy, effectiveness, cost-effectiveness, and safety of ultrasound and shock wave to treat LBP. Systematic review. An electronic search was performed in MEDLINE, EMBASE, and the Cochrane Library databases up to July 2009 to identify randomized controlled trials (RCTs) comparing vibrotherapy with placebo or with other treatments for LBP. No language restrictions were applied. Additional data were requested from the authors of the original studies. The risk of bias of each study was assessed following the criteria recommended by the Cochrane Back Review Group. Thirteen studies were identified. The four RCTs complying with the inclusion criteria included 252 patients. Two of the three RCTs on ultrasound had a high risk of bias. For acute patients with LBP and leg pain attributed to disc herniation, ultrasound, traction, and low-power laser obtained similar results. For chronic LBP patients without leg pain, ultrasound was less effective than spinal manipulation, whereas a shock wave device and transcutaneous electrical nerve stimulation led to similar results. Results from the only study comparing ultrasound versus a sham procedure are unreliable because of the inappropriateness of the sham procedure, low sample size, and lack of adjustment for potential confounders. No study assessed cost-effectiveness. No adverse events were reported. The available evidence does not support the effectiveness of ultrasound or shock wave for treating LBP. High-quality RCTs are needed to assess their efficacy versus appropriate sham procedures, and their effectiveness and cost-effectiveness versus other procedures shown to be effective for LBP. In the absence of such evidence, the clinical use of these forms of treatment is not justified and should be discouraged. Copyright © 2011 Elsevier Inc. All rights reserved.

Key findings from the International Ovarian Tumor Analysis (IOTA) study: an approach to the optimal ultrasound based characterisation of adnexal pathology

PubMed Central

Bourne, Tom; De Rijdt, Sylvie; Van Holsbeke, Caroline; Sayasneh, Ahmad; Valentin, Lil; Van Calster, Ben; Timmerman, Dirk

2015-01-01

Abstract The principal aim of the IOTA project has been to develop approaches to the evaluation of adnexal pathology using ultrasound that can be transferred to all examiners. Creating models that use simple, easily reproducible ultrasound characteristics is one approach. PMID:28191150

Corrected High-Frame Rate Anchored Ultrasound with Software Alignment

ERIC Educational Resources Information Center

Miller, Amanda L.; Finch, Kenneth B.

2011-01-01

Purpose: To improve lingual ultrasound imaging with the Corrected High Frame Rate Anchored Ultrasound with Software Alignment (CHAUSA; Miller, 2008) method. Method: A production study of the IsiXhosa alveolar click is presented. Articulatory-to-acoustic alignment is demonstrated using a Tri-Modal 3-ms pulse generator. Images from 2 simultaneous…

ULTRASOUND PRETREATMENT OF ELEMENTAL IRON: KINETIC STUDIES OF DEHALOGENATION REACTION ENHANCEMENT AND SURFACE EFFECTS. (R828598C743)

EPA Science Inventory

This work presents data showing the kinetic improvement afforded by ultrasound pretreatment and illustrates the physical and chemical changes that take place at the iron surface. First-order rate constants improved as much as 78% with 2 h of ultrasound pretreatment. Scann...

Noncontact modal analysis of a pipe organ reed using airborne ultrasound stimulated vibrometry.

PubMed

Huber, Thomas M; Fatemi, Mostafa; Kinnick, Randy; Greenleaf, James

2006-04-01

The goal of this study was to excite and measure, in a noncontact manner, the vibrational modes of the reed from a reed organ pipe. To perform ultrasound stimulated excitation, the audio-range difference frequency between a pair of ultrasound beams produced a radiation force that induced vibrations. The resulting vibrational deflection shapes were measured with a scanning laser vibrometer. The resonances of any relatively small object can be studied in air using this technique. For a 36 mm x 6 mm brass reed, displacements and velocities in excess of 5 microm and 4 mm/s could be imparted at the fundamental frequency of 145 Hz. Using the same ultrasound transducer, excitation across the entire range of audio frequencies was obtained. Since the beam was focused on the reed, ultrasound stimulated excitation eliminated background effects observed during mechanical shaker excitation, such as vibrations of clamps and supports. The results obtained using single, dual and confocal ultrasound transducers in AM and two-beam modes, along with results obtained using a mechanical shaker and audio excitation using a speaker are discussed.

No effect of prolonged pulsed high frequency ultrasound imaging of the basilar membrane on cochlear function or hair cell survival found in an initial study.

PubMed

Landry, Thomas G; Bance, Manohar L; Adamson, Robert B; Brown, Jeremy A

2018-06-01

Miniature high frequency ultrasound devices show promise as tools for clinical middle ear and basal cochlea imaging and vibrometry. However, before clinical use it is important to verify that the ultrasound exposure does not damage the cochlea. In this initial study, electrophysiological responses of the cochlea were measured for a range of stimulus frequencies in both ears of anesthetized chinchillas, before and after exposing the organ of Corti region of one ear to pulsed focused ultrasound for 30 min. Measurements were again taken after an 11 day survival period. Cochlear tissue was examined with a confocal microscope for signs of damage to the cochlear hair cells. No significant change in response thresholds due to exposure was found, and no signs of ultrasound-induced tissue damage were observed, although one animal (out of ten) did have a region of extensive tissue damage in the exposed cochlea. However, after further analysis this was concluded to be not likely a result of the ultrasound exposure. Copyright © 2017 Elsevier B.V. All rights reserved.

Aptamer-conjugated nanobubbles for targeted ultrasound molecular imaging.

PubMed

Wang, Chung-Hsin; Huang, Yu-Fen; Yeh, Chih-Kuang

2011-06-07

Targeted ultrasound contrast agents can be prepared by some specific bioconjugation techniques. The biotin-avidin complex is an extremely useful noncovalent binding system, but the system might induce immunogenic side effects in human bodies. Previous proposed covalently conjugated systems suffered from low conjugation efficiency and complex procedures. In this study, we propose a covalently conjugated nanobubble coupling with nucleic acid ligands, aptamers, for providing a higher specific affinity for ultrasound targeting studies. The sgc8c aptamer was linked with nanobubbles through thiol-maleimide coupling chemistry for specific targeting to CCRF-CEM cells. Further improvements to reduce the required time and avoid the degradation of nanobubbles during conjugation procedures were also made. Several investigations were used to discuss the performance and consistency of the prepared nanobubbles, such as size distribution, conjugation efficiency analysis, and flow cytometry assay. Further, we applied our conjugated nanobubbles to ex vivo ultrasound targeted imaging and compared the resulting images with optical images. The results indicated the availability of aptamer-conjugated nanobubbles in targeted ultrasound imaging and the practicability of using a highly sensitive ultrasound system in noninvasive biological research.

Nonlocal Total-Variation-Based Speckle Filtering for Ultrasound Images.

PubMed

Wen, Tiexiang; Gu, Jia; Li, Ling; Qin, Wenjian; Wang, Lei; Xie, Yaoqin

2016-07-01

Ultrasound is one of the most important medical imaging modalities for its real-time and portable imaging advantages. However, the contrast resolution and important details are degraded by the speckle in ultrasound images. Many speckle filtering methods have been developed, but they are suffered from several limitations, difficult to reach a balance between speckle reduction and edge preservation. In this paper, an adaptation of the nonlocal total variation (NLTV) filter is proposed for speckle reduction in ultrasound images. The speckle is modeled via a signal-dependent noise distribution for the log-compressed ultrasound images. Instead of the Euclidian distance, the statistical Pearson distance is introduced in this study for the similarity calculation between image patches via the Bayesian framework. And the Split-Bregman fast algorithm is used to solve the adapted NLTV despeckling functional. Experimental results on synthetic and clinical ultrasound images and comparisons with some classical and recent algorithms are used to demonstrate its improvements in both speckle noise reduction and tissue boundary preservation for ultrasound images. © The Author(s) 2015.

Fusion of multi-parametric MRI and temporal ultrasound for characterization of prostate cancer: in vivo feasibility study

NASA Astrophysics Data System (ADS)

Imani, Farhad; Ghavidel, Sahar; Abolmaesumi, Purang; Khallaghi, Siavash; Gibson, Eli; Khojaste, Amir; Gaed, Mena; Moussa, Madeleine; Gomez, Jose A.; Romagnoli, Cesare; Cool, Derek W.; Bastian-Jordan, Matthew; Kassam, Zahra; Siemens, D. Robert; Leveridge, Michael; Chang, Silvia; Fenster, Aaron; Ward, Aaron D.; Mousavi, Parvin

2016-03-01

Recently, multi-parametric Magnetic Resonance Imaging (mp-MRI) has been used to improve the sensitivity of detecting high-risk prostate cancer (PCa). Prior to biopsy, primary and secondary cancer lesions are identified on mp-MRI. The lesions are then targeted using TRUS guidance. In this paper, for the first time, we present a fused mp-MRI-temporal-ultrasound framework for characterization of PCa, in vivo. Cancer classification results obtained using temporal ultrasound are fused with those achieved using consolidated mp-MRI maps determined by multiple observers. We verify the outcome of our study using histopathology following deformable registration of ultrasound and histology images. Fusion of temporal ultrasound and mp-MRI for characterization of the PCa results in an area under the receiver operating characteristic curve (AUC) of 0.86 for cancerous regions with Gleason scores (GSs)>=3+3, and AUC of 0.89 for those with GSs>=3+4.

Evaluation of eyes with relative pupillary block by indentation ultrasound biomicroscopy gonioscopy.

PubMed

Matsunaga, Koichi; Ito, Kunio; Esaki, Koji; Sugimoto, Kota; Sano, Toru; Miura, Katsuya; Sasoh, Mikio; Uji, Yukitaka

2004-03-01

To investigate changes in anterior chamber angle configuration with indentation ultrasound biomicroscopy gonioscopy of relative pupillary block (RPB). Cross-sectional study. This study included 26 eyes of 26 patients with RPB. We determined angle opening distance 500 and angle recess area using indentation ultrasound biomicroscopy gonioscopy and compared a small-sized standard eye cup with a new eye cup with an area for inducing pressure. Indentation ultrasound biomicroscopy images documented concavity of the iris in eyes with RPB. Both the new and the small standard eye cups widened the anterior chamber angle significantly (P <.0001) without causing corneal damage. Angle changes were significantly greater for the new eye cup design. Indentation ultrasound biomicroscopy gonioscopy is a useful technique for observation and diagnosis of RPB. Using a small standard or the newly designed eye cup, the procedure can be performed easily and without causing corneal damage.

Investigating the sonophoresis effect on the permeation of diclofenac sodium using 3D skin equivalent.

PubMed

Aldwaikat, Mai; Alarjah, Mohammed

2015-01-01

Ultrasound temporally increases skin permeability by altering stratum corneum SC function (sonophoresis). The objective of this study was to evaluate the effect of variable ultrasound conditions on the permeation of diclofenac sodium DS with range of physicochemical properties through EpiDerm™. Permeation studies were carried out in vitro using Franz diffusion cell. HPLC method was used for the determination of the concentration of diclofenac sodium in receiving compartment. Parameters like ultrasound frequency, application time, amplitude, and mode of sonication and distance of ultrasound horn from skin were investigated, and the conditions where the maximum enhancement rate obtained were determined. Application of ultrasound enhanced permeation of diclofenac sodium across EpiDerm™ by fivefolds. The most effective enhancing parameters were power sonication of 20kHz frequency, 20% amplitude at continuous mode for 5min. Copyright © 2014. Published by Elsevier B.V.

Simulation Study of Effects of the Blind Deconvolution on Ultrasound Image

NASA Astrophysics Data System (ADS)

He, Xingwu; You, Junchen

2018-03-01

Ultrasonic image restoration is an essential subject in Medical Ultrasound Imaging. However, without enough and precise system knowledge, some traditional image restoration methods based on the system prior knowledge often fail to improve the image quality. In this paper, we use the simulated ultrasound image to find the effectiveness of the blind deconvolution method for ultrasound image restoration. Experimental results demonstrate that the blind deconvolution method can be applied to the ultrasound image restoration and achieve the satisfactory restoration results without the precise prior knowledge, compared with the traditional image restoration method. And with the inaccurate small initial PSF, the results shows blind deconvolution could improve the overall image quality of ultrasound images, like much better SNR and image resolution, and also show the time consumption of these methods. it has no significant increasing on GPU platform.

Biological response in vitro of skeletal muscle cells treated with different intensity continuous and pulsed ultrasound fields

NASA Astrophysics Data System (ADS)

Abrunhosa, Viviane M.; Mermelstein, Claudia S.; Costa, Manoel L.; Costa-Felix, Rodrigo P. B.

2011-02-01

Therapeutic ultrasound has been used in physiotherapy to accelerate tissue healing. Although the ultrasonic wave is widely used in clinical practice, not much is known about the biological effects of ultrasound on cells and tissues. This study aims to evaluate the biological response of ultrasound in primary cultures of chick myogenic cells. To ensure the metrological reliability of whole measurement process, the ultrasound equipment was calibrated in accordance with IEC 61689:2007. The skeletal muscle cells were divided in four samples. One sample was used as a control group and the others were submitted to different time and intensity and operation mode of ultrasound: 1) 0.5 W/cm2 continuous for 5 minutes, 2) 0.5 W/cm2 pulsed for 5 minutes, 3) 1.0 W/cm2 pulsed for 10 minutes. The samples were analyzed with phase contrast optical microscopy before and after the treatment. The results showed alignment of myogenic cells in the sample treated with 0.5 W/cm2 continuous during 5 minutes when compared with the control group and the other samples. This study is a first step towards a metrological and scientific based protocol to cells and tissues treatment under different ultrasound field exposures.

Ultrasonically-induced electrical potentials in demineralized bovine cortical bone

NASA Astrophysics Data System (ADS)

Mori, Shunki; Makino, Taiki; Koyama, Daisuke; Takayanagi, Shinji; Yanagitani, Takahiko; Matsukawa, Mami

2018-04-01

While the low-intensity pulsed ultrasound technique has proved useful for healing of bone fractures, the ultrasound healing mechanism is not yet understood. To understand the initial physical effects of the ultrasound irradiation process on bone, we have studied the anisotropic piezoelectric properties of bone in the MHz range. Bone is known to be composed of collagen and hydroxyapatite (HAp) and shows strong elastic anisotropy. In this study, the effects of HAp on the piezoelectricity were investigated experimentally. To remove the HAp crystallites from the bovine cortical bone, demineralization was performed using ethylene diamine tetra-acetic acid (EDTA) solutions. To investigate the piezoelectricity, we have fabricated ultrasound transducers using the cortical bone or demineralized cortical bone. The induced electrical potentials due to the piezoelectricity were observed as the output of these transducers under pulsed ultrasound irradiation in the MHz range. The cortical bone transducer (before mineralization) showed anisotropic piezoelectric behavior. When the ultrasound irradiation was applied normal to the transducer surface, the observed induced electrical potentials had minimum values. The potential increased under off-axis ultrasound irradiation with changes in polarization. In the demineralized bone transducer case, however, the anisotropic behavior was not observed in the induced electrical potentials. These results therefore indicate that the HAp crystallites affect the piezoelectric characteristics of bone.

[Abdominal ultrasound and magnetic resonance imaging: a comparative study on the non-alcoholic fatty liver disease diagnosis in morbidly obese patients].

PubMed

Chaves, Gabriela Villaça; Pereira, Sílvia Elaine; Saboya, Carlos José; Cortes, Caroline; Ramalho, Rejane

2009-01-01

To evaluate the concordance between abdominal ultrasound and an MRI (Magnetic Resonance Imaging) in the diagnosis of non-alcoholic fatty liver disease (NAFLD), and concordance of these two methods with the histopathological exam. The population studied was comprised of 145 patients with morbid obesity (BMI > or = 40 Kg/m(2)), of both genders. NAFLD diagnosis was performed by MRI and Ultrasound. Liver biopsy was performed in a sub-sample (n=40). To evaluate the concordance of these two methods, the kappa coefficient was used. Concordance between both methods (MRI and Ultrasound) was poor and not significant (Kappa adjusted= 0.27; CI 95%= 0.07-0.39.) Nevertheless a slight concordance was found between diagnosis of NAFLD by ultrasound and the hepatic biopsy, with 83.,3% of concordant results and Kappa adjusted= 0.67.Results of an MRI and the histopathological exam were compared and results showed 53.6% of concordant results and kappa adjusted= 0.07. The concordance found in the diagnosis performed using the ultrasound method and the hepatic biopsy, shows a need to implement and perform more research on the use of ultrasound to validate and reconsider these methods. This would minimize the need to perform biopsies to detect and diagnose such disease.

High-intensity focused ultrasound ablation for treatment of hepatocellular carcinoma and hypersplenism: preliminary study.

PubMed

Zhu, Jing; Zhu, Hui; Mei, Zhechuan; Jin, Chengbing; Ran, Lifeng; Zhou, Kun; Yang, Wei; Zhang, Lian; She, Chaokun

2013-10-01

The purpose of this work was to preliminarily investigate the efficacy and safety of high-intensity focused ultrasound treatment of hepatocellular carcinoma and hypersplenism. Nine patients with hepatocellular carcinoma complicated by hypersplenism (5 male and 4 female; median age, 56 years; range, 51-66 years) were treated with ultrasound-guided high-intensity focused ultrasound. Complications were recorded. Laboratory examination and magnetic resonance imaging were used to evaluate the efficacy. After high-intensity focused ultrasound treatment, mean spleen ablation ± SD of 28.76% ± 6.1% was discovered; meanwhile, the white blood cell count, platelet count, and liver function of the patients were substantially improved during the follow-up period. In addition, symptoms such as epistaxis and gingival bleeding were ameliorated or even eliminated, and the quality of life was improved. Follow-up imaging showed a nonperfused volume in the spleen and an absence of a tumor blood supply at the treated lesions in the liver. For the first time to our knowledge, high-intensity focused ultrasound ablation was used to treat hepatocellular carcinoma complicated by hypersplenism. High-intensity focused ultrasound may be an effective and safe alternative for treatment of hepatocellular carcinoma complicated by hypersplenism, but further studies are necessary to clarify the mechanisms.

Ultrasound determination of rotator cuff tear repairability

PubMed Central

Tse, Andrew K; Lam, Patrick H; Walton, Judie R; Hackett, Lisa

2015-01-01

Background Rotator cuff repair aims to reattach the torn tendon to the greater tuberosity footprint with suture anchors. The present study aimed to assess the diagnostic accuracy of ultrasound in predicting rotator cuff tear repairability and to assess which sonographic and pre-operative features are strongest in predicting repairability. Methods The study was a retrospective analysis of measurements made prospectively in a cohort of 373 patients who had ultrasounds of their shoulder and underwent rotator cuff repair. Measurements of rotator cuff tear size and muscle atrophy were made pre-operatively by ultrasound to enable prediction of rotator cuff repairability. Tears were classified following ultrasound as repairable or irreparable, and were correlated with intra-operative repairability. Results Ultrasound assessment of rotator cuff tear repairability has a sensitivity of 86% (p < 0.0001) and a specificity of 67% (p < 0.0001). The strongest predictors of rotator cuff repairability were tear size (p < 0.001) and age (p = 0.004). Sonographic assessments of tear size ≥4 cm2 or anteroposterior tear length ≥25 mm indicated an irreparable rotator cuff tear. Conclusions Ultrasound assessment is accurate in predicting rotator cuff tear repairability. Tear size or anteroposterior tear length and age were the best predictors of repairability. PMID:27582996

The finite element method for micro-scale modeling of ultrasound propagation in cancellous bone.

PubMed

Vafaeian, B; El-Rich, M; El-Bialy, T; Adeeb, S

2014-08-01

Quantitative ultrasound for bone assessment is based on the correlations between ultrasonic parameters and the properties (mechanical and physical) of cancellous bone. To elucidate the correlations, understanding the physics of ultrasound in cancellous bone is demanded. Micro-scale modeling of ultrasound propagation in cancellous bone using the finite-difference time-domain (FDTD) method has been so far utilized as one of the approaches in this regard. However, the FDTD method accompanies two disadvantages: staircase sampling of cancellous bone by finite difference grids leads to generation of wave artifacts at the solid-fluid interface inside the bone; additionally, this method cannot explicitly satisfy the needed perfect-slip conditions at the interface. To overcome these disadvantages, the finite element method (FEM) is proposed in this study. Three-dimensional finite element models of six water-saturated cancellous bone samples with different bone volume were created. The values of speed of sound (SOS) and broadband ultrasound attenuation (BUA) were calculated through the finite element simulations of ultrasound propagation in each sample. Comparing the results with other experimental and simulation studies demonstrated the capabilities of the FEM for micro-scale modeling of ultrasound in water-saturated cancellous bone. Copyright © 2014 Elsevier B.V. All rights reserved.

Ultrasonic wave propagation in trabecular bone predicted by the stratified model

NASA Technical Reports Server (NTRS)

Lin, W.; Qin, Y. X.; Rubin, C.

2001-01-01

The objective of this study was to investigate ultrasound propagation in trabecular bone by considering the wave reflection and transmission in a multilayered medium. The use of ultrasound to identify those at risk of osteoporosis is a promising diagnostic method providing a measure of bone mineral density (BMD). A stratified model was proposed to study the effect of transmission and reflection of ultrasound wave within the trabecular architecture on the relationship between ultrasound and BMD. The results demonstrated that ultrasound velocity in trabecular bone was highly correlated with the bone apparent density (r=0.97). Moreover, a consistent pattern of the frequency dependence of ultrasound attenuation coefficient has been observed between simulation using this model and experimental measurement of trabecular bone. The normalized broadband ultrasound attenuation (nBUA) derived from the simulation results revealed that nBUA was nonlinear with respect to trabecular porosity and BMD. The curve of the relationship between nBUA and BMD was parabolic in shape, and the peak magnitude of nBUA was observed at approximately 60% of bone porosity. These results agreed with the published experimental data and demonstrated that according to the stratified model, reflection and transmission were important factors in the ultrasonic propagation through the trabecular bone.

Smart Ultrasound Remote Guidance Experiment (SURGE) Preliminary Findings

NASA Technical Reports Server (NTRS)

Hurst, Victor; Dulchavsky, Scott; Garcia, Kathleen; Sargsyan, Ashot; Ebert, Doug

2009-01-01

To date, diagnostic quality ultrasound images were obtained aboard the International Space Station (ISS) using the ultrasound of the Human Research Facility (HRF) rack in the Laboratory module. Through the Advanced Diagnostic Ultrasound in Microgravity (ADUM) and the Braslet-M Occlusion Cuffs (BRASLET SDTO) studies, non-expert ultrasound operators aboard the ISS have performed cardiac, thoracic, abdominal, vascular, ocular, and musculoskeletal ultrasound assessments using remote guidance from ground-based ultrasound experts. With exploration class missions to the lunar and Martian surfaces on the horizon, crew medical officers will necessarily need to operate with greater autonomy given communication delays (round trip times of up to 5 seconds for the Moon and 90 minutes for Mars) and longer periods of communication blackouts (due to orbital constraints of communication assets). The SURGE project explored the feasibility and training requirements of having non-expert ultrasound operators perform autonomous ultrasound assessments in a simulated exploration mission outpost. The project aimed to identify experience, training, and human factors requirements for crew medical officers to perform autonomous ultrasonography. All of these aims pertained to the following risks from the NASA Bioastronautics Road Map: 1) Risk 18: Major Illness and Trauna; 2) Risk 20) Ambulatory Care; 3) Risk 22: Medical Informatics, Technologies, and Support Systems; and 4) Risk 23: Medical Skill Training and Maintenance.

Ultrasound image-guided therapy enhances antitumor effect of cisplatin.

PubMed

Sasaki, Noboru; Kudo, Nobuki; Nakamura, Kensuke; Lim, Sue Yee; Murakami, Masahiro; Kumara, W R Bandula; Tamura, Yu; Ohta, Hiroshi; Yamasaki, Masahiro; Takiguchi, Mitsuyoshi

2014-01-01

The aim of this study was to clarify whether ultrasound image-guided cisplatin delivery with an intratumor microbubble injection enhances the antitumor effect in a xenograft mouse model. Canine thyroid adenocarcinoma cells were used for all experiments. Before in vivo experiments, the cisplatin and microbubble concentration and ultrasound exposure time were optimized in vitro. For in vivo experiments, cells were implanted into the back of nude mice. Observed by a diagnostic ultrasound machine, a mixture of cisplatin and ultrasound contrast agent, Sonazoid, microbubbles was injected directly into tumors. The amount of injected cisplatin and microbubbles was 1 μg/tumor and 1.2 × 10(7) microbubbles/tumor, respectively, with a total injected volume of 20 μl. Using the same diagnostic machine, tumors were exposed to ultrasound for 15 s. The treatment was repeated four times. The combination of cisplatin, microbubbles, and ultrasound significantly delayed tumor growth as compared with no treatment (after 18 days, 157 ± 55 vs. 398 ± 49 mm(3), P = 0.049). Neither cisplatin alone nor the combination of cisplatin and ultrasound delayed tumor growth. The treatment did not decrease the body weight of mice. Ultrasound image-guided anticancer drug delivery may enhance the antitumor effects of drugs without obvious side effects.

Is it necessary to perform prophylactic cholecystectomy for all symptomatic gallbladder polyps diagnosed with ultrasound?

PubMed

Velidedeoğlu, Mehmet; Çitgez, Bülent; Arıkan, Akif Enes; Ayan, Fadıl

2017-01-01

The main aim of this study is to determine the necessity of cholecystectomy in patients with ultrasound diagnosed symptomatic polypoid lesions of the gallbladder. The data of 82 patients with polypoid lesions of the gallbladder who had cholecystectomy between 2000 and 2012 were analyzed retrospectively with preoperative ultrasound and histopathology results. The mean age was 48.05±11.18 years (range 25-74 years). All patients underwent preoperative ultrasound examination. Eighteen (22%) of the 82 patients were asymptomatic; their polypoid lesions of the gallbladder were detected with ultrasound during a check-up or other reasons. In 45 (55%) of cases pathology reported no polypoid lesions of the gallbladder. Right upper quadrant or epigastric pain was the most common symptom (41.46%) that led to hepatobiliary ultrasound, the other symptom was dyspepsia (36.59%). On preoperative ultrasound evaluation, 22 patients had multiple polyps, and 9 of these 22 patients had at least 3 polyps. There is an inaccuracy of ultrasound to detect polypoid lesions of the gallbladder. After diagnosing polypoid lesions of the gallbladder by using standard ultrasound, further pre-operative diagnostic tests are needed to help discriminating benign lesions from malignant ones, which may prevent unnecessary surgery regardless of symptoms.

Ultrasound assisted enzyme catalyzed hydrolysis of waste cooking oil under solvent free condition.

PubMed

Waghmare, Govind V; Rathod, Virendra K

2016-09-01

The present work demonstrates the hydrolysis of waste cooking oil (WCO) under solvent free condition using commercial available immobilized lipase (Novozyme 435) under the influence of ultrasound irradiation. The process parameters were optimized using a sequence of experimental protocol to evaluate the effects of temperature, molar ratios of substrates, enzyme loading, duty cycle and ultrasound intensity. It has been observed that ultrasound-assisted lipase-catalyzed hydrolysis of WCO would be a promising alternative for conventional methods. A maximum conversion of 75.19% was obtained at mild operating parameters: molar ratio of oil to water (buffer pH 7) 3:1, catalyst loading of 1.25% (w/w), lower ultrasound power 100W (ultrasound intensity - 7356.68Wm(-2)), duty cycle 50% and temperature (50°C) in a relatively short reaction time (2h). The activation energy and thermodynamic study shows that the hydrolysis reaction is more feasible when ultrasound is combined with mechanical agitation as compared with the ultrasound alone and simple conventional stirring technique. Application of ultrasound considerably reduced the reaction time as compared to conventional reaction. The successive use of the catalyst for repetitive cycles under the optimum experimental conditions resulted in a loss of enzymatic activity and also minimized the product conversion. Copyright © 2016. Published by Elsevier B.V.

Accuracy of contrast-enhanced ultrasound in the detection of bladder cancer

PubMed Central

Nicolau, C; Bunesch, L; Peri, L; Salvador, R; Corral, J M; Mallofre, C; Sebastia, C

2011-01-01

Objective To assess the accuracy contrast-enhanced ultrasound (CEUS) in bladder cancer detection using transurethral biopsy in conventional cystoscopy as the reference standard and to determine whether CEUS improves the bladder cancer detection rate of baseline ultrasound. Methods 43 patients with suspected bladder cancer underwent conventional cystoscopy with transurethral biopsy of the suspicious lesions. 64 bladder cancers were confirmed in 33 out of 43 patients. Baseline ultrasound and CEUS were performed the day before surgery and the accuracy of both techniques for bladder cancer detection and number of detected tumours were analysed and compared with the final diagnosis. Results CEUS was significantly more accurate than ultrasound in determining presence or absence of bladder cancer: 88.37% vs 72.09%. Seven of eight uncertain baseline ultrasound results were correctly diagnosed using CEUS. CEUS sensitivity was also better than that of baseline ultrasound per number of tumours: 65.62% vs 60.93%. CEUS sensitivity for bladder cancer detection was very high for tumours larger than 5 mm (94.7%) but very low for tumours <5 mm (20%) and also had a very low negative predictive value (28.57%) in tumours <5 mm. Conclusion CEUS provided higher accuracy than baseline ultrasound for bladder cancer detection, being especially useful in non-conclusive baseline ultrasound studies. PMID:21123306

Mechanism study of multimode ultrasound pretreatment on the enzymolysis of wheat gluten.

PubMed

Zhang, Yanyan; Li, Jing; Li, Suyun; Ma, Haile; Zhang, Hua

2018-03-01

Ultrasound pretreatment could improve the angiotensin-I converting enzyme (ACE) inhibitory activity of hydrolysates of wheat gluten (WG). The working mode of ultrasound has an important effect on the enzymatic hydrolysis of protein. The results showed that the optimum working mode of ultrasound was alternate dual-frequency mode (20/35 kHz), substrate concentration was 30 g L -1 , initial temperature of the suspension was 30 °C, ultrasound pretreatment time was 10 min and power density was 150 W L -1 . Under optimised conditions, ACE inhibitory activity of WG hydrolysates reached to its maximum value in advance. The surface hydrophobicity (H 0 ) of WG and the content of small peptides at the beginning of the enzymolysis were improved by the ultrasound pretreatment. The structure of WG was destroyed by the ultrasound pretreatment. The enzymatic residue of ultrasound pretreated WG were damaged greater than control. It was concluded that alternate dual-frequency ultrasound pretreatment improved the ACE inhibitory activity. Ultrasonic pretreatment may loosen the tissue of WG aggregate, and help the enzyme alcalase to attack the interior of WG aggregate easily, which resulted in the release of low molecular weight peptides from WG aggregate. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Effects of low-frequency ultrasound on heterogenous deacetylation of chitin.

PubMed

Ngo, Thi Hoai Duong; Ngo, Dang Nghia

2017-11-01

The effects of low frequency ultrasound to the heterogeneous deacetylation of chitin from the shell of white shrimp (Penaeus vannamei) were examined. The deacetylation process was carried out in the range of NaOH concentrations from 35% to 65% (w/w) with and without the ultrasound in the frequency of 37kHz, RMS=300W. The chitosan obtained was characterized in the degree of deacetylation, solubility, FT-IR and X-ray diffraction. The results showed that the behaviors of the deacetylation in two cases, with and without ultrasound, were similar but the ultrasound enhanced the deacetylation rate and therefore reduced the time of the reaction to get the same degree of deacetylation. The role of ultrasound in the process showed more clearly in the low concentration of sodium hydroxide, below 45% (w/w). At the higher concentration of sodium hydroxide, the influence of ultrasound on facilitating deacetylation decreased significantly, however, ultrasound was still keeping on its improving effect on the solubility of the chitosan obtained. The data from FT-IR and X-ray diffraction did not show any considerable change in structure of both kinds of chitosan. This study showed the potential of using low frequency ultrasound in enhancing the deacetylation of chitin for reducing the chemical consumption. Copyright © 2017 Elsevier B.V. All rights reserved.

CAN ULTRASOUND ABDOMEN HELP IN EARLY DIAGNOSIS OF DIABETES MELLITUS? AN OBSERVATIONAL STUDY.

PubMed

Anwar, Javed; Aamir, Muhammad Omer; Sanaullah; Imdad, Zeeshan ul Hasnain; Parveen, Ishrat; Yousaf, Nasreen

2015-01-01

Diabetes mellitus is a common disease. Similarly, ultrasound findings of fatty change and renal crystals are commonly seen on ultrasound. In the personal observation of the main author over the past so many years it was noticed that Diabetes Mellitus, Fatty liver and renal crystals all sit well together. This study tries to establish a relationship between diabetes mellitus renal echogenic foci and fatty liver. This study is first of its kind, as nobody has ever before investigated an association between the renal echogenic foci and fatty liver in relation to diabetes mellitus. This cross-sectional, observational study was conducted at Radiology Department Combined Military Hospital, Kohat From 2nd June 2013 to 30th May 2014. Three hundred patients were collected on the basis of having fatty liver and renal echogenic foci on ultrasound and three hundred more patients were collected who had no fatty liver or renal echogenic foci on ultrasound. Their labs were done for diabetes mellitus. The patients having renal echogenic foci together with fatty liver had 83% positive rate of being diabetics, while patients with no fatty liver and no echogenic foci on ultrasonography had only 0.6% Positive rate of being diabetics. Our results provided the first demonstration of an association between renal echogenic foci together with fatty liver with the diabetes mellitus. Thus ultrasound examination of abdomen can be helpful in its early diagnosis if we make a protocol of doing fasting and random blood sugars in all those patients who have positive renal echogenic foci and fatty liver on their ultrasound examination.

[Proposal for the systematization of the elastographic study of mammary lesions through ultrasound scan].

PubMed

Fleury, Eduardo de Faria Castro; Fleury, Jose Carlos Vendramini; Oliveira, Vilmar Marques de; Rinaldi, Jose Francisco; Piato, Sebastiao; Roveda Junior, Decio

2009-01-01

Proposal of systematization for the elastographic study in the ultrasound routine. Evaluation was made of 308 patients forwarded to the breast intervention service in the CTC-Genesis from May 1, 2007 to March 1, 2008 to perform percutaneous breast biopsy. Prior to the percutaneous biopsy, an ultrasound study and an elastography were performed. Lesions were primarily analyzed and classified according to the Bi-Rads lexicon criteria by the conventional ultrasound scan (B mode). The elastography was then performed and analyzed in accordance with the systematization proposed by the authors, using images obtained during compression and after decompression of the area of interest. Lesions were classified following the system developed by the authors using a four-point scale, where scores (1) and (2) were considered benign, score (3) probably benign and score (4) suspicion of malignancy. Results obtained by the two methods were compared with the histological results using the areas within the ROC (receiver operator curves) curves. The area within the curve for elastography was of 0.952 with a confidence interval between 0.910 and 0.966, error of 0.023, and of 0.867 with a confidence interval between 0.823 and 0.903, error of 0.0333 for the ultrasound. When the areas were compared, a difference between the curves of 0.026 was observed, which was statistically significant. This work shows the systematization of the elastographic study using information obtained during compression and after decompression of the ultrasound scan sample, thus showing that elastography might enhance the assessment of risk of malignancy for lesions characterized by the ultrasound.

Ultrasound vs. Computed Tomography for Severity of Hydronephrosis and Its Importance in Renal Colic.

PubMed

Leo, Megan M; Langlois, Breanne K; Pare, Joseph R; Mitchell, Patricia; Linden, Judith; Nelson, Kerrie P; Amanti, Cristopher; Carmody, Kristin A

2017-06-01

Supporting an "ultrasound-first" approach to evaluating renal colic in the emergency department (ED) remains important for improving patient care and decreasing healthcare costs. Our primary objective was to compare emergency physician (EP) ultrasound to computed tomography (CT) detection of hydronephrosis severity in patients with suspected renal colic. We calculated test characteristics of hydronephrosis on EP-performed ultrasound for detecting ureteral stones or ureteral stone size >5mm. We then analyzed the association of hydronephrosis on EP-performed ultrasound, stone size >5mm, and proximal stone location with 30-day events. This was a prospective observational study of ED patients with suspected renal colic undergoing CT. Subjects had an EP-performed ultrasound evaluating for the severity of hydronephrosis. A chart review and follow-up phone call was performed. We enrolled 302 subjects who had an EP-performed ultrasound. CT and EP ultrasound results were comparable in detecting severity of hydronephrosis ( x 2 =51.7, p<0.001). Hydronephrosis on EP-performed ultrasound was predictive of a ureteral stone on CT (PPV 88%; LR+ 2.91), but lack of hydronephrosis did not rule it out (NPV 65%). Lack of hydronephrosis on EP-performed ultrasound makes larger stone size >5mm less likely (NPV 89%; LR- 0.39). Larger stone size > 5mm was associated with 30-day events (OR 2.30, p=0.03). Using an ultrasound-first approach to detect hydronephrosis may help physicians identify patients with renal colic. The lack of hydronephrosis on ultrasound makes the presence of a larger ureteral stone less likely. Stone size >5mm may be a useful predictor of 30-day events.

Ultrasound vs. Computed Tomography for Severity of Hydronephrosis and Its Importance in Renal Colic

PubMed Central

Leo, Megan M.; Langlois, Breanne K.; Pare, Joseph R.; Mitchell, Patricia; Linden, Judith; Nelson, Kerrie P.; Amanti, Cristopher; Carmody, Kristin A.

2017-01-01

Introduction Supporting an “ultrasound-first” approach to evaluating renal colic in the emergency department (ED) remains important for improving patient care and decreasing healthcare costs. Our primary objective was to compare emergency physician (EP) ultrasound to computed tomography (CT) detection of hydronephrosis severity in patients with suspected renal colic. We calculated test characteristics of hydronephrosis on EP-performed ultrasound for detecting ureteral stones or ureteral stone size >5mm. We then analyzed the association of hydronephrosis on EP-performed ultrasound, stone size >5mm, and proximal stone location with 30-day events. Methods This was a prospective observational study of ED patients with suspected renal colic undergoing CT. Subjects had an EP-performed ultrasound evaluating for the severity of hydronephrosis. A chart review and follow-up phone call was performed. Results We enrolled 302 subjects who had an EP-performed ultrasound. CT and EP ultrasound results were comparable in detecting severity of hydronephrosis (x2=51.7, p<0.001). Hydronephrosis on EP-performed ultrasound was predictive of a ureteral stone on CT (PPV 88%; LR+ 2.91), but lack of hydronephrosis did not rule it out (NPV 65%). Lack of hydronephrosis on EP-performed ultrasound makes larger stone size >5mm less likely (NPV 89%; LR− 0.39). Larger stone size > 5mm was associated with 30-day events (OR 2.30, p=0.03). Conclusion Using an ultrasound-first approach to detect hydronephrosis may help physicians identify patients with renal colic. The lack of hydronephrosis on ultrasound makes the presence of a larger ureteral stone less likely. Stone size >5mm may be a useful predictor of 30-day events. PMID:28611874

Comparison of a pocket-size ultrasound device with a premium ultrasound machine: diagnostic value and time required in bedside ultrasound examination.

PubMed

Stock, Konrad Friedrich; Klein, Bettina; Steubl, Dominik; Lersch, Christian; Heemann, Uwe; Wagenpfeil, Stefan; Eyer, Florian; Clevert, Dir-Andre

2015-10-01

Time savings and clinical accuracy of a new miniature ultrasound device was investigated utilizing comparison with conventional high-end ultrasound instruments. Our objective was to determine appropriate usage and limitations of this diagnostic tool in internal medicine. We investigated 28 patients from the internal-medicine department. Patients were examined with the Acuson P10 portable device and a Sonoline Antares instrument in a cross-over design. All investigations were carried out at the bedside; the results were entered on a standardized report form. The time for the ultrasound examination (transfer time, setting up and disassembly, switching on and off, and complete investigation time) was recorded separately. Mean time for overall examination per patient with the portable ultrasound device was shorter (25.0 ± 4.5 min) than with the high-end machine (29.4 ± 4.4 min; p < 0.001). When measuring the size of liver, spleen, and kidneys, the values obtained differed significantly between portable device and the high-end instrument. In our study, we identified 113 pathological ultrasound findings with the high-end ultrasound machine, while 82 pathological findings (73%) were concordantly detected with the portable ultrasound device. The main diagnostic strengths of the portable device were in the detection of ascites (sensitivity 80%), diagnosis of fatty liver, and identification of severe parenchymal liver damage. The clinical utility of portable ultrasound machines is limited. There will be clinical roles for distinct clinical questions such as detection of ascites or pleural effusion when used by experienced examiners. However, sensitivity in detecting multiple pathologies is not comparable to high-end ultrasound machines.

Calibration and Evaluation of Ultrasound Thermography Using Infrared Imaging.

PubMed

Hsiao, Yi-Sing; Deng, Cheri X

2016-02-01

Real-time monitoring of the spatiotemporal evolution of tissue temperature is important to ensure safe and effective treatment in thermal therapies including hyperthermia and thermal ablation. Ultrasound thermography has been proposed as a non-invasive technique for temperature measurement, and accurate calibration of the temperature-dependent ultrasound signal changes against temperature is required. Here we report a method that uses infrared thermography for calibration and validation of ultrasound thermography. Using phantoms and cardiac tissue specimens subjected to high-intensity focused ultrasound heating, we simultaneously acquired ultrasound and infrared imaging data from the same surface plane of a sample. The commonly used echo time shift-based method was chosen to compute ultrasound thermometry. We first correlated the ultrasound echo time shifts with infrared-measured temperatures for material-dependent calibration and found that the calibration coefficient was positive for fat-mimicking phantom (1.49 ± 0.27) but negative for tissue-mimicking phantom (-0.59 ± 0.08) and cardiac tissue (-0.69 ± 0.18°C-mm/ns). We then obtained the estimation error of the ultrasound thermometry by comparing against the infrared-measured temperature and revealed that the error increased with decreased size of the heated region. Consistent with previous findings, the echo time shifts were no longer linearly dependent on temperature beyond 45°C-50°C in cardiac tissues. Unlike previous studies in which thermocouples or water bath techniques were used to evaluate the performance of ultrasound thermography, our results indicate that high-resolution infrared thermography is a useful tool that can be applied to evaluate and understand the limitations of ultrasound thermography methods. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Patterns of physical activity and ultrasound attenuation by heel bone among Norfolk cohort of European Prospective Investigation of Cancer (EPIC Norfolk): population based study

PubMed Central

Jakes, Rupert W; Khaw, Kay-Tee; Day, Nicholas E; Bingham, Sheila; Welch, Ailsa; Oakes, Suzy; Luben, Robert; Dalzell, Nicola; Reeve, Jonathan; Wareham, Nicholas J

2001-01-01

Objectives To study associations between patterns of physical activity and ultrasound attenuation by the heel bone in men and women. Design Cross sectional, population based study. Setting Norfolk. Participants 2296 men and 2914 women aged 45-74 registered with general practices participating in European Prospective Investigation into Cancer (EPIC Norfolk). Results Self reported time spent in high impact physical activity was strongly and positively associated with ultrasound attenuation by the heel bone, independently of age, weight, and other confounding factors. Men who reported participating in ⩾2 hours/week of high impact activity had 8.44 dB/MHz (95% confidence interval 4.49 to 12.40) or 9.5%, higher ultrasound attenuation than men who reported no activity of this type. In women, the difference in ultrasound attenuation between those reporting any high impact activity and those reporting none was 2.41 dB/MHz (0.45 to 4.37) or 3.4% higher. In women this effect was similar in size to that of an age difference of four years. Moderate impact activity had no effect. However, climbing stairs was strongly independently associated with ultrasound attenuation in women (0.64 dB/MHz (0.19 to 1.09) for each additional five flights of stairs). There was a significant negative association in women between time spent watching television or video and heel bone ultrasound attenuation, which decreased by 0.08 dB/MHz (0.02 to 0.14) for each additional hour of viewing a week. Conclusions High impact physical activity is independently associated with ultrasound attenuation by the heel bone in men and women. As low ultrasound attenuation has been shown to predict increased risk of hip fracture, interventions to promote participation in high impact activities may help preserve bone density and reduce the risk of fracture. However, in older people such interventions may be inappropriate as they could increase the likelihood of falls. PMID:11159572

Ultrasound—biophysics mechanisms†

PubMed Central

O'Brien, William D.

2007-01-01

Ultrasonic biophysics is the study of mechanisms responsible for how ultrasound and biological materials interact. Ultrasound-induced bioeffect or risk studies focus on issues related to the effects of ultrasound on biological materials. On the other hand, when biological materials affect the ultrasonic wave, this can be viewed as the basis for diagnostic ultrasound. Thus, an understanding of the interaction of ultrasound with tissue provides the scientific basis for image production and risk assessment. Relative to the bioeffect or risk studies, that is, the biophysical mechanisms by which ultrasound affects biological materials, ultrasound-induced bioeffects are generally separated into thermal and nonthermal mechanisms. Ultrasonic dosimetry is concerned with the quantitative determination of ultrasonic energy interaction with biological materials. Whenever ultrasonic energy is propagated into an attenuating material such as tissue, the amplitude of the wave decreases with distance. This attenuation is due to either absorption or scattering. Absorption is a mechanism that represents that portion of ultrasonic wave that is converted into heat, and scattering can be thought of as that portion of the wave, which changes direction. Because the medium can absorb energy to produce heat, a temperature rise may occur as long as the rate of heat production is greater than the rate of heat removal. Current interest with thermally mediated ultrasound-induced bioeffects has focused on the thermal isoeffect concept. The non-thermal mechanism that has received the most attention is acoustically generated cavitation wherein ultrasonic energy by cavitation bubbles is concentrated. Acoustic cavitation, in a broad sense, refers to ultrasonically induced bubble activity occurring in a biological material that contains pre-existing gaseous inclusions. Cavitation-related mechanisms include radiation force, microstreaming, shock waves, free radicals, microjets and strain. It is more challenging to deduce the causes of mechanical effects in tissues that do not contain gas bodies. These ultrasonic biophysics mechanisms will be discussed in the context of diagnostic ultrasound exposure risk concerns. PMID:16934858

Imaging of idle breast implants with ultrasound-strain elastography- A first experimental study to establish criteria for accurate imaging of idle implants via ultrasound-strain elastography.

PubMed

Kuehlmann, Britta; Prantl, Lukas; Michael Jung, Ernst

2016-01-01

To investigate whether there are fundamental sonographic and elastographic criteria to precisely assess different surfaces and fillings of idle breast implants and to determine their most distinctive parameters. This was a comparative study of different unused breast implant materials, neighter in animals nor in humans. This knowledge should be transferred in vivo to develop an objective measurement tool. Nine idle breast implants-silicone and polyurethane (PU)-were examined in an experimental study by using ultrasound B-mode with tissue harmonic imaging (THI), speckle reduction imaging (SRI, level 0-4), cross-beam (CB, low, medium, high), photopic and the colour coded ultrasound-strain elastography with a multifrequency probe (9-15 MHz).Using a standardised protocol the implants' centre as well as the edge were analysed by one experienced examiner. Two independent readers performed analysis and evaluation. For image interpretation a score was created (score 0:inadequate image, score 5:best image quality). The highest score result for the centre was achieved by using ultrasound with B-mode in addition with CB level medium, SRI level 2, THI and photopic (mean:3.22±SD:1.56), but without any statistic significant difference (t-value = 0.71). With elastography the implants' edge in general was represented without disruptive artefacts (3.89±0.60) with statistic significant difference (t-value = 5.29). Implants filled with inner cohesive silicone gel II° showed best imaging conditions for their centre via ultrasound (5±0) as well as for their edge via elastography (4.50±0.71). Ultrasound-strain elastography and high resolution ultrasound represent a valuable measurement tool to evaluate different properties of idle breast implants. These modified ultrasound examinations could be an additional help for clinical investigations and be correlated with Baker's Classification.

Ultrasound assisted biogas production from landfill leachate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oz, Nilgün Ayman, E-mail: nilgunayman@comu.edu.tr; Yarimtepe, Canan Can

Highlights: • Effect of low frequency ultrasound pretreatment on leachate was investigated. • Three different ultrasound energy inputs (200, 400 and 600 W/l) was applied. • Low-frequency ultrasound treatment increased soluble COD in landfill leachate. • Application of ultrasound to leachate increased biogas production about 40%. • Application of ultrasound to leachate increased total methane production rate about 20%. - Abstract: The aim of this study is to increase biogas production and methane yield from landfill leachate in anaerobic batch reactors by using low frequency ultrasound as a pretreatment step. In the first part of the study, optimum conditions formore » solubilization of organic matter in leachate samples were investigated using various sonication durations at an ultrasound frequency of 20 kHz. The level of organic matter solubilization during ultrasonic pretreatment experiments was determined by calculating the ratio of soluble chemical oxygen demand (sCOD) to total chemical oxygen demand (tCOD). The sCOD/tCOD ratio was increased from 47% in raw leachate to 63% after 45 min sonication at 600 W/l. Non-parametric Friedman’s test indicated that ultrasonic pretreatment has a significant effect on sCOD parameter for leachate (p < 0.05). In the second part of the study, anaerobic batch reactors were operated for both ultrasonically pretreated and untreated landfill leachate samples in order to assess the effect of sonication on biogas and methane production rate. In anaerobic batch reactor feed with ultrasonically pretreated leachate, 40% more biogas was obtained compared to the control reactor. For statistical analysis, Mann–Whitney U test was performed to compare biogas and methane production rates for raw and pretreated leachate samples and it has been found that ultrasonic pretreatment significantly enhanced biogas and methane production rates from leachate (p < 0.05) in anaerobic batch reactors. The overall results showed that low frequency ultrasound pretreatment can be potentially used for wastewater management especially with integration of anaerobic processes.« less

Reversible and irreversible vascular bioeffects induced by ultrasound and microbubbles in chorioallantoic membrane model

NASA Astrophysics Data System (ADS)

Tarapacki, Christine; Kuebler, Wolfgang M.; Tabuchi, Arata; Karshafian, Raffi

2017-03-01

Background: The application of ultrasound and microbubbles at therapeutic conditions has been shown to improve delivery of molecules, cause vasoconstriction, modulate blood flow and induce a vascular shut down in in vivo cancerous tissues. The underlying mechanism has been associated with the interaction of ultrasonically-induced microbubble oscillation and cavitation with the blood vessel wall. In this study, the effect of ultrasound and microbubbles on blood flow and vascular architecture was studied using a fertilized chicken egg CAM (chorioallantoic membrane) model. Methods: CAM at day 12 of incubation (Hamburger-Hamilton stage 38-40) were exposed to ultrasound at varying acoustic pressures (160, 240 and 320 kPa peak negative pressure) in the presence of Definity microbubbles and 70 kDa FITC dextran fluorescent molecules. A volume of 50 µL Definity microbubbles were injected into a large anterior vein of the CAM prior to ultrasound exposure. The ultrasound treatment sequence consisted of 5 s exposure at 500 kHz frequency, 8 cycles and 1 kHz pulse repetition frequency with 5 s off for a total exposure of 2 minutes. Fluorescent videos and images of the CAM vasculature were acquired using intravital microscopy prior, during and following the ultrasound exposure. Perfusion was quantified by measuring the length of capillaries in a region of interest using Adobe Illustrator. Results and Discussion: The vascular bioeffects induced by USMB increased with acoustic peak negative pressure. At 160 kPa, no visible differences were observed compared to the control. At 240 kPa, a transient decrease in perfusion with subsequent recovery within 15 minutes was observed, whereas at 320 kPa, the fluorescent images showed an irreversible vascular damage. The study indicates that a potential mechanism for the transient decrease in perfusion may be related to blood coagulation. The results suggest that ultrasound and microbubbles can induce reversible and irreversible vascular changes depending on the ultrasound exposure pressure.

A Comparison of 1- and 3.2-MHz Low-Intensity Pulsed Ultrasound on Osteogenesis on Porous Titanium Alloy Scaffolds: An In Vitro and In Vivo Study.

PubMed

Feng, Lifang; Liu, Xiaohan; Cao, Hongjuan; Qin, Limei; Hou, Wentao; Wu, Lin

2018-05-21

Low-intensity pulsed ultrasound (LIPUS) combined with porous scaffolds can be used as a new therapy to treat bone defect repair. The aim of this study was to evaluate the effects of 1 and 3.2 MHz LIPUS on osteogenesis on porous Ti64 alloy scaffolds for both in vitro and in vivo studies. Scaffolds were randomly divided into the high-frequency ultrasound group, low-frequency ultrasound group, and control group. Mouse pre-osteoblast cells were cultured with porous Ti-6Al-4V scaffolds in vitro to evaluate cell proliferation and differentiation. In addition, scaffolds were implanted into rabbit mandibular defects in vivo. The effects of LIPUS on bone regeneration were evaluated by observing the micro-computed tomography (micro-CT), toluidine blue staining, and von Kossa staining. The results revealed no significant difference in the cell counting kit-8 values between the ultrasound groups and control groups (P > .05). Compared with the control group, ultrasound promoted alkaline phosphatase activity and osteocalcin levels of the cells on the scaffolds (P < .05), but there was no significant difference between the two frequencies. In addition, histomorphologic analyses revealed that the volume and amount of new bone formation increased and that bone maturity improved in the ultrasound groups compared with the control group, but no significant difference was noted between the two frequencies. Under the present experimental conditions, LIPUS promoted osteoblast differentiation and promoted bone maturity on porous Ti64 scaffolds. No significant differences were noted between the two frequencies. © 2018 by the American Institute of Ultrasound in Medicine.

COMPARISON OF THORACIC ULTRASONOGRAPHY AND RADIOGRAPHY FOR THE DETECTION OF INDUCED SMALL VOLUME PNEUMOTHORAX IN THE HORSE.

PubMed

Partlow, Jessica; David, Florent; Hunt, Luanne Michelle; Relave, Fabien; Blond, Laurent; Pinilla, Manuel; Lavoie, Jean-Pierre

2017-05-01

Small volume pneumothorax can be challenging to diagnose in horses. The current standard method for diagnosis is standing thoracic radiography. We hypothesized that thoracic ultrasonography would be more sensitive. Objectives of this prospective, experimental study were to describe a thoracic ultrasound method for detection of small volume pneumothorax in horses and to compare results of radiography and ultrasound in a sample of horses with induced small volume pneumothorax. Six mature healthy horses were recruited for this study. For each horse, five 50 ml air boluses were sequentially introduced via a teat cannula into the pleural space. Lateral thoracic radiographs and standardized ultrasound (2D and M-mode) examinations of both hemithoraces were performed following administration of each 50 ml air bolus. Radiographs and ultrasound images/videos were analyzed for detection of pneumothorax by four independent investigators who were unaware of treatment status. Sensitivity, specificity, positive predictive values, negative predictive values, and agreement among investigators (Kappa test, κ) were calculated for radiography, 2D and M-mode ultrasound. Comparisons were made using a chi-squared exact test with significance set at P < 0.05. Two-dimensional (84%) and M-mode (80%) ultrasound were more sensitive than radiography (48%) for pneumothorax detection (P = 0.02 and P = 0.04, respectively). Specificity and positive predictive values were similar for all three imaging modalities (P = 1). Agreement between investigators for pneumothorax detection was excellent for 2D ultrasound (κ = 1), very good for M-mode ultrasound (κ = 0.87), and good for radiography (κ = 0.79). Findings from this experimental study supported the use of thoracic ultrasonography as a diagnostic method for detecting pneumothorax in horses. © 2017 American College of Veterinary Radiology.

Performance of Ultrasound in the Diagnosis of Gout in a Multi-Center Study: Comparison with Monosodium Urate Crystal Analysis as the Gold Standard

PubMed Central

Ogdie, Alexis; Taylor, William J; Neogi, Tuhina; Fransen, Jaap; Jansen, Tim L; Schumacher, H. Ralph; Louthrenoo, Worawit; Vazquez-Mellado, Janitzia; Eliseev, Maxim; McCarthy, Geraldine; Stamp, Lisa K.; Perez-Ruiz, Fernando; Sivera, Francisca; Ea, Hang-Korng; Gerritsen, Martijn; Cagnotto, Giovanni; Cavagna, Lorenzo; Lin, Chingtsai; Chou, Yin-Yi; Tausche, Anne-Kathrin; Ochtrop, Manuella Lima Gomes; Janssen, Matthijs; Chen, Jiunn-Horng; Slot, Ole; Lazovskis, Juris; White, Douglas; Cimmino, Marco A.; Uhlig, Till; Dalbeth, Nicola

2017-01-01

Objectives To examine the performance of ultrasound for the diagnosis of gout using presence of monosodium urate (MSU) crystals as the gold standard. Methods We analyzed data from the Study for Updated Gout Classification Criteria (SUGAR), a large, multi-center observational cross-sectional study of consecutive subjects with at least one swollen joint who conceivably may have gout. All subjects underwent arthrocentesis; cases were subjects with MSU crystal confirmation. Rheumatologists or radiologists, blinded to the results of the MSU crystal analysis, performed ultrasound on one or more clinically affected joints. Ultrasound findings of interest were: double contour sign (DCS), tophus, and ‘snowstorm’ appearance. Sensitivity, specificity, positive and negative predictive values (PPV and NPV) were calculated. Multivariable logistic regression models were used to examine factors associated with positive ultrasound results among subjects with gout. Results Ultrasound was performed in 824 subjects (416 cases and 408 controls). The sensitivity, specificity, PPV and NPV for the presence of any one of the features were 76.9%, 84.3%, 83.3% and 78.1% respectively. Sensitivity was higher among subjects with disease ≥2 years duration and among subjects with subcutaneous nodules on exam (suspected tophus). Associations with a positive ultrasound finding included suspected clinical tophus (odds ratio 4.77; 95% CI 2.23–10.21), any abnormal plain film radiograph (4.68; 2.68–8.17) and serum urate (1.31; 1.06–1.62). Conclusions Ultrasound features of MSU crystal deposition had high specificity and high positive predictive value but more limited sensitivity for early gout. The specificity remained high in subjects with early disease and without clinical signs of tophi. PMID:27748084

Impact of Focused Ultrasound-enhanced Drug Delivery on Survival in Rats with Glioma

NASA Astrophysics Data System (ADS)

Treat, Lisa Hsu; Zhang, Yongzhi; McDannold, Nathan; Hynynen, Kullervo

2009-04-01

Malignancies of the brain remain difficult to treat with chemotherapy because the selective permeability of the blood-brain barrier (BBB) blocks many potent agents from reaching their target. Previous studies have illustrated the feasibility of drug and antibody delivery across the BBB using MRI-guided focused ultrasound. In this study, we investigated the impact of focused ultrasound-enhanced delivery of doxorubicin on survival in rats with aggressive glioma. Sprague-Dawley rats were implanted with 9 L gliosarcoma cells in the brain. Eight days after implantation, each rat received one of the following: (1) no treatment (control), (2) a single treatment with microbubble-enhanced MRI-guided focused ultrasound (FUS only), (3) a single treatment with i.v. liposomal doxorubicin (DOX only), or (4) a single treatment with microbubble-enhanced MRI-guided focused ultrasound and concurrent i.v. injections of liposomal doxorubicin (FUS+DOX). The survival time from implantation to death or euthanasia was recorded. We observed a modest but significant increase in median survival time in rats treated with combined MRI-guided focused ultrasound chemotherapy, compared to chemotherapy alone (p<0.001). There was no significant improvement in survival between those who received stand-alone chemotherapy and those who did not receive any treatment (p>0.10). Our study demonstrates for the first time a therapeutic benefit achieved with ultrasound-enhanced drug delivery across the blood-brain barrier. This confirmation of efficacy in an in vivo tumor model indicates that targeted drug delivery using MRI-guided focused ultrasound has the potential to have a major impact on the treatment of patients with brain tumors and other neurological disorders.

The diagnostic performance of ultrasound for acute appendicitis in pregnant and young nonpregnant women: A case-control study.

PubMed

Segev, Lior; Segev, Yakir; Rayman, Shlomi; Nissan, Aviram; Sadot, Eran

2016-10-01

Ultrasonography is frequently used to diagnose acute appendicitis in women of reproductive age, but its diagnostic value in pregnant patients remains unclear. This study sought to compare the diagnostic performance of ultrasound in pregnant and young nonpregnant women with suspected acute appendicitis. The database of a single tertiary medical center was reviewed for all women of reproductive age who underwent appendectomy either during pregnancy (2000-2014) or in the nonpregnant state (2004-2007) following ultrasound evaluation. The performance of ultrasound in terms of predicting the final pathologic diagnosis was compared between the pregnant and non pregnant groups using receiver operating characteristic curve analysis. Of 586 young women treated for appendicitis during the study periods (92 pregnant, 494 non-pregnant), 200 underwent preoperative ultrasound [67 pregnant, and 133 nonpregnant young women]. The pregnant and nonpregnant groups were comparable in age and presenting symptoms. There was no significant difference in the predictive performance of ultrasound between the two groups (AUC 0.76 and 0.73 respectively, p = 0.78) or within the pregnant group, by trimester [first (n = 23), AUC 0.73; second (n = 32), AUC 0.67; third (n = 12), AUC 0.86; p = 0.4]. Ultrasound had a positive predictive value of 0.94 in the pregnant group and 0.91 in the nonpregnant group; corresponding negative predictive values were 0.40 and 0.43. There appears to be no difference in the ability of ultrasound to predict the diagnosis of acute appendicitis between pregnant women and nonpregnant women of reproductive age. Therefore, similar preoperative imaging algorithms may be used in both patient populations. Copyright © 2016 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.

Transvaginal ultrasound-guided embryo transfer in IVF.

PubMed

Larue, L; Keromnes, G; Massari, A; Roche, C; Moulin, J; Gronier, H; Bouret, D; Cassuto, N G; Ayel, J P

2017-05-01

To determine whether transvaginal ultrasound-guided embryo transfer is a technique that can be used routinely, whether it improves IVF outcomes and whether it makes difficult transfers easier and more successful. Non-randomized retrospective study conducted between 2012 and 2016 in the fertility center of the Diaconesses-Croix St-Simon hospital group. The outcomes of 3910 transfers, performed by 5 senior operators, under transabdominal ultrasound guidance are compared with those of 800 transfers, performed by 1 senior operator under transvaginal ultrasound guidance. The criteria studied are the feasibility of the technique and the percentage of pregnancies per transfer in the two populations described, as well as in the difficult and very difficult transfer populations. All the transfers were feasible under transvaginal ultrasound guidance without the use of forceps or additional instruments. The percentage of pregnancies per transfer is significantly increased, when the transfer is performed under transvaginal ultrasound guidance compared with that performed under transabdominal ultrasound guidance, in the general population (38%, n=800 vs 30%, n=3910; P 0.0004) and in the reference population characterized by age <38 years and >6 oocytes collected per puncture (45%, n=490 vs 36%, n=1968; P 0.002). The percentage of pregnancies per transfer (P/T) is not significantly different in the populations of easy transfers (n 695, 38% P/T), difficult transfers (n 58, 46% P/T; P=ns) and very difficult transfers (n 47, 34% P/T; P=ns). Embryo transfer is a key stage in IVF, in which the quality of performance determines the outcome. In this study, transvaginal ultrasound guidance of the transfer, which is the reference procedure in gynaecological imaging, significantly increases the percentage of pregnancies per transfer, both in the general population and in the reference population, compared with transfers performed under transabdominal ultrasound guidance. Transvaginal ultrasound facilitates the performance of difficult transfers and in particular achieves outcomes in these situations that are not significantly different from those of easy transfers. Visual monitoring of transcervical passage, which is rendered more precise and less traumatic and precision of embryo deposition are the factors that probably account for the improvement in outcomes. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Ultrasound pregnancy

MedlinePlus

Pregnancy sonogram; Obstetric ultrasonography; Obstetric sonogram; Ultrasound - pregnancy; IUGR - ultrasound; Intrauterine growth - ultrasound; Polyhydramnios - ultrasound; Oligohydramnios - ultrasound; Placenta previa - ultrasound; Multiple pregnancy - ultrasound; ...

Establishing an Ultrasound Curriculum in Undergraduate Medical Education: How Much Time Does It Take?

PubMed

Siegel-Richman, Yonaton; Kendall, John

2018-03-01

Over the years, the use of ultrasound in the medical profession has become a common occurrence. As a result, many medical schools are considering an ultrasound curriculum for first- and second-year medical students. The question posed by many of these programs is how much time and effort are required to establish such a curriculum. We at the University of Colorado School of Medicine sought to quantify the resources and time required. We conducted a cohort study that analyzed the time spent teaching, as well as the types of instructors (eg, faculty, resident, and peer student) that contributed to our ultrasound curriculum. The study population consisted of instructors who participated in the curriculum during the 2014-2015 academic year. We analyzed the amount of time that facilitators spent teaching and tabulated these data using their specialty. Our data revealed that within an academic year, a combined total of 484 hours were spent teaching ultrasound to first- and second-year medical students combined. A total of 6 days were required to teach ultrasound to first-year medical students, and a total of 5 days were required for second-year medical students. It required 1 instructor for every 8 students, and most the faculty who volunteered time were from the field of emergency medicine, followed by family medicine and radiology. We describe the number of hours and instructors required to implement an ultrasound curriculum for undergraduate medical education. © 2017 by the American Institute of Ultrasound in Medicine.

Adopting Ultrasound Guidance for Prone Percutaneous Nephrolithotomy: Evaluating the Learning Curve for the Experienced Surgeon

PubMed Central

Usawachintachit, Manint; Masic, Selma; Allen, Isabel E.; Li, Jianxing

2016-01-01

Abstract Objectives: To define the learning curve associated with adopting ultrasound guidance for prone percutaneous nephrolithotomy (PCNL) for the experienced surgeon. Methods: A prospective cohort study of consecutive patients undergoing PCNL with ultrasound guidance for renal tract access and dilation was performed. Clinical data reviewed included success in gaining renal access with ultrasound guidance, total fluoroscopic screening time, and radiation exposure dose. PCNL cases performed with fluoroscopic guidance matched for stone size served as control cases. Results: One hundred consecutive ultrasound-guided procedures performed by a single experienced endourologist were divided into five experience groups. Significant improvement in renal access success rate with ultrasound was seen after 20 cases (p < 0.05). Total fluoroscopic screening time, radiation exposure dose, and operative time were also statistically significantly improved over the study period. When compared with fluoroscopy-guided PCNL, significant decreases in total fluoroscopic screening time (33.4 ± 35.3 seconds vs 157.5 ± 84.9 seconds, p < 0.05) and radiation exposure (7.0 ± 8.7 mGy vs 47.8 ± 45.9 mGy, p < 0.05) were seen. No differences in complication rates were found. Conclusions: Ultrasound-guided renal access for PCNL can be performed effectively after 20 cases. Transition to the use of ultrasound will quickly reduce radiation exposure for patients and intraoperative personnel. PMID:27150671

The influence of external ultrasound on the histologic architecture of the organic capsule around smooth silicone implants: experimental study in rats.

PubMed

Mendes, F H; Viterbo, F; DeLucca, L

2008-05-01

Capsular contracture is the main complication related to breast silicone implants, and its prevention remains a medical challenge. The authors present experimental research examining the effect of external ultrasound on the formation and contracture of peri-implant capsules. In this study, 42 male Wistar rats had a 2-mm smooth surface implant placed in a dorsal submuscular pocket. They then were separated into "ultrasound" and "control" groups that received repeated external applications either with or without the ultrasound power on. Ultrasound applications were given three times a week for a period of 90 days. After that, both groups were housed under the same conditions with no application scheduled. Five animals of each group, killed at 30, 60, 90, and 180 days, had their implants removed along with the capsule, which received a special histologic preparation via annular sectioning that provided wide circumferential observation of the capsular tissue. Sections were stained with hematoxylin/eosin stain, Masson's trichrome stain, and Pricrosirius Red stain for regular microscopic evaluation under normal and polarized light. Histologic data showed that capsules from the ultrasound and control groups had statistically significant differences. Ultrasound application developed a capsular architecture similar to that shown within textured silicone implants, and its effect had an early definition with subsequent stabilization. The authors conclude that early and repeated external ultrasound application enhances the thickness, cellular count, and vascularity of smooth silicone capsular tissue, whereas it diminishes the pattern of parallel orientation of collagen fibers.

Ultrasound-mediated structural changes in cells revealed by FTIR spectroscopy: A contribution to the optimization of gene and drug delivery

NASA Astrophysics Data System (ADS)

Grimaldi, Paola; Di Giambattista, Lucia; Giordani, Serena; Udroiu, Ion; Pozzi, Deleana; Gaudenzi, Silvia; Bedini, Angelico; Giliberti, Claudia; Palomba, Raffaele; Congiu Castellano, Agostina

2011-12-01

Ultrasound effects on biological samples are gaining a growing interest concerning in particular, the intracellular delivery of drugs and genes in a safe and in a efficient way. Future progress in this field will require a better understanding of how ultrasound and acoustic cavitation affect the biological system properties. The morphological changes of cells due to ultrasound (US) exposure have been extensively studied, while little attention has been given to the cells structural changes. We have exposed two different cell lines to 1 MHz frequency ultrasound currently used in therapy, Jurkat T-lymphocytes and NIH-3T3 fibroblasts, both employed as models respectively in the apoptosis and in the gene therapy studies. The Fourier Transform Infrared (FTIR) Spectroscopy was used as probe to reveal the structural changes in particular molecular groups belonging to the main biological systems. The genotoxic damage of cells exposed to ultrasound was ascertained by the Cytokinesis-Block Micronucleus (CBMN) assay. The FTIR spectroscopy results, combined with multivariate statistical analysis, regarding all cellular components (lipids, proteins, nucleic acids) of the two cell lines, show that Jurkat cells are more sensitive to therapeutic ultrasound in the lipid and protein regions, whereas the NIH-3T3 cells are more sensitive in the nucleic acids region; a meaningful genotoxic effect is present in both cell lines only for long sonication times while in the Jurkat cells also a significant cytotoxic effect is revealed for long times of exposure to ultrasound.

Point-of-Care Ultrasound for Pulmonary Concerns in Remote Spaceflight Triage Environments.

PubMed

Johansen, Benjamin D; Blue, Rebecca S; Castleberry, Tarah L; Antonsen, Erik L; Vanderploeg, James M

2018-02-01

With the development of the commercial space industry, growing numbers of spaceflight participants will engage in activities with a risk for pulmonary injuries, including pneumothorax, ebullism, and decompression sickness, as well as other concomitant trauma. Medical triage capabilities for mishaps involving pulmonary conditions have not been systematically reviewed. Recent studies have advocated the use of point-of-care ultrasound to screen for lung injury or illness. The operational utility of portable ultrasound systems in disaster relief and other austere settings may be relevant to commercial spaceflight. A systematic review of published literature was conducted concerning the use of point-of-care pulmonary ultrasound techniques in austere environments, including suggested examination protocols for triage and diagnosis. Recent studies support the utility of pulmonary ultrasound examinations when performed by skilled operators, and comparability of the results to computed tomography and chest radiography for certain conditions, with important implications for trauma management in austere environments. Pulmonary injury and illness are among the potential health risks facing spaceflight participants. Implementation of point-of-care ultrasound protocols could aid in the rapid diagnosis, triage, and treatment of such conditions. Though operator-dependent, ultrasound, with proper training, experience, and equipment, could be a valuable tool in the hands of a first responder supporting remote spaceflight operations.Johansen BD, Blue RS, Castleberry TL, Antonsen EL, Vanderploeg JM. Point-of-care ultrasound for pulmonary concerns in remote spaceflight triage environments. Aerosp Med Hum Perform. 2018; 89(2):122-129.

Degradation of edible oil during food processing by ultrasound: electron paramagnetic resonance, physicochemical, and sensory appreciation.

PubMed

Pingret, Daniella; Durand, Grégory; Fabiano-Tixier, Anne-Sylvie; Rockenbauer, Antal; Ginies, Christian; Chemat, Farid

2012-08-08

During ultrasound processing of lipid-containing food, some off-flavors can be detected, which can incite depreciation by consumers. The impacts of ultrasound treatment on sunflower oil using two different ultrasound horns (titanium and pyrex) were evaluated. An electron paramagnetic resonance study was performed to identify and quantify the formed radicals, along with the assessment of classical physicochemical parameters such as peroxide value, acid value, anisidine value, conjugated dienes, polar compounds, water content, polymer quantification, fatty acid composition, and volatiles profile. The study shows an increase of formed radicals in sonicated oils, as well as the modification of physicochemical parameters evidencing an oxidation of treated oils.

Ultrasound-assisted drug delivery for treatment of venous thrombosis: a case study.

PubMed

Marchiondo, Kathleen; Frink, Amber

2008-01-01

Ultrasound-assisted drug delivery is a relatively new medical intervention that combines low-intensity ultrasound waves with infusion of a thrombolytic agent directly into a thrombosed vein. Studies have demonstrated that clots are eradicated faster, more completely, and with fewer bleeding events with the use of ultrasound-assisted drug delivery for treatment of deep vein thrombosis compared to that of traditional therapies. Critical care nurses are responsible for preprocedure assessment and teaching and continuous monitoring of the patient during therapy for effectiveness and potential complications. An advantage of this technology from a nursing perspective is the minimal amount of time required for monitoring the drug delivery system, allowing greater focus on patient assessment and care.

Ultrasound-Enhanced Delivery of Antibiotics and Anti-Inflammatory Drugs into the Eye

PubMed Central

Nabili, Marjan; Patel, Hetal; Mahesh, Sankaranarayana P.; Liu, Ji; Geist, Craig; Zderic, Vesna

2013-01-01

Delivery of sufficient amounts of therapeutic drugs into the eye is often a challenging task. In this study, ultrasound application (frequencies of 400 KHz to 1 MHz, intensities of 0.3–1.0 W/cm2 and exposure duration of 5 min) was investigated to overcome the barrier properties of cornea, which is a typical route for topical administration of ophthalmic drugs. Permeability of ophthalmic drugs, tobramycin and dexamethasone and sodium fluorescein, a drug-mimicking compound, was studied in ultrasound- and sham-treated rabbit corneas in vitro using a standard diffusion cell setup. Light microscopy observations were used to determine ultrasound-induced structural changes in the cornea. For tobramycin, an increase in permeability for ultrasound- and sham-treated corneas was not statistically significant. Increase of 46%–126% and 32%–109% in corneal permeability was observed for sodium fluorescein and dexamethasone, respectively, with statistical significance (p < 0.05) achieved at all treatment parameter combinations (compared with sham treatments) except for 1-MHz ultrasound applications for dexamethasone experiments. This permeability increase was highest at 400 kHz and appeared to be higher at higher intensities applied. Histologic analysis showed structural changes that were limited to epithelial layers of cornea. In summary, ultrasound application provided enhancement of drug delivery, increasing the permeability of the cornea for the anti-inflammatory ocular drug dexamethasone. Future investigations are needed to determine the effectiveness and safety of this application in in vivo long-term survival studies. (E-mail: mnabili@gwu.edu) PMID:23415283

Enhancement of mass transfer by ultrasound: Application to adsorbent regeneration and food drying/dehydration.

PubMed

Yao, Ye

2016-07-01

The physical mechanisms of heat and mass transfer enhancement by ultrasound have been identified by people. Basically, the effect of 'cavitation' induced by ultrasound is the main reason for the enhancement of heat and mass transfer in a liquid environment, and the acoustic streaming and vibration are the main reasons for that in a gaseous environment. The adsorbent regeneration and food drying/dehydration are typical heat and mass transfer process, and the intensification of the two processes by ultrasound is of complete feasibility. This paper makes an overview on recent studies regarding applications of power ultrasound to adsorbent regeneration and food drying/dehydration. The concerned adsorbents include desiccant materials (typically like silica gel) for air dehumidification and other ones (typically active carbon and polymeric resin) for water treatment. The applications of ultrasound in the regeneration of these adsorbents have been proved to be energy saving. The concerned foods are mostly fruits and vegetables. Although the ultrasonic treatment may cause food degradation or nutrient loss, it can greatly reduce the food processing time and decrease drying temperature. From the literature, it can be seen that the ultrasonic conditions (i.e., acoustic frequency and power levels) are always focused on during the study of ultrasonic applications. The increasing number of relevant studies argues that ultrasound is a very promising technology applied to the adsorbent regeneration and food drying/dehydration. Copyright © 2016 Elsevier B.V. All rights reserved.

Modeling analysis on germination and seedling growth using ultrasound seed pretreatment in switchgrass.

PubMed

Wang, Quanzhen; Chen, Guo; Yersaiyiti, Hayixia; Liu, Yuan; Cui, Jian; Wu, Chunhui; Zhang, Yunwei; He, Xueqing

2012-01-01

Switchgrass is a perennial C4 plant with great potential as a bioenergy source and, thus, a high demand for establishment from seed. This research investigated the effects of ultrasound treatment on germination and seedling growth in switchgrass. Using an orthogonal matrix design, conditions for the ultrasound pretreatment in switchgrass seed, including sonication time (factor A), sonication temperature (factor B) and ultrasound output power (factor C), were optimized for germinating and stimulating seedling growth (indicated as plumular and radicular lengths) through modeling analysis. The results indicate that sonication temperature (B) was the most effective factor for germination, whereas output power (C) had the largest effect on seedling growth when ultrasound treatment was used. Combined with the analyses of range, variance and models, the final optimal ultrasonic treatment conditions were sonication for 22.5 min at 39.7°C and at an output power of 348 W, which provided the greatest germination percentage and best seedling growth. For this study, the orthogonal matrix design was an efficient method for optimizing the conditions of ultrasound seed treatment on switchgrass. The electrical conductivity of seed leachates in three experimental groups (control, soaked in water only, and ultrasound treatment) was determined to investigate the effects of ultrasound on seeds and eliminate the effect of water in the ultrasound treatments. The results showed that the electrical conductivity of seed leachates during either ultrasound treatment or water bath treatment was significantly higher than that of the control, and that the ultrasound treatment had positive effects on switchgrass seeds.

A deconvolution method for deriving the transit time spectrum for ultrasound propagation through cancellous bone replica models.

PubMed

Langton, Christian M; Wille, Marie-Luise; Flegg, Mark B

2014-04-01

The acceptance of broadband ultrasound attenuation for the assessment of osteoporosis suffers from a limited understanding of ultrasound wave propagation through cancellous bone. It has recently been proposed that the ultrasound wave propagation can be described by a concept of parallel sonic rays. This concept approximates the detected transmission signal to be the superposition of all sonic rays that travel directly from transmitting to receiving transducer. The transit time of each ray is defined by the proportion of bone and marrow propagated. An ultrasound transit time spectrum describes the proportion of sonic rays having a particular transit time, effectively describing lateral inhomogeneity of transit times over the surface of the receiving ultrasound transducer. The aim of this study was to provide a proof of concept that a transit time spectrum may be derived from digital deconvolution of input and output ultrasound signals. We have applied the active-set method deconvolution algorithm to determine the ultrasound transit time spectra in the three orthogonal directions of four cancellous bone replica samples and have compared experimental data with the prediction from the computer simulation. The agreement between experimental and predicted ultrasound transit time spectrum analyses derived from Bland-Altman analysis ranged from 92% to 99%, thereby supporting the concept of parallel sonic rays for ultrasound propagation in cancellous bone. In addition to further validation of the parallel sonic ray concept, this technique offers the opportunity to consider quantitative characterisation of the material and structural properties of cancellous bone, not previously available utilising ultrasound.

A novel transcutaneous, non-focused ultrasound energy delivering device is able to induce subcutaneous adipose tissue destruction in an animal model.

PubMed

Levi, Assi; Amitai, Dan Ben; Lapidoth, Moshe

2017-01-01

The understanding that adipocytes are greatly influenced by thermal changes combined with the advancement of non-invasive ultrasound technologies have led to the application of ultrasound as an energy source to induce thermal fat destruction. While application of high intensity focused, ultrasound energy have been widely explored, there is far less information regarding the effects of non-focused ultrasound on adipose tissue. The purpose of this study was to characterize the effects of a novel transcutaneous, multi-elements, non-focused ultrasound energy regimen in an animal model, as a proof-of-concept of its potential to treat non-invasive subcutaneous benign tumors. The non-invasive transcutaneous ultrasound system prototype (LUMENIS, Ltd., Yoqneam, Israel) was applied to thermally induce adipocytes' death. During treatment, the ultrasound energy was transmitted into the subcutaneous adipose tissue (SAT) of 12 domestic adult female pigs. Two modes of operation (long and short), which differ in both the acoustic energy applied to the tissue and in their time durations (i.e., differ in their power settings), were used in this study. Efficacy and safety assessments included: Temperature measurement of skin and subcutaneous adipose tissue (SAT) visual inspection and ultrasound imaging of the thermally affected areas, histopathological assessment of tissue samples using hematoxylin & eosin, and Masson's trichrome stains and in situ cell death detection kit for apoptosis assessment. The long and short treatment modes led to a 13.2°C and 17.8°C rise from baseline, respectively, in the SAT, whereas skin surface temperature was practically unaffected. Visual, ultrasonographic, and histopathological evaluation of the treated area showed SAT ablation. No treatment-related changes were observed in the epidermis, dermis subcutaneous muscle and nerves, or in livers and kidneys of treated animals. Additionally, no significant changes from baseline in blood- and urine-borne analytes were detected post-treatment. The novel transcutaneous, multi-elements, non-focused ultrasound energy regimen used in this study, proved effective in non-invasively ablating SAT in an animal model. The usage of low energy settings such as in the current study might reduce unwanted side effects related to high energy application. Lasers Surg. Med. 49:110-121, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Virtual Ultrasound Guidance for Inexperienced Operators

NASA Technical Reports Server (NTRS)

Caine, Timothy; Martin, David

2012-01-01

Medical ultrasound or echocardiographic studies are highly operator-dependent and generally require lengthy training and internship to perfect. To obtain quality echocardiographic images in remote environments, such as on-orbit, remote guidance of studies has been employed. This technique involves minimal training for the user, coupled with remote guidance from an expert. When real-time communication or expert guidance is not available, a more autonomous system of guiding an inexperienced operator through an ultrasound study is needed. One example would be missions beyond low Earth orbit in which the time delay inherent with communication will make remote guidance impractical. The Virtual Ultrasound Guidance system is a combination of hardware and software. The hardware portion includes, but is not limited to, video glasses that allow hands-free, full-screen viewing. The glasses also allow the operator a substantial field of view below the glasses to view and operate the ultrasound system. The software is a comprehensive video program designed to guide an inexperienced operator through a detailed ultrasound or echocardiographic study without extensive training or guidance from the ground. The program contains a detailed description using video and audio to demonstrate equipment controls, ergonomics of scanning, study protocol, and scanning guidance, including recovery from sub-optimal images. The components used in the initial validation of the system include an Apple iPod Classic third-generation as the video source, and Myvue video glasses. Initially, the program prompts the operator to power-up the ultrasound and position the patient. The operator would put on the video glasses and attach them to the video source. After turning on both devices and the ultrasound system, the audio-video guidance would then instruct on patient positioning and scanning techniques. A detailed scanning protocol follows with descriptions and reference video of each view along with advice on technique. The program also instructs the operator regarding the types of images to store and how to overcome pitfalls in scanning. Images can be forwarded to the ground or other site when convenient. Following study completion, the video glasses, video source, and ultrasound system are powered down and stored. Virtually any equipment that can play back video can be used to play back the program. This includes a DVD player, personal computer, and some MP3 players.

Investigation of mass transfer intensification under power ultrasound irradiation using 3D computational simulation: A comparative analysis.

PubMed

Sajjadi, Baharak; Asgharzadehahmadi, Seyedali; Asaithambi, Perumal; Raman, Abdul Aziz Abdul; Parthasarathy, Rajarathinam

2017-01-01

This paper aims at investigating the influence of acoustic streaming induced by low-frequency (24kHz) ultrasound irradiation on mass transfer in a two-phase system. The main objective is to discuss the possible mass transfer improvements under ultrasound irradiation. Three analyses were conducted: i) experimental analysis of mass transfer under ultrasound irradiation; ii) comparative analysis between the results of the ultrasound assisted mass transfer with that obtained from mechanically stirring; and iii) computational analysis of the systems using 3D CFD simulation. In the experimental part, the interactive effects of liquid rheological properties, ultrasound power and superficial gas velocity on mass transfer were investigated in two different sonicators. The results were then compared with that of mechanical stirring. In the computational part, the results were illustrated as a function of acoustic streaming behaviour, fluid flow pattern, gas/liquid volume fraction and turbulence in the two-phase system and finally the mass transfer coefficient was specified. It was found that additional turbulence created by ultrasound played the most important role on intensifying the mass transfer phenomena compared to that in stirred vessel. Furthermore, long residence time which depends on geometrical parameters is another key for mass transfer. The results obtained in the present study would help researchers understand the role of ultrasound as an energy source and acoustic streaming as one of the most important of ultrasound waves on intensifying gas-liquid mass transfer in a two-phase system and can be a breakthrough in the design procedure as no similar studies were found in the existing literature. Copyright © 2016. Published by Elsevier B.V.

Is ultrasound perfusion imaging capable of detecting mismatch? A proof-of-concept study in acute stroke patients.

PubMed

Reitmeir, Raluca; Eyding, Jens; Oertel, Markus F; Wiest, Roland; Gralla, Jan; Fischer, Urs; Giquel, Pierre-Yves; Weber, Stefan; Raabe, Andreas; Mattle, Heinrich P; Z'Graggen, Werner J; Beck, Jürgen

2017-04-01

In this study, we compared contrast-enhanced ultrasound perfusion imaging with magnetic resonance perfusion-weighted imaging or perfusion computed tomography for detecting normo-, hypo-, and nonperfused brain areas in acute middle cerebral artery stroke. We performed high mechanical index contrast-enhanced ultrasound perfusion imaging in 30 patients. Time-to-peak intensity of 10 ischemic regions of interests was compared to four standardized nonischemic regions of interests of the same patient. A time-to-peak >3 s (ultrasound perfusion imaging) or >4 s (perfusion computed tomography and magnetic resonance perfusion) defined hypoperfusion. In 16 patients, 98 of 160 ultrasound perfusion imaging regions of interests of the ischemic hemisphere were classified as normal, and 52 as hypoperfused or nonperfused. Ten regions of interests were excluded due to artifacts. There was a significant correlation of the ultrasound perfusion imaging and magnetic resonance perfusion or perfusion computed tomography (Pearson's chi-squared test 79.119, p < 0.001) (OR 0.1065, 95% CI 0.06-0.18). No perfusion in ultrasound perfusion imaging (18 regions of interests) correlated highly with diffusion restriction on magnetic resonance imaging (Pearson's chi-squared test 42.307, p < 0.001). Analysis of receiver operating characteristics proved a high sensitivity of ultrasound perfusion imaging in the diagnosis of hypoperfused area under the curve, (AUC = 0.917; p < 0.001) and nonperfused (AUC = 0.830; p < 0.001) tissue in comparison with perfusion computed tomography and magnetic resonance perfusion. We present a proof of concept in determining normo-, hypo-, and nonperfused tissue in acute stroke by advanced contrast-enhanced ultrasound perfusion imaging.

TU-A-9A-06: Semi-Automatic Segmentation of Skin Cancer in High-Frequency Ultrasound Images: Initial Comparison with Histology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gao, Y; Li, X; Fishman, K

Purpose: In skin-cancer radiotherapy, the assessment of skin lesion is challenging, particularly with important features such as the depth and width hard to determine. The aim of this study is to develop interative segmentation method to delineate tumor boundary using high-frequency ultrasound images and to correlate the segmentation results with the histopathological tumor dimensions. Methods: We analyzed 6 patients who comprised a total of 10 skin lesions involving the face, scalp, and hand. The patient’s various skin lesions were scanned using a high-frequency ultrasound system (Episcan, LONGPORT, INC., PA, U.S.A), with a 30-MHz single-element transducer. The lateral resolution was 14.6more » micron and the axial resolution was 3.85 micron for the ultrasound image. Semiautomatic image segmentation was performed to extract the cancer region, using a robust statistics driven active contour algorithm. The corresponding histology images were also obtained after tumor resection and served as the reference standards in this study. Results: Eight out of the 10 lesions are successfully segmented. The ultrasound tumor delineation correlates well with the histology assessment, in all the measurements such as depth, size, and shape. The depths measured by the ultrasound have an average of 9.3% difference comparing with that in the histology images. The remaining 2 cases suffered from the situation of mismatching between pathology and ultrasound images. Conclusion: High-frequency ultrasound is a noninvasive, accurate and easy-accessible modality to image skin cancer. Our segmentation method, combined with high-frequency ultrasound technology, provides a promising tool to estimate the extent of the tumor to guide the radiotherapy procedure and monitor treatment response.« less

[An attempt to use ultrasonic technique for confirming the diagnosis, planning and observation of long-term treatment results of painful temporo-mandibular joint dysfunction].

PubMed

Ey-Chmielewska, H

1998-01-01

The author presents an attempt of using ultrasonographic technique in diagnosis, planning and observation of treatment results of temporo-mandibular joint pain dysfunctions. Temporo-mandibular joint pain dysfunctions are interchangeably also called temporo-mandibular joint functional disorders. The assessment of pain symptoms in temporo-mandibular joint dysfunctions pain symptoms is principally based on a subjective estimation by the examining practitioner. There is no univocal definition of the disease or a simple index evidencing important symptoms in decision making. Additionally X-ray technique examinations, being hitherto used, in early stages of the disorder do not allow to diagnose it, and are also burdensome to a patient. The aim of this study was to confirm visibility of anatomical elements of the temporo-mandibular joint in an ultrasound examination, assess the mobility of the articular disc before, during and after prosthetic treatment with and without the use of ultrasound technique, and to determine the period of time necessary to obtain a therapeutic effect. The study material consisted of 180 patients, 128 women and 52 men, aged 20 to 60 years, treated by applying prostheses because of temporo-mandibular joint pain dysfunction, in the Department of Prosthetic Dentistry of the Pomeranian Medical Academy. The patients were divided into 2 groups, control and study group. The control group consisted of 90 patients, 63 women and 27 men. In this group prosthetic treatment planning and observation of results was based on a subjective estimation of the practitioner. The study group here comprised 90 patients, 65 women and 25 men, aged 26 to 60 years. In this group prosthetic treatment planning and observation of treatment results were carried on with the use of ultrasound technique. Data from both groups concerning history, results of examinations carried out by ultrasound technique, and the assessment of ultrasound examination were noted on standard examination records used in the Department of Prosthetic Dentistry. For the need of this study an own ultrasound technique was elaborated which allowed for analyzing the ultrasound image in a static situation and during functioning. The ultrasound examination was accomplished with the use of Acuson 128 XP apparatus, linear probe 7.5 MHz. In both groups prosthetic treatment was carried out using different prosthetic methods such as: splints, occlusal adjustment on fixed prosthetic restorations in therapeutical occulus et height in abnormal occlusion. In the study group the therapeutical occulus height was determined under the control of ultrasound technique. Statistical analysis of the obtained results was performed with the use of chi-square test and chi-square test with Yates correction. On the basis of the accomplished study it has been determined that the ultrasound technique makes it possible to visualize morphological elements and facilitates functional observation of the temporo-mandibular joint, articular disc, mandibular condyle and lateral pterygoid muscle in a degree which allows for planning the treatment and the observation of results (Tab. 1-6). The use of ultrasound technique in determining spatial position of the mandible in temporo-mandibular joint permitted to objectively estimate examination results in the study group. A small number of publications on the use of ultrasound technique in functional examination of the temporo-mandibular joint accessible in foreign literature and general reference on the subject in Polish literature do not allow for an objective comparison of obtained study results.

Ultrasound as an Adjunct to Mammography for Breast Cancer Screening: A Health Technology Assessment

PubMed Central

Nikitovic-Jokic, Milica; Tu, Hong Anh; Palimaka, Stefan; Higgins, Caroline; Holubowich, Corinne

2016-01-01

Background Screening with mammography can detect breast cancer early, before clinical symptoms appear. Some cancers, however, are not captured with mammography screening alone. Ultrasound has been suggested as a safe adjunct screening tool that can detect breast cancers missed on mammography. We investigated the benefits, harms, cost-effectiveness, and cost burden of ultrasound as an adjunct to mammography compared with mammography alone for screening women at average risk and at high risk for breast cancer. Methods We searched Ovid MEDLINE, Ovid Embase, EBM Reviews, and the NHS Economic Evaluation Database, from January 1998 to June 2015, for evidence of effectiveness, harms, diagnostic accuracy, and cost-effectiveness. Only studies evaluating the use of ultrasound as an adjunct to mammography in the specified populations were included. We also conducted a cost analysis to estimate the costs in Ontario over the next 5 years to fund ultrasound as an adjunct to mammography in breast cancer screening for high-risk women who are contraindicated for MRI, the current standard of care to supplement mammography. Results No studies in average-risk women met the inclusion criteria of the clinical review. We included 5 prospective, paired cohort studies in high-risk women, 4 of which were relevant to the Ontario context. Adjunct ultrasound identified between 2.3 and 5.9 additional breast cancers per 1,000 screens. The average pooled sensitivity of mammography and ultrasound was 53%, a statistically significant increase relative to mammography alone (absolute increase 13%; P < .05). The average pooled specificity of the combined test was 96%, an absolute increase in the false-positive rate of 2% relative to mammography screening alone. The GRADE for this body of evidence was low. Additional annual costs of using breast ultrasound as an adjunct to mammography for high-risk women in Ontario contraindicated for MRI would range from $15,500 to $30,250 in the next 5 years. Conclusions We found no evidence that evaluated the comparative effectiveness or diagnostic accuracy of screening breast ultrasound as an adjunct to mammography among average-risk women aged 50 years and over. In women at high risk of developing breast cancer, there is low-quality evidence that screening with mammography and adjunct ultrasound detects additional cases of disease, with improved sensitivity compared to mammography alone. Screening with adjunct ultrasound also increases the number of false-positive findings and subsequent biopsy recommendations. It is unclear if the use of screening breast ultrasound as an adjunct to mammography will reduce breast cancer–related mortality among high-risk women. The annual cost burden of using adjunct ultrasound to screen high-risk women who cannot receive MRI in Ontario would be small. PMID:27468326

2ND International Symposium on HIFU Therapy HIFU Seattle 2002

DTIC Science & Technology

2002-12-01

Drug Delivery, and Sonodynamic Therapy. One can see from this topic coverage that the symposium was largely on HIFU (essentially the first five topics), yet also broad enough to cover most aspects of therapeutic ultrasound ....This book is a compilation of papers presented at the 2nd International Symposium on Therapeutic Ultrasound , held in Seattle, Washington, July 29...number of topic categories, viz., Clinical Studies, Laboratory Studies, Simulation and Monitoring, Dosimetry, Engineering, Lithotripsy, Ultrasound -Enhanced

Novel ultrasound method to reposition kidney stones

PubMed Central

Shah, Anup; Owen, Neil R.; Lu, Wei; Cunitz, Bryan W.; Kaczkowski, Peter J.; Harper, Jonathan D.; Bailey, Michael R.; Crum, Lawrence A.

2011-01-01

The success of surgical management of lower pole stones is principally dependent on stone fragmentation and residual stone clearance. Choice of surgical method depends on stone size, yet all methods are subject to post-surgical complications resulting from residual stone fragments. Here we present a novel method and device to reposition kidney stones using ultrasound radiation force delivered by focused ultrasound and guided by ultrasound imaging. The device couples a commercial imaging array with a focused annular array transducer. Feasibility of repositioning stones was investigated by implanting artificial and human stones into a kidney-mimicking phantom that simulated a lower pole and collecting system. During experiment, stones were located by ultrasound imaging and repositioned by delivering short bursts of focused ultrasound. Stone motion was concurrently monitored by fluoroscopy, ultrasound imaging, and video photography, from which displacement and velocity were estimated. Stones were seen to move immediately after delivering focused ultrasound and successfully repositioned from the lower pole to the collecting system. Estimated velocities were on the order of 1 cm/s. This in vitro study demonstrates a promising modality to facilitate spontaneous clearance of kidney stones and increased clearance of residual stone fragments after surgical management. PMID:20967437

Apoptosis induced by low-intensity ultrasound in vitro: Alteration of protein profile and potential molecular mechanism

NASA Astrophysics Data System (ADS)

Feng, Yi; Wan, Mingxi

2017-03-01

To analyze the potential mechanism related to the apoptosis induced by low intensity focused ultrasound, comparative proteomic method was introduced in the study. After ultrasound irradiation (3.0 W/cm2, 1 minute, 6 hours incubation post-irradiation), the human SMMC-7721 hepatocarcinoma cells were stained by trypan blue to detect the morphologic changes, and then the percentage of early apoptosis were tested by the flow cytometry with double staining of FITC-labelled Annexin V/Propidium iodide. Two-dimensional SDS polyacrylamide gel electrophoresis was used to get the protein profile and some proteins differently expressed after ultrasound irradiation were identified by MALDI-TOF mass spectrometry. It's proved early apoptosis of cells were induced by low intentisy focused ultrasound. After ultrasound irradiation, the expressing characteristics of several proteins changed, in which protein p53 and heat shock proteins are associated with apoptosis initiation. It is suggested that the low-intensity ultrasound-induced apoptotic cancer therapy has the potential application via understanding its relevant molecular signaling and key proteins. Moreover, the comparative proteomic method is proved to be useful to supply information about the protein expression to analyze the metabolic processes related to bio-effects of biomedical ultrasound.

Characterization of enzymatically induced degradation of articular cartilage using high frequency ultrasound

NASA Astrophysics Data System (ADS)

Töyräs, J.; Rieppo, J.; Nieminen, M. T.; Helminen, H. J.; Jurvelin, J. S.

1999-11-01

Ultrasound may provide a quantitative technique for the characterization of cartilage changes typical of early osteoarthrosis. In this study, specific changes in bovine articular cartilage were induced using collagenase and chondroitinase ABC, enzymes that selectively degrade collagen fibril network and digest proteoglycans, respectively. Changes in cartilage structure and properties were quantified using high frequency ultrasound, microscopic analyses and mechanical indentation tests. The ultrasound reflection coefficient of the physiological saline-cartilage interface (R1) decreased significantly (-96.4%, p<0.01) in the collagenase digested cartilage compared to controls. Also a significantly lower ultrasound velocity (-6.2%, p<0.01) was revealed after collagenase digestion. After chondroitinase ABC digestion, a new acoustic interface at the depth of the enzyme penetration front was detected. Cartilage thickness, as determined with ultrasound, showed a high, linear correlation (R = 0.943, n = 60, average difference 0.073 mm (4.0%)) with the thickness measured by the needle-probe method. Both enzymes induced a significant decrease in the Young's modulus of cartilage (p<0.01). Our results indicate that high frequency ultrasound provides a sensitive technique for the analysis of cartilage structure and properties. Possibly ultrasound may be utilized in vivo as a quantitative probe during arthroscopy.

Assessment of Curve Flexibility on Scoliotic Surgical Candidates Using Ultrasound Imaging Method.

PubMed

Zheng, Rui; Hill, Doug; Hedden, Douglas; Moreau, Marc; Le, Lawrence H; Raso, Jim; Lou, Edmond

2017-05-01

The ultrasound imaging method was implemented to assess the spinal curve flexibility of scoliotic surgical candidates, or how much correction it can achieve while patients are bending or lying down. Fifteen participants were recruited. Pre-operative radiographs and ultrasound images in both standing and bending positions were acquired. The post-operative standing radiographs were obtained 1 wk after surgery. Two raters (RZ, EL) measured the ultrasound images twice, 1 wk apart. A curve correction index (C I ) was developed to estimate the curve flexibility. The C I from the pre-operative bending radiograph, ultrasound and post-operative radiograph were 0.51 ± 0.18; R1: 0.74 ± 0.08 vs R2: 0.72 ± 0.09 and 0.60 ± 0.10, respectively. The correlation of C I between ultrasound and post-operative radiography was slightly higher than the pre-operative bending and post-operative radiography. This pilot study demonstrated the bending ultrasound method is a promising supplemental tool to assess curve flexibility before surgical intervention for scoliotic surgical candidates. Copyright © 2017 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Differences in Multi-Modal Ultrasound Imaging between Triple Negative and Non-Triple Negative Breast Cancer.

PubMed

Li, Ziyao; Tian, Jiawei; Wang, Xiaowei; Wang, Ying; Wang, Zhenzhen; Zhang, Lei; Jing, Hui; Wu, Tong

2016-04-01

The objective of this study was to identify multi-modal ultrasound imaging parameters that could potentially help to differentiate between triple negative breast cancer (TNBC) and non-TNBC. Conventional ultrasonography, ultrasound strain elastography and 3-D ultrasound (3-D-US) findings from 50 TNBC and 179 non-TNBC patients were retrospectively reviewed. Immunohistochemical examination was used as the reference gold standard for cancer subtyping. Different ultrasound modalities were initially analyzed to define TNBC-related features. Subsequently, logistic regression analysis was applied to TNBC-related features to establish models for predicting TNBC. TNBCs often presented as micro-lobulated, markedly hypo-echoic masses with an abrupt interface (p = 0.015, 0.0015 and 0.004, compared with non-TNBCs, respectively) on conventional ultrasound, and showed a diminished retraction pattern phenomenon in the coronal plane (p = 0.035) on 3-D-US. Our findings suggest that B-mode ultrasound and 3-D-US in multi-modality ultrasonography could be a useful non-invasive technique for differentiating TNBCs from non-TNBCs. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Prenatal ultrasound diagnosis and outcome of placenta previa accreta after cesarean delivery: a systematic review and meta-analysis.

PubMed

Jauniaux, Eric; Bhide, Amar

2017-07-01

Women with a history of previous cesarean delivery, presenting with a placenta previa, have become the largest group with the highest risk for placenta previa accreta. The objective of the study was to evaluate the accuracy of ultrasound imaging in the prenatal diagnosis of placenta accreta and the impact of the depth of villous invasion on management in women presenting with placenta previa or low-lying placenta and with 1 or more prior cesarean deliveries. We searched PubMed, Google Scholar, clinicalTrials.gov, and MEDLINE for studies published between 1982 and November 2016. Criteria for the study were cohort studies that provided data on previous mode of delivery, placenta previa, or low-lying placenta on prenatal ultrasound imaging and pregnancy outcome. The initial search identified 171 records, of which 5 retrospective and 9 prospective cohort studies were eligible for inclusion in the quantitative analysis. The studies were scored on methodological quality using the Quality Assessment of Diagnostic Accuracy Studies tool. The 14 cohort studies included 3889 pregnancies presenting with placenta previa or low-lying placenta and 1 or more prior cesarean deliveries screened for placenta accreta. There were 328 cases of placenta previa accreta (8.4%), of which 298 (90.9%) were diagnosed prenatally by ultrasound. The incidence of placenta previa accreta was 4.1% in women with 1 prior cesarean and 13.3% in women with ≥2 previous cesarean deliveries. The pooled performance of ultrasound for the antenatal detection of placenta previa accreta was higher in prospective than retrospective studies, with a diagnostic odds ratios of 228.5 (95% confidence interval, 67.2-776.9) and 80.8 (95% confidence interval, 13.0-501.4), respectively. Only 2 studies provided detailed data on the relationship between the depth of villous invasion and the number of previous cesarean deliveries, independently of the depth of the villous invasion. A cesarean hysterectomy was performed in 208 of 232 cases (89.7%) for which detailed data on management were available. Positive correlations were found in the largest prospective studies between the cumulative rates of the more invasive forms of accreta placentation and the sensitivity and specificity of ultrasound imaging but not with diagnostic odds ratio values. We found no data on the ultrasound screening of placenta accreta at the routine midtrimester ultrasound examination from the nonexpert ultrasound units. Planning individual management for delivery is possible only with accurate evaluation of prenatal risk of accreta placentation in women presenting with a low-lying placenta/previa and a history of prior cesarean delivery. Ultrasound is highly sensitive and specific in the prenatal diagnosis of accreta placentation when performed by skilled operators. Developing a prenatal screening protocol is now essential to further improve the outcome of this increasingly more common major obstetric complication. Copyright © 2017 Elsevier Inc. All rights reserved.

Simulation of laser generated ultrasound with application to defect detection

NASA Astrophysics Data System (ADS)

Pantano, A.; Cerniglia, D.

2008-06-01

Laser generated ultrasound holds substantial promise for use as a tool for defect detection in remote inspection thanks to its ability to produce frequencies in the MHz range, enabling fine spatial resolution of defects. Despite the potential impact of laser generated ultrasound in many areas of science and industry, robust tools for studying the phenomenon are lacking and thus limit the design and optimization of non-destructive testing and evaluation techniques. The laser generated ultrasound propagation in complex structures is an intricate phenomenon and is extremely hard to analyze. Only simple geometries can be studied analytically. Numerical techniques found in the literature have proved to be limited in their applicability, by the frequencies in the MHz range and very short wavelengths. The objective of this research is to prove that by using an explicit integration rule together with diagonal element mass matrices, instead of the almost universally adopted implicit integration rule to integrate the equations of motion in a dynamic analysis, it is possible to efficiently and accurately solve ultrasound wave propagation problems with frequencies in the MHz range travelling in relatively large bodies. Presented results on NDE testing of rails demonstrate that the proposed FE technique can provide a valuable tool for studying the laser generated ultrasound propagation.

Gd(III)-DOTA-modified sonosensitive liposomes for ultrasound-triggered release and MR imaging

NASA Astrophysics Data System (ADS)

Jung, Suk Hyun; Na, Kyunga; Lee, Seul A.; Cho, Sun Hang; Seong, Hasoo; Shin, Byung Cheol

2012-08-01

Ultrasound-sensitive (sonosensitive) liposomes for tumor targeting have been studied in order to increase the antitumor efficacy of drugs and decrease the associated severe side effects. Liposomal contrast agents having Gd(III) are known as a nano-contrast agent system for the efficient and selective delivery of contrast agents into pathological sites. The objective of this study was to prepare Gd(III)-DOTA-modified sonosensitive liposomes (GdSL), which could deliver a model drug, doxorubicin (DOX), to a specific site and, at the same time, be capable of magnetic resonance (MR) imaging. The GdSL was prepared using synthesized Gd(III)-DOTA-1,2-distearoyl- sn-glycero-3-phosphoethanolamine lipid. Sonosensitivity of GdSL to 20-kHz ultrasound induced 33% to 40% of DOX release. The relaxivities ( r 1) of GdSL were 6.6 to 7.8 mM-1 s-1, which were higher than that of MR-bester®. Intracellular uptake properties of GdSL were evaluated according to the intensity of ultrasound. Intracellular uptake of DOX for ultrasound-triggered GdSL was higher than that for non-ultrasound-triggered GdSL. The results of our study suggest that the paramagnetic and sonosensitive liposomes, GdSL, may provide a versatile platform for molecular imaging and targeted drug delivery.

Nucleation in food colloids

NASA Astrophysics Data System (ADS)

Povey, Malcolm J. W.

2016-12-01

Nucleation in food colloids has been studied in detail using ultrasound spectroscopy. Our data show that classical nucleation theory (CNT) remains a sound basis from which to understand nucleation in food colloids and analogous model systems using n-alkanes. Various interpretations and modifications of CNT are discussed with regard to their relevance to food colloids. Much of the evidence presented is based on the ultrasound velocity spectrometry measurements which has many advantages for the study of nucleating systems compared to light scattering and NMR due to its sensitivity at low solid contents and its ability to measure true solid contents in the nucleation and early crystal growth stages. Ultrasound attenuation spectroscopy also responds to critical fluctuations in the induction region. We show, however, that a periodic pressure fluctuation such as a quasi-continuous (as opposed to a pulse comprising only a few pressure cycles) ultrasound field can alter the nucleation process, even at very low acoustic intensity. Thus care must be taken when using ultrasound techniques that the measurements do not alter the studied processes. Quasi-continuous ultrasound fields may enhance or suppress nucleation and the criteria to determine such effects are derived. The conclusions of this paper are relevant to colloidal systems in foods, pharmaceuticals, agro-chemicals, cosmetics, and personal products.

Photoreactivation and dark repair of environmental E. coli strains following 24 kHz continuous ultrasound and UV-C irradiation.

PubMed

Kaur, Jasjeet; Karthikeyan, Raghupathy; Pillai, Suresh D

2016-07-02

In this study, effects of 24 kHz continuous ultrasound and UV-C on inactivation and potential repair of environmental E. coli strains were studied through a culture based method and a metabolic activity assay. Three environmental E. coli strains isolated from fecal samples of feral hog and deer and treated wastewater effluent were studied and compared with a laboratory E. coli strain (ATCC® 10798). Metabolic activity of E. coli cells during the inactivation and repair period was assessed using the AlamarBlue® assay. Transmission electron microscopy assays were also performed to evaluate morphological damage of bacterial cell wall. After 24 h of photoreactivation period, laboratory E. coli strain (ATCC® 10798) reactivated by 30% and 42% in contrast to E. coli isolate from treated wastewater effluent, which reactivated by 53% and 82% after ultrasound and UV-C treatment, respectively. Possible shearing and reduction in cell size of E. coli strains exposed to ultrasound was revealed by transmission electron micrographs. Metabolic activity of E. coli strains was greatly reduced due to morphological damage to cell membrane caused by 24 kHz continuous ultrasound. Based upon experimental data and TEM micrographs, it could be concluded that ultrasound irradiation has potential in advanced water treatment and water reuse applications.

Treatment Options

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... disease (e.g. through a physical exam, blood tests and imaging studies such as an ultrasound). So talk to your ... monitor your health through a physical exam, blood tests and imaging studies (such as an ultrasound, FibroScan [Transient Elastography] or ...

Obstetric ultrasound aids prompt referral of gestational trophoblastic disease in marginalized populations on the Thailand-Myanmar border.

PubMed

McGregor, Kathryn; Myat Min, Aung; Karunkonkowit, Noaeni; Keereechareon, Suporn; Tyrosvoutis, Mary Ellen; Tun, Nay Win; Rijken, Marcus J; Hoogenboom, Gabie; Boel, Machteld; Chotivanich, Kesinee; Nosten, François; McGready, Rose

2017-01-01

The use of obstetric ultrasound in the diagnosis of gestational trophoblastic disease (GTD) in high-income settings is well established, leading to prompt management and high survival rates. Evidence from low-income settings suggests ultrasound is essential in identifying complicated pregnancies, but with limited studies reviewing specific conditions including GTD. The aim of this study is to review the role of ultrasound in diagnosis and management of GTD in a marginalized population on the Thailand-Myanmar border. Antenatal ultrasound became available in this rural setting in 2001 and care for women with GTD has been provided by Thailand public hospitals for 20 years. Retrospective record review. The incidence of GTD was 103 of 57,004 pregnancies in Karen and Burmese women on the Thailand-Myanmar border from 1993-2013. This equates to a rate of 1.8 (95% CI 1.5-2.2) per 1000 or 1 in 553 pregnancies. Of the 102 women with known outcomes, one (1.0%) died of haemorrhage at home. The median number of days between first antenatal clinic attendance and referral to hospital was reduced from 20 (IQR 5-35; range 1-155) to 2 (IQR 2-6; range 1-179) days (p = 0.002) after the introduction of ultrasound. The proportion of severe outcomes (death and total abdominal hysterectomy) was 25% (3/12) before ultrasound compared to 8.9% (8/90) with ultrasound (p = 0.119). A recurrence rate of 2.5% (2/80) was observed in the assessable population. The presence of malaria parasites in maternal blood was not associated with GTD. The rate of GTD in pregnancy in this population is comparable to rates previously reported within South-East Asia. Referral time for uterine evacuation was significantly shorter for those women who had an ultrasound. Ultrasound is an effective method to improve diagnosis of GTD in low-income settings and an effort to increase availability in marginalized populations is required.

Does Maternal Body Mass Index Have an Effect on the Accuracy of Ultrasound-Derived Estimated Birth Weight?: A Retrospective Study.

PubMed

Gonzalez, Maritza G; Reed, Kathryn L; Center, Katherine E; Hill, Meghan G

2017-05-01

The purpose of this study was to investigate the relationship between the maternal body mass index (BMI) and the accuracy of ultrasound-derived birth weight. A retrospective chart review was performed on women who had an ultrasound examination between 36 and 43 weeks' gestation and had complete delivery data available through electronic medical records. The ultrasound-derived fetal weight was adjusted by 30 g per day of gestation that elapsed between the ultrasound examination and delivery to arrive at the predicted birth weight. A total of 403 pregnant women met inclusion criteria. Age ranged from 13-44 years (mean ± SD, 28.38 ± 5.97 years). The mean BMI was 32.62 ± 8.59 kg/m 2 . Most of the women did not have diabetes (n = 300 [74.0%]). The sample was primarily white (n = 165 [40.9%]) and Hispanic (n = 147 [36.5%]). The predicted weight of neonates at delivery (3677.07 ± 540.51 g) was higher than the actual birth weight (3335.92 ± 585.46 g). Based on regression analyses, as the BMI increased, so did the predicted weight (P < .01) and weight at delivery (P < .01). The accuracy of the estimated ultrasound-derived birth weight was not predicted by the maternal BMI (P = .22). Maternal race and diabetes status were not associated with the accuracy of ultrasound in predicting birth weight. Both predicted and actual birth weight increased as the BMI increased. However, the BMI did not affect the accuracy of the estimated ultrasound-derived birth weight. Maternal race and diabetes status did not influence the accuracy of the ultrasound-derived predicted birth weight. © 2017 by the American Institute of Ultrasound in Medicine.

SU-E-J-118: Verification of Intrafractional Positional Accuracy Using Ultrasound Autoscan Tracking for Prostate Cancer Treatment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yu, S; Hristov, D; Phillips, T

Purpose: Transperineal ultrasound imaging is attractive option for imageguided radiation therapy as there is no need to implant fiducials, no extra imaging dose, and real time continuous imaging is possible during treatment. The aim of this study is to verify the tracking accuracy of a commercial ultrasound system under treatment conditions with a male pelvic phantom. Methods: A CT and ultrasound scan were acquired for the male pelvic phantom. The phantom was then placed in a treatment mimicking position on a motion platform. The axial and lateral tracking accuracy of the ultrasound system were verified using an independent optical trackingmore » system. The tracking accuracy was evaluated by tracking the phantom position detected by the ultrasound system, and comparing it to the optical tracking system under the conditions of beam on (15 MV), beam off, poor image quality with an acoustic shadow introduced, and different phantom motion cycles (10 and 20 second periods). Additionally, the time lag between the ultrasound-detected and actual phantom motion was investigated. Results: Displacement amplitudes reported by the ultrasound system and optical system were within 0.5 mm of each other for both directions and all conditions. The ultrasound tracking performance in axial direction was better than in lateral direction. Radiation did not interfere with ultrasound tracking while image quality affected tracking accuracy. The tracking accuracy was better for periodic motion with 20 second period. The time delay between the ultrasound tracking system and the phantom motion was clinically acceptable. Conclusion: Intrafractional prostate motion is a potential source of treatment error especially in the context of emerging SBRT regimens. It is feasible to use transperineal ultrasound daily to monitor prostate motion during treatment. Our results verify the tracking accuracy of a commercial ultrasound system to be better than 1 mm under typical external beam treatment conditions.« less

Complications and adequacy of transplant kidney biopsies: A comparison of techniques.

PubMed

Plattner, Brett W; Chen, Pauline; Cross, Richard; Leavitt, Matthew A; Killen, Paul D; Heung, Michael

2018-05-01

Kidney biopsies are an essential tool in the diagnosis and management of kidney diseases, particularly in kidney transplant recipients. Biopsies carry a risk for serious complications and not all biopsies achieve adequate tissue. We examined the impact of kidney biopsy technique on complications and biopsy adequacy. The cohort consisted of consecutive kidney transplant patients undergoing biopsy by one of three techniques: ultrasound localization, real-time ultrasound guidance, and ultrasound-guided trocar placement. Variables of interest included patient characteristics and procedural characteristics. The primary outcome was serious complication attributable to kidney biopsy, and the secondary outcome was biopsy adequacy as defined by Banff criteria. Among 263 patients undergoing biopsy, 27 (10.3%) had a complication (14 with gross hematuria, 10 requiring blood transfusion, 3 requiring an unplanned interventional radiology procedure, 1 kidney loss; no deaths). Complications were more common among patients biopsied using ultrasound-guided trocar compared to real-time ultrasound and ultrasound localization (21.4% vs 7.9% vs 7.1%, respectively, p = 0.008). After adjusting for patient and procedure characteristics, technique was no longer significantly associated with complication. Biopsy adequacy was significantly higher when using ultrasound localization and real-time ultrasound compared to ultrasound-guided trocar (84.6% vs 86.8% vs 69.6%, p = 0.029), and this finding persisted in adjusted analysis. Kidney biopsy complications appear to be similar when using any of the three techniques examined in our study. However, ultrasound-guided trocar technique may yield lower biopsy adequacy when compared to non-trocar techniques.

Diagnosing pulmonary edema: lung ultrasound versus chest radiography.

PubMed

Martindale, Jennifer L; Noble, Vicki E; Liteplo, Andrew

2013-10-01

Diagnosing the underlying cause of acute dyspnea can be challenging. Lung ultrasound may help to identify pulmonary edema as a possible cause. To evaluate the ability of residents to recognize pulmonary edema on lung ultrasound using chest radiographs as a comparison standard. This is a prospective, blinded, observational study of a convenience sample of resident physicians in the Departments of Emergency Medicine (EM), Internal Medicine (IM), and Radiology. Residents were given a tutorial on interpreting pulmonary edema on both chest radiograph and lung ultrasound. They were then shown both ultrasounds and chest radiographs from 20 patients who had presented to the emergency department with dyspnea, 10 with a primary diagnosis of pulmonary edema, and 10 with alternative diagnoses. Cohen's κ values were calculated to describe the strength of the correlation between resident and gold standard interpretations. Participants included 20 EM, 20 IM, and 20 Radiology residents. The overall agreement with gold standard interpretation of pulmonary edema on lung ultrasound (74%, κ = 0.51, 95% confidence interval 0.46-0.55) was superior to chest radiographs (58%, κ = 0.25, 95% confidence interval 0.20-0.30) (P < 0.0001). EM residents interpreted lung ultrasounds more accurately than IM residents. Radiology residents interpreted chest radiographs more accurately than did EM and IM residents. Residents were able to more accurately identify pulmonary edema with lung ultrasound than with chest radiograph. Physicians with minimal exposure to lung ultrasound may be able to correctly recognize pulmonary edema on lung ultrasound.

Improved Anatomical Specificity of Non-invasive Neuro-stimulation by High Frequency (5 MHz) Ultrasound

NASA Astrophysics Data System (ADS)

Li, Guo-Feng; Zhao, Hui-Xia; Zhou, Hui; Yan, Fei; Wang, Jing-Yao; Xu, Chang-Xi; Wang, Cong-Zhi; Niu, Li-Li; Meng, Long; Wu, Song; Zhang, Huai-Ling; Qiu, Wei-Bao; Zheng, Hai-Rong

2016-04-01

Low frequency ultrasound (<1 MHz) has been demonstrated to be a promising approach for non-invasive neuro-stimulation. However, the focal width is limited to be half centimeter scale. Minimizing the stimulation region with higher frequency ultrasound will provide a great opportunity to expand its application. This study first time examines the feasibility of using high frequency (5 MHz) ultrasound to achieve neuro-stimulation in brain, and verifies the anatomical specificity of neuro-stimulation in vivo. 1 MHz and 5 MHz ultrasound stimulation were evaluated in the same group of mice. Electromyography (EMG) collected from tail muscles together with the motion response videos were analyzed for evaluating the stimulation effects. Our results indicate that 5 MHz ultrasound can successfully achieve neuro-stimulation. The equivalent diameter (ED) of the stimulation region with 5 MHz ultrasound (0.29 ± 0.08 mm) is significantly smaller than that with 1 MHz (0.83 ± 0.11 mm). The response latency of 5 MHz ultrasound (45 ± 31 ms) is also shorter than that of 1 MHz ultrasound (208 ± 111 ms). Consequently, high frequency (5 MHz) ultrasound can successfully activate the brain circuits in mice. It provides a smaller stimulation region, which offers improved anatomical specificity for neuro-stimulation in a non-invasive manner.

Transvaginal ultrasound

MedlinePlus

Endovaginal ultrasound; Ultrasound - transvaginal; Fibroids - transvaginal ultrasound; Vaginal bleeding - transvaginal ultrasound; Uterine bleeding - transvaginal ultrasound; Menstrual bleeding - transvaginal ultrasound; ...

Structure formation and properties of a copper-aluminum joint produced by ultrasound-assisted explosive welding

NASA Astrophysics Data System (ADS)

Kuz'min, E. V.; Peev, A. P.; Kuz'min, S. V.; Lysak, V. I.

2017-08-01

The effect of ultrasound-assisted explosive welding on the structure formation and the properties of copper-aluminum joints is studied. Ultrasound-assisted explosive welding improves the quality of formed copper-aluminum joints, i.e., enhances their strength and significantly reduces the amount of fused metal over the entire weldability range. It is shown that ultrasound-assisted explosive welding can noticeably extend the weldability range of the copper-aluminum pair to obtain equal-in-strength joints with minimum structural heterogeneity in the wide welding range.

Ceramic membrane ultrafiltration of natural surface water with ultrasound enhanced backwashing.

PubMed

Boley, A; Narasimhan, K; Kieninger, M; Müller, W-R

2010-01-01

Ultrafiltration membrane cleaning with ultrasound enhanced backwashing was investigated with two ceramic membrane systems in parallel. One of them was subjected to ultrasound during backwashing, the other acted as a reference system. The feed water was directly taken from a creek with a sedimentation process as only pre-treatment. The cleaning performance was improved with ultrasound but after 3 weeks of operation damages occurred on the membranes. These effects were studied with online measurements of flux, trans-membrane-pressure and temperature, but also with integrity tests, turbidity measurements and visual examination.

Picture perfect: benefits and risk of fetal 3D ultrasound.

PubMed

Wiseman, Claudia S; Kiehl, Ermalynn M

2007-01-01

The purpose of this literature review was to survey available information and research related to routine three-dimensional (3D) ultrasound technology in obstetrics, with an emphasis on current medical uses, safety, and availability issues. Several data bases, including Cochrane, WHO, NIH, CINALH, Blackwell Synergy, ERIC, PubMed, and Medline, were used along with information from Internet search engines. Although fetal 3D ultrasound is used in both medical and commercial settings, recent studies focus on its possible uses rather than the more difficult issues of safety and commercial applications. Professional organizations associated with ultrasound technology support limiting ultrasounds in pregnancy to medically necessary events, whereas commercial venues use "direct to consumer" marketing to promote this technology as a way to "see" the baby before it is born. How safe is routine or frequent use of 3D ultrasound? Further research is needed to address these important questions.

Guiding intramuscular diaphragm injections using real-time ultrasound and electromyography.

PubMed

Sarwal, Aarti; Cartwright, Michael S; Mitchell, Erin; Williams, Koudy; Walker, Francis O; Childers, Martin K

2015-02-01

We describe a unique method that combines ultrasound and electromyography to guide intramuscular diaphragm injections in anesthetized large animals. Ultrasound was used to visualize the diaphragm on each side of spontaneously breathing, anesthetized beagle dogs and cynomolgus macaques. An electromyography (EMG) needle was introduced and directed by ultrasound to confirm that the needle entered the muscular portion of the diaphragm, and methylene blue was injected. Injection accuracy was confirmed upon necropsy by tracking the spread of methylene blue. All methylene blue injections were confirmed to have been placed appropriately into the diaphragm. This study demonstrates the feasibility and accuracy of using ultrasound and EMG to guide injections and to reduce complications associated with conventional blind techniques. Ultrasound guidance can be used for clinical EMG of the diaphragm. Future applications may include targeted diaphragm injections with gene replacement therapy in neuromuscular diseases. © 2014 Wiley Periodicals, Inc.

Guiding Intramuscular Diaphragm Injections Using Real-time Ultrasound & Electromyography

PubMed Central

Sarwal, Aarti; Cartwright, Michael S.; Mitchell, Erin; Williams, Koudy; Walker, Francis O.; Childers, Martin K.

2014-01-01

Introduction We describe a unique method that combines ultrasound and electromyography to guide intramuscular diaphragm injections in anesthetized large animals. Methods Ultrasound was used to visualize the diaphragm on each side of spontaneously breathing, anesthetized beagle dogs and cynomolgus macaques. An electromyography needle was introduced and directed by ultrasound to confirm that the needle entered the muscular portion of the diaphragm, and methylene blue was injected. Injection accuracy was confirmed upon necropsy by tracking the spread of methylene blue. Results All methylene blue injections were confirmed to have been placed appropriately into the diaphragm. Conclusions This study demonstrates the feasibility and accuracy of using ultrasound and EMG to guide injections and to reduce complications associated with conventional blind techniques. Ultrasound guidance can be used for clinical electromyography of the diaphragm. Future applications may include targeted diaphragm injections with gene replacement therapy in neuromuscular diseases. PMID:25354257

Frequency Dependence of Ultrasound Neurostimulation in the Mouse Brain

PubMed Central

Ye, Patrick Peiyong; Brown, Julian R.; Pauly, Kim Butts

2016-01-01

Ultrasound neuromodulation holds promise as a non-invasive technique for neuromodulation of the central nervous system. However, much remains to be determined about how the technique can be transformed into a useful technology, including the effect of ultrasound frequency. Previous studies have demonstrated neuromodulation in vivo using frequencies less than 1 MHz, with a trend towards improved efficacy with lower frequency. However, using higher frequencies could offer improved ultrasound spatial resolution. We investigate the ultrasound neuromodulation effects in mice at various frequencies both below and above 1 MHz and find that frequencies up to 2.9 MHz can still be effective for generating motor responses, but also confirm that as frequency increases, sonications require significantly more intensity to achieve equivalent efficacy. We argue that our results provide evidence that favors either a particle displacement or a cavitation-based mechanism for the phenomenon of ultrasound neuromodulation. PMID:27090861

Motion Detection in Ultrasound Image-Sequences Using Tensor Voting

NASA Astrophysics Data System (ADS)

Inba, Masafumi; Yanagida, Hirotaka; Tamura, Yasutaka

2008-05-01

Motion detection in ultrasound image sequences using tensor voting is described. We have been developing an ultrasound imaging system adopting a combination of coded excitation and synthetic aperture focusing techniques. In our method, frame rate of the system at distance of 150 mm reaches 5000 frame/s. Sparse array and short duration coded ultrasound signals are used for high-speed data acquisition. However, many artifacts appear in the reconstructed image sequences because of the incompleteness of the transmitted code. To reduce the artifacts, we have examined the application of tensor voting to the imaging method which adopts both coded excitation and synthetic aperture techniques. In this study, the basis of applying tensor voting and the motion detection method to ultrasound images is derived. It was confirmed that velocity detection and feature enhancement are possible using tensor voting in the time and space of simulated ultrasound three-dimensional image sequences.

A brief history of ultrasound in rheumatology: where we were.

PubMed

Grassi, Walter; Filippucci, Emilio

2014-01-01

Ultrasonography in the '70s was a well-known and widely used method within several medical specialties but not in rheumatology. Initial development of the field was led by radiologists who mainly investigated the potential of ultrasound in the assessment of large joints. In the late '80s, the first studies supporting the role of ultrasound in the detection of soft tissue changes and bone erosions in the hands of patients with rheumatoid arthritis were published. In the '90s, the dramatic improvement of spatial resolution due to the new generation high frequency probes opened up new avenues for the exploration of otherwise undetectable anatomical details. Ultrasound research during this period was enhanced by the growing use of colour Doppler and power Doppler and by the first prototypes of three dimensional ultrasound. Over the last 10 years, the buzz words in ultrasound research in rheumatology have been standardisation, early diagnosis and therapy monitoring.

Candle soot nanoparticles-polydimethylsiloxane composites for laser ultrasound transducers

NASA Astrophysics Data System (ADS)

Chang, Wei-Yi; Huang, Wenbin; Kim, Jinwook; Li, Sibo; Jiang, Xiaoning

2015-10-01

Generation of high power laser ultrasound strongly demands the advanced materials with efficient laser energy absorption, fast thermal diffusion, and large thermoelastic expansion capabilities. In this study, candle soot nanoparticles-polydimethylsiloxane (CSNPs-PDMS) composite was investigated as the functional layer for an optoacoustic transducer with high-energy conversion efficiency. The mean diameter of the collected candle soot carbon nanoparticles is about 45 nm, and the light absorption ratio at 532 nm wavelength is up to 96.24%. The prototyped CSNPs-PDMS nano-composite laser ultrasound transducer was characterized and compared with transducers using Cr-PDMS, carbon black (CB)-PDMS, and carbon nano-fiber (CNFs)-PDMS composites, respectively. Energy conversion coefficient and -6 dB frequency bandwidth of the CSNPs-PDMS composite laser ultrasound transducer were measured to be 4.41 × 10-3 and 21 MHz, respectively. The unprecedented laser ultrasound transduction performance using CSNPs-PDMS nano-composites is promising for a broad range of ultrasound therapy applications.

PRESAGE® as a new calibration method for high intensity focused ultrasound therapy

NASA Astrophysics Data System (ADS)

Costa, M.; McErlean, C.; Rivens, I.; Adamovics, J.; Leach, M. O.; ter Haar, G.; Doran, S. J.

2015-01-01

High Intensity Focused ultrasound (HIFU) is a non-invasive cancer therapy that makes use of the mainly thermal effects of ultrasound to destroy tissue. In order to achieve reliable treatment planning, it is necessary to characterise the ultrasound source (transducer) and to understand how the wave propagates in tissue and the energy deposition in the focal region. This novel exploratory study investigated how HIFU affects PRESAGE®, an optical phantom used for radiotherapy dosimetry, which is potentially a rapid method of calibrating the transducer. Samples, of two different formulations, were exposed to focused ultrasound and imaged using Optical Computed Tomography. First results showed that, PRESAGE® changes colour on ultrasound exposure (darker green regions were observed) with the alterations being related to the acoustic power and sample composition. Future work will involve quantification of these alterations and understanding how to relate them to the mechanisms of action of HIFU.

The growth of oscillating bubbles in an ultrasound field

NASA Astrophysics Data System (ADS)

Yamauchi, Risa; Yamashita, Tatsuya; Ando, Keita

2017-11-01

From our recent experiments to test particle removal by underwater ultrasound, dissolved gas supersaturation is found to play an important role in physical cleaning; cavitation bubble nucleation can be triggered easily by weak ultrasound under the supersaturation and mild motion of the bubbles contributes to efficient cleaning without erosion. The state of gas bubble nuclei in water is critical to the determination of a cavitation inception threshold. Under ultrasound forcing, the size of bubble nuclei is varied by the transfer of dissolved gas (i.e., rectified diffusion); the growth rate will be promoted by the supersaturation and is thus expected to contribute to cavitation activity enhancement. In the present work, we experimentally study rectified diffusion for bubbles attached at glass surfaces in an ultrasound field. We will present the evolution of bubble nuclei sizes with varying parameters such as dissolved oxygen supersaturation, and ultrasound intensity and frequency. the Research Grant of Keio Leading-edge Laboratory of Science & Technology.

Laser-nucleated acoustic cavitation in focused ultrasound.

PubMed

Gerold, Bjoern; Kotopoulis, Spiros; McDougall, Craig; McGloin, David; Postema, Michiel; Prentice, Paul

2011-04-01

Acoustic cavitation can occur in therapeutic applications of high-amplitude focused ultrasound. Studying acoustic cavitation has been challenging, because the onset of nucleation is unpredictable. We hypothesized that acoustic cavitation can be forced to occur at a specific location using a laser to nucleate a microcavity in a pre-established ultrasound field. In this paper we describe a scientific instrument that is dedicated to this outcome, combining a focused ultrasound transducer with a pulsed laser. We present high-speed photographic observations of laser-induced cavitation and laser-nucleated acoustic cavitation, at frame rates of 0.5×10(6) frames per second, from laser pulses of energy above and below the optical breakdown threshold, respectively. Acoustic recordings demonstrated inertial cavitation can be controllably introduced to the ultrasound focus. This technique will contribute to the understanding of cavitation evolution in focused ultrasound including for potential therapeutic applications. © 2011 American Institute of Physics

Assistive technology for ultrasound-guided central venous catheter placement.

PubMed

Ikhsan, Mohammad; Tan, Kok Kiong; Putra, Andi Sudjana

2018-01-01

This study evaluated the existing technology used to improve the safety and ease of ultrasound-guided central venous catheterization. Electronic database searches were conducted in Scopus, IEEE, Google Patents, and relevant conference databases (SPIE, MICCAI, and IEEE conferences) for related articles on assistive technology for ultrasound-guided central venous catheterization. A total of 89 articles were examined and pointed to several fields that are currently the focus of improvements to ultrasound-guided procedures. These include improving needle visualization, needle guides and localization technology, image processing algorithms to enhance and segment important features within the ultrasound image, robotic assistance using probe-mounted manipulators, and improving procedure ergonomics through in situ projections of important information. Probe-mounted robotic manipulators provide a promising avenue for assistive technology developed for freehand ultrasound-guided percutaneous procedures. However, there is currently a lack of clinical trials to validate the effectiveness of these devices.

Fusion imaging of contrast-enhanced ultrasound and contrast-enhanced CT or MRI before radiofrequency ablation for liver cancers.

PubMed

Bo, Xiao-Wan; Xu, Hui-Xiong; Wang, Dan; Guo, Le-Hang; Sun, Li-Ping; Li, Xiao-Long; Zhao, Chong-Ke; He, Ya-Ping; Liu, Bo-Ji; Li, Dan-Dan; Zhang, Kun

2016-11-01

To investigate the usefulness of fusion imaging of contrast-enhanced ultrasound (CEUS) and CECT/CEMRI before percutaneous ultrasound-guided radiofrequency ablation (RFA) for liver cancers. 45 consecutive patients with 70 liver lesions were included between March 2013 and October 2015, and all the lesions were identified on CEMRI/CECT prior to inclusion in the study. Planning ultrasound for percutaneous RFA was performed using conventional ultrasound, ultrasound-CECT/CEMRI and CEUS and CECT/CEMRI fusion imaging during the same session. The numbers of the conspicuous lesions on ultrasound and fusion imaging were recorded. RFA was performed according to the results of fusion imaging. Complete response (CR) rate was calculated and the complications were recorded. On conventional ultrasound, 25 (35.7%) of the 70 lesions were conspicuous, whereas 45 (64.3%) were inconspicuous. Ultrasound-CECT/CEMRI fusion imaging detected additional 24 lesions thus increased the number of the conspicuous lesions to 49 (70.0%) (70.0% vs 35.7%; p < 0.001 in comparison with conventional ultrasound). With the use of CEUS and CECT/CEMRI fusion imaging, the number of the conspicuous lesions further increased to 67 (95.7%, 67/70) (95.7% vs 70.0%, 95.7% vs 35.7%; both p < 0.001 in comparison with ultrasound and ultrasound-CECT/CEMRI fusion imaging, respectively). With the assistance of CEUS and CECT/CEMRI fusion imaging, the confidence level of the operator for performing RFA improved significantly with regard to visualization of the target lesions (p = 0.001). The CR rate for RFA was 97.0% (64/66) in accordance to the CECT/CEMRI results 1 month later. No procedure-related deaths and major complications occurred during and after RFA. Fusion of CEUS and CECT/CEMRI improves the visualization of those inconspicuous lesions on conventional ultrasound. It also facilitates improvement in the RFA operators' confidence and CR of RFA. Advances in knowledge: CEUS and CECT/CEMRI fusion imaging is better than both conventional ultrasound and ultrasound-CECT/CEMRI fusion imaging for lesion visualization and improves the operator confidence, thus it should be recommended to be used as a routine in ultrasound-guided percutaneous RFA procedures for liver cancer.

Fusion imaging of contrast-enhanced ultrasound and contrast-enhanced CT or MRI before radiofrequency ablation for liver cancers

PubMed Central

Bo, Xiao-Wan; Wang, Dan; Guo, Le-Hang; Sun, Li-Ping; Li, Xiao-Long; Zhao, Chong-Ke; He, Ya-Ping; Liu, Bo-Ji; Li, Dan-Dan; Zhang, Kun

2016-01-01

Objective: To investigate the usefulness of fusion imaging of contrast-enhanced ultrasound (CEUS) and CECT/CEMRI before percutaneous ultrasound-guided radiofrequency ablation (RFA) for liver cancers. Methods: 45 consecutive patients with 70 liver lesions were included between March 2013 and October 2015, and all the lesions were identified on CEMRI/CECT prior to inclusion in the study. Planning ultrasound for percutaneous RFA was performed using conventional ultrasound, ultrasound-CECT/CEMRI and CEUS and CECT/CEMRI fusion imaging during the same session. The numbers of the conspicuous lesions on ultrasound and fusion imaging were recorded. RFA was performed according to the results of fusion imaging. Complete response (CR) rate was calculated and the complications were recorded. Results: On conventional ultrasound, 25 (35.7%) of the 70 lesions were conspicuous, whereas 45 (64.3%) were inconspicuous. Ultrasound-CECT/CEMRI fusion imaging detected additional 24 lesions thus increased the number of the conspicuous lesions to 49 (70.0%) (70.0% vs 35.7%; p < 0.001 in comparison with conventional ultrasound). With the use of CEUS and CECT/CEMRI fusion imaging, the number of the conspicuous lesions further increased to 67 (95.7%, 67/70) (95.7% vs 70.0%, 95.7% vs 35.7%; both p < 0.001 in comparison with ultrasound and ultrasound-CECT/CEMRI fusion imaging, respectively). With the assistance of CEUS and CECT/CEMRI fusion imaging, the confidence level of the operator for performing RFA improved significantly with regard to visualization of the target lesions (p = 0.001). The CR rate for RFA was 97.0% (64/66) in accordance to the CECT/CEMRI results 1 month later. No procedure-related deaths and major complications occurred during and after RFA. Conclusion: Fusion of CEUS and CECT/CEMRI improves the visualization of those inconspicuous lesions on conventional ultrasound. It also facilitates improvement in the RFA operators' confidence and CR of RFA. Advances in knowledge: CEUS and CECT/CEMRI fusion imaging is better than both conventional ultrasound and ultrasound-CECT/CEMRI fusion imaging for lesion visualization and improves the operator confidence, thus it should be recommended to be used as a routine in ultrasound-guided percutaneous RFA procedures for liver cancer. PMID:27626506

Estimation of feline renal volume using computed tomography and ultrasound.

PubMed

Tyson, Reid; Logsdon, Stacy A; Werre, Stephen R; Daniel, Gregory B

2013-01-01

Renal volume estimation is an important parameter for clinical evaluation of kidneys and research applications. A time efficient, repeatable, and accurate method for volume estimation is required. The purpose of this study was to describe the accuracy of ultrasound and computed tomography (CT) for estimating feline renal volume. Standardized ultrasound and CT scans were acquired for kidneys of 12 cadaver cats, in situ. Ultrasound and CT multiplanar reconstructions were used to record renal length measurements that were then used to calculate volume using the prolate ellipsoid formula for volume estimation. In addition, CT studies were reconstructed at 1 mm, 5 mm, and 1 cm, and transferred to a workstation where the renal volume was calculated using the voxel count method (hand drawn regions of interest). The reference standard kidney volume was then determined ex vivo using water displacement with the Archimedes' principle. Ultrasound measurement of renal length accounted for approximately 87% of the variability in renal volume for the study population. The prolate ellipsoid formula exhibited proportional bias and underestimated renal volume by a median of 18.9%. Computed tomography volume estimates using the voxel count method with hand-traced regions of interest provided the most accurate results, with increasing accuracy for smaller voxel sizes in grossly normal kidneys (-10.1 to 0.6%). Findings from this study supported the use of CT and the voxel count method for estimating feline renal volume in future clinical and research studies. © 2012 Veterinary Radiology & Ultrasound.

Efficacy of ultrasound-guided percutaneous needle treatment of calcific tendinitis.

PubMed

Vignesh, K Nithin; McDowall, Adam; Simunovic, Nicole; Bhandari, Mohit; Choudur, Hema N

2015-01-01

The purpose of this study was to conduct a systematic review of the efficacy of ultrasound-guided needle lavage in treating calcific tendinitis. Two independent assessors searched medical databases and screened studies for eligibility. Eleven articles were included. Heterogeneity among included studies precluded meta-analysis. Results of randomized controlled trials suggested no difference in pain relief between needle lavage and other interventions, but the studies were of low quality. Additional high-quality evidence is required to determine the relative efficacy of ultrasound-guided needle lavage in the management of calcific tendinitis of the rotator cuff.

Monitoring of Lactic Fermentation Process by Ultrasonic Technique

NASA Astrophysics Data System (ADS)

Alouache, B.; Touat, A.; Boutkedjirt, T.; Bennamane, A.

The non-destructive control by using ultrasound techniques has become of great importance in food industry. In this work, Ultrasound has been used for quality control and monitoring the fermentation stages of yogurt, which is a highly consumed product. On the contrary to the physico-chemical methods, where the measurement instruments are directly introduced in the sample, ultrasound techniques have the advantage of being non-destructive and contactless, thus reducing the risk of contamination. Results obtained in this study by using ultrasound seem to be in good agreement with those obtained by physico-chemical methods such as acidity measurement by using a PH-meter instrument. This lets us to conclude that ultrasound method may be an alternative for a healthy control of yoghurt fermentation process.

Clinical combination of multiphoton tomography and high frequency ultrasound imaging for evaluation of skin diseases

NASA Astrophysics Data System (ADS)

König, K.; Speicher, M.; Koehler, M. J.; Scharenberg, R.; Elsner, P.; Kaatz, M.

2010-02-01

For the first time, high frequency ultrasound imaging, multiphoton tomography, and dermoscopy were combined in a clinical study. Different dermatoses such as benign and malign skin cancers, connective tissue diseases, inflammatory skin diseases and autoimmune bullous skin diseases have been investigated with (i) state-of-the-art and highly sophisticated ultrasound systems for dermatology, (ii) the femtosecond-laser multiphoton tomograph DermaInspectTM and (iii) dermoscopes. Dermoscopy provides two-dimensional color imaging of the skin surface with a magnification up to 70x. Ultrasound images are generated from reflections of the emitted ultrasound signal, based on inhomogeneities of the tissue. These echoes are converted to electrical signals. Depending on the ultrasound frequency the penetration depth varies from about 1 mm to 16 mm in dermatological application. The 100-MHz-ultrasound system provided an axial resolution down to 16 μm and a lateral resolution down to 32 μm. In contrast to the wide-field ultrasound images, multiphoton tomography provided horizontal optical sections of 0.36×0.36 mm2 down to 200 μm tissue depth with submicron resolution. The autofluorescence of mitochondrial coenzymes, melanin, and elastin as well as the secondharmonic- generation signal of the collagen network were imaged. The combination of ultrasound and multiphoton tomography provides a novel opportunity for diagnostics of skin disorders.

Degradation of polycyclic aromatic hydrocarbons (PAHs) in textile dyeing sludge with ultrasound and Fenton processes: Effect of system parameters and synergistic effect study.

PubMed

Lin, Meiqing; Ning, Xun-an; An, Taicheng; Zhang, Jianhao; Chen, Changmin; Ke, Yaowei; Wang, Yujie; Zhang, Yaping; Sun, Jian; Liu, Jingyong

2016-04-15

To establish an efficient oxidation process for the degradation of polycyclic aromatic hydrocarbons (PAHs) in textile dyeing sludge, the effects of various operating parameters were optimized during the ultrasound process, Fenton process and the combined ultrasound-Fenton process. The results showed that the ultrasonic density of 1.80w/cm(3), both H2O2 and Fe(2+) dosages of 140mmol/L and pH 3 were favorable conditions for the degradation of PAHs. The degradation efficiency of high molecular weight PAHs was close to or even higher than that of light molecular weight PAHs. The highest degradation efficiencies of Σ16 PAHs were obtained within 30min in the order of: Fenton (83.5%) >ultrasound-Fenton (75.5%) >ultrasound (45.5%), then the efficiencies were decreased in the other of: ultrasound-Fenton (73.0%) >Fenton (70.3%) >ultrasound (41.4%) in 60min. The extra PAHs were released from the intracellular substances and the cavities of sludge due to the disruption of sludge during the oxidation process. Also, the degradation of PAHs could be inhibited by the other organic matter in the sludge. The combined ultrasound-Fenton process showed more efficient than both ultrasound process and Fenton process not only in the surface of sludge but also in the sludge interior. Copyright © 2015 Elsevier B.V. All rights reserved.

Effect of ultrasound sonication on clonogenic survival and mitochondria of ovarian cancer cells in the presence of methylene blue.

PubMed

Xiang, Junyan; Leung, Albert Wingnang; Xu, Chuanshan

2014-10-01

This study aimed to investigate the effect of ultrasound sonication in the presence of methylene blue on clonogenic survival and mitochondria of ovarian cancer cells. Human ovarian cancer HO-8910 cells, which were incubated with different concentrations of methylene blue for 1 hour, were exposed to an ultrasonic wave for 5 seconds with intensity of 0.46 W/cm(2). Clonogenic survival of HO-8910 cells after ultrasound sonication was measured by a colony-forming unit assay. Mitochondrial structural changes were observed on transmission electron microscopy, and the mitochondrial membrane potential was evaluated by confocal laser-scanning microscopy with rhodamine 123 staining. The colony-forming units of HO-8910 cells decreased considerably after ultrasound sonication in the presence of methylene blue. Transmission electron microscopy showed slightly enlarged mitochondria in the ultrasound-treated cells in the absence of methylene blue; however, seriously damaged mitochondria, even with almost complete disappearance of cristae, were found in the cells treated by ultrasound sonication in the presence of methylene blue. The mitochondrial membrane potential collapsed significantly when HO-8910 cells were treated by ultrasound sonication in the presence of methylene blue (P < .05). Ultrasound sonication in the presence of methylene blue markedly damaged mitochondrial structure and function and decreased clonogenic survival of HO-8910 cells. © 2014 by the American Institute of Ultrasound in Medicine.

Ultrasound-enhanced delivery of targeted echogenic liposomes in a novel ex vivo mouse aorta model.

PubMed

Hitchcock, Kathryn E; Caudell, Danielle N; Sutton, Jonathan T; Klegerman, Melvin E; Vela, Deborah; Pyne-Geithman, Gail J; Abruzzo, Todd; Cyr, Peppar E P; Geng, Yong-Jian; McPherson, David D; Holland, Christy K

2010-06-15

The goal of this study was to determine whether targeted, Rhodamine-labeled echogenic liposomes (Rh-ELIP) containing nanobubbles could be delivered to the arterial wall, and whether 1-MHz continuous wave ultrasound would enhance this delivery profile. Aortae excised from apolipoprotein-E-deficient (n=8) and wild-type (n=8) mice were mounted in a pulsatile flow system through which Rh-ELIP were delivered in a stream of bovine serum albumin. Half the aortae from each group were treated with 1-MHz continuous wave ultrasound at 0.49 MPa peak-to-peak pressure, and half underwent sham exposure. Ultrasound parameters were chosen to promote stable cavitation and avoid inertial cavitation. A broadband hydrophone was used to monitor cavitation activity. After treatment, aortic sections were prepared for histology and analyzed by an individual blinded to treatment conditions. Delivery of Rh-ELIP to the vascular endothelium was observed, and sub-endothelial penetration of Rh-ELIP was present in five of five ultrasound-treated aortae and was absent in those not exposed to ultrasound. However, the degree of penetration in the ultrasound-exposed aortae was variable. There was no evidence of ultrasound-mediated tissue damage in any specimen. Ultrasound-enhanced delivery within the arterial wall was demonstrated in this novel model, which allows quantitative evaluation of therapeutic delivery. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Value of transperineal ultrasound on the observation of paravaginal support.

PubMed

Dou, Chaoran; Li, Qin; Ying, Tao; Shui, Wen; Yan, Yulin; Luo, Yijia; Wang, Xia

2018-04-01

To explore the feasibility of three-dimensional (3D) transperineal ultrasound on the observation of paravaginal support in nulliparous and postpartum women. Volume datasets were acquired in 50 nulliparous and 100 postpartum women using 3D transperineal ultrasound. Paravaginal supports were observed by studying the vaginal cross-sectional morphology. The extent of paravaginal support in specific level were evaluated by counting out at a 2 mm interval in tomographic ultrasound imaging mode in all subjects. The Mann-Whitney U test were applied to establish comparisons between the two groups. Three representative manifestations of vaginal cross-sectional morphology corresponding to different paravaginal support were presented from the dorsal side to the caudal side, both in nulliparous women and postpartum women. The extent of paravaginal support in middle vagina was 11 slices (range 9-12) in nulliparous women and 7 slices (range 4-10) in postpartum women (P < 0.05). This pilot study confirmed that it was feasible to indirectly study paravaginal support by observing the vaginal cross-sectional morphology using 3D transperineal ultrasound.

Multispectral photoacoustic imaging of nerves with a clinical ultrasound system

NASA Astrophysics Data System (ADS)

Mari, Jean Martial; West, Simeon; Beard, Paul C.; Desjardins, Adrien E.

2014-03-01

Accurate and efficient identification of nerves is of great importance during many ultrasound-guided clinical procedures, including nerve blocks and prostate biopsies. It can be challenging to visualise nerves with conventional ultrasound imaging, however. One of the challenges is that nerves can have very similar appearances to nearby structures such as tendons. Several recent studies have highlighted the potential of near-infrared optical spectroscopy for differentiating nerves and adjacent tissues, as this modality can be sensitive to optical absorption of lipids that are present in intra- and extra-neural adipose tissue and in the myelin sheaths. These studies were limited to point measurements, however. In this pilot study, a custom photoacoustic system with a clinical ultrasound imaging probe was used to acquire multi-spectral photoacoustic images of nerves and tendons from swine ex vivo, across the wavelength range of 1100 to 1300 nm. Photoacoustic images were processed and overlaid in colour onto co-registered conventional ultrasound images that were acquired with the same imaging probe. A pronounced optical absorption peak centred at 1210 nm was observed in the photoacoustic signals obtained from nerves, and it was absent in those obtained from tendons. This absorption peak, which is consistent with the presence of lipids, provides a novel image contrast mechanism to significantly enhance the visualization of nerves. In particular, image contrast for nerves was up to 5.5 times greater with photoacoustic imaging (0.82 +/- 0.15) than with conventional ultrasound imaging (0.148 +/- 0.002), with a maximum contrast of 0.95 +/- 0.02 obtained in photoacoustic mode. This pilot study demonstrates the potential of photoacoustic imaging to improve clinical outcomes in ultrasound-guided interventions in regional anaesthesia and interventional oncology.

Diagnostic ultrasound imaging for lateral epicondylalgia: a case-control study.

PubMed

Heales, Luke James; Broadhurst, Nathan; Mellor, Rebecca; Hodges, Paul William; Vicenzino, Bill

2014-11-01

Lateral epicondylalgia (LE) is clinically diagnosed as pain over the lateral elbow that is provoked by gripping. Usually, LE responds well to conservative intervention; however, those who fail such treatment require further evaluation, including musculoskeletal ultrasound. Previous studies of musculoskeletal ultrasound have methodological flaws, such as lack of assessor blinding and failure to control for participant age, sex, and arm dominance. The purpose of this study was to assess the diagnostic use of blinded ultrasound imaging in people with clinically diagnosed LE compared with that in a control group matched for age, sex, and arm dominance. Participants (30 with LE and 30 controls) underwent clinical examination as the criterion standard test. Unilateral LE was defined as pain over the lateral epicondyle, which was provoked by palpation, resisted wrist and finger extension, and gripping. Controls without symptoms were matched for age, sex, and arm dominance. Ultrasound investigations were performed by two sonographers using a standardized protocol. Grayscale images were assessed for signs of tendon pathology and rated on a four-point ordinal scale. Power Doppler was used to assess neovascularity and rated on a five-point ordinal scale. The combination of grayscale and power Doppler imaging revealed an overall sensitivity of 90% and specificity of 47%. The positive and negative likelihood ratios for combined grayscale and power Doppler imaging were 1.69 and 0.21, respectively. Although ultrasound imaging helps confirm the absence of LE, when findings are negative for tendinopathic changes, the high prevalence of tendinopathic changes in pain-free controls challenges the specificity of the measure. The validity of ultrasound imaging to confirm tendon pathology in clinically diagnosed LE requires further study with strong methodology.

Imaging Performance of a Handheld Ultrasound System With Real-Time Computer-Aided Detection of Lumbar Spine Anatomy: A Feasibility Study.

PubMed

Tiouririne, Mohamed; Dixon, Adam J; Mauldin, F William; Scalzo, David; Krishnaraj, Arun

2017-08-01

The aim of this study was to evaluate the imaging performance of a handheld ultrasound system and the accuracy of an automated lumbar spine computer-aided detection (CAD) algorithm in the spines of human subjects. This study was approved by the institutional review board of the University of Virginia. The authors designed a handheld ultrasound system with enhanced bone image quality and fully automated CAD of lumbar spine anatomy. The imaging performance was evaluated by imaging the lumbar spines of 68 volunteers with body mass index between 18.5 and 48 kg/m. The accuracy, sensitivity, and specificity of the lumbar spine CAD algorithm were assessed by comparing the algorithm's results to ground-truth segmentations of neuraxial anatomy provided by radiologists. The lumbar spine CAD algorithm detected the epidural space with a sensitivity of 94.2% (95% confidence interval [CI], 85.1%-98.1%) and a specificity of 85.5% (95% CI, 81.7%-88.6%) and measured its depth with an error of approximately ±0.5 cm compared with measurements obtained manually from the 2-dimensional ultrasound images. The spine midline was detected with a sensitivity of 93.9% (95% CI, 85.8%-97.7%) and specificity of 91.3% (95% CI, 83.6%-96.9%), and its lateral position within the ultrasound image was measured with an error of approximately ±0.3 cm. The bone enhancement imaging mode produced images with 5.1- to 10-fold enhanced bone contrast when compared with a comparable handheld ultrasound imaging system. The results of this study demonstrate the feasibility of CAD for assisting with real-time interpretation of ultrasound images of the lumbar spine at the bedside.

Quantitative assessment of placental perfusion by contrast-enhanced ultrasound in macaques and human subjects

PubMed Central

Roberts, Victoria HJ; Lo, Jamie O; Salati, Jennifer A; Lewandowski, Katherine S; Lindner, Jonathan R; Morgan, Terry K; Frias, Antonio E

2016-01-01

Background The utero-placental vascular supply is a critical determinant of placental function and fetal growth. Current methods for the in vivo assessment of placental blood flow are limited. Objective Here we demonstrate the feasibility of utilizing contrast-enhanced ultrasound to visualize and quantify perfusion kinetics in the intervillous space of the primate placenta. Study design Pregnant Japanese macaques were studied at mid second trimester and in the early third trimester. Markers of injury were assessed in placenta samples from animals with or without contrast-enhanced ultrasound exposure (n=6/group). Human subjects were recruited immediately prior to scheduled first trimester pregnancy termination. All studies were performed with maternal intravenous infusion of lipid-shelled octofluoropropane microbubbles with image acquisition using a multipulse contrast-specific algorithm with destruction-replenishment analysis of signal intensity for assessment of perfusion. Results In macaques, rate of perfusion in the intervillous space was increased with advancing gestation. No evidence of microvascular hemorrhage or acute inflammation was found in placental villous tissue and expression levels of caspase-3, nitrotyrosine and HSP70 as markers of apoptosis, nitrative and oxidative stress respectively were unchanged by contrast-enhanced ultrasound exposure. In humans, placental perfusion was visualized at 11wks gestation and preliminary data reveal regional differences in intervillous space perfusion within an individual placenta. By electron microscopy, we demonstrate no evidence of ultrastructure damage to the microvilli on the syncytiotrophoblast following first trimester ultrasound studies. Conclusions Use of contrast-enhanced ultrasound did not result in placental structural damage, and was able to identify intervillous space perfusion rate differences within a placenta. Contrast-enhanced ultrasound may offer a safe clinical tool for the identification of pregnancies at-risk for vascular insufficiency; early recognition may facilitate intervention and improved pregnancy outcomes. PMID:26928151

Diagnostic accuracy of ultrasound in upper and lower extremity long bone fractures of emergency department trauma patients.

PubMed

Frouzan, Arash; Masoumi, Kambiz; Delirroyfard, Ali; Mazdaie, Behnaz; Bagherzadegan, Elnaz

2017-08-01

Long bone fractures are common injuries caused by trauma. Some studies have demonstrated that ultrasound has a high sensitivity and specificity in the diagnosis of upper and lower extremity long bone fractures. The aim of this study was to determine the accuracy of ultrasound compared with plain radiography in diagnosis of upper and lower extremity long bone fractures in traumatic patients. This cross-sectional study assessed 100 patients admitted to the emergency department of Imam Khomeini Hospital, Ahvaz, Iran with trauma to the upper and lower extremities, from September 2014 through October 2015. In all patients, first ultrasound and then standard plain radiography for the upper and lower limb was performed. Data were analyzed by SPSS version 21 to determine the specificity and sensitivity. The mean age of patients with upper and lower limb trauma were 31.43±12.32 years and 29.63±5.89 years, respectively. Radius fracture was the most frequent compared to other fractures (27%). Sensitivity, specificity, positive predicted value, and negative predicted value of ultrasound compared with plain radiography in the diagnosis of upper extremity long bones were 95.3%, 87.7%, 87.2% and 96.2%, respectively, and the highest accuracy was observed in left arm fractures (100%). Tibia and fibula fractures were the most frequent types compared to other fractures (89.2%). Sensitivity, specificity, PPV and NPV of ultrasound compared with plain radiography in the diagnosis of upper extremity long bone fractures were 98.6%, 83%, 65.4% and 87.1%, respectively, and the highest accuracy was observed in men, lower ages and femoral fractures. The results of this study showed that ultrasound compared with plain radiography has a high accuracy in the diagnosis of upper and lower extremity long bone fractures.

Integrated phenotypic-genotypic approach to understand the influence of ultrasound on metabolic response of Lactobacillus sakei.

PubMed

Ojha, K Shikha; Burgess, Catherine M; Duffy, Geraldine; Kerry, Joseph P; Tiwari, Brijesh K

2018-01-01

The lethal effects of soundwaves on a range of microorganisms have been known for almost a century whereas, the use of ultrasound to promote or control their activity is much more recent. Moreover, the fundamental molecular mechanism influencing the behaviour of microorganisms subjected to ultrasonic waves is not well established. In this study, we investigated the influence of ultrasonic frequencies of 20, 45, 130 and 950 kHz on growth kinetics of Lactobacillus sakei. A significant increase in the growth rate of L. sakei was observed following ultrasound treatment at 20 kHz despite the treatment yielding a significant reduction of ca. 3 log cfu/mL in cells count. Scanning electron microscopy showed that ultrasound caused significant changes on the cell surface of L. sakei culture with the formation of pores "sonoporation". Phenotypic microarrays showed that all ultrasound treated L. sakei after exposure to various carbon, nitrogen, phosphorus and sulphur sources had significant variations in nutrient utilisation. Integration of this phenotypic data with the genome of L. sakei revealed that various metabolic pathways were being influenced by the ultrasound treatments. Results presented in this study showed that the physiological response of L. sakei in response to US is frequency dependent and that it can influence metabolic pathways. Hence, ultrasound treatments can be employed to modulate microbial activity for specialised applications.

Integrated phenotypic-genotypic approach to understand the influence of ultrasound on metabolic response of Lactobacillus sakei

PubMed Central

Ojha, K. Shikha; Burgess, Catherine M.; Duffy, Geraldine; Kerry, Joseph P.

2018-01-01

The lethal effects of soundwaves on a range of microorganisms have been known for almost a century whereas, the use of ultrasound to promote or control their activity is much more recent. Moreover, the fundamental molecular mechanism influencing the behaviour of microorganisms subjected to ultrasonic waves is not well established. In this study, we investigated the influence of ultrasonic frequencies of 20, 45, 130 and 950 kHz on growth kinetics of Lactobacillus sakei. A significant increase in the growth rate of L. sakei was observed following ultrasound treatment at 20 kHz despite the treatment yielding a significant reduction of ca. 3 log cfu/mL in cells count. Scanning electron microscopy showed that ultrasound caused significant changes on the cell surface of L. sakei culture with the formation of pores “sonoporation”. Phenotypic microarrays showed that all ultrasound treated L. sakei after exposure to various carbon, nitrogen, phosphorus and sulphur sources had significant variations in nutrient utilisation. Integration of this phenotypic data with the genome of L. sakei revealed that various metabolic pathways were being influenced by the ultrasound treatments. Results presented in this study showed that the physiological response of L. sakei in response to US is frequency dependent and that it can influence metabolic pathways. Hence, ultrasound treatments can be employed to modulate microbial activity for specialised applications. PMID:29370210

Computer model for harmonic ultrasound imaging.

PubMed

Li, Y; Zagzebski, J A

2000-01-01

Harmonic ultrasound imaging has received great attention from ultrasound scanner manufacturers and researchers. In this paper, we present a computer model that can generate realistic harmonic images. In this model, the incident ultrasound is modeled after the "KZK" equation, and the echo signal is modeled using linear propagation theory because the echo signal is much weaker than the incident pulse. Both time domain and frequency domain numerical solutions to the "KZK" equation were studied. Realistic harmonic images of spherical lesion phantoms were generated for scans by a circular transducer. This model can be a very useful tool for studying the harmonic buildup and dissipation processes in a nonlinear medium, and it can be used to investigate a wide variety of topics related to B-mode harmonic imaging.

Computer model for harmonic ultrasound imaging.

PubMed

Li, Y; Zagzebski, J A

2000-01-01

Harmonic ultrasound imaging has received great attention from ultrasound scanner manufacturers and researchers. Here, the authors present a computer model that can generate realistic harmonic images. In this model, the incident ultrasound is modeled after the "KZK" equation, and the echo signal is modeled using linear propagation theory because the echo signal is much weaker than the incident pulse. Both time domain and frequency domain numerical solutions to the "KZK" equation were studied. Realistic harmonic images of spherical lesion phantoms were generated for scans by a circular transducer. This model can be a very useful tool for studying the harmonic buildup and dissipation processes in a nonlinear medium, and it can be used to investigate a wide variety of topics related to B-mode harmonic imaging.

Calibration and Evaluation of Ultrasound Thermography using Infrared Imaging

PubMed Central

Hsiao, Yi-Sing; Deng, Cheri X.

2015-01-01

Real-time monitoring of the spatiotemporal evolution of tissue temperature is important to ensure safe and effective treatment in thermal therapies including hyperthermia and thermal ablation. Ultrasound thermography has been proposed as a non-invasive technique for temperature measurement, and accurate calibration of the temperature-dependent ultrasound signal changes against temperature is required. Here we report a method that uses infrared (IR) thermography for calibration and validation of ultrasound thermography. Using phantoms and cardiac tissue specimens subjected to high-intensity focused ultrasound (HIFU) heating, we simultaneously acquired ultrasound and IR imaging data from the same surface plane of a sample. The commonly used echo time shift-based method was chosen to compute ultrasound thermometry. We first correlated the ultrasound echo time shifts with IR-measured temperatures for material-dependent calibration and found that the calibration coefficient was positive for fat-mimicking phantom (1.49 ± 0.27) but negative for tissue-mimicking phantom (− 0.59 ± 0.08) and cardiac tissue (− 0.69 ± 0.18 °C-mm/ns). We then obtained the estimation error of the ultrasound thermometry by comparing against the IR measured temperature and revealed that the error increased with decreased size of the heated region. Consistent with previous findings, the echo time shifts were no longer linearly dependent on temperature beyond 45 – 50 °C in cardiac tissues. Unlike previous studies where thermocouples or water-bath techniques were used to evaluate the performance of ultrasound thermography, our results show that high resolution IR thermography provides a useful tool that can be applied to evaluate and understand the limitations of ultrasound thermography methods. PMID:26547634

Diagnostic Performance of Wells Score Combined With Point-of-care Lung and Venous Ultrasound in Suspected Pulmonary Embolism.

PubMed

Nazerian, Peiman; Volpicelli, Giovanni; Gigli, Chiara; Becattini, Cecilia; Sferrazza Papa, Giuseppe Francesco; Grifoni, Stefano; Vanni, Simone

2017-03-01

Lung and venous ultrasound are bedside diagnostic tools increasingly used in the early diagnostic approach of suspected pulmonary embolism (PE). However, the possibility of improving the conventional prediction rule for PE by integrating ultrasound has never been investigated. We performed lung and venous ultrasound in consecutive patients suspected of PE in four emergency departments. Conventional Wells score (Ws) was adjudicated by the attending physician, and ultrasound was performed by one of 20 investigators. Signs of deep venous thrombosis (DVT) at venous ultrasound and signs of pulmonary infarcts or alternative diagnoses at lung ultrasound were considered to recalculate two items of the Ws: signs and symptoms of DVT and alternative diagnosis less likely than PE. The diagnostic performances of the ultrasound-enhanced Ws (USWs) and Ws were then compared after confirmation of the final diagnosis. A total of 446 patients were studied. PE was confirmed in 125 patients (28%). USWs performed significantly better than Ws, with a sensitivity of 69.6% versus 57.6% and a specificity of 88.2% versus 68.2%. In combination with D-dimer, USWs showed an optimal failure rate (0.8%) and a significantly superior efficiency than Ws (32.3% vs. 27.2%). A strategy based on lung and venous ultrasound combined with D-dimer would allow to avoid CT pulmonary angiography in 50.5% of patients with suspected PE, compared to 27.2% when the rule without ultrasound is applied. A pretest risk stratification enhanced by ultrasound of lung and venous performs better than Ws in the early diagnostic process of PE. © 2016 by the Society for Academic Emergency Medicine.

Ultrasound Elastography: The New Frontier in Direct Measurement of Muscle Stiffness

PubMed Central

Brandenburg, Joline E.; Eby, Sarah F.; Song, Pengfei; Zhao, Heng; Brault, Jeffrey S.; Chen, Shigao; An, Kai-Nan

2014-01-01

The use of brightness-mode ultrasound and Doppler ultrasound in physical medicine and rehabilitation has increased dramatically. The continuing evolution of ultrasound technology has also produced ultrasound elastography, a cutting-edge technology that can directly measure the mechanical properties of tissue, including muscle stiffness. Its real-time and direct measurements of muscle stiffness can aid the diagnosis and rehabilitation of acute musculoskeletal injuries and chronic myofascial pain. It can also help monitor outcomes of interventions affecting muscle in neuromuscular and musculoskeletal diseases, and it can better inform the functional prognosis. This technology has implications for even broader use of ultrasound in physical medicine and rehabilitation practice, but more knowledge about its uses and limitations is essential to its appropriate clinical implementation. In this review, we describe different ultrasound elastography techniques for studying muscle stiffness, including strain elastography, acoustic radiation force impulse imaging, and shear-wave elastography. We discuss the basic principles of these techniques, including the strengths and limitations of their measurement capabilities. We review the current muscle research, discuss physiatric clinical applications of these techniques, and note directions for future research. PMID:25064780

Ultrasound-guided peripheral nerve blockade.

PubMed

Chin, Ki Jinn; Chan, Vincent

2008-10-01

The use of ultrasound for peripheral nerve blockade is becoming popular. Although the feasibility of ultrasound-guided nerve blockade is now clear, it is uncertain at this time whether it represents the new standard for regional anesthesia in terms of efficacy and safety. The ability to visualize nerve location, needle advancement, needle-nerve interaction, and local anesthetic spread makes ultrasound-guided nerve block an attractive option. Study results indicate that these advantages can improve the ease of block performance, block success rates, and complications. At the same time there is evidence that ultrasound-guided regional anesthesia is a unique skill in its own right, and that proficiency in it requires training and experience. Ultrasound is a valuable tool that is now available to the regional anesthesiologist, and it is fast becoming a standard part of practice. It promises to be of especial value to the less experienced practitioner. Ultrasound does not in itself, however, guarantee the efficacy and safety of peripheral nerve blockade. Proper training in its use is required and we can expect to see the development of formal standards and guidelines in this regard.

An interventional multispectral photoacoustic imaging platform for the guidance of minimally invasive procedures

NASA Astrophysics Data System (ADS)

Xia, Wenfeng; Nikitichev, Daniil I.; Mari, Jean Martial; West, Simeon J.; Ourselin, Sebastien; Beard, Paul C.; Desjardins, Adrien E.

2015-07-01

Precise and efficient guidance of medical devices is of paramount importance for many minimally invasive procedures. These procedures include fetal interventions, tumor biopsies and treatments, central venous catheterisations and peripheral nerve blocks. Ultrasound imaging is commonly used for guidance, but it often provides insufficient contrast with which to identify soft tissue structures such as vessels, tumors, and nerves. In this study, a hybrid interventional imaging system that combines ultrasound imaging and multispectral photoacoustic imaging for guiding minimally invasive procedures was developed and characterized. The system provides both structural information from ultrasound imaging and molecular information from multispectral photoacoustic imaging. It uses a commercial linear-array ultrasound imaging probe as the ultrasound receiver, with a multimode optical fiber embedded in a needle to deliver pulsed excitation light to tissue. Co-registration of ultrasound and photoacoustic images is achieved with the use of the same ultrasound receiver for both modalities. Using tissue ex vivo, the system successfully discriminated deep-located fat tissue from the surrounding muscle tissue. The measured photoacoustic spectrum of the fat tissue had good agreement with the lipid spectrum in literature.

Cavitation thresholds of contrast agents in an in vitro human clot model exposed to 120-kHz ultrasound.

PubMed

Gruber, Matthew J; Bader, Kenneth B; Holland, Christy K

2014-02-01

Ultrasound contrast agents (UCAs) can be employed to nucleate cavitation to achieve desired bioeffects, such as thrombolysis, in therapeutic ultrasound applications. Effective methods of enhancing thrombolysis with ultrasound have been examined at low frequencies (<1 MHz) and low amplitudes (<0.5 MPa). The objective of this study was to determine cavitation thresholds for two UCAs exposed to 120-kHz ultrasound. A commercial ultrasound contrast agent (Definity(®)) and echogenic liposomes were investigated to determine the acoustic pressure threshold for ultraharmonic (UH) and broadband (BB) generation using an in vitro flow model perfused with human plasma. Cavitation emissions were detected using two passive receivers over a narrow frequency bandwidth (540-900 kHz) and a broad frequency bandwidth (0.54-1.74 MHz). UH and BB cavitation thresholds occurred at the same acoustic pressure (0.3 ± 0.1 MPa, peak to peak) and were found to depend on the sensitivity of the cavitation detector but not on the nucleating contrast agent or ultrasound duty cycle.

Value of Ultrasound in Detecting Urinary Tract Anomalies After First Febrile Urinary Tract Infection in Children.

PubMed

Ghobrial, Emad E; Abdelaziz, Doaa M; Sheba, Maha F; Abdel-Azeem, Yasser S

2016-05-01

Background Urinary tract infection (UTI) is an infection that affects part of the urinary tract. Ultrasound is a noninvasive test that can demonstrate the size and shape of kidneys, presence of dilatation of the ureters, and the existence of anatomic abnormalities. The aim of the study is to estimate the value of ultrasound in detecting urinary tract anomalies after first attack of UTI. Methods This study was conducted at the Nephrology Clinic, New Children's Hospital, Faculty of Medicine, Cairo University, from August 2012 to March 2013, and included 30 children who presented with first attack of acute febrile UTI. All patients were subjected to urine analysis, urine culture and sensitivity, serum creatinine, complete blood count, and imaging in the form of renal ultrasound, voiding cysto-urethrography, and renal scan. Results All the patients had fever with a mean of 38.96°C ± 0.44°C and the mean duration of illness was 6.23 ± 5.64 days. Nineteen patients (63.3%) had an ultrasound abnormality. The commonest abnormalities were kidney stones (15.8%). Only 2 patients who had abnormal ultrasound had also vesicoureteric reflux on cystourethrography. Sensitivity of ultrasound was 66.7%, specificity was 37.5%, positive predictive value was 21.1%, negative predictive value was 81.8%, and total accuracy was 43.33%. Conclusion We concluded that ultrasound alone was not of much value in diagnosing and putting a plan of first attack of febrile UTI. It is recommended that combined investigations are the best way to confirm diagnosis of urinary tract anomalies. © The Author(s) 2015.

Extraction mechanism of ultrasound assisted extraction and its effect on higher yielding and purity of artemisinin crystals from Artemisia annua L. leaves.

PubMed

Chemat, Smain; Aissa, Abdallah; Boumechhour, Abdenour; Arous, Omar; Ait-Amar, Hamid

2017-01-01

This study proposes an ultrasound-horn system for the extraction of a natural active compound "artemisinin" from Artemisia annua L. leaves as an alternative to hot maceration technique. Ultrasound leaching improves artemisinin recovery at all temperatures where only ten minutes is required to recover 70% (4.42mgg -1 ) compared to 60min of conventional hot leaching for the same yield. For instance, ultrasound treatment at 30°C produced a higher yield than the one obtained by conventional maceration at 40°C. Kinetic study suggests that the extraction pattern can be assimilated, during the first ten minutes, to a first order steady state, from which activation energy calculations revealed that each gram of artemisinin required 7.38kJ in ultrasound versus 10.3kJ in the conventional system. Modeling results indicate the presence of two extraction stages, a faster stage with a diffusion coefficient of 19×10 -5 cm 2 min -1 for ultrasound technique at 40°C, seven times higher than the conventional one; and a second deceleration stage similar for both techniques with diffusion coefficient ranging from 1.7 to 3.1×10 -5 cm 2 min -1 . It is noted that the efficient ultrasound extraction potential implies extraction of higher amount of co-metabolites so low artemisinin crystal purity is engendered but a combination with a purification step using activated charcoal and celite adsorbents produced crystals with comparable purity for conventional and ultrasound samples. Copyright © 2016 Elsevier B.V. All rights reserved.

Ultrasound-mediated structural changes in cells revealed by FTIR spectroscopy: a contribution to the optimization of gene and drug delivery.

PubMed

Grimaldi, Paola; Di Giambattista, Lucia; Giordani, Serena; Udroiu, Ion; Pozzi, Deleana; Gaudenzi, Silvia; Bedini, Angelico; Giliberti, Claudia; Palomba, Raffaele; Castellano, Agostina Congiu

2011-12-15

Ultrasound effects on biological samples are gaining a growing interest concerning in particular, the intracellular delivery of drugs and genes in a safe and in a efficient way. Future progress in this field will require a better understanding of how ultrasound and acoustic cavitation affect the biological system properties. The morphological changes of cells due to ultrasound (US) exposure have been extensively studied, while little attention has been given to the cells structural changes. We have exposed two different cell lines to 1 MHz frequency ultrasound currently used in therapy, Jurkat T-lymphocytes and NIH-3T3 fibroblasts, both employed as models respectively in the apoptosis and in the gene therapy studies. The Fourier Transform Infrared (FTIR) Spectroscopy was used as probe to reveal the structural changes in particular molecular groups belonging to the main biological systems. The genotoxic damage of cells exposed to ultrasound was ascertained by the Cytokinesis-Block Micronucleus (CBMN) assay. The FTIR spectroscopy results, combined with multivariate statistical analysis, regarding all cellular components (lipids, proteins, nucleic acids) of the two cell lines, show that Jurkat cells are more sensitive to therapeutic ultrasound in the lipid and protein regions, whereas the NIH-3T3 cells are more sensitive in the nucleic acids region; a meaningful genotoxic effect is present in both cell lines only for long sonication times while in the Jurkat cells also a significant cytotoxic effect is revealed for long times of exposure to ultrasound. Copyright © 2011 Elsevier B.V. All rights reserved.

Are Prenatal Ultrasound Scans Associated with the Autism Phenotype? Follow-Up of a Randomised Controlled Trial

ERIC Educational Resources Information Center

Stoch, Yonit K.; Williams, Cori J.; Granich, Joanna; Hunt, Anna M.; Landau, Lou I.; Newnham, John P.; Whitehouse, Andrew J. O.

2012-01-01

An existing randomised controlled trial was used to investigate whether multiple ultrasound scans may be associated with the autism phenotype. From 2,834 single pregnancies, 1,415 were selected at random to receive ultrasound imaging and continuous wave Doppler flow studies at five points throughout pregnancy (Intensive) and 1,419 to receive a…

"I Thought My Heart Would Burst": The Role of Ultrasound Technology on Expectant Grandmotherhood

ERIC Educational Resources Information Center

Harpel, Tammy S.; Hertzog, Jodie

2010-01-01

Using both quantitative and qualitative data, this study investigates the role of ultrasound technology on feelings of attachment and emotions experienced by expectant grandmothers. A total of 109 expectant grandmothers complete the 84-question Web-based survey. A 12-item scale is used to assess the impact of ultrasound on attachment. As expected,…

The Effects of Practicing with a Virtual Ultrasound Trainer on FAST Window Identification, Acquisition, and Diagnosis. CRESST Report 787

ERIC Educational Resources Information Center

Chung, Gregory K. W. K.; Gyllenhammer, Ruth G.; Baker, Eva L.

2011-01-01

In this study, we compared the effects of simulator-based virtual ultrasound scanning practice to classroom-based hands-on ultrasound scanning practice on participants' knowledge of FAST window quadrants and interpretation, and on participants' performance on live patient FAST exams. Twenty-five novice participants were randomly assigned to the…

Evaluation of an Innovative Hands-On Anatomy-Centered Ultrasound Curriculum to Supplement Graduate Gross Anatomy Education

ERIC Educational Resources Information Center

Royer, Danielle F.; Kessler, Ross; Stowell, Jeffrey R.

2017-01-01

Ultrasound (US) can enhance anatomy education, yet is incorporated into few non-medical anatomy programs. This study is the first to evaluate the impact of US training in gross anatomy for non-medical students in the United States. All 32 master's students enrolled in gross anatomy with the anatomy-centered ultrasound (ACUS) curriculum were…

Ultrasound as pretreatment to convective drying of Andean blackberry (Rubus glaucus Benth).

PubMed

Romero J, Carlos A; Yépez V, Byron D

2015-01-01

In this study, we evaluated the use of ultrasound as a pretreatment for convective drying of Andean blackberry (Rubus glaucus Benth). For this, a Box-Behnken experimental design was used to study the effect of ultrasound vibration amplitude (0-90μm), time of sonication (10-30min) and air temperature (40-60°C) on the retention of antioxidant compounds and on the kinetics of convective drying. The results showed that the antioxidant activity on fruit was reduced as the vibration amplitude and time of sonication increased, while was found that vibration amplitude ultrasound and air drying temperature were the variables that more affect the drying rate of blackberries. The drying rate increased by almost five times when samples were treated with ultrasound at 90μm for 20min. They were then dried using air at 60°C. It is concluded that the application of ultrasound in blackberry processing allows to obtain a dehydrated product with better functional quality and shows to be effective in reducing the time necessary to achieve a given value of moisture during convective drying. Copyright © 2014 Elsevier B.V. All rights reserved.

Diagnostic value of chest ultrasound after cardiac surgery: a comparison with chest X-ray and auscultation.

PubMed

Vezzani, Antonella; Manca, Tullio; Brusasco, Claudia; Santori, Gregorio; Valentino, Massimo; Nicolini, Francesco; Molardi, Alberto; Gherli, Tiziano; Corradi, Francesco

2014-12-01

Chest auscultation and chest x-ray commonly are used to detect postoperative abnormalities and complications in patients admitted to intensive care after cardiac surgery. The aim of the study was to evaluate whether chest ultrasound represents an effective alternative to bedside chest x-ray to identify early postoperative abnormalities. Diagnostic accuracy of chest auscultation and chest ultrasound were compared in identifying individual abnormalities detected by chest x-ray, considered the reference method. Cardiac surgery intensive care unit. One hundred fifty-one consecutive adult patients undergoing cardiac surgery. All patients included were studied by chest auscultation, ultrasound, and x-ray upon admission to intensive care after cardiac surgery. Six lung pathologic changes and endotracheal tube malposition were found. There was a highly significant correlation between abnormalities detected by chest ultrasound and x-ray (k = 0.90), but a poor correlation between chest auscultation and x-ray abnormalities (k = 0.15). Chest auscultation may help identify endotracheal tube misplacement and tension pneumothorax but it may miss most major abnormalities. Chest ultrasound represents a valid alternative to chest x-ray to detect most postoperative abnormalities and misplacements. Copyright © 2014 Elsevier Inc. All rights reserved.

Accuracy and safety of ward based pleural ultrasound in the Australian healthcare system.

PubMed

Hammerschlag, Gary; Denton, Matthew; Wallbridge, Peter; Irving, Louis; Hew, Mark; Steinfort, Daniel

2017-04-01

Ultrasound has been shown to improve the accuracy and safety of pleural procedures. Studies to date have been performed in large, specialized units, where pleural procedures are performed by a small number of highly specialized physicians. There are no studies examining the safety and accuracy of ultrasound in the Australian healthcare system where procedures are performed by junior doctors with a high staff turnover. We performed a retrospective review of the ultrasound database in the Respiratory Department at the Royal Melbourne Hospital to determine accuracy and complications associated pleural procedures. A total of 357 ultrasounds were performed between October 2010 and June 2013. Accuracy of pleural procedures was 350 of 356 (98.3%). Aspiration of pleural fluid was successful in 121 of 126 (96%) of patients. Two (0.9%) patients required chest tube insertion for management of pneumothorax. There were no recorded pleural infections, haemorrhage or viscera puncture. Ward-based ultrasound for pleural procedures is safe and accurate when performed by appropriately trained and supported junior medical officers. Our findings support this model of pleural service care in the Australian healthcare system. © 2016 Asian Pacific Society of Respirology.

Optical Detection of Ultrasound in Photoacoustic Imaging

PubMed Central

Dong, Biqin; Sun, Cheng; Zhang, Hao F.

2017-01-01

Objective Photoacoustic (PA) imaging emerges as a unique tool to study biological samples based on optical absorption contrast. In PA imaging, piezoelectric transducers are commonly used to detect laser-induced ultrasonic waves. However, they typically lack adequate broadband sensitivity at ultrasonic frequency higher than 100 MHz while their bulky size and optically opaque nature cause technical difficulties in integrating PA imaging with conventional optical imaging modalities. To overcome these limitations, optical methods of ultrasound detection were developed and shown their unique applications in photoacoustic imaging. Methods We provide an overview of recent technological advances in optical methods of ultrasound detection and their applications in PA imaging. A general theoretical framework describing sensitivity, bandwidth, and angular responses of optical ultrasound detection is also introduced. Results Optical methods of ultrasound detection can provide improved detection angle and sensitivity over significantly extended bandwidth. In addition, its versatile variants also offer additional advantages, such as device miniaturization, optical transparency, mechanical flexibility, minimal electrical/mechanical crosstalk, and potential noncontact PA imaging. Conclusion The optical ultrasound detection methods discussed in this review and their future evolution may play an important role in photoacoustic imaging for biomedical study and clinical diagnosis. PMID:27608445

Real-Time Ultrasound-Guided Spinal Anaesthesia: A Prospective Observational Study of a New Approach

PubMed Central

Conroy, P. H.; Luyet, C.; McCartney, C. J.; McHardy, P. G.

2013-01-01

Identification of the subarachnoid space has traditionally been achieved by either a blind landmark-guided approach or using prepuncture ultrasound assistance. To assess the feasibility of performing spinal anaesthesia under real-time ultrasound guidance in routine clinical practice we conducted a single center prospective observational study among patients undergoing lower limb orthopaedic surgery. A spinal needle was inserted unassisted within the ultrasound transducer imaging plane using a paramedian approach (i.e., the operator held the transducer in one hand and the spinal needle in the other). The primary outcome measure was the success rate of CSF acquisition under real-time ultrasound guidance with CSF being located in 97 out of 100 consecutive patients within median three needle passes (IQR 1–6). CSF was not acquired in three patients. Subsequent attempts combining landmark palpation and pre-puncture ultrasound scanning resulted in successful spinal anaesthesia in two of these patients with the third patient requiring general anaesthesia. Median time from spinal needle insertion until intrathecal injection completion was 1.2 minutes (IQR 0.83–4.1) demonstrating the feasibility of this technique in routine clinical practice. PMID:23365568

[Splenic nodules and sickle cell anemia].

PubMed

Jouini, S; Sehili, S; Mokrani, A; Ayadi, K; Fakunle, Y; Daghfous, M H; Ladeb, M F

2001-11-01

We report 4 patients with sickle cell anemia presenting with intra-splenic benign nodules corresponding to islands of preserved tissue within splenic ferro-calcinosis. Ultrasound, CT and MRI findings were evaluated and compared to a follow-up study by ultrasound and CT done after 6 to 12 months. Ultrasound showed multiple well-defined rounded nodules appearing hypoechoic compared to the rest of the spleen that was hyperechoic. On CT, the nodules were homogenous, hypodense relative to the spleen, isodense to the liver in 3 cases and hypodense to the liver in 1 case. On MRI, the nodules appeared relatively hyperintense within low-signal-intensity spleens. The ultrasound and CT follow-up study demonstrated no remarkable change. In sickle cell patients, intra-splenic benign nodules corresponding to normal splenic tissue may be identified on imaging studies. The differential diagnosis is discussed.

Impact of Lesion Visibility on Transrectal Ultrasound on the Prediction of Clinically Significant Prostate Cancer (Gleason Score 3 + 4 or Greater) with Transrectal Ultrasound-Magnetic Resonance Imaging Fusion Biopsy.

PubMed

Garcia-Reyes, Kirema; Nguyen, Hao G; Zagoria, Ronald J; Shinohara, Katsuto; Carroll, Peter R; Behr, Spencer C; Westphalen, Antonio C

2017-09-20

The purpose of this study was to estimate the impact of lesion visibility with transrectal ultrasound on the prediction of clinically significant prostate cancer with transrectal ultrasound-magnetic resonance imaging fusion biopsy. This HIPAA (Health Insurance Portability and Accountability Act) compliant, institutional review board approved, retrospective study was performed in 178 men who were 64.7 years old with prostate specific antigen 8.9 ng/ml. They underwent transrectal ultrasound-magnetic resonance imaging fusion biopsy from January 2013 to September 2016. Visible lesions on magnetic resonance imaging were assigned a PI-RADS™ (Prostate Imaging Reporting and Data System), version 2 score of 3 or greater. Transrectal ultrasound was positive when a hypoechoic lesion was identified. We used a 3-level, mixed effects logistic regression model to determine how transrectal ultrasound-magnetic resonance imaging concordance predicted the presence of clinically significant prostate cancer. The diagnostic performance of the 2 methods was estimated using ROC curves. A total of 1,331 sextants were targeted by transrectal ultrasound-magnetic resonance imaging fusion or systematic biopsies, of which 1,037 were negative, 183 were Gleason score 3 + 3 and 111 were Gleason score 3 + 4 or greater. Clinically significant prostate cancer was diagnosed by transrectal ultrasound and magnetic resonance imaging alone at 20.5% and 19.7% of these locations, respectively. Men with positive imaging had higher odds of clinically significant prostate cancer than men without visible lesions regardless of modality (transrectal ultrasound OR 14.75, 95% CI 5.22-41.69, magnetic resonance imaging OR 12.27, 95% CI 6.39-23.58 and the 2 modalities OR 28.68, 95% CI 14.45-56.89, all p <0.001). The ROC AUC to detect clinically significant prostate cancer using the 2 methods (0.85, 95% CI 0.81-0.89) was statistically greater than that of transrectal ultrasound alone (0.80, 95% CI 0.76-0.85, p = 0.001) and magnetic resonance imaging alone (0.83, 95% CI 0.79-0.87, p = 0.04). The sensitivity and specificity of transrectal ultrasound were 42.3% and 91.6%, and the sensitivity and specificity of magnetic resonance imaging were 62.2% and 84.1%, respectively. Lesion visibility on magnetic resonance imaging or transrectal ultrasound denotes a similar probability of clinically significant prostate cancer. This probability is greater when each examination is positive. Copyright © 2018 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Lung ultrasound compared with chest X-ray in diagnosing postoperative pulmonary complications following cardiothoracic surgery: a prospective observational study.

PubMed

Touw, H R; Parlevliet, K L; Beerepoot, M; Schober, P; Vonk, A; Twisk, J W; Elbers, P W; Boer, C; Tuinman, P R

2018-03-12

Postoperative pulmonary complications are common after cardiothoracic surgery and are associated with adverse outcomes. The ability to detect postoperative pulmonary complications using chest X-rays is limited, and this technique requires radiation exposure. Little is known about the diagnostic accuracy of lung ultrasound for the detection of postoperative pulmonary complications after cardiothoracic surgery, and we therefore aimed to compare lung ultrasound with chest X-ray to detect postoperative pulmonary complications in this group of patients. We performed this prospective, observational, single-centre study in a tertiary intensive care unit treating adult patients who had undergone cardiothoracic surgery. We recorded chest X-ray findings upon admission and on postoperative days 2 and 3, as well as rates of postoperative pulmonary complications and clinically-relevant postoperative pulmonary complications that required therapy according to the treating physician as part of their standard clinical practice. Lung ultrasound was performed by an independent researcher at the time of chest X-ray. We compared lung ultrasound with chest X-ray for the detection of postoperative pulmonary complications and clinically-relevant postoperative pulmonary complications. We also assessed inter-observer agreement for lung ultrasound, and the time to perform both imaging techniques. Subgroup analyses were performed to compare the time to detection of clinically-relevant postoperative pulmonary complications by both modalities. We recruited a total of 177 patients in whom both lung ultrasound and chest X-ray imaging were performed. Lung ultrasound identified 159 (90%) postoperative pulmonary complications on the day of admission compared with 107 (61%) identified with chest X-ray (p < 0.001). Lung ultrasound identified 11 out of 17 patients (65%) and chest X-ray 7 out of 17 patients (41%) with clinically-relevant postoperative pulmonary complications (p < 0.001). The clinically-relevant postoperative pulmonary complications were detected earlier using lung ultrasound compared with chest X-ray (p = 0.024). Overall inter-observer agreement for lung ultrasound was excellent (κ = 0.907, p < 0.001). Following cardiothoracic surgery, lung ultrasound detected more postoperative pulmonary complications and clinically-relevant postoperative pulmonary complications than chest X-ray, and at an earlier time-point. Our results suggest lung ultrasound may be used as the primary imaging technique to search for postoperative pulmonary complications after cardiothoracic surgery, and will enhance bedside decision making. © 2018 The Authors. Anaesthesia published by John Wiley & Sons Ltd on behalf of Association of Anaesthetists of Great Britain and Ireland.

Utility of rapid on-site cytologic evaluation during endobronchial ultrasound with a guide sheath for peripheral pulmonary lesions.

PubMed

Izumo, Takehiro; Matsumoto, Yuji; Sasada, Shinji; Chavez, Christine; Nakai, Toshiyuki; Tsuchida, Takaaki

2017-03-01

The utility of rapid on-site evaluation during endobronchial ultrasound with a guide sheath for peripheral pulmonary lesions is unclear. The aim of this study was to evaluate the role of rapid on-site evaluation during endobronchial ultrasound with a guide sheath for peripheral pulmonary lesions. Consecutive patients who underwent endobronchial ultrasound with a guide sheath for the diagnosis of peripheral pulmonary lesions at our hospital between September 2012 and July 2014 were included in this retrospective study. Cytology slides were air-dried, and modified Giemsa (Diff-Quik) staining was used for rapid on-site evaluation. Additional smears were prepared for Papanicolaou staining and tissue samples were placed in formalin for histologic evaluation. The results of rapid on-site evaluation were compared with the final diagnoses of endobronchial ultrasound with a guide sheath. A total of 718 cases were included in the study population. The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of rapid on-site evaluation during endobronchial ultrasound with a guide sheath for peripheral pulmonary lesions was 88.6%, 65.9%, 81.2%, 77.7% and 80.1%, respectively. There were no procedure-related deaths. Rapid on-site evaluation during endobronchial ultrasound with a guide sheath had high sensitivity for peripheral pulmonary lesions. When carrying out rapid on-site evaluation of transbronchial biopsy samples from peripheral pulmonary lesions, careful interpretation and clinical correlation are necessary. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

Comparing diagnostic accuracy of bedside ultrasound and radiography for bone fracture screening in multiple trauma patients at the ED.

PubMed

Bolandparvaz, Shahram; Moharamzadeh, Payman; Jamali, Kazem; Pouraghaei, Mahboob; Fadaie, Maryam; Sefidbakht, Sepideh; Shahsavari, Kavous

2013-11-01

Long bone fractures are currently diagnosed using radiography, but radiography has some disadvantages (radiation and being time consuming). The present study compared the diagnostic accuracy of bedside ultrasound and radiography in multiple trauma patients at the emergency department (ED). The study assessed 80 injured patients with multiple trauma from February 2011 to July 2012. The patients were older than 18 years and triaged to the cardiopulmonary resuscitation ward of the ED. Bedside ultrasound and radiography were conducted for them. The findings were separately and blindly assessed by 2 radiologists. Sensitivity, specificity, the positive and negative predictive value, and κ coefficient were measured to assess the accuracy and validity of ultrasound as compared with radiography. The sensitivity of ultrasound for diagnosis of limb bone fractures was not high enough and ranged between 55% and 75% depending on the fracture site. The specificity of this diagnostic method had an acceptable range of 62% to 84%. Ultrasound negative prediction value was higher than other indices under study and ranged between 73% and 83%, but its positive prediction value varied between 33.3% and 71%. The κ coefficient for diagnosis of long bone fractures of upper limb (κ = 0.58) and upper limb joints (κ = 0.47) and long bones of lower limb (κ = 0.52) was within the medium range. However, the value for diagnosing fractures of lower limb joints (κ = 0.47) was relatively low. Bedside ultrasound is not a reliable method for diagnosing fractures of upper and lower limb bones compared with radiography. © 2013 Elsevier Inc. All rights reserved.

American Institute of Ultrasound in Medicine

MedlinePlus

... Ultrasound Pediatric Ultrasound Point-of-Care Ultrasound Sonography Therapeutic Ultrasound Ultrasound in Global Health Ultrasound in Medical Education CME Center CME Tracker Annual Convention Journal Tests ...

PULSED FOCUSED ULTRASOUND TREATMENT OF MUSCLE MITIGATES PARALYSIS-INDUCED BONE LOSS IN THE ADJACENT BONE: A STUDY IN A MOUSE MODEL

PubMed Central

Poliachik, Sandra L.; Khokhlova, Tatiana D.; Wang, Yak-Nam; Simon, Julianna C.; Bailey, Michael R.

2015-01-01

Bone loss can result from bed rest, space flight, spinal cord injury or age-related hormonal changes. Current bone loss mitigation techniques include pharmaceutical interventions, exercise, pulsed ultrasound targeted to bone and whole body vibration. In this study, we attempted to mitigate paralysis-induced bone loss by applying focused ultrasound to the midbelly of a paralyzed muscle. We employed a mouse model of disuse that uses onabotulinumtoxinA-induced paralysis, which causes rapid bone loss in 5 d. A focused 2 MHz transducer applied pulsed exposures with pulse repetition frequency mimicking that of motor neuron firing during walking (80 Hz), standing (20 Hz), or the standard pulsed ultrasound frequency used in fracture healing (1 kHz). Exposures were applied daily to calf muscle for 4 consecutive d. Trabecular bone changes were characterized using micro-computed tomography. Our results indicated that application of certain focused pulsed ultrasound parameters was able to mitigate some of the paralysis-induced bone loss. PMID:24857416

Preliminary Clinical Experience with a Combined Automated Breast Ultrasound and Digital Breast Tomosynthesis System.

PubMed

Larson, Eric D; Lee, Won-Mean; Roubidoux, Marilyn A; Goodsitt, Mitchell M; Lashbrook, Chris; Davis, Cynthia E; Kripfgans, Oliver D; Carson, Paul L

2018-03-01

We analyzed the performance of a mammographically configured, automated breast ultrasound (McABUS) scanner combined with a digital breast tomosynthesis (DBT) system. The GE Invenia ultrasound system was modified for integration with GE DBT systems. Ultrasound and DBT imaging were performed in the same mammographic compression. Our small preliminary study included 13 cases, six of whom had contained invasive cancers. From analysis of these cases, current limitations and corresponding potential improvements of the system were determined. A registration analysis was performed to compare the ease of McABUS to DBT registration for this system with that of two systems designed previously. It was observed that in comparison to data from an earlier study, the McABUS-to-DBT registration alignment errors for both this system and a previously built combined system were smaller than those for a previously built standalone McABUS system. Copyright © 2018 World Federation for Ultrasound in Medicine and Biology. Published by Elsevier Inc. All rights reserved.

Comparison Between Neck and Shoulder Stiffness Determined by Shear Wave Ultrasound Elastography and a Muscle Hardness Meter.

PubMed

Akagi, Ryota; Kusama, Saki

2015-08-01

The goals of this study were to compare neck and shoulder stiffness values determined by shear wave ultrasound elastography with those obtained with a muscle hardness meter and to verify the correspondence between objective and subjective stiffness in the neck and shoulder. Twenty-four young men and women participated in the study. Their neck and shoulder stiffness was determined at six sites. Before the start of the measurements, patients rated their present subjective symptoms of neck and shoulder stiffness on a 6-point verbal scale. At all measurement sites, the correlation coefficients between the values of muscle hardness indices determined by the muscle hardness meter and shear wave ultrasound elastography were not significant. Furthermore, individuals' subjective neck and shoulder stiffness did not correspond to their objective symptoms. These results suggest that the use of shear wave ultrasound elastography is essential to more precisely assess neck and shoulder stiffness. Copyright © 2015 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Minimum anesthetic volume in regional anesthesia by using ultrasound-guidance.

PubMed

Di Filippo, Alessandro; Falsini, Silvia; Adembri, Chiara

2016-01-01

The ultrasound guidance in regional anesthesia ensures the visualization of needle placement and the spread of Local Anesthetics. Over the past few years there was a substantial interest in determining the Minimum Effective Anesthetic Volume necessary to accomplish surgical anesthesia. The precise and real-time visualization of Local Anesthetics spread under ultrasound guidance block may represent the best requisite for reducing Local Anesthetics dose and Local Anesthetics-related effects. We will report a series of studies that have demonstrated the efficacy of ultrasound guidance blocks to reduce Local Anesthetics and obtain surgical anesthesia as compared to block performed under blind or electrical nerve stimulation technique. Unfortunately, the results of studies are widely divergent and not seem to indicate a dose considered effective, for each block, in a definitive way; but it is true that, through the use of ultrasound guidance, it is possible to reduce the dose of anesthetic in the performance of anesthetic blocks. Copyright © 2014 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

Reproducibility of Ultrasound-Guided High Intensity Focused Ultrasound (HIFU) Thermal Lesions in Minimally-Invasive Brain Surgery

NASA Astrophysics Data System (ADS)

Zahedi, Sulmaz

This study aims to prove the feasibility of using Ultrasound-Guided High Intensity Focused Ultrasound (USg-HIFU) to create thermal lesions in neurosurgical applications, allowing for precise ablation of brain tissue, while simultaneously providing real time imaging. To test the feasibility of the system, an optically transparent HIFU compatible tissue-mimicking phantom model was produced. USg-HIFU was then used for ablation of the phantom, with and without targets. Finally, ex vivo lamb brain tissue was imaged and ablated using the USg-HIFU system. Real-time ultrasound images and videos obtained throughout the ablation process showing clear lesion formation at the focal point of the HIFU transducer. Post-ablation gross and histopathology examinations were conducted to verify thermal and mechanical damage in the ex vivo lamb brain tissue. Finally, thermocouple readings were obtained, and HIFU field computer simulations were conducted to verify findings. Results of the study concluded reproducibility of USg-HIFU thermal lesions for neurosurgical applications.

Enhancement of Cell Ingrowth, Proliferation, and Early Differentiation in a Three-Dimensional Silicon Carbide Scaffold Using Low-Intensity Pulsed Ultrasound

PubMed Central

Lin, Liangjun

2015-01-01

Concerns over the use of autografts or allografts have necessitated the development of biomaterials for bone regeneration. Various studies have been performed to optimize the cultivation of osteogenic cells using osteoconductive porous scaffolds. The aim of this study was to evaluate the osteogenic efficiency of bone cell ingrowth, proliferation, and early differentiation in a silicon carbide (SiC) porous ceramic scaffold promoted with low-intensity pulsed ultrasound. MC3T3-E1 mouse preosteoblasts were seeded onto scaffolds and cultured for 4 and 7 days with daily of 20-min ultrasound treatment. The cells were evaluated for cell attachment, morphology, viability, ingrowth depth, volumetric proliferation, and early differentiation. After 4 and 7 days of culture and ultrasound exposure, the cell density was higher in the ultrasound-treated group compared with the sham-treated group on SiC scaffolds. The cell ingrowth depths inside the SiC scaffolds were 149.2±27.3 μm at 1 day, 310.1±12.6 μm for the ultrasound-treated group and 248.0±19.7 μm for the sham control at 4 days, and 359.6±18.5 μm for the ultrasound-treated group and 280.0±17.7 μm for the sham control at 7 days. They were significantly increased, that is, 25% (p=0.0029) and 28% (p=0.0008) increase, respectively, with ultrasound radiation force as compared with those in sham control at 4 and 7 days postseeding. The dsDNA contents were 583.5±19.1 ng/scaffold at 1 day, 2749.9±99.9 ng/scaffold for the ultrasound-treated group and 2514.9±114.7 ng/scaffold for the sham control at 4 days, and 3582.3±325.3 ng/scaffold for the ultrasound-treated group and 2825.7±134.3 ng/scaffold for the sham control at 7 days. There was a significant difference in the dsDNA content between the ultrasound- and sham-treated groups at 4 and 7 days. The ultrasound-treated group with the SiC construct showed a 9% (p=0.00029) and 27% (p=0.00017) increase in the average dsDNA content at 4 and 7 days over the sham control group, respectively. Alkaline phosphatase activity was significantly increased by the treatment of ultrasound at 4 (p=0.012) and 7 days (p=0.035). These results suggested that ultrasound treatment with low-intensity acoustic energy facilitated the cellular ingrowth and enhanced the proliferation and early differentiation of osteoblasts in SiC scaffolds. PMID:24935158

Ultra-high Speed Optical Imaging of Ultrasound-activated Microbubbles in Mesenteric Microvessels

NASA Astrophysics Data System (ADS)

Chen, Hong

Ultrasound contrast agent microbubbles have gained widespread applications in diagnostic and therapeutic ultrasound. Animal studies of bioeffects induced by ultrasound-activated microbubbles have demonstrated that microbubbles can cause microvessel damage. Much scientific attention has been attracted to such microvascular bioeffects, not only because of the related safety concerns, but also because of the potential useful applications of microbubbles in the intravascular delivery of drugs and genetic materials into target tissues. A significant challenge in using microbubbles in medical ultrasound is the lack of knowledge about how the microbubbles behave in blood vessels when exposed to ultrasound and how their interactions with ultrasound cause vascular damage. Although extensive studies were performed in the past to study the dynamics of microbubbles, most of those studies were performed in vitro and did not directly address the clinical environment in which microbubbles are injected into blood vessels. In this thesis work, a synchronized optical-acoustic system was set up for ultrahigh speed imaging of insonated microbubbles in microvessels. The recorded images revealed the formation of microjets penetrating the microbubbles, as well as vessel distention (motion outward against the surrounding tissue) and vessel invagination (motion inward toward the lumen) caused by the expansion and collapse of the microbubbles, respectively. Contrary to current paradigms which propose that microbubbles damage vessels either by distending them or by forming liquid jets impinging on them, microbubbles translation and jetting were in the direction away from the nearest vessel wall; furthermore, invagination typically exceeded distention in arterioles and venules. Vessel invagination was found to be associated with vascular damage. These studies suggest that vessel invagination may be a newly discovered potential mechanism for vascular damage by ultrasound-activated microbubbles. The dynamics of bubble-vessel interactions are coupled intimately with the viscoelastic properties of the microvessels. To probe these properties, a method based on the relaxation times of the invaginated microvessels was used to estimate the relaxation time constants of the microvessels. It was found that the time constants were on microsecond time scales, which provided insight into the unique and unknown viscoelastic properties of the microvessels.

Biological effects of low frequency high intensity ultrasound application on ex vivo human adipose tissue.

PubMed

Palumbo, P; Cinque, B; Miconi, G; La Torre, C; Zoccali, G; Vrentzos, N; Vitale, A R; Leocata, P; Lombardi, D; Lorenzo, C; D'Angelo, B; Macchiarelli, G; Cimini, A; Cifone, M G; Giuliani, M

2011-01-01

In the present work the effects of a new low frequency, high intensity ultrasound technology on human adipose tissue ex vivo were studied. In particular, we investigated the effects of both external and surgical ultrasound-irradiation (10 min) by evaluating, other than sample weight loss and fat release, also histological architecture alteration as well apoptosis induction. The influence of saline buffer tissue-infiltration on the effects of ultrasound irradiation was also examined. The results suggest that, in our experimental conditions, both transcutaneous and surgical ultrasound exposure caused a significant weight loss and fat release. This effect was more relevant when the ultrasound intensity was set at 100 % (~2.5 W/cm², for external device; ~19-21 W/cm2, for surgical device) compared to 70 % (~1.8 W/cm² for external device; ~13-14 W/cm2 for surgical device). Of note, the effectiveness of ultrasound was much higher when the tissue samples were previously infiltrated with saline buffer, in accordance with the knowledge that ultrasonic waves in aqueous solution better propagate with a consequently more efficient cavitation process. Moreover, the overall effects of ultrasound irradiation did not appear immediately after treatment but persisted over time, being significantly more relevant at 18 h from the end of ultrasound irradiation. Evaluation of histological characteristics of ultrasound-irradiated samples showed a clear alteration of adipose tissue architecture as well a prominent destruction of collagen fibers which were dependent on ultrasound intensity and most relevant in saline buffer-infiltrated samples. The structural changes of collagen bundles present between the lobules of fat cells were confirmed through scanning electron microscopy (SEM) which clearly demonstrated how ultrasound exposure induced a drastic reduction in the compactness of the adipose connective tissue and an irregular arrangement of the fibers with a consequent alteration in the spatial architecture. The analysis of the composition of lipids in the fat released from adipose tissue after ultrasound treatment with surgical device showed, in agreement with the level of adipocyte damage, a significant increase mainly of triglycerides and cholesterol. Finally, ultrasound exposure had been shown to induce apoptosis as shown by the appearance DNA fragmentation. Accordingly, ultrasound treatment led to down-modulation of procaspase-9 expression and an increased level of caspase-3 active form.

Ultrasound Stimulation of Insulin Release from Pancreatic Beta Cells

NASA Astrophysics Data System (ADS)

Suarez Castellanos, Ivan M.

Type 2 diabetes (T2D) mellitus is a complex metabolic disease that has reached epidemic proportions in the United States and around the world. Controlling T2D is often difficult as pharmacological management routinely requires complex therapy with multiple medications, and loses its effectiveness over time. The objective of this dissertation was to explore a novel, non-pharmacological approach that utilizes the application of ultrasound energy to stimulate insulin release. Our experiments have focused on determination of effectiveness and safety of ultrasound application in stimulation of insulin release from the pancreatic beta cells. Our results showed that ultrasound treatment, applied at frequencies of 800 kHz and 1 MHz and intensities of 0.5 W/cm2 and 1 W/cm2, did not produce any significant effects on cell viability compared to sham group as assessed with trypan blue dye exclusion test and MTT cytotoxicity assay. ELISA quantification of insulin release from beta cells resulting from ultrasound treatment showed clinically-significant amounts of released insulin as compared to sham-treated beta cells. Carbon fiber amperometry detection of secretory events from dopamine-loaded beta cells treated with ultrasound showed that release of secretory content could be temporally controlled by careful selection of ultrasound parameters. Both ELISA and amperometry experiments demonstrated that ultrasound-stimulated insulin release is a calcium-dependent process, potentially mediated by the mechanical effects of ultrasound. This study demonstrated that therapeutic ultrasound is a technique capable of stimulating the release of insulin from pancreatic beta cells in a safe, effective and controlled manner.

A successful model to learn and implement ultrasound-guided venous catheterization in apheresis.

PubMed

Gopalasingam, Nigopan; Thomsen, Anna-Marie Eller; Folkersen, Lars; Juhl-Olsen, Peter; Sloth, Erik

2017-12-01

Apheresis treatments can be performed with peripheral venous catheters (PVC), although central venous catheters (CVC) are inserted when PVCs fail or patient with history of difficult vascular access prior to the apheresis. Ultrasound guidance for PVC has shown promising results in other settings. To investigate if ultrasound guidance for PVC could be implemented among apheresis nurses. Second, how implementation of ultrasound guidance affected the number of CVCs used for apheresis per patient. Apheresis nurses completed a systematic training program for ultrasound-guided vascular access. All independent catheterizations were registered during the implementation stage. The number of CVCs in the pre- and postimplementation stages of the ultrasound guidance was compared. Six nurses completed the training program within a median of 48 days (range 38-83 days). In 77 patients, 485 independent ultrasound-guided PVC placements were performed during the implementation stage. All apheresis treatments (485/485) were accomplished using PVCs without requiring CVC as rescue. During the preimplementation stage, 125 of 273 (45.8%) procedures required a CVC for completion of apheresis procedures; during the postimplementation stage only 30 of 227 (13.2%) procedures required a CVC (p < 0.001). In the postimplementation stage, no CVCs were placed as rescue caused by failed PVCs but were only placed for patients where the ultrasound machine was unavailable. It indicates an effective success rate of 100% for ultrasound-guided PVC use. This study showed that ultrasound guidance could be implemented among apheresis nurses as a routine tool eliminating the need of CVC as a rescue. © 2017 Wiley Periodicals, Inc.

Evidence for an absence of deleterious effects of ultrasound on human oocytes.

PubMed

Mahadevan, M; Chalder, K; Wiseman, D; Leader, A; Taylor, P J

1987-10-01

Animal and human data would suggest that ultrasound causes deleterious effects to oocytes during meiosis. We directly compared the fertilization rate and embryonic development following in vitro fertilization and embryo transfer of those oocytes exposed to ultrasound and those not exposed in the same patient. In 39 unscreened patients a combination of laparoscopy and ultrasound was used for oocyte recovery. Laparoscopy was performed first on the most accessible ovary (usually the right) and at least one oocyte was obtained. Ultrasound-guided oocyte recovery was successful in the other inaccessible ovary. To assess how oocytes obtained by ultrasound or laparoscopy related to the pregnancy rate, two groups of patients were evaluated in whom the embryos transferred either had been exposed to ultrasound or had not been. The fertilization and the embryo cleavage rates were not significantly different between the ultrasound-exposed and the unexposed groups. The pregnancy rate was also not significantly different [9 of 49 (18.4%) for ultrasound exposed versus 14 of 74 (18.9%) for unexposed]. There was one early spontaneous abortion in each group. Further analysis of a group of 40 patients, in whom the oocytes were exposed to ultrasound in situ, after the endogenous luteinizing hormone (LH) surge had begun 1-27 hr earlier, revealed that 6 became pregnant (15%). This preliminary study suggests that exposure of human oocytes to ultrasonic waves, either during the different phases of meiosis or after the completion of meiosis, did not significantly influence the developmental potential of the in vitro fertilized embryos.

Utility of 3-dimensional ultrasound imaging to evaluate carotid artery stenosis: comparison with magnetic resonance angiography.

PubMed

Igase, Keiji; Kumon, Yoshiaki; Matsubara, Ichiro; Arai, Masamori; Goishi, Junji; Watanabe, Hideaki; Ohnishi, Takanori; Sadamoto, Kazuhiko

2015-01-01

We evaluated the utility of 3-dimensional (3-D) ultrasound imaging for assessment of carotid artery stenosis, as compared with similar assessment via magnetic resonance angiography (MRA). Subjects comprised 58 patients with carotid stenosis who underwent both 3-D ultrasound imaging and MRA. We studied whether abnormal findings detected by ultrasound imaging could be diagnosed using MRA. Ultrasound images were generated using Voluson 730 Expert and Voluson E8. The degree of stenosis was mild in 17, moderate in 16, and severe in 25 patients, according to ultrasound imaging. Stenosis could not be recognized using MRA in 4 of 17 patients diagnosed with mild stenosis using ultrasound imaging. Ultrasound imaging showed ulceration in 13 patients and mobile plaque in 6 patients. When assessing these patients, MRA showed ulceration in only 2 of 13 patients and did not detect mobile plaque in any of these 6 patients. Static 3-D B mode images demonstrated distributions of plaque, ulceration, and mobile plaque, and static 3-D flow images showed flow configuration as a total structure. Real-time 3-D B mode images demonstrated plaque and vessel movement. Carotid artery stenting was not selected for patients diagnosed with ulceration or mobile plaque. Ultrasound imaging was necessary to detect mild stenosis, ulcerated plaque, or mobile plaque in comparison with MRA, and 3-D ultrasound imaging was useful to recognize carotid stenosis and flow pattern as a total structure by static and real-time 3-D demonstration. This information may contribute to surgical planning. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Comparison of clinical marking and ultrasound-guided injection of Botulinum type A toxin into the masseter muscles for treating bruxism and its cosmetic effects.

PubMed

Quezada-Gaon, Natacha; Wortsman, Ximena; Peñaloza, Osvaldo; Carrasco, Juan Eduardo

2016-09-01

Botulinum toxin type A has been used for treating the hypertrophy of the masseter muscles and its cosmetic effects. Ultrasound is increasingly used in dermatology, along with the guidance of mini-invasive procedures. To evaluate the role of ultrasound for guiding the application of Botulinum A toxin in patients with cosmetic alterations due to bruxism, correlate the clinical landmarks with the ultrasound findings, and study the effect on the symptoms, cosmetics, and quality of life. Twenty individuals with bruxism and cosmetic alterations underwent an ultrasound-guided injection of Botulinum toxin type A in each masseter muscle. Clinical and ultrasound marking of the procedure was compared. Clinical and sonographic evaluation was performed at the time of injection and 3 months later. Ten normal individuals underwent ultrasound of the masseter muscles as a control group. Up to 65% of individuals showed anatomical variants of the salivary glands. The method for clinically marking the skin showed a frequently erroneous location of the anterior point (up to 40% of cases) that was proven by ultrasound to be out of the muscle. In 20% of cases, ultrasound showed that the needle should be longer to enter the muscle. After injection, most of the patients demonstrated a decrease of the symptoms and cosmetic and quality of life improvements. Ultrasound can be a potent tool for guiding the injection of Botulinum toxin into the masseter muscles. It may contribute to a more personalized procedure, better cosmetic results, and help to avoid potential complications. © 2016 Wiley Periodicals, Inc.

High-frequency ultrasound imaging for breast cancer biopsy guidance

PubMed Central

Cummins, Thomas; Yoon, Changhan; Choi, Hojong; Eliahoo, Payam; Kim, Hyung Ham; Yamashita, Mary W.; Hovanessian-Larsen, Linda J.; Lang, Julie E.; Sener, Stephen F.; Vallone, John; Martin, Sue E.; Kirk Shung, K.

2015-01-01

Abstract. Image-guided core needle biopsy is the current gold standard for breast cancer diagnosis. Microcalcifications, an important radiographic finding on mammography suggestive of early breast cancer such as ductal carcinoma in situ, are usually biopsied under stereotactic guidance. This procedure, however, is uncomfortable for patients and requires the use of ionizing radiation. It would be preferable to biopsy microcalcifications under ultrasound guidance since it is a faster procedure, more comfortable for the patient, and requires no radiation. However, microcalcifications cannot reliably be detected with the current standard ultrasound imaging systems. This study is motivated by the clinical need for real-time high-resolution ultrasound imaging of microcalcifications, so that biopsies can be accurately performed under ultrasound guidance. We have investigated how high-frequency ultrasound imaging can enable visualization of microstructures in ex vivo breast tissue biopsy samples. We generated B-mode images of breast tissue and applied the Nakagami filtering technique to help refine image output so that microcalcifications could be better assessed during ultrasound-guided core biopsies. We describe the preliminary clinical results of high-frequency ultrasound imaging of ex vivo breast biopsy tissue with microcalcifications and without Nakagami filtering and the correlation of these images with the pathology examination by hematoxylin and eosin stain and whole slide digital scanning. PMID:26693167

Value of contrast-enhanced ultrasound in the differential diagnosis of gallbladder lesion

PubMed Central

Zhang, Hui-Ping; Bai, Min; Gu, Ji-Ying; He, Ying-Qian; Qiao, Xiao-Hui; Du, Lian-Fang

2018-01-01

AIM To describe contrast-enhanced ultrasound (CEUS) features and evaluate differential diagnosis value of CEUS and conventional ultrasound for patients with benign and malignant gallbladder lesions. METHODS This study included 105 gallbladder lesions. Before surgical resection and pathological examination, conventional ultrasound and CEUS were performed to examine for lesions. Then, all the lesions were diagnosed as (1) benign, (2) probably benign, (3) probably malignant or (4) malignant using both conventional ultrasound and CEUS. The CEUS features of these gallbladder lesions were analyzed and diagnostic efficiency between conventional ultrasound and CEUS was compared. RESULTS There were total 17 cases of gallbladder cancer and 88 cases of benign lesion. Some gallbladder lesions had typical characteristics on CEUS (e.g., gallbladder adenomyomatosis had typical characteristics of small nonenhanced areas on CEUS). The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of CEUS were 94.1%, 95.5%, 80.0%, 98.8% and 95.2%, respectively. These were significantly higher than conventional ultrasound (82.4%, 89.8%, 60.9%, 96.3% and 88.6%, respectively). CEUS had an accuracy of 100% for gallbladder sludge and CEUS helped in differential diagnosis among gallbladder polyps, gallbladder adenoma and gallbladder cancer. CONCLUSION CEUS may provide more useful information and improve the diagnosis efficiency for the diagnosis of gallbladder lesions than conventional ultrasound. PMID:29456413

Ultrasound assisted forward osmosis concentration of fruit juice and natural colorant.

PubMed

Chanukya, B S; Rastogi, Navin K

2017-01-01

The present study deals with the effect of higher and lower molecular weight compounds present in the feed on concentration polarization during forward osmosis concentration and its mitigation by the application of ultrasound. The effects of ultrasound on transmembrane water flux at different forward osmosis membrane orientations and different model feed solutions consisting of sucrose and pectin have also been evaluated. The feed containing sucrose and pectin subjected towards active layer of the membrane was found to be the most suitable orientation. The application of ultrasound (30kHz) significantly reduced the concentration polarization when the feed contains sucrose concentration up to 5%. Whereas, in case of feed containing 0.5% pectin, the ultrasound was not found to be effective in dislodging the gel layer formation resulting in severe external concentration polarization on the membrane surface. In comparison to the ordinary forward osmosis process, the ultrasound-assisted forward osmosis process resulted in higher water fluxes in case of sweet lime juice as well as rose extract containing anthocyanin. The degradation of rose anthocyanin due to ultrasound was found to be 1.82%. Application of ultrasound was found to be an effective way in mitigating concentration polarization on the forward osmosis membrane resulting in increased flux. Copyright © 2016 Elsevier B.V. All rights reserved.

Ultrasound effects on brain-targeting mannosylated liposomes: in vitro and blood-brain barrier transport investigations.

PubMed

Zidan, Ahmed S; Aldawsari, Hibah

2015-01-01

Delivering drugs to intracerebral regions can be accomplished by improving the capacity of transport through blood-brain barrier. Using sertraline as model drug for brain targeting, the current study aimed at modifying its liposomal vesicles with mannopyranoside. Box-Behnken design was employed to statistically optimize the ultrasound parameters, namely ultrasound amplitude, time, and temperature, for maximum mannosylation capacity, sertraline entrapment, and surface charge while minimizing vesicular size. Moreover, in vitro blood-brain barrier transport model was established to assess the transendothelial capacity of the optimized mannosylated vesicles. Results showed a dependence of vesicular size, mannosylation capacity, and sertraline entrapment on cavitation and bubble implosion events that were related to ultrasound power amplitude, temperature. However, short ultrasound duration was required to achieve >90% mannosylation with nanosized vesicles (<200 nm) of narrow size distribution. Optimized ultrasound parameters of 65°C, 27%, and 59 seconds for ultrasound temperature, amplitude, and time were elucidated to produce 81.1%, 46.6 nm, and 77.6% sertraline entrapment, vesicular size, and mannosylation capacity, respectively. Moreover, the transendothelial ability was significantly increased by 2.5-fold by mannosylation through binding with glucose transporters. Hence, mannosylated liposomes processed by ultrasound could be a promising approach for manufacturing and scale-up of brain-targeting liposomes.

High-frequency ultrasound-responsive block copolymer micelle.

PubMed

Wang, Jie; Pelletier, Maxime; Zhang, Hongji; Xia, Hesheng; Zhao, Yue

2009-11-17

Micelles of a diblock copolymer composed of poly(ethylene oxide) and poly(2-tetrahydropyranyl methacrylate) (PEO-b-PTHPMA) in aqueous solution could be disrupted by high-frequency ultrasound (1.1 MHz). It was found that, upon exposure to a high-intensity focused ultrasound (HIFU) beam at room temperature, the pH value of the micellar solution decreased over irradiation time. The infrared spectroscopic analysis of solid block copolymer samples collected from the ultrasound irradiated micellar solution revealed the formation of carboxylic acid dimers and hydroxyl groups. These characterization results suggest that the high-frequency HIFU beam could induce the hydrolysis reaction of THPMA at room temperature resulting in the cleavage of THP groups. The disruption of PEO-b-PTHPMA micelles by ultrasound was investigated by using dynamic light scattering, atomic force microscopy, and fluorescence spectroscopy. On the basis of the pH change, it was found that the disruption process was determined by a number of factors such as the ultrasound power, the micellar solution volume and the location of the focal spot of the ultrasound beam. This study shows the potential to develop ultrasound-sensitive block copolymer micelles by having labile chemical bonds in the polymer structure, and to use the high-frequency HIFU to trigger a chemical reaction for the disruption of micelles.

Comparative evaluation of ultrasound scanner accuracy in distance measurement

NASA Astrophysics Data System (ADS)

Branca, F. P.; Sciuto, S. A.; Scorza, A.

2012-10-01

The aim of the present study is to develop and compare two different automatic methods for accuracy evaluation in ultrasound phantom measurements on B-mode images: both of them give as a result the relative error e between measured distances, performed by 14 brand new ultrasound medical scanners, and nominal distances, among nylon wires embedded in a reference test object. The first method is based on a least squares estimation, while the second one applies the mean value of the same distance evaluated at different locations in ultrasound image (same distance method). Results for both of them are proposed and explained.

Combined magnetic resonance imaging and ultrasound echography guidance for motion compensated HIFU interventions

NASA Astrophysics Data System (ADS)

Ries, Mario; de Senneville, Baudouin Denis; Regard, Yvan; Moonen, Chrit

2012-11-01

The objective of this study is to evaluate the feasibility to integrate ultrasound echography as an additional imaging modality for continuous target tracking, while performing simultaneously real-time MR- thermometry to guide a High Intensity Focused Ultrasound (HIFU) ablation. Experiments on a moving phantom were performed with MRI-guided HIFU during continuous ultrasound echography. Real-time US echography-based target tracking during MR-guided HIFU heating was performed with heated area dimensions similar to those obtained for a static target. The combination of both imaging modalities shows great potential for real-time beam steering and MR-thermometry.

Safety of Microbubbles and Transcranial Ultrasound in Rabbits

NASA Astrophysics Data System (ADS)

Culp, William C.; Brown, Aliza T.; Hennings, Leah; Lowery, John; Culp, Benjamin C.; Erdem, Eren; Roberson, Paula; Matsunaga, Terry O.

2007-05-01

The object of this study was to evaluate the safety of large doses of microbubbles and ultrasound administered to the head of rabbits as if they were receiving acute stroke therapy of a similar nature. Materials and Methods: Female New Zealand White rabbits were used, N=24, in three groups 1] n=4 control (no treatment), 2] n=10 bubble control (ultrasound plus aspirin), and 3] n=10 target group (ultrasound plus aspirin plus MRX-815 microbubbles). Group 3 was infused with IV bubbles over 1 hour at 0.16cc/kg. Ultrasound was delivered to the dehaired side of the head during bubble infusion and for 1 additional hour at 0.8 W/cm2 20% pulsed wave. Rabbits survived for 22 to 24 hours, were imaged with computerized tomography and 3 Tesla magnetic resonance imaging including contrast studies, and sacrificed. Tetrazolium (TTC) and Hematoxylin and Eosin (H&E) sections were made for pathological examination. Results: All 24 animals showed absence of bleeding, endothelial damage, EKG abnormalities, stroke, blood-brain-barrier breakdown, or other acute abnormalities. CT and MRI showed no bleeding or signs of stroke, but two animals had mild hydrocephalus. The EKGs showed normal variation in QTc. Rabbit behavior was normal in all. Minimal chronic inflammation unrelated to the study was seen in 5. Two animals were excluded because of protocol violations and replaced during the study. Conclusion: The administered dose of microbubbles and ultrasound demonstrated no detrimental effects on the healthy rabbit animal model.

The Role of Ultrasound Compared to Biopsy of Temporal Arteries in the Diagnosis and Treatment of Giant Cell Arteritis (TABUL): a diagnostic accuracy and cost-effectiveness study.

PubMed

Luqmani, Raashid; Lee, Ellen; Singh, Surjeet; Gillett, Mike; Schmidt, Wolfgang A; Bradburn, Mike; Dasgupta, Bhaskar; Diamantopoulos, Andreas P; Forrester-Barker, Wulf; Hamilton, William; Masters, Shauna; McDonald, Brendan; McNally, Eugene; Pease, Colin; Piper, Jennifer; Salmon, John; Wailoo, Allan; Wolfe, Konrad; Hutchings, Andrew

2016-11-01

Giant cell arteritis (GCA) is a relatively common form of primary systemic vasculitis, which, if left untreated, can lead to permanent sight loss. We compared ultrasound as an alternative diagnostic test with temporal artery biopsy, which may be negative in 9-61% of true cases. To compare the clinical effectiveness and cost-effectiveness of ultrasound with biopsy in diagnosing patients with suspected GCA. Prospective multicentre cohort study. Secondary care. A total of 381 patients referred with newly suspected GCA. Sensitivity, specificity and cost-effectiveness of ultrasound compared with biopsy or ultrasound combined with biopsy for diagnosing GCA and interobserver reliability in interpreting scan or biopsy findings. We developed and implemented an ultrasound training programme for diagnosing suspected GCA. We recruited 430 patients with suspected GCA. We analysed 381 patients who underwent both ultrasound and biopsy within 10 days of starting treatment for suspected GCA and who attended a follow-up assessment (median age 71.1 years; 72% female). The sensitivity of biopsy was 39% [95% confidence interval (CI) 33% to 46%], which was significantly lower than previously reported and inferior to ultrasound (54%, 95% CI 48% to 60%); the specificity of biopsy (100%, 95% CI 97% to 100%) was superior to ultrasound (81%, 95% CI 73% to 88%). If we scanned all suspected patients and performed biopsies only on negative cases, sensitivity increased to 65% and specificity was maintained at 81%, reducing the need for biopsies by 43%. Strategies combining clinical judgement (clinician's assessment at 2 weeks) with the tests showed sensitivity and specificity of 91% and 81%, respectively, for biopsy and 93% and 77%, respectively, for ultrasound; cost-effectiveness (incremental net monetary benefit) was £485 per patient in favour of ultrasound with both cost savings and a small health gain. Inter-rater analysis revealed moderate agreement among sonographers (intraclass correlation coefficient 0.61, 95% CI 0.48 to 0.75), similar to pathologists (0.62, 95% CI 0.49 to 0.76). There is no independent gold standard diagnosis for GCA. The reference diagnosis used to determine accuracy was based on classification criteria for GCA that include clinical features at presentation and biopsy results. We have demonstrated the feasibility of providing training in ultrasound for the diagnosis of GCA. Our results indicate better sensitivity but poorer specificity of ultrasound compared with biopsy and suggest some scope for reducing the role of biopsy. The moderate interobserver agreement for both ultrasound and biopsy indicates scope for improving assessment and reporting of test results and challenges the assumption that a positive biopsy always represents GCA. Further research should address the issue of an independent reference diagnosis, standards for interpreting and reporting test results and the evaluation of ultrasound training, and should also explore the acceptability of these new diagnostic strategies in GCA. The National Institute for Health Research Health Technology Assessment programme.

Heart rate is a marker of amiodarone mortality reduction in severe heart failure. The GESICA-GEMA Investigators. Grupo de Estudio de la Sobrevida en la Insuficiencia Cardiaca en Argentina-Grupo de Estudios Multicéntricos en Argentina.

PubMed

Nul, D R; Doval, H C; Grancelli, H O; Varini, S D; Soifer, S; Perrone, S V; Prieto, N; Scapin, O

1997-05-01

The impact of amiodarone on mortality in patients with severe congestive heart failure (CHF) (New York Heart Association functional classes II [advanced], III and IV; left ventricular ejection fraction < 35%) In the Grupo de Estudio de la Sobrevida en la Insuficiencia Cardiaca en Argentina (GESICA) trial was analyzed in relation to initial mean baseline heart rate (BHR) and its change after 6 months of follow-up. Trials of amiodarone therapy in CHF have produced discordant results, suggesting that the effect is not uniform in all patient subgroups with regard to survival. The present analysis was carried out in 516 patients randomized to receive amiodarone, 300 mg/day (n = 260), or nonantiarrhythmic therapy (n = 256, control group) and followed up for 2 years. Survival was evaluated for patients with a BHR > or = 90 beats/min (control: n = 132; amiodarone: n = 122) and < 90 beats/min (control: n = 124; amiodarone: n = 138). Survival was also analyzed according to heart rate reduction at 6 months for 367 patients. For patients with a BHR > or = 90 beats/min, amiodarone therapy reduced mortality to 38.4% compared with 62.4% in control patients (relative risk [RR] 0.55, 95% confidence interval [CI] 0.35 to 0.95, p < 0.002). Both sudden death (RR 0.46, 95% CI 0.24 to 0.90, p < 0.02) and progressive heart failure death (RR 0.60, 95% CI 0.30 to 1.03, p < 0.06) were reduced, and functional capacity was improved. In patients with a BHR < 90 beats/min, amiodarone did not alter survival. Among 367 patients who completed 6 months of follow-up, amiodarone reduced 2-year mortality only in those with a BHR > or = 90 beats/min, which was reduced at 6 months. Elevated rest heart rates in severe CHF identify a subgroup of patients who benefit from treatment with amiodarone. Amiodarone-induced heart rate slowing may be an important benefit for patients.

Dual-frequency ultrasound focal therapy for MRI-guided transurethral treatment of the prostate: Study in gel phantom

NASA Astrophysics Data System (ADS)

N'Djin, W. Apoutou; Mougenot, Charles; Kobelevskiy, Ilya; Ramsay, Elizabeth; Bronskill, Michael; Chopra, Rajiv

2012-11-01

Ultrasound thermal therapy of localized prostate cancer offers a minimally-invasive non-ionizing alternative [1-3] to surgery and radiotherapy. MRI-controlled transurethral ultrasound prostate therapy [4-6] has previously been investigated in a pilot human feasibility study [7], by treating a small sub-volume of prostate tissue. In this study, the feasibility of transurethral dual-frequency ultrasound focal therapy has been investigated in gel phantom. A database of pelvic anatomical models of human prostate cancer patients have been created using MR clinical images. The largest prostate boundary (47 cm3) was used to fabricate an anatomical gel phantom which included various MR characteristics to mimic prostate tissues, 4 localized tumors and surrounding prostate tissues. A 9-element transurethral ultrasound applicator working in dual-frequency mode (f = 4.6/14.5 MHz) was evaluated to heat: (i) the entire prostate volume (Full prostate treatment strategy), (ii) a prostate region restricted to tumors (Focal therapy). Acoustic power of each element and rotation rate of the device were adjusted in realtime based on MR-thermometry feedback control (nine thermal slices updated every 6.2s). Experiments have been performed using dual-frequency ultrasound exposures (surface Pmax: 20W.cm-2). (i) For full prostate heating, 7 elements of the device were used to cover the entire prostate length. The heating process was completed within 35 min. Ultrasound exposures at the fundamental frequency allowed full heating of the largest prostate radii (>18 mm), while exposures at the 3rd harmonic ensured homogeneous treatment of the smallest radii. Undertreated and overtreated regions represented respectively 2% and 17% of the prostate volume. (ii) For focal therapy, the target region was optimized to maintain safe regions in the prostate and to cover all tumor-mimics. Only 5 ultrasound elements were used to treat successfully all tumor-mimics within 26 min. Undertreated and overtreated regions each represented 7% of the prostate volume. MRI-guided transurethral ultrasound procedure enables full treatment and focal therapy in human prostate geometry. Prostate volume heating was fast compared to standard HIFU prostate treatments. Dual-frequency ultrasound exposures allowed optimal heat deposition in all prostate regions. The focal therapy strategy is promising as regard to safety and could contribute to enhance the post-treatment autonomy of the patient.

Comparison of the analgesic efficacy of ultrasound-guided rectus sheath block and local anesthetic infiltration for laparoscopic percutaneous extraperitoneal closure in children.

PubMed

Uchinami, Yuka; Sakuraya, Fumika; Tanaka, Nobuhiro; Hoshino, Koji; Mikami, Eri; Ishikawa, Taro; Fujii, Hitomi; Ishikawa, Takehiko; Morimoto, Yuji

2017-05-01

Ultrasound-guided rectus sheath block and local anesthetic infiltration are the standard options to improve postoperative pain for children undergoing surgery with a midline incision. However, there is no study comparing the effect of ultrasound-guided rectus sheath block with local anesthetic infiltration for children undergoing laparoscopic surgery. The aim of this trial was to compare the onset of ultrasound-guided rectus sheath block with that of local anesthetic infiltration for laparoscopic percutaneous extraperitoneal closure in children. We performed an observer-blinded, randomized, prospective trial. Enrolled patients were assigned to either an ultrasound-guided rectus sheath block group or a local anesthetic infiltration group. The ultrasound-guided rectus sheath block group (n = 17) received ultrasound-guided rectus sheath block with 0.2 ml·kg -1 of 0.375% ropivacaine per side in the posterior rectus sheath compartment. The local anesthetic infiltration group (n = 17) received local anesthetic infiltration with 0.2 ml·kg -1 of 0.75% ropivacaine. The Face, Legs, Activity, Cry, and Consolability (FLACC) pain scores were recorded at 0, 30, 60 min after arrival at the postanesthesia care unit. Of the 37 patients enrolled in this study, 34 completed the study protocol. A significant difference in the pain scale between the ultrasound-guided rectus sheath block group and local anesthetic infiltration group was found at 0 min (median: 0, interquartile range [IQR]: 0-1.5, vs median: 1, IQR 0-5, confidence interval of median [95% CI]: 0-3, P = 0.048), but no significant difference was found at 30 min (median: 1, IQR: 0-4 vs median: 6, IQR: 0-7, 95% CI: 0-5, P = 0.061), or 60 min (median: 0, IQR: 0-2 vs median: 1, IQR: 0-3, 95% CI: -1 to 1, P = 0.310). No significant difference was found in anesthesia time between the ultrasound-guided rectus sheath block and local anesthetic infiltration groups. No procedure-related complications were observed in either group. Ultrasound-guided rectus sheath block is a quicker way to control postoperative pain for pediatric patients undergoing laparoscopic extraperitoneal closure than local anesthetic infiltration, and thus may provide a clinical benefit. © 2017 John Wiley & Sons Ltd.

Opto-acoustic breast imaging with co-registered ultrasound

NASA Astrophysics Data System (ADS)

Zalev, Jason; Clingman, Bryan; Herzog, Don; Miller, Tom; Stavros, A. Thomas; Oraevsky, Alexander; Kist, Kenneth; Dornbluth, N. Carol; Otto, Pamela

2014-03-01

We present results from a recent study involving the ImagioTM breast imaging system, which produces fused real-time two-dimensional color-coded opto-acoustic (OA) images that are co-registered and temporally inter- leaved with real-time gray scale ultrasound using a specialized duplex handheld probe. The use of dual optical wavelengths provides functional blood map images of breast tissue and tumors displayed with high contrast based on total hemoglobin and oxygen saturation of the blood. This provides functional diagnostic information pertaining to tumor metabolism. OA also shows morphologic information about tumor neo-vascularity that is complementary to the morphological information obtained with conventional gray scale ultrasound. This fusion technology conveniently enables real-time analysis of the functional opto-acoustic features of lesions detected by readers familiar with anatomical gray scale ultrasound. We demonstrate co-registered opto-acoustic and ultrasonic images of malignant and benign tumors from a recent clinical study that provide new insight into the function of tumors in-vivo. Results from the Feasibility Study show preliminary evidence that the technology may have the capability to improve characterization of benign and malignant breast masses over conventional diagnostic breast ultrasound alone and to improve overall accuracy of breast mass diagnosis. In particular, OA improved speci city over that of conventional diagnostic ultrasound, which could potentially reduce the number of negative biopsies performed without missing cancers.

Ultrasonically targeted delivery into endothelial and smooth muscle cells in ex vivo arteries

PubMed Central

Hallow, Daniel M.; Mahajan, Anuj D.; Prausnitz, Mark R.

2007-01-01

This study tested the hypothesis that ultrasound can target intracellular uptake of drugs into vascular endothelial cells (ECs) at low to intermediate energy and into smooth muscle cells (SMCs) at high energy. Ultrasound-enhanced delivery has been shown to enhance and target intracellular drug and gene delivery in the vasculature to treat cardiovascular disease, but quantitative studies of the delivery process are lacking. Viable ex vivo porcine carotid arteries were placed in a solution containing a model drug, TO-PRO®-1, and Optison® microbubbles. Arteries were exposed to ultrasound at 1.1 MHz and acoustic energies of 5.0, 66, or 630 J/cm2. Using confocal microscopy and fluorescent labeling of cells, the artery endothelium and media were imaged to determine the localization and to quantify intracellular uptake and cell death. At low to intermediate ultrasound energy, ultrasound was shown to target intracellular delivery into viable cells that represented 9 – 24% of exposed ECs. These conditions also typically caused 7 – 25% EC death. At high energy, intracellular delivery was targeted to SMCs, which was associated with denuding or death of proximal ECs. This work represents the first known in-depth study to evaluate intracellular uptake into cells in tissue. We conclude that significant intracellular uptake of molecules can be targeted into ECs and SMCs by ultrasound-enhanced delivery suggesting possible applications for treatment of cardivascular diseases and dysfunctions. PMID:17291619

Not all ultrasounds are created equal: general sonography versus musculoskeletal sonography in the detection of rotator cuff tears

PubMed Central

Cole, Brandi; Twibill, Kristen; Lam, Patrick; Hackett, Lisa

2016-01-01

Background This cross-sectional analytic diagnostic accuracy study was designed to compare the accuracy of ultrasound performed by general sonographers in local radiology practices with ultrasound performed by an experienced musculoskeletal sonographer for the detection of rotator cuff tears. Methods In total, 238 patients undergoing arthroscopy who had previously had an ultrasound performed by both a general sonographer and a specialist musculoskeletal sonographer made up the study cohort. Accuracy of diagnosis was compared with the findings at arthroscopy. Results When analyzed as all tears versus no tears, musculoskeletal sonography had an accuracy of 97%, a sensitivity of 97% and a specificity of 95%, whereas general sonography had an accuracy of 91%, a sensitivity of 91% and a specificity of 86%. When the partial tears were split with those ≥ 50% thickness in the tear group and those < 50% thickness in the no-tear group, musculoskeletal sonography had an accuracy of 97%, a sensitivity of 97% and a specificity of 100% and general sonography had an accuracy of 85%, a sensitivity of 84% and a specificity of 87%. Conclusions Ultrasound in the hands of an experienced musculoskeletal sonographer is highly accurate for the diagnosis of rotator cuff tears. General sonography has improved subsequent to earlier studies but remains inferior to an ultrasound performed by a musculoskeletal sonographer. PMID:27660657

Correlates of mammographic density in B-mode ultrasound and real time elastography.

PubMed

Jud, Sebastian Michael; Häberle, Lothar; Fasching, Peter A; Heusinger, Katharina; Hack, Carolin; Faschingbauer, Florian; Uder, Michael; Wittenberg, Thomas; Wagner, Florian; Meier-Meitinger, Martina; Schulz-Wendtland, Rüdiger; Beckmann, Matthias W; Adamietz, Boris R

2012-07-01

The aim of our study involved the assessment of B-mode imaging and elastography with regard to their ability to predict mammographic density (MD) without X-rays. Women, who underwent routine mammography, were prospectively examined with additional B-mode ultrasound and elastography. MD was assessed quantitatively with a computer-assisted method (Madena). The B-mode and elastography images were assessed by histograms with equally sized gray-level intervals. Regression models were built and cross validated to examine the ability to predict MD. The results of this study showed that B-mode imaging and elastography were able to predict MD. B-mode seemed to give a more accurate prediction. R for B-mode image and elastography were 0.67 and 0.44, respectively. Areas in the B-mode images that correlated with mammographic dense areas were either dark gray or of intermediate gray levels. Concerning elastography only the gray levels that represent extremely stiff tissue correlated positively with MD. In conclusion, ultrasound seems to be able to predict MD. Easy and cheap utilization of regular breast ultrasound machines encourages the use of ultrasound in larger case-control studies to validate this method as a breast cancer risk predictor. Furthermore, the application of ultrasound for breast tissue characterization could enable comprehensive research concerning breast cancer risk and breast density in young and pregnant women.

Study and optimization of the ultrasound-enhanced cleaning of an ultrafiltration ceramic membrane through a combined experimental-statistical approach.

PubMed

Alventosa-deLara, E; Barredo-Damas, S; Alcaina-Miranda, M I; Iborra-Clar, M I

2014-05-01

Membrane fouling is one of the main drawbacks of ultrafiltration technology during the treatment of dye-containing effluents. Therefore, the optimization of the membrane cleaning procedure is essential to improve the overall efficiency. In this work, a study of the factors affecting the ultrasound-assisted cleaning of an ultrafiltration ceramic membrane fouled by dye particles was carried out. The effect of transmembrane pressure (0.5, 1.5, 2.5 bar), cross-flow velocity (1, 2, 3 ms(-1)), ultrasound power level (40%, 70%, 100%) and ultrasound frequency mode (37, 80 kHz and mixed wave) on the cleaning efficiency was evaluated. The lowest frequency showed better results, although the best cleaning performance was obtained using the mixed wave mode. A Box-Behnken Design was used to find the optimal conditions for the cleaning procedure through a response surface study. The optimal operating conditions leading to the maximum cleaning efficiency predicted (32.19%) were found to be 1.1 bar, 3 ms(-1) and 100% of power level. Finally, the optimized response was compared to the efficiency of a chemical cleaning with NaOH solution, with and without the use of ultrasound. By using NaOH, cleaning efficiency nearly triples, and it improves up to 25% by adding ultrasound. Copyright © 2013 Elsevier B.V. All rights reserved.

Level of In Utero Cocaine Exposure and Neonatal Ultrasound Findings

PubMed Central

Frank, Deborah A.; McCarten, Kathleen M.; Robson, Caroline D.; Mirochnick, Mark; Cabral, Howard; Park, Henry; Zuckerman, Barry

2008-01-01

Objective To assess whether there is an association between the level of in utero cocaine exposure and findings on neonatal cranial ultrasound, controlling for potentially confounding variables. Study Design In a prospective longitudinal study, three cocaine exposure groups were defined by maternal report and infant meconium assay: unexposed, heavier cocaine exposure (>75th percentile self-reported days of use or of meconium benzoylecogonine concentration) or lighter cocaine exposure (all others). Neonatal ultrasounds from 241 well, term infants were read by a single radiologist who was masked to the exposure group. Results Infants with lighter cocaine exposure did not differ from the unexposed infants on any ultrasound findings. After controlling for infant gender, gestational age, and birth weight z scores and for maternal parity, blood pressure in labor, ethnicity, and use of cigarettes, alcohol, and marijuana during pregnancy, the more heavily cocaine-exposed infants were more likely than the unexposed infants to show subependymal hemorrhage in the caudothalamic groove (covariate adjusted odds ratio: 3.88; 95% confidence interval: 1.45, 10.35). Conclusions This is the first study to demonstrate that ultrasound findings suggestive of vascular injury to the neonatal central nervous system are related to the level of prenatal cocaine exposure. Inconsistency in previous research in identifying an association between prenatal cocaine exposure and neonatal cranial ultrasound findings may reflect failure to consider dose effects. PMID:10545554

Virtual Ultrasound Guidance for Inexperienced Operators

NASA Technical Reports Server (NTRS)

Caine, Timothy; Martin, Davis

2012-01-01

Medical ultrasound or echocardiographic studies are highly operator-dependent and generally require lengthy training and internship to perfect. To obtain quality echocardiographic images in remote environments, such as on-orbit, remote guidance of studies has been employed. This technique involves minimal training for the user, coupled with remote guidance from an expert. When real-time communication or expert guidance is not available, a more autonomous system of guiding an inexperienced operator through an ultrasound study is needed. One example would be missions beyond low Earth orbit, in which the time delay inherent with communication will make remote guidance impractical.

Might telesonography be a new useful diagnostic tool aboard merchant ships? A pilot study.

PubMed

Nikolić, Nebojsa; Mozetić, Vladimir; Modrcin, Bob; Jaksić, Slaven

2006-01-01

Developments of new, ultra-light diagnostic ultrasound systems (UTS) and modern satellite telecommunication networks are opening new potential applications for diagnostic sonography. One such area is maritime medicine. It is our belief that ship officers can be trained to use diagnostic ultrasound systems with the aim to generate ultrasound images of sufficient quality to be interpreted by medical professionals qualified to read sonograms. To test our thesis we included lectures and hands on scanning practice to the current maritime medicine curriculum at the Faculty of Maritime Studies at the University of Rijeka. Following the didactic and practical training all participating students examined several patients, some with pathology some without. Images obtained by students were then submitted for interpretation to a qualified physician (specialist of general surgery trained in UTS) who was unaware of the patient's pathology. In total, 37 students performed 37 examinations and made 45 ultrasound images, on 3 patients. In this paper, results on this pilot study are presented. It is possible to teach ship officers to produce diagnostically usable ultrasound pictures aboard ships at sea. But before reaching final conclusion about applicability of telesonography on board merchant ships, further studies are necessary, that would include studies of economic feasibility, and on validity of introducing such a diagnostic tool to the maritime medical practice.

Does use of a PACS increase the number of images per study? A case study in ultrasound.

PubMed

Horii, Steven; Nisenbaum, Harvey; Farn, James; Coleman, Beverly; Rowling, Susan; Langer, Jill; Jacobs, Jill; Arger, Peter; Pinheiro, Lisa; Klein, Wendy; Reber, Michele; Iyoob, Christopher

2002-03-01

The purpose of this study was to determine if the use of a picture archiving and communications system (PACS) in ultrasonography increased the number of images acquired per examination. The hypothesis that such an increase does occur was based on anecdotal information; this study sought to test the hypothesis. A random sample of all ultrasound examination types was drawn from the period 1998 through 1999. The ultrasound PACS in use (ACCESS; Kodak Health Information Systems, Dallas, TX) records the number of grayscale and color images saved as part of each study. Each examination in the sample was checked in the ultrasound PACS database,.and the number of grayscale and color images was recorded. The comparison film-based sample was drawn from the period 1994 through 1995. The number of examinations of each type selected was based on the overall statistics of the section; that is, the sample was designed to represent the approximate frequency with which the various examination types are done. For film-based image counts, the jackets were retrieved, and the number of grayscale and color images were counted. The number of images obtained per examination (for most examinations) in ultrasound increased with PACS use. This was more evident with some examination types (eg, pelvis). This result, however, has to be examined for possible systematic biases because ultrasound practice has changed over the time since the authors stopped using film routinely. The use of PACS in ultrasonography was not associated with an increase in the number of images per examination based solely on the use of PACS, with the exception of neonatal head studies. Increases in the number of images per study was otherwise associated with examinations for which changes in protocols resulted in the increased image counts.

Preliminary study of ergonomic behavior during simulated ultrasound-guided regional anesthesia using a head-mounted display.

PubMed

Udani, Ankeet D; Harrison, T Kyle; Howard, Steven K; Kim, T Edward; Brock-Utne, John G; Gaba, David M; Mariano, Edward R

2012-08-01

A head-mounted display provides continuous real-time imaging within the practitioner's visual field. We evaluated the feasibility of using head-mounted display technology to improve ergonomics in ultrasound-guided regional anesthesia in a simulated environment. Two anesthesiologists performed an equal number of ultrasound-guided popliteal-sciatic nerve blocks using the head-mounted display on a porcine hindquarter, and an independent observer assessed each practitioner's ergonomics (eg, head turning, arching, eye movements, and needle manipulation) and the overall block quality based on the injectate spread around the target nerve for each procedure. Both practitioners performed their procedures without directly viewing the ultrasound monitor, and neither practitioner showed poor ergonomic behavior. Head-mounted display technology may offer potential advantages during ultrasound-guided regional anesthesia.

Optical micromachined ultrasound transducers (OMUT)--a new approach for high-frequency transducers.

PubMed

Tadayon, Mohammad Amin; Ashkenazi, Shai

2013-09-01

The sensitivity and reliability of piezoelectric ultrasound transducers severely degrade in applications requiring high frequency and small element size. Alternative technologies such as capacitive micromachined ultrasound transducers (CMUT) and optical sensing and generation of ultrasound have been proposed and studied for several decades. In this paper, we present a new type of device based on optical micromachined ultrasound transducer (OMUT) technology. OMUTs rely on microfabrication techniques to construct micrometerscale air cavities capped by an elastic membrane. A modified photoresist bonding process has been developed to facilitate the fabrication of these devices. We will describe the design, fabrication, and testing of prototype OMUT devices which implement a receive-only function. Future design modifications are proposed for incorporating complete transmit¿receive functionality in a single element.

Economical Sponge Phantom for Teaching, Understanding, and Researching A- and B-Line Reverberation Artifacts in Lung Ultrasound.

PubMed

Blüthgen, Christian; Sanabria, Sergio; Frauenfelder, Thomas; Klingmüller, Volker; Rominger, Marga

2017-10-01

This project evaluated a low-cost sponge phantom setup for its capability to teach and study A- and B-line reverberation artifacts known from lung ultrasound and to numerically simulate sound wave interaction with the phantom using a finite-difference time-domain (FDTD) model. Both A- and B-line artifacts were reproducible on B-mode ultrasound imaging as well as in the FDTD-based simulation. The phantom was found to be an easy-to-set up and economical tool for understanding, teaching, and researching A- and B-line artifacts occurring in lung ultrasound. The FDTD method-based simulation was able to reproduce the artifacts and provides intuitive insight into the underlying physics. © 2017 by the American Institute of Ultrasound in Medicine.

Early detection of ovarian cancer by serum marker and targeted ultrasound imaging | Division of Cancer Prevention

Cancer.gov

We propose to test the validity and specificity of our targeted ultrasound imaging probes in detecting early stage ovarian cancer (OVCA) by transvaginal ultrasound imaging (TVUS). We then test the predictive validity of these probes in a longitudinal study using the laying hen – the only widely available animal model of spontaneous OVCA. OVCA is a fatal gynecological

Studying Materials Using Acoustic Waves

DTIC Science & Technology

1988-03-01

Biological Materials." J. Acoust. Soc. Am. 7£, 636 (1981). Robert E. Apfel "Acoustic Cavitation : A Possible Consequence of Biomedical Uses of Ultrasound ...Soc. Am. 19_, 148 (1986). Robert E. Apfel "Possibility of Micro- Cavitation from Diagnostic Ultrasound ." IEEE Trans. on Ultrasonics...Madanshetty and R.A. Roy "Thresholds for Acoustic Cavitation Produced in Water by Pulsed Ultrasound ." Ultrasonics (UK) - in Press. Robert E. Apfel

Development and implementation of ultrasound picture archiving and communication system

NASA Astrophysics Data System (ADS)

Weinberg, Wolfram S.; Tessler, Franklin N.; Grant, Edward G.; Kangarloo, Hooshang; Huang, H. K.

1990-08-01

The Department of Radiological Sciences at the UCLA School of Medicine is developing an archiving and communication system (PACS) for digitized ultrasound images. In its final stage the system will involve the acquisition and archiving of ultrasound studies from four different locations including the Center for Health Sciences, the Department for Mental Health and the Outpatient Radiology and Endoscopy Departments with a total of 200-250 patient studies per week. The concept comprises two stages of image manipulation for each ultrasound work area. The first station is located close to the examination site and accomodates the acquisition of digital images from up to five ultrasound devices and provides for instantaneous display and primary viewing and image selection. Completed patient studies are transferred to a main workstation for secondary review, further analysis and comparison studies. The review station has an on-line storage capacity of 10,000 images with a resolution of 512x512 8 bit data to allow for immediate retrieval of active patient studies of up to two weeks. The main work stations are connected through the general network and use one central archive for long term storage and a film printer for hardcopy output. First phase development efforts concentrate on the implementation and testing of a system at one location consisting of a number of ultrasound units with video digitizer and network interfaces and a microcomputer workstation as host for the display station with two color monitors, each allowing simultaneous display of four 512x512 images. The discussion emphasizes functionality, performance and acceptance of the system in the clinical environment.

Manipulating neuronal activity with low frequency transcranial ultrasound

NASA Astrophysics Data System (ADS)

Moore, Michele Elizabeth

Stimulation of the rodent cerebral cortex is used to investigate the underlying biological basis for the restorative effects of slow wave sleep. Neuronal activation by optogenetic and ultrasound stimulation elicits changes in action potentials across the cerebral cortex that are recorded as electroencephalograms. Optogenetic stimulation requires an invasive implantation procedure limiting its application in human studies. We sought to determine whether ultrasound stimulation could be as effective as optogenetic techniques currently used, in an effort to further understand the physiological and metabolic requirements of sleep. We successfully recorded electroencephalograms in response to transcranial ultrasound stimulation of the barrel cortex at 1 and 7 Hz frequencies, comparing them to those recorded in response to optogenetic stimuli applied at the same frequencies. Our results showed application of a 473 nm blue LED positioned 6 cm above the skull and ultrasound stimulation at an output voltage of 1000 mVpp produced electroencephalograms with physiological responses of similar amplitude. We concluded that there exists an intensity-proportionate response in the optogenetic stimulation, but not with ultrasound stimulation at the frequencies we surveyed. Activation of neuronal cells in response to optogenetic stimulation in a Thy1-ChR2 transgenic mouse line is specifically targeted to pyramidal cells in the cerebral cortex. ChR2 responses to optogenetic stimulation are mediated by a focal activation of neuronal ion channels. We measured electrophysiological responses to ultrasound stimulation, comparing them to those recorded from optogenetic stimuli. Our results show striking similarities between ultrasound-induced responses and optogenetically-induced responses, which may indicate that transcranial ultrasound stimulation is also mediated by ion channel dependent processes in cerebral cortical neurons. The biophysical substrates for electrical excitability of neurons impose temporal constraints on their response to stimulation. If ultrasound-mediated responses are, in fact, ion channel mediated responses, ultrasound-induced responses should exhibit time-dependence characteristics similar to those of optogenetically-triggered responses. Minimal stimulus duration thresholds and the temporal limits of paired pulse facilitation for ultrasound stimulation were identical to those of optogenetic stimulation. Collectively, these experiments demonstrate an electrophysiological basis for low-frequency transcranial ultrasound stimulation of cerebral cortical neuronal activity.

Ultrasound in space

NASA Technical Reports Server (NTRS)

Martin, David S.; South, Donna A.; Garcia, Kathleen M.; Arbeille, Philippe

2003-01-01

Physiology of the human body in space has been a major concern for space-faring nations since the beginning of the space era. Ultrasound (US) is one of the most cost effective and versatile forms of medical imaging. As such, its use in characterizing microgravity-induced changes in physiology is being realized. In addition to the use of US in related ground-based studies, equipment has also been modified to fly in space. This involves alteration to handle the stresses of launch and different power and cooling requirements. Study protocols also have been altered to accommodate the microgravity environment. Ultrasound studies to date have shown a pattern of adaptation to microgravity that includes changes in cardiac chamber sizes and vertebral spacing. Ultrasound has been and will continue to be an important component in the investigation of physiological and, possibly, pathologic changes occurring in space or as a result of spaceflight.

Monitoring Progression of Amyotrophic Lateral Sclerosis Using Ultrasound Morpho-Textural Muscle Biomarkers: A Pilot Study.

PubMed

Martínez-Payá, Jacinto J; Ríos-Díaz, José; Medina-Mirapeix, Francesc; Vázquez-Costa, Juan F; Del Baño-Aledo, María Elena

2018-01-01

The need is increasing for progression biomarkers that allow the loss of motor neurons in amyotrophic lateral sclerosis (ALS) to be monitored in clinical trials. In this prospective longitudinal study, muscle thickness, echointensity, echovariation and gray level co-occurrence matrix textural features are examined as possible progression ultrasound biomarkers in ALS patients during a 5-mo follow-up period. We subjected 13 patients to 3 measurements for 20 wk. They showed a significant loss of muscle, an evident tendency to loss of thickness and increased echointensity and echovariation. In regard to textural parameters, muscle heterogeneity tended to increase as a result of the neoformation of non-contractile tissue through denervation. Considering some limitations of the study, the quantitative muscle ultrasound biomarkers evaluated showed a promising ability to monitor patients affected by ALS. Copyright © 2018 World Federation for Ultrasound in Medicine and Biology. Published by Elsevier Inc. All rights reserved.

Guiding tissue regeneration with ultrasound in vitro and in vivo

NASA Astrophysics Data System (ADS)

Dalecki, Diane; Comeau, Eric S.; Raeman, Carol H.; Child, Sally Z.; Hobbs, Laura; Hocking, Denise C.

2015-05-01

Developing new technologies that enable the repair or replacement of injured or diseased tissues is a major focus of regenerative medicine. This paper will discuss three ultrasound technologies under development in our laboratories to guide tissue regeneration both in vitro and in vivo. A critical obstacle in tissue engineering is the need for rapid and effective tissue vascularization strategies. To address this challenge, we are developing acoustic patterning techniques for microvascular tissue engineering. Acoustic radiation forces associated with ultrasound standing wave fields provide a rapid, non-invasive approach to spatially pattern cells in three dimensions without affecting cell viability. Acoustic patterning of endothelial cells leads to the rapid formation of microvascular networks throughout the volumes of three-dimensional hydrogels, and the morphology of the resultant microvessel networks can be controlled by design of the ultrasound field. A second technology under development uses ultrasound to noninvasively control the microstructure of collagen fibers within engineered tissues. The microstructure of extracellular matrix proteins provides signals that direct cell functions critical to tissue regeneration. Thus, controlling collagen microfiber structure with ultrasound provides a noninvasive approach to regulate the mechanical properties of biomaterials and control cellular responses. The third technology employs therapeutic ultrasound to enhance the healing of chronic wounds. Recent studies demonstrate increased granulation tissue thickness and collagen deposition in murine dermal wounds exposed to pulsed ultrasound. In summary, ultrasound technologies offer noninvasive approaches to control cell behaviors and extracellular matrix organization and thus hold great promise to advance tissue regeneration in vitro and in vivo.

Assessment of articular disc displacement of temporomandibular joint with ultrasound.

PubMed

Razek, Ahmed Abdel Khalek Abdel; Al Mahdy Al Belasy, Fouad; Ahmed, Wael Mohamed Said; Haggag, Mai Ahmed

2015-06-01

To assess pattern of articular disc displacement in patients with internal derangement (ID) of temporomandibular joint (TMJ) with ultrasound. Prospective study was conducted upon 40 TMJ of 20 patients (3 male, 17 female with mean age of 26.1 years) with ID of TMJ. They underwent high-resolution ultrasound and MR imaging of TMJ. The MR images were used as the gold standard for calculating sensitivity, specificity, accuracy, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (PLR), and negative likelihood ratio (NLR) of ultrasound for diagnosis of anterior or sideway displacement of the disc. The anterior displaced disc was seen in 26 joints at MR and 22 joints at ultrasound. The diagnostic efficacy of ultrasound for anterior displacement has sensitivity of 79.3 %, specificity of 72.7 %, accuracy of 77.5 %, PPV of 88.5 %, NPV of 57.1 %, PLR of 2.9 and NLR of 0.34. The sideway displacement of disc was seen in four joints at MR and three joints at ultrasound. The diagnostic efficacy of ultrasound for sideway displacement has a sensitivity of 75 %, specificity of 63.6 %, accuracy of 66.7 %, PPV of 42.8, NPV of 87.5 %, PLR of 2.06, and NLR of 0.39. We concluded that ultrasound is a non-invasive imaging modality used for assessment of anterior and sideway displacement of the articular disc in patients with ID of TMJ.

Emergency ultrasound in the acute assessment of haemothorax

PubMed Central

Brooks, A; Davies, B; Smethhurst, M; Connolly, J

2004-01-01

Aims: To evaluate thoracic ultrasound for the detection of haemothorax in patients with thoracic trauma against established investigations. Methods: Thoracic ultrasound was performed as an extension of the standard focused assessment with sonography for trauma (FAST) protocol used at the Queen's Medical Centre for the assessment of adult patients with torso trauma. Fluid was sought in both pleural cavities using a hand portable ultrasound system by one of two non-radiologists trained in FAST. Findings were compared against subsequent investigations/procedures performed at the discretion of the attending emergency physician—supine chest radiography, intercostal drain, computed tomography, or thoracotomy. The sensitivity of the technique and the time taken to diagnosis for each investigation were recorded. Results: Sixty one patients, 54 (89%) after blunt trauma, underwent thoracic ultrasound evaluation during the study. Twelve patients had a haemothorax detected by ultrasound and confirmed by computed tomography or by tube thoracostomy. Four haemothoraces detected on ultrasound were not apparent on trauma chest radiography. There were 12 true positives, 48 true negatives, no false positives, and one false negative scan. The sensitivity of ultrasound was 92% and specificity 100% with a positive predictive value of 100% and negative predictive value 98% for the detection of haemothorax after trauma. Conclusions: Emergency ultrasound of the chest performed as part of the primary survey of the traumatised patient can rapidly and accurately diagnose haemothorax and is a valuable tool to augment the immediate clinical assessment of these patients. PMID:14734374

Clinical workflow for spinal curvature measurement with portable ultrasound

NASA Astrophysics Data System (ADS)

Tabanfar, Reza; Yan, Christina; Kempston, Michael; Borschneck, Daniel; Ungi, Tamas; Fichtinger, Gabor

2016-03-01

PURPOSE: Spinal curvature monitoring is essential in making treatment decisions in scoliosis. Monitoring entails radiographic examinations, however repeated ionizing radiation exposure has been shown to increase cancer risk. Ultrasound does not emit ionizing radiation and is safer for spinal curvature monitoring. We investigated a clinical sonography protocol and challenges associated with position-tracked ultrasound in spinal curvature measurement in scoliosis. METHODS: Transverse processes were landmarked along each vertebra using tracked ultrasound snapshots. The transverse process angle was used to determine the orientation of each vertebra. We tested our methodology on five patients in a local pediatric scoliosis clinic, comparing ultrasound to radiographic curvature measurements. RESULTS: Despite strong correlation between radiographic and ultrasound curvature angles in phantom studies, we encountered new challenges in the clinical setting. Our main challenge was differentiating transverse processes from ribs and other structures during landmarking. We observed up to 13° angle variability for a single vertebra and a 9.85° +/- 10.81° difference between ultrasound and radiographic Cobb angles for thoracic curvatures. Additionally, we were unable to visualize anatomical landmarks in the lumbar region where soft tissue depth was 25-35mm. In volunteers with large Cobb angles (greater than 40° thoracic and 60° lumbar), we observed spinal protrusions resulting in incomplete probe-skin contact and partial ultrasound images not suitable for landmarking. CONCLUSION: Spinal curvature measurement using tracked ultrasound is viable on phantom spine models. In the clinic, new challenges were encountered which must be resolved before a universal sonography protocol can be developed.

Dynamic adsorption properties of n-alkyl glucopyranosides determine their ability to inhibit cytolysis mediated by acoustic cavitation.

PubMed

Sostaric, Joe Z; Miyoshi, Norio; Cheng, Jason Y; Riesz, Peter

2008-10-09

Suspensions of human leukemia (HL-60) cells readily undergo cytolysis when exposed to ultrasound above the acoustic cavitation threshold. However, n-alkyl glucopyranosides (hexyl, heptyl, and octyl) completely inhibit ultrasound-induced (1057 kHz) cytolysis (Sostaric, et al. Free Radical Biol. Med. 2005, 39, 1539-1548). The efficacy of protection from ultrasound-induced cytolysis was determined by the n-alkyl chain length of the glucopyranosides, indicating that protection efficacy depended on adsorption of n-alkyl glucopyranosides to the gas/solution interface of cavitation bubbles and/or the lipid membrane of cells. The current study tests the hypothesis that "sonoprotection" (i.e., protection of cells from ultrasound-induced cytolysis) in vitro depends on the adsorption of glucopyranosides at the gas/solution interface of cavitation bubbles. To test this hypothesis, the effect of ultrasound frequency (from 42 kHz to 1 MHz) on the ability of a homologous series of n-alkyl glucopyranosides to protect cells from ultrasound-induced cytolysis was investigated. It is expected that ultrasound frequency will affect sonoprotection ability since the nature of the cavitation bubble field will change. This will affect the relative importance of the possible mechanisms for ultrasound-induced cytolysis. Additionally, ultrasound frequency will affect the lifetime and rate of change of the surface area of cavitation bubbles, hence the dynamically controlled adsorption of glucopyranosides to their surface. The data support the hypothesis that sonoprotection efficiency depends on the ability of glucopyranosides to adsorb at the gas/solution interface of cavitation bubbles.

Verification and compensation of respiratory motion using an ultrasound imaging system.

PubMed

Chuang, Ho-Chiao; Hsu, Hsiao-Yu; Chiu, Wei-Hung; Tien, Der-Chi; Wu, Ren-Hong; Hsu, Chung-Hsien

2015-03-01

The purpose of this study was to determine if it is feasible to use ultrasound imaging as an aid for moving the treatment couch during diagnosis and treatment procedures associated with radiation therapy, in order to offset organ displacement caused by respiratory motion. A noninvasive ultrasound system was used to replace the C-arm device during diagnosis and treatment with the aims of reducing the x-ray radiation dose on the human body while simultaneously being able to monitor organ displacements. This study used a proposed respiratory compensating system combined with an ultrasound imaging system to monitor the compensation effect of respiratory motion. The accuracy of the compensation effect was verified by fluoroscopy, which means that fluoroscopy could be replaced so as to reduce unnecessary radiation dose on patients. A respiratory simulation system was used to simulate the respiratory motion of the human abdomen and a strain gauge (respiratory signal acquisition device) was used to capture the simulated respiratory signals. The target displacements could be detected by an ultrasound probe and used as a reference for adjusting the gain value of the respiratory signal used by the respiratory compensating system. This ensured that the amplitude of the respiratory compensation signal was a faithful representation of the target displacement. The results show that performing respiratory compensation with the assistance of the ultrasound images reduced the compensation error of the respiratory compensating system to 0.81-2.92 mm, both for sine-wave input signals with amplitudes of 5, 10, and 15 mm, and human respiratory signals; this represented compensation of the respiratory motion by up to 92.48%. In addition, the respiratory signals of 10 patients were captured in clinical trials, while their diaphragm displacements were observed simultaneously using ultrasound. Using the respiratory compensating system to offset, the diaphragm displacement resulted in compensation rates of 60%-84.4%. This study has shown that a respiratory compensating system combined with noninvasive ultrasound can provide real-time compensation of the respiratory motion of patients.

A technique for evaluating the oil/heavy-oil viscosity changes under ultrasound in a simulated porous medium.

PubMed

Hamidi, Hossein; Mohammadian, Erfan; Junin, Radzuan; Rafati, Roozbeh; Manan, Mohammad; Azdarpour, Amin; Junid, Mundzir

2014-02-01

Theoretically, Ultrasound method is an economical and environmentally friendly or "green" technology, which has been of interest for more than six decades for the purpose of enhancement of oil/heavy-oil production. However, in spite of many studies, questions about the effective mechanisms causing increase in oil recovery still existed. In addition, the majority of the mechanisms mentioned in the previous studies are theoretical or speculative. One of the changes that could be recognized in the fluid properties is viscosity reduction due to radiation of ultrasound waves. In this study, a technique was developed to investigate directly the effect of ultrasonic waves (different frequencies of 25, 40, 68 kHz and powers of 100, 250, 500 W) on viscosity changes of three types of oil (Paraffin oil, Synthetic oil, and Kerosene) and a Brine sample. The viscosity calculations in the smooth capillary tube were based on the mathematical models developed from the Poiseuille's equation. The experiments were carried out for uncontrolled and controlled temperature conditions. It was observed that the viscosity of all the liquids was decreased under ultrasound in all the experiments. This reduction was more significant for uncontrolled temperature condition cases. However, the reduction in viscosity under ultrasound was higher for lighter liquids compare to heavier ones. Pressure difference was diminished by decreasing in the fluid viscosity in all the cases which increases fluid flow ability, which in turn aids to higher oil recovery in enhanced oil recovery (EOR) operations. Higher ultrasound power showed higher liquid viscosity reduction in all the cases. Higher ultrasound frequency revealed higher and lower viscosity reduction for uncontrolled and controlled temperature condition experiments, respectively. In other words, the reduction in viscosity was inversely proportional to increasing the frequency in temperature controlled experiments. It was concluded that cavitation, heat generation, and viscosity reduction are three of the promising mechanisms causing increase in oil recovery under ultrasound. Copyright © 2013 Elsevier B.V. All rights reserved.

Two sides of the same coin--an interview study of Swedish obstetricians' experiences using ultrasound in pregnancy management.

PubMed

Åhman, Annika; Persson, Margareta; Edvardsson, Kristina; Lalos, Ann; Graner, Sophie; Small, Rhonda; Mogren, Ingrid

2015-11-20

The extended use of ultrasound that is seen in maternity care in most Western countries has not only affected obstetric care but also impacted on the conception of the fetus in relation to the pregnant woman. This situation has also raised concerns regarding the pregnant woman's reproductive freedom. The purpose of this study was to explore Swedish obstetricians' experiences and views on the role of obstetric ultrasound particularly in relation to clinical management of complicated pregnancy, and in relation to situations where the interests of maternal and fetal health conflict. A qualitative study design was applied, and data were collected in 2013 through interviews with 11 obstetricians recruited from five different obstetric clinics in Sweden. Data were analysed using qualitative content analysis. The theme that emerged in the analysis 'Two sides of the same coin' depicts the view of obstetric ultrasound as a very important tool in obstetric care while it also was experienced as having given rise to new and challenging issues in the management of pregnancy. This theme was built on three categories: I. Ultrasound is essential and also demanding; II. A woman's health interest is prioritised in theory, but not always in practice; and III. Ultrasound is rewarding but may also cause unwarranted anxiety. The widespread use of ultrasound in obstetric care has entailed new challenges for clinicians due to enhanced possibilities to diagnose and treat fetal conditions, which in turn might conflict with the health interests of the pregnant woman. There is a need for further ethical discussions regarding the obstetrician's position in management of situations where maternal and fetal health interests conflict. The continuing advances in the potential of ultrasound to impact on pregnancy management will also increase the need for adequate and appropriate information and counselling. Together with other health care professionals, obstetricians therefore need to develop improved ways of enabling pregnant women and their partners to make informed decisions regarding pregnancy management.

Study of distributed fiber-optic laser-ultrasound generation based on ghost-mode of tilted fiber Bragg gratings

NASA Astrophysics Data System (ADS)

Tian, Jiajun; Zhang, Qi; Han, Ming

2013-05-01

Fiber-optic ultrasonic transducers are an important component of an active ultrasonic testing system for structural health monitoring. Fiber-optic transducers have several advantages such as small size, light weight, and immunity to electromagnetic interference that make them much more attractive than the current available piezoelectric transducers, especially as embedded and permanent transducers in active ultrasonic testing for structural health monitoring. In this paper, a distributed fiber-optic laser-ultrasound generation based on the ghost-mode of tilted fiber Bragg gratings is studied. The influences of the laser power and laser pulse duration on the laser-ultrasound generation are investigated. The results of this paper are helpful to understand the working principle of this laser-ultrasound method and improve the ultrasonic generation efficiency.

Consensus statement for use and technical requirements of thyroid ultrasound in endocrinology units.

PubMed

Martín-Hernández, Tomás; Díez Gómez, Juan José; Díaz-Soto, Gonzalo; Torres Cuadro, Alberto; Navarro González, Elena; Oleaga Alday, Amelia; Sambo Salas, Marcel; Reverter Calatayud, Jordi L; Argüelles Jiménez, Iñaki; Mancha Doblas, Isabel; Fernández García, Diego; Galofré, Juan Carlos

2017-03-01

Thyroid nodule detection has increased with widespread use of ultrasound, which is currently the main tool for detection, monitoring, diagnosis and, in some instances, treatment of thyroid nodules. Knowledge of ultrasound and adequate instruction on its use require a position statement by the scientific societies concerned. The working groups on thyroid cancer and ultrasound techniques of the Spanish Society of Endocrinology and Nutrition have promoted this document, based on a thorough analysis of the current literature, the results of multicenter studies and expert consensus, in order to set the requirements for the best use of ultrasound in clinical practice. The objectives include the adequate framework for use of thyroid ultrasound, the technical and legal requirements, the clinical situations in which it is recommended, the levels of knowledge and learning processes, the associated responsibility, and the establishment of a standardized reporting of results and integration into hospital information systems and endocrinology units. Copyright © 2017 SEEN. Publicado por Elsevier España, S.L.U. All rights reserved.

Sonodynamic therapy--a review of the synergistic effects of drugs and ultrasound.

PubMed

Rosenthal, Ionel; Sostaric, Joe Z; Riesz, Peter

2004-09-01

Sonodynamic therapy, the ultrasound dependent enhancement of cytotoxic activities of certain compounds (sonosensitizers) in studies with cells in vitro and in tumor bearing animals, is reviewed. The attractive features of this modality for cancer treatment emerges from the ability to focus the ultrasound energy on malignancy sites buried deep in tissues and to locally activate a preloaded sonosensitizer. Possible mechanisms of sonodynamic therapy include generation of sonosensitizer derived radicals which initiate chain peroxidation of membrane lipids via peroxyl and/or alkoxyl radicals, the physical destabilization of the cell membrane by the sonosensitizer thereby rendering the cell more susceptible to shear forces or ultrasound enhanced drug transport across the cell membrane (sonoporation). Evidence against the role of singlet oxygen in sonodynamic therapy is discussed. The mechanism of sonodynamic therapy is probably not governed by a universal mechanism, but may be influenced by multiple factors including the nature of the biological model, the sonosensitizer and the ultrasound parameters. The current review emphasizes the effect of ultrasound induced free radicals in sonodynamic therapy.

Proof of principle in vitro study of a prototype ultrasound technology to size stone fragments during ureteroscopy.

PubMed

Sorensen, Mathew D; Teichman, Joel M H; Bailey, Michael R

2009-07-01

Proof-of-principle in vitro experiments evaluated a prototype ultrasound technology to size kidney stone fragments. Nineteen human stones were measured using manual calipers. A 10-MHz, 1/8'' (10F) ultrasound transducer probe pinged each stone on a kidney tissue phantom submerged in water using two methods. In Method 1, the instrument was aligned such that the ultrasound pulse traveled through the stone. In Method 2, the instrument was aligned partially over the stone such that the ultrasound pulse traveled through water. For Method 1, the correlation between caliper- and ultrasound-determined stone size was r(2) = 0.71 (P < 0.0001). All but two stone measurements were accurate and precise to within 1 mm. For Method 2, the correlation was r(2) = 0.99 (P < 0.0001), and measurements were accurate and precise to within 0.25 mm. The prototype technology and either method measured stone size with good accuracy and precision. This technology may be possible to incorporate into ureteroscopy.

Numerical Study on Focusing of Ultrasounds in Microbubble-enhanced HIFU

NASA Astrophysics Data System (ADS)

Matsumoto, Yoichiro; Okita, Kohei; Takagi, Shu

2011-11-01

The injection of microbubbles into the target tissue enhances tissue heating in High-Intensity Focused Ultrasound therapy, via inertial cavitation. The control of the inertial cavitation is required to achieve the efficient tissue ablation. Microbubbles between a transducer and a target disturb the ultrasound propagation depending on the conditions. A method to clear such microbubbles has been proposed by Kajiyama et al. [Physics Procedia 3 (2010) 305-314]. In the method, the irradiation of intense ultrasounds with a burst waveform fragmentize microbubbles in the pathways before the irradiation of ultrasounds for tissue heating. The vitro experiment using a gel containing microbubbles has showed that the method enables to heat the target correctly by controlling the microbubble distribution. Following the experiment, we simulate the focusing of ultrasounds through a mixture containing microbubbles with considering the size and number density distributions in space. The numerical simulation shows that the movement of the heating region from the transducer side to the target by controlling the microbubble distributions. The numerical results elucidate well the experimental ones.

Point-of-care ultrasound in aerospace medicine: known and potential applications.

PubMed

Wagner, Michael S; Garcia, Kathleen; Martin, David S

2014-07-01

Since its initial introduction into the bedside assessment of the trauma patient via the Focused Assessment with Sonography for Trauma (FAST) exam, the use of point-of-care ultrasound has expanded rapidly. A growing body of literature demonstrates ultrasound can be used by nonradiologists as an extension of the physical exam to accurately diagnose or exclude a variety of conditions. These conditions include, but are not limited to, hemoperitoneum, pneumothorax, pulmonary edema, long-bone fracture, deep vein thrombosis, and elevated intracranial pressure. As ultrasound machines have become more compact and portable, their use has extended outside of hospitals to places where the physical exam and diagnostic capabilities may be limited, including the aviation environment. A number of studies using focused sonography have been performed to meet the diagnostic challenges of space medicine. The following article reviews the available literature on portable ultrasound use in aerospace medicine and highlights both known and potential applications of point-of-care ultrasound for the aeromedical clinician.

Cranial Ultrasound Lesions in the NICU Predict Cerebral Palsy at Age 2 Years in Children Born at Extremely Low Gestational Age

PubMed Central

Kuban, Karl C. K.; Allred, Elizabeth N.; O’Shea, T. Michael; Paneth, Nigel; Pagano, Marcello; Dammann, Olaf; Leviton, Alan; Du Plessis, Adré; Westra, Sjirk J.; Miller, Cindy R.; Bassan, Haim; Krishnamoorthy, Kalpathy; Junewick, Joseph; Olomu, Nicholas; Romano, Elaine; Seibert, Joanna; Engelke, Steve; Karna, Padmani; Batton, Daniel; O’Connor, Sunila E.; Keller, Cecelia E.

2009-01-01

Our prospective cohort study of extremely low gestational age newborns evaluated the association of neonatal head ultrasound abnormalities with cerebral palsy at age 2 years. Cranial ultrasounds in 1053 infants were read with respect to intraventricular hemorrhage, ventriculomegaly, and echolucency, by multiple sonologists. Standardized neurological examinations classified cerebral palsy, and functional impairment was assessed. Forty-four percent with ventriculomegaly and 52% with echolucency developed cerebral palsy. Compared with no ultrasound abnormalities, children with echolucency were 24 times more likely to have quadriparesis and 29 times more likely to have hemiparesis. Children with ventriculomegaly were 17 times more likely to have quadriparesis or hemiparesis. Forty-three percent of children with cerebral palsy had normal head ultrasound. Focal white matter damage (echolucency) and diffuse damage (late ventriculomegaly) are associated with a high probability of cerebral palsy, especially quadriparesis. Nearly half the cerebral palsy identified at 2 years is not preceded by a neonatal brain ultrasound abnormality. PMID:19168819

Mechanotransduction of Ultrasound is Frequency Dependent Below the Cavitation Threshold

PubMed Central

Louw, Tobias M.; Budhiraja, Gaurav; Viljoen, Hendrik J.; Subramanian, Anuradha

2013-01-01

This study provides evidence that low-intensity ultrasound directly affects nuclear processes, and the magnitude of the effect varies with frequency. In particular, we show that the transcriptional induction of first load-inducible genes, which is independent of new protein synthesis, is frequency dependent. Bovine chondrocytes were exposed to low-intensity below the cavitational threshold) ultrasound at 2,5 and 8 MHz. Ultrasound elevated the expression of early response genes c-Fos, c-Jun and c-Myc, maximized at 5 MHz. The phosphorylated ERK inhibitor PD98059 abrogated any increase in c-series gene expression, suggesting that signaling occurs via the MAPPK/ERK pathway. However, phosphorylated ERK levels did not change with ultrasound frequency, indicating that processes downstream of ERK phosphorylation (such as nuclear transport and chromatin reorganization) respond to ultrasound with frequency dependence. A quantitative, biphasic mathematical model based on Biot theory predicted that cytoplasmic and nuclear stress is maximized at 5.2 ± 0.8 MHz for a chondrocyte, confirming experimental measurements. PMID:23562015

Pharmacokinetics of quercetin-loaded nanodroplets with ultrasound activation and their use for bioimaging

PubMed Central

Chang, Li-Wen; Hou, Mei-Ling; Hung, Shuo-Hui; Lin, Lie-Chwen; Tsai, Tung-Hu

2015-01-01

Bubble formulations have both diagnostic and therapeutic applications. However, research on nanobubbles/nanodroplets remains in the initial stages. In this study, a nanodroplet formulation was prepared and loaded with a novel class of chemotherapeutic drug, ie, quercetin, to observe its pharmacokinetic properties and ultrasonic bioimaging of specific sites, namely the abdominal vein and bladder. Four parallel groups were designed to investigate the effects of ultrasound and nanodroplets on the pharmacokinetics of quercetin. These groups were quercetin alone, quercetin triggered with ultrasound, quercetin-encapsulated in nanodroplets, and quercetin encapsulated in nanodroplets triggered with ultrasound. Spherical vesicles with a mean diameter of 280 nm were formed, and quercetin was completely encapsulated within. In vivo ultrasonic imaging confirmed that the nanodroplets could be treated by ultrasound. The results indicate that the initial 5-minute serum concentration, area under the concentration–time curve, elimination half-life, and clearance of quercetin were significantly enhanced by nanodroplets with or without ultrasound. PMID:25945049

Biophysical characterization of low-frequency ultrasound interaction with dental pulp stem cells

PubMed Central

2013-01-01

Background Low-intensity ultrasound is considered an effective non-invasive therapy to stimulate hard tissue repair, in particular to accelerate delayed non-union bone fracture healing. More recently, ultrasound has been proposed as a therapeutic tool to repair and regenerate dental tissues. Our recent work suggested that low-frequency kilohertz-range ultrasound is able to interact with dental pulp cells which could have potential to stimulate dentine reparative processes and hence promote the viability and longevity of teeth. Methods In this study, the biophysical characteristics of low-frequency ultrasound transmission through teeth towards the dental pulp were explored. We conducted cell culture studies using an odontoblast-like/dental pulp cell line, MDPC-23. Half of the samples underwent ultrasound exposure while the other half underwent ‘sham treatment’ where the transducer was submerged into the medium but no ultrasound was generated. Ultrasound was applied directly to the cell cultures using a therapeutic ultrasound device at a frequency of 45 kHz with intensity settings of 10, 25 and 75 mW/cm2 for 5 min. Following ultrasound treatment, the odontoblast-like cells were detached from the culture using a 0.25% Trypsin/EDTA solution, and viable cell numbers were counted. Two-dimensional tooth models based on μ-CT 2D images of the teeth were analyzed using COMSOL as the finite element analysis platform. This was used to confirm experimental results and to demonstrate the potential theory that with the correct combination of frequency and intensity, a tooth can be repaired using small doses of ultrasound. Frequencies in the 30 kHz–1 MHz range were analyzed. For each frequency, pressure/intensity plots provided information on how the intensity changes at each point throughout the propagation path. Spatial peak temporal average (SPTA) intensity was calculated and related to existing optimal spatial average temporal average (SATA) intensity deemed effective for cell proliferation during tooth repair. Results The results demonstrate that odontoblast MDPC-23 cell numbers were significantly increased following three consecutive ultrasound treatments over a 7-day culture period as compared with sham controls underscoring the anabolic effects of ultrasound on these cells. Data show a distinct increase in cell number compared to the sham data after ultrasound treatment for intensities of 10 and 25 mW/cm2 (p < 0.05 and p < 0.01, respectively). Using finite element analysis, we demonstrated that ultrasound does indeed propagate through the mineralized layers of the teeth and into the pulp chamber where it forms a ‘therapeutic’ force field to interact with the living dental pulp cells. This allowed us to observe the pressure/intensity of the wave as it propagates throughout the tooth. A selection of time-dependent snapshots of the pressure/intensity reveal that the lower frequency waves propagate to the pulp and remain within the chamber for a while, which is ideal for cell excitation. Input frequencies and pressures of 30 kHz (70 Pa) and 45 kHz (31 kPa), respectively, with an average SPTA of up to 120 mW/cm2 in the pulp seem to be optimal and agree with the SATA intensities reported experimentally. Conclusions Our data suggest that ultrasound can be harnessed to propagate to the dental pulp region where it can interact with the living cells to promote dentine repair. Further research is required to analyze the precise physical and biological interactions of low-frequency ultrasound with the dental pulp to develop a novel non-invasive tool for dental tissue regeneration. PMID:25516801

Manual B-mode versus automated radio-frequency carotid intima-media thickness measurements.

PubMed

Dogan, Soner; Plantinga, Yvonne; Dijk, Joke M; van der Graaf, Yolanda; Grobbee, Diederick E; Bots, Michiel L

2009-10-01

Carotid intima-media thickness (CIMT) serves as an indicator of atherosclerosis and cardiovascular risk. Manual measurements of B-mode ultrasound images are the most applied method. Automated measurements with radiofrequency (RF) ultrasound have been suggested as an alternative. The aim of this study was to compare these methods in terms of risk-factor relations and associations with future events. Data from participants of the Second Manifestations of Arterial Disease (SMART) study were used. Far wall common CIMT was measured online with manual B-mode and automated RF ultrasound. Measurements were performed by a group of 6 sonographers. Risk-factor information was obtained. All participants were followed for the occurrence of vascular events (mean follow-up, 2.1 years). CIMT was related to risk factors with linear regression models and to future events with Cox proportional-hazards models. Data were available for 2,146 participants. Agreement between the methods was modest (intraclass correlation coefficient = 0.34). Risk-factor relations with age and systolic blood pressure were stronger for B-mode than for RF ultrasound. Association with future events was better for B-mode than for RF ultrasound (vascular death, 1.27 vs 1.00; ischemic stroke, 1.45 vs 1.03). In participants with CIMT < 0.9 mm (without plaque), the intraclass correlation between the measures was 0.50. In addition, in that subgroup, RF ultrasound showed a stronger association with future events than B-mode ultrasound (all events, 1.59 vs 1.09; vascular death, 1.72 vs 0.93; coronary ischemic events, 1.65 vs 1.05). The preference for either B-mode or RF measurements may be driven by the type of study population, the expected presence of local atherosclerotic abnormalities, and the main aim of the study (assessing risk factors or events). However, in this study, as in many others, the B-mode approach was shown to be robust in risk-factor relations and the prediction of events.

Image Gallery

MedlinePlus

... Ultrasound Pediatric Ultrasound Point-of-Care Ultrasound Sonography Therapeutic Ultrasound Ultrasound in Global Health Ultrasound in Medical Education CME Center CME Tracker Annual Convention Journal Tests ...

Duplex ultrasound

MedlinePlus

Vascular ultrasound; Peripheral vascular ultrasound ... A duplex ultrasound combines: Traditional ultrasound: This uses sound waves that bounce off blood vessels to create pictures. Doppler ultrasound: This ...

Critical care ultrasound training: a survey of US fellowship directors.

PubMed

Mosier, Jarrod M; Malo, Josh; Stolz, Lori A; Bloom, John W; Reyes, Nathaniel A; Snyder, Linda S; Adhikari, Srikar

2014-08-01

The purpose of this study is to describe the current state of bedside ultrasound use and training among critical care (CC) training programs in the United States. This was a cross-sectional survey of all program directors for Accreditation Council for Graduate Medical Education accredited programs during the 2012 to 2013 academic year in CC medicine, surgical CC, pulmonary and critical care, and anesthesia CC. Availability, current use, and barriers to training in CC ultrasound were assessed. Sixty of 195 (31%; 95% confidence interval [CI], 24%-38%) program directors responded. Most of the responding programs had an ultrasound system available for use (54/60, 90%; 95% CI, 79%-96%) and identified ultrasound training as useful (59/60, 98%; 95% CI, 91%-100%) but lacked a formal curriculum (25/60, 42%; 95% CI, 29%-55%) or trained faculty (mean percentage of faculty trained in ultrasound: pulmonary and critical care, 25%; surgical CC, 33%; anesthesia CC, 20%; CC medicine, 7%), and relied on informal teaching (45/60, 77%; 95% CI, 62%-85%). Faculty with expertise (53/60, 88%; 95% CI, 77%-95%), simulation training (60/60, 100%; 95% CI, 94%-100%), establishing and meeting required number of examinations (47/60, 78%; 95% CI, 66%-88%), and regular review sessions (49/60, 82%; 95% CI, 70%-90%) were identified as necessary to improve ultrasound training. Most responding programs (32/35 91%; 95% CI, 77%-98%) without a formal curriculum plan to create one in the next 5 years. This study identified deficiencies in current training, suggesting a need for a formal curriculum for bedside ultrasound training in CC fellowship programs. Copyright © 2014 Elsevier Inc. All rights reserved.

Ultrasound Elasticity Imaging System with Chirp-Coded Excitation for Assessing Biomechanical Properties of Elasticity Phantom

PubMed Central

Chun, Guan-Chun; Chiang, Hsing-Jung; Lin, Kuan-Hung; Li, Chien-Ming; Chen, Pei-Jarn; Chen, Tainsong

2015-01-01

The biomechanical properties of soft tissues vary with pathological phenomenon. Ultrasound elasticity imaging is a noninvasive method used to analyze the local biomechanical properties of soft tissues in clinical diagnosis. However, the echo signal-to-noise ratio (eSNR) is diminished because of the attenuation of ultrasonic energy by soft tissues. Therefore, to improve the quality of elastography, the eSNR and depth of ultrasound penetration must be increased using chirp-coded excitation. Moreover, the low axial resolution of ultrasound images generated by a chirp-coded pulse must be increased using an appropriate compression filter. The main aim of this study is to develop an ultrasound elasticity imaging system with chirp-coded excitation using a Tukey window for assessing the biomechanical properties of soft tissues. In this study, we propose an ultrasound elasticity imaging system equipped with a 7.5-MHz single-element transducer and polymethylpentene compression plate to measure strains in soft tissues. Soft tissue strains were analyzed using cross correlation (CC) and absolution difference (AD) algorithms. The optimal parameters of CC and AD algorithms used for the ultrasound elasticity imaging system with chirp-coded excitation were determined by measuring the elastographic signal-to-noise ratio (SNRe) of a homogeneous phantom. Moreover, chirp-coded excitation and short pulse excitation were used to measure the elasticity properties of the phantom. The elastographic qualities of the tissue-mimicking phantom were assessed in terms of Young’s modulus and elastographic contrast-to-noise ratio (CNRe). The results show that the developed ultrasound elasticity imaging system with chirp-coded excitation modulated by a Tukey window can acquire accurate, high-quality elastography images. PMID:28793718

Sound waves and antineoplastic drugs: The possibility of an enhanced combined anticancer therapy.

PubMed

Feril, Loreto B; Kondo, Takashi; Umemura, Shin-Ichiro; Tachibana, Katsuro; Manalo, Angelo H; Riesz, Peter

2002-12-01

Kremkau wrote a historical review of the use of ultrasound in cancer therapy in 1979((1)) In 1990, Kondo and Kano published a Japanese review of the implications of the thermal and nonthermal effects of ultrasound in the treatment of cancer(2)). Again in 2000, Kondo et al reviewed the therapeutic applications of ultrasound and shock wave, emphasizing their thermal and cavitational effects(3)). Here we focus on the effects of ultrasound or shock waves in combination with anticancer agents, emphasizing their mechanisms of action and interaction. Most of the studies cited here reported promising results. Although the extent of the augmented combined effects in vivo is limited, synergism is the rule in vitro. In addition to the thermal effect of ultrasound, cavitational effects undoubtedly played a major role in both ultrasound and, more prominently, in shock wave therapy. Although the mechanism of the nonthermal noncavitational effects on biological processes is obscure, several factors, including temperature and the occurrence of cavitation and inertial cavitation, probably coexist and blend with these other effects. Magnification of anticancer activity results mainly from increased localization of drugs or other agents in vivo and increased intracellular permeabilisation both in vivo and in vitro. On the other hand, sublethal damage caused by ultrasound or shock waves may render cells more susceptible, to the effects of the agents, and both may act together, further amplifying these effects. We thus conclude that proper combination of an appropriate agent and ultrasound or shock wave should help improve cancer therapy by minimizing the side effects of drugs by lowering the effective dose and reducing the systemic concentration while increasing the efficiency of the therapy as a whole. Future studies should reveal specific conditions in this combined therapy that will lead to optimal outcome.

[Contrastive study on conventional ultrasound, compression elastography and acoustic radiation force impulse imaging in the differential diagnosis of benign and malignant breast tumors].

PubMed

Zhang, Lu; Zhou, Ping; Deng, Jin; Tian, Shuangming; Qian, Ying; Wu, Xiaomin; Ma, Shuhua; Li, Jiale

2014-12-01

To evaluate the diagnostic performance of conventional ultrasound, compression elastography (CE) and acoustic radiation force impulse imaging (ARFI) in differential diagnosis of benign and malignant breast tumors. A total of 98 patients with liver lesions were included in the study. The images of conventional ultrasound, CE and the values of virtual touch tissue quantification (VTQ) of breast lesions were obtained. The diagnostic performance of conventional ultrasound, CE and ARFI were assessed by using pathology as the gold standard, and then evaluate the diagnosis efficiency of these three approaches in differential diagnosing benign and malignant breast tumors. The specificity, sensitivity and accuracy in the diagnosis of malignant breast tumors for conventional ultrasound were 80.0%, 81.1% and 81.7%, respectively, whereas for CE elastic score were 85.7%, 86.7% and 86.3%, respectively. With a cutoff value of 3.71 for the SR, the sensitivity, specificity, accuracy in diagnosis of malignant breast tumors were 97.1%, 83.3% and 88.4%, respectively. With a cutoff value of 3.78 m/s for VTQ, the sensitivity, specificity, accuracy in diagnosis of malignant breast tumors were 94.3%, 91.7% and 92.6%, respectively. The difference in diagnosis efficiency among ARFI, CE and conventional ultrasound in differential diagnosis of benign and malignant breast tumors was significant (P< 0.05). Conventional ultrasound, CE and ARFI are all useful for the differential diagnosis of benign and malignant breast tumors. But the diagnosis efficiency of ARFI is superior to CE and conventional ultrasound. The three approaches can help each other in differential diagnosis of benign and malignant breast tumors.

Ultrasound is a reproducible and valid tool for measuring scar height in children with burn scars: A cross-sectional study of the psychometric properties and utility of the ultrasound and 3D camera.

PubMed

Simons, M; Kee, E Gee; Kimble, R; Tyack, Z

2017-08-01

The aim of this study was to investigate the reproducibility and validity of measuring scar height in children using ultrasound and 3D camera. Using a cross-sectional design, children with discrete burn scars were included. Reproducibility was tested using Intraclass Correlation Coefficient (ICC) for reliability, and percentage agreement within 1mm between test and re-test, standard error of measurement (SEM), smallest detectable change (SDC) and Bland Altman limits of agreement for agreement. Concurrent validity was tested using Spearman's rho for support of pre-specified hypotheses. Forty-nine participants (55 scars) were included. For ultrasound, test-retest and inter-rater reproducibility of scar thickness was acceptable for scarred skin (ICC=0.95, SDC=0.06cm and ICC=0.82, SDC=0.14cm). The ultrasound picked up changes of <1mm. Inter-rater reproducibility of maximal scar height using the 3D camera was acceptable (ICC=0.73, SDC=0.55cm). Construct validity of the ultrasound was supported with a strong correlation between the measure of scar thickness and observer ratings of thickness using the POSAS (ρ=0.61). Construct validity of the 3D camera was also supported with a moderate correlation (ρ=0.37) with the same measure using maximal scar height. The ultrasound is capable of detecting smaller changes or differences in scar thickness than the 3D camera, in children with burn scars. However agreement as part of reproducibility was lower than expected between raters for the ultrasound. Improving the accuracy of scar relocation may go some way to address agreement. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Point-of-care ultrasound versus auscultation in determining the position of double-lumen tube

PubMed Central

Hu, Wei-Cai; Xu, Lei; Zhang, Quan; Wei, Li; Zhang, Wei

2018-01-01

Abstract This study was designed to assess the accuracy of point-of-care ultrasound in determining the position of double-lumen tubes (DLTs). A total of 103 patients who required DLT intubation were enrolled into the study. After DLTs were tracheal intubated in the supine position, an auscultation researcher and ultrasound researcher were sequentially invited in the operating room to conduct their evaluation of the DLT. After the end of their evaluation, fiberscope researchers (FRs) were invited in the operating room to evaluate the position of DLT using a fiberscope. After the patients were changed to the lateral position, the same evaluation process was repeated. These 3 researchers were blind to each other when they made their conclusions. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were obtained by statistical analysis. When left DLTs (LDLTs) were used, the accuracy of ultrasound (84.2% [72.1%, 92.5%]) was higher than the accuracy of auscultation (59.7% [45.8%, 72.4%]) (P < .01). When right DLTs (RDLTs) were used, the accuracy of ultrasound (89.1% [76.4%, 96.4%]) was higher than the accuracy of auscultation (67.4% [52.0%, 80.5%]) (P < .01). When LDLTs were used in the lateral position, the accuracy of ultrasound (75.4% [62.2%, 85.9%]) was higher than the accuracy of auscultation (54.4% [40.7%, 67.6%]) (P < .05). When RDLT were used, the accuracy of ultrasound (73.9% [58.9%, 85.7%]) was higher than the accuracy of auscultation (47.8% [32.9%, 63.1%]) (P < .05). Assessment via point-of-care ultrasound is superior to auscultation in determining the position of DLTs. PMID:29595696

Point-of-care ultrasound versus auscultation in determining the position of double-lumen tube.

PubMed

Hu, Wei-Cai; Xu, Lei; Zhang, Quan; Wei, Li; Zhang, Wei

2018-03-01

This study was designed to assess the accuracy of point-of-care ultrasound in determining the position of double-lumen tubes (DLTs).A total of 103 patients who required DLT intubation were enrolled into the study. After DLTs were tracheal intubated in the supine position, an auscultation researcher and ultrasound researcher were sequentially invited in the operating room to conduct their evaluation of the DLT. After the end of their evaluation, fiberscope researchers (FRs) were invited in the operating room to evaluate the position of DLT using a fiberscope. After the patients were changed to the lateral position, the same evaluation process was repeated. These 3 researchers were blind to each other when they made their conclusions. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were obtained by statistical analysis.When left DLTs (LDLTs) were used, the accuracy of ultrasound (84.2% [72.1%, 92.5%]) was higher than the accuracy of auscultation (59.7% [45.8%, 72.4%]) (P < .01). When right DLTs (RDLTs) were used, the accuracy of ultrasound (89.1% [76.4%, 96.4%]) was higher than the accuracy of auscultation (67.4% [52.0%, 80.5%]) (P < .01). When LDLTs were used in the lateral position, the accuracy of ultrasound (75.4% [62.2%, 85.9%]) was higher than the accuracy of auscultation (54.4% [40.7%, 67.6%]) (P < .05). When RDLT were used, the accuracy of ultrasound (73.9% [58.9%, 85.7%]) was higher than the accuracy of auscultation (47.8% [32.9%, 63.1%]) (P < .05).Assessment via point-of-care ultrasound is superior to auscultation in determining the position of DLTs.

Discrepancy in term calculation from second trimester ultrasound scan versus last menstrual period in women with type 1 diabetes.

PubMed

Eidem, Ingvild; Vangen, Siri; Henriksen, Tore; Vollset, Stein E; Hanssen, Kristian F; Joner, Geir; Stene, Lars C

2014-08-01

To study differences in ultrasound-based compared to menstrual-based term estimation in women with type 1 diabetes. Nationwide register study. Norway. Deliveries in Norway 1999-2004 by women registered in the Norwegian Childhood Diabetes Registry (n = 342) and the background population (n = 307 248), with data on both ultrasound-based and menstrual-based gestational age notified in the Birth Registry of Norway. Births with major malformations were excluded. Linkage of two nationwide registries, the Medical Birth Registry of Norway and the Norwegian Childhood Diabetes Registry. Estimated gestational age at delivery based on routine second trimester ultrasound measurements and last menstrual period. In women with type 1 diabetes, the distribution of gestational age at delivery was shifted considerably towards a lower gestational age when using second trimester ultrasound data for estimation, compared with last menstrual period data. The difference between the two estimation methods was larger among women with type 1 diabetes, although also evident in the general population. One in four women with diabetes and a certain last menstrual period date had their ultrasound-calculated term postponed 1 week or more, while one in 10 had it postponed 2 weeks or more. Corresponding numbers in the background population were one in five and one in 20. We found a systematic postponement of ultrasound-based compared with menstrual-based term estimation in women with type 1 diabetes. Relying solely on routine ultrasound-based term calculation for delivery decision may imply a risk of going beyond an optimal pregnancy length. © 2014 Nordic Federation of Societies of Obstetrics and Gynecology.

In vitro comparative study of vibro-acoustography versus pulse-echo ultrasound in imaging permanent prostate brachytherapy seeds

PubMed Central

Mitri, F.G.; Davis, B.J.; Greenleaf, J.F.; Fatemi, M.

2010-01-01

Background Permanent prostate brachytherapy (PPB) is a common treatment for early stage prostate cancer. While the modern approach using trans-rectal ultrasound guidance has demonstrated excellent outcome, the efficacy of PPB depends on achieving complete radiation dose coverage of the prostate by obtaining a proper radiation source (seed) distribution. Currently, brachytherapy seed placement is guided by trans-rectal ultrasound imaging and fluoroscopy. A significant percentage of seeds are not detected by trans-rectal ultrasound because certain seed orientations are invisible making accurate intra-operative feedback of radiation dosimetry very difficult, if not impossible. Therefore, intra-operative correction of suboptimal seed distributions cannot easily be done with current methods. Vibro-acoustography (VA) is an imaging modality that is capable of imaging solids at any orientation, and the resulting images are speckle free. Objective and methods The purpose of this study is to compare the capabilities of VA and pulse-echo ultrasound in imaging PPB seeds at various angles and show the sensitivity of detection to seed orientation. In the VA experiment, two intersecting ultrasound beams driven at f1 = 3.00 MHz and f2 = 3.020 MHz respectively were focused on the seeds attached to a latex membrane while the amplitude of the acoustic emission produced at the difference frequency 20 kHz was detected by a low frequency hydrophone. Results Finite element simulations and results of experiments conducted under well-controlled conditions in a water tank on a series of seeds indicate that the seeds can be detected at any orientation with VA, whereas pulse-echo ultrasound is very sensitive to the seed orientation. Conclusion It is concluded that vibro-acoustography is superior to pulse-echo ultrasound for detection of PPB seeds. PMID:18538365

What is ultrasound?

PubMed

Leighton, Timothy G

2007-01-01

This paper is based on material presented at the start of a Health Protection Agency meeting on ultrasound and infrasound. In answering the question 'what is ultrasound?', it shows that the simple description of a wave which transports mechanical energy through the local vibration of particles at frequencies of 20 kHz or more, with no net transport of the particles themselves, can in every respect be misleading or even incorrect. To explain the complexities responsible for this, the description of ultrasound is first built up from the fundamental properties of these local particle vibrations. This progresses through an exposition of the characteristics of linear waves, in order to explain the propensity for, and properties of, the nonlinear propagation which occurs in many practical ultrasonic fields. Given the Health Protection environment which framed the original presentation, explanation and examples are given of how these complexities affect issues of practical importance. These issues include the measurement and description of fields and exposures, and the ability of ultrasound to affect tissue (through microstreaming, streaming, cavitation, heating, etc.). It is noted that there are two very distinct regimes, in terms of wave characteristics and potential for bioeffect. The first concerns the use of ultrasound in liquids/solids, for measurement or material processing. For biomedical applications (where these two processes are termed diagnosis and therapy, respectively), the issue of hazard has been studied in depth, although this has not been done to such a degree for industrial uses of ultrasound in liquids/solids (sonar, non-destructive testing, ultrasonic processing etc.). However, in the second regime, that of the use of ultrasound in air, although the waves in question tend to be of much lower intensities than those used in liquids/solids, there is a greater mismatch between the extent to which hazard has been studied, and the growth in commercial applications for airborne ultrasound.

Ultrasound elastomicroscopy for articular cartilage: from static to transient and 1D to 2D

NASA Astrophysics Data System (ADS)

Zheng, Yongping; Bridal, Sharon L.; Shi, Jun; Saied, Amena; Lu, Minghua; Jaffre, Britta; Mak, Arthur F. T.; Laugier, Pascal; Qin, Ling

2003-05-01

Articular cartilage (AC) is a biological weight-bearing tissue covering the ends of articulating bones within synovial joints. Its function very much depends on the unique multi-layered structure and the depth-dependent material properties, which have not been well invetigated nondestructively. In this study, transient depth-dependent material properties of bovine patella cartilage were measured using ultrasound elastomicroscopy methods. A 50 MHz focused ultrasound transducer was used to collect A-mode ultrasound echoes from the articular cartilage during the compression and subsequent force-relaxation. The transient displacements of the cartilage tissues at different depths were calculated from the ultrasound echoes using a cross-correlation technique. It was observed that the strains in the superficial zone were much larger than those in the middle and deep zones as the equilibrium state was approached. The tissues inside the AC layer continued to move during the force-relaxation phase after the compression was completed. This process has been predicted by a biphasic theory. In this study, it has been verified experimentally. It was also observed that the tissue deformations at different depths of AC were much more evenly distributed before force-relaxation. AC specimens were also investigated using a 2D ultrasound elastomicroscopy system that included a 3D translating system for moving the ultrasound transducer over the specimens. B-mode RF ultrasound signals were collected from the specimens under different loading levels applied with a specially designed compressor. Preliminary results demonstrated that the scanning was repeatable with high correlation of radio frequency signals obtained from the same site during different scans when compression level was unchanged (R2 > 0.97). Strains of the AC specimens were mapped using data collected with this ultrasound elastomicroscope. This system can also be potentially used for the assessment of other biological tissues, bioengineered tissues or biomaterials with fine structures.

Ultrasound confirmation of central venous catheter position via a right supraclavicular fossa view using a microconvex probe: an observational pilot study.

PubMed

Kim, Se-Chan; Heinze, Ingo; Schmiedel, Alexandra; Baumgarten, Georg; Knuefermann, Pascal; Hoeft, Andreas; Weber, Stefan

2015-01-01

Visualisation of a central venous catheter (CVC) with ultrasound is restricted to the internal jugular vein (IJV). CVC tip position is confirmed by chest radiography, intracardiac ECG or transoesophageal/transthoracic echocardiography (TEE/TTE). We explored the feasibility, safety and accuracy of a right supraclavicular view for visualisation of the lower superior vena cava (SVC) and the right pulmonary artery (RPA) as an ultrasound landmark for real-time ultrasound-guided CVC tip positioning via the right IJV. Ultrasound was then compared with chest radiography. An observational pilot study. Bonn, University Hospital, Germany. From July to October 2012. Fifty-one patients scheduled for elective surgery. Reasons for exclusion were emergency procedure, thrombosis or small IJV lumen and mechanical obstacle to guidewire advancement. In 48 patients, CVC insertion via the right IJV and progress of the guidewire into the lower SVC were continuously guided by an ultrasound transducer in the right supraclavicular fossa. CVC tip position in lower SVC and tip-to-carina distance were assessed with chest radiography as a reference method and additionally with TEE in cardiothoracic patients. Insertion depth was compared with intracardiac ECG and body-height formula. The guidewire tip was seen in the SVC of all patients. In four patients, the tip was not visible in proximity of the RPA. Chest radiography and TEE confirmed CVC tip position in the lower SVC (zone A). Bland-Altman analysis revealed an average of difference of 1.6 cm for ultrasound versus ECG (95% limit of agreement -2 to 5 cm) and an average of difference of 1 cm for ultrasound versus body-height formula (95% limit of agreement -2 to 4 cm). Ultrasound via a right supraclavicular view is a feasible, well tolerated and accurate approach and should be further explored. Chest radiography confirmed CVC position in the lower SVC.

An uncovered risk factor of sonothrombolysis: Substantial fluctuation of ultrasound transmittance through the human skull.

PubMed

Wang, Zuojun; Komatsu, Teppei; Mitsumura, Hidetaka; Nakata, Norio; Ogawa, Takeki; Iguchi, Yasuyuki; Yokoyama, Masayuki

2017-05-01

Sonothrombolysis is one of the most feasible methods for enhancing clot lysis with a recombinant tissue plasminogen activator (rt-PA) in cases of acute ischemic strokes. For safe and efficient clinical practices of sonothrombolysis, accurate estimation of ultrasound transmittance through the human skull is critical. Previously, we reported substantial and periodic fluctuation of ultrasound transmittance through a bone-phantom plate following changes to ultrasound frequency, the thickness of the bone-phantom plate, and the distance between a transducer and the bone-phantom plate. In the present study, we clarify the transmittance behavior of medium-frequency ultrasound (from 400kHz to 600kHz) through the human skull, and examine reduction of the transmittance fluctuation. For the study, we measured transmittance of sinusoidal ultrasound waves at 400kHz, 500kHz, and 600kHz at 13 temple spots on 3 human skulls by changing the distance between a transducer and the skull bone, and found substantial and periodic fluctuation in the transmittance behaviors for these sinusoidal voltage excitations. Degrees of the fluctuation varied depending on the measurement spots. A fluctuation ratio between the maximum transmittance and the minimum transmittance reached 3 in some spots. This large transmittance fluctuation is considered to be a risk factor for sonothrombolysis therapies. We examined a modulated ultrasound wave to reduce the fluctuation, and succeeded in obtaining considerable reduction. The average fluctuation ratios for 400-kHz, 500-kHz, and 600-kHz waves were 2.38, 2.38, and 2.07, respectively. We successfully reduced the ratio to 1.72 by using a periodic selection of random frequency (PSRF)-type of modulation wave. The thus obtained results indicate that attention to the fluctuation in ultrasound transmittance through the skull is necessary for safe and effective sonothrombolysis therapies, and that modulated ultrasound waves constitute a powerful method for reducing the risk of fluctuation. Copyright © 2017 Elsevier B.V. All rights reserved.

SU-E-J-114: Towards Integrated CT and Ultrasound Guided Radiation Therapy Using A Robotic Arm with Virtual Springs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ding, K; Zhang, Y; Sen, H

Purpose: Currently there is an urgent need in Radiation Therapy for noninvasive and nonionizing soft tissue target guidance such as localization before treatment and continuous monitoring during treatment. Ultrasound is a portable, low cost option that can be easily integrated with the LINAC room. We are developing a cooperatively controlled robot arm that has high intrafraction reproducibility with repositioning of the ultrasound probe. In this study, we introduce virtual springs (VS) to assist with interfraction probe repositioning and we compare the soft tissue deformation introduced by VS to the deformation that would exist without them. Methods: Three metal markers weremore » surgically implanted in the kidney of one dog. The dog was anesthetized and immobilized supine in an alpha cradle. The reference ultrasound probe position and force to ideally visualize the kidney was defined by an experienced ultrasonographer using the Clarity ultrasound system and robot sensor. For each interfraction study, the dog was removed from the cradle and re-setup based on CBCT with bony anatomy alignment to mimic regular patient setup. The ultrasound probe was automatically returned to the reference position using the robot. To accommodate the soft tissue anatomy changes between each setup the operator used the VS feature to adjust the probe and obtain an ultrasound image that matched the reference image. CBCT images were acquired and each interfraction marker location was compared with the first interfraction Result. Results: Analysis of the marker positions revealed that the kidney was displaced by 18.8 ± 6.4 mm without VS and 19.9 ± 10.5 mm with VS. No statistically significant differences were found between two procedures. Conclusion: The VS feature is necessary to obtain matching ultrasound images, and they do not introduce further changes to the tissue deformation. Future work will focus on automatic VS based on ultrasound feedback. Supported in part by: NCI R01 CA161613; Elekta Sponsored Research.« less

High Intensity Focused Ultrasound (HIFU) Based Thrombolysis Using Multiple Frequency Excitations

NASA Astrophysics Data System (ADS)

Suo, Dingjie

High intensity focused ultrasound (HIFU) based thrombolysis has emerged as a promising drug-free approach for ischemic stroke treatment. The large amount of acoustic power required by this approach, however, poses a critical challenge to the future clinical translation because of the potential thermal damages. In this dissertation, multi-frequency acoustic waves at MHz range (near 1.5 MHz) were first introduced as HIFU excitations to reduce the required treatment power as well as the treatment time. It was found that dual-frequency thrombolysis efficiency was statistically better than that of single-frequency, under the same acoustic power and excitation condition. Microbubbles (MBs) combined with dual-frequency focused ultrasound (DFFU) for thrombolysis in vitro was then proposed to further reduce the power required. MBs are widely used in therapeutic ultrasound thrombolysis due to the nonlinear characteristics of their harmonic responses, coalescence and cavitation effects, which could further enhance efficiency. It was shown in this study that MBs, with sufficient concentration, could significantly lower the power threshold for thrombolysis for both DFFU and single-frequency focused ultrasound (SFFU). MBs mediated DFFU thrombolysis were then studied with a flow system that mimicked the blood flow in the artery of the brain. It was found that the cavitation threshold of a DFFU excitation yielded a lower level than that of a SFFU excitation. All the experimental results indicated that multi-frequency ultrasound could improve the thrombolysis efficiency. However, this was not well established numerically. Hence, a numerical investigation on the inertial cavitation threshold of MBs under multifrequency ultrasound irradiation was then investigated to confirm the benefit of using multi-frequency ultrasound for various applications. The main contribution and findings of this dissertation are as follows: 1) For the HIFU along study, when varying the acoustic power while fixing the duty cycle at 5%, it was found that almost 30% of the power can be saved by dual frequency ultrasound to achieve the same thrombolysis efficiency. In the experiment where the duty cycle was increased from 0.5% to 10%, it was shown that dual-frequency ultrasound can achieve the same thrombolysis efficiency with only half of the duty cycle of singlefrequency. Dual-frequency ultrasound could also accelerate the thrombolysis by a factor of 2-4 as demonstrated in this study. The measured cavitation doses of dual-frequency and triple-frequency excitations were at about the same level, both significantly higher than that of single-frequency. 2) For the MBs mediated thrombolysis study, SFFU needed about 96%-156% higher energy to achieve the same thrombolysis efficiency as that of DFFU. The thrombolysis efficiency was also found to increase with the duty cycle. The measured cavitation signals reveal that the enhanced inertial cavitation may contribute to the improved thrombolysis under DFFU and MBs. By adding the flow system, the inertial cavitation was higher than the static model. One reason could be the dissolution of MBs into the flow that lowered the concentration of MBs by a significant amount. In both cases, the inertial cavitation thresh holds of DFFU were lower than SFFU. 3) For the numerical study, we investigated the inertial cavitation threshold of MBs under multi-frequency ultrasound irradiation. The relationships between the cavitation threshold and MB size at various frequencies and in different media were investigated. The results for single, dual and triple frequency sonication showed that inertial cavitation thresholds can be reduced by introducing additional frequencies, which was consistent with previous experimental work. In addition, no significant difference was observed between dual frequency sonication with various frequency differences. This study also provided a possible route for optimizing ultrasound excitations for initiating inertial cavitation.

Seeing Is Believing: Evaluating a Point-of-Care Ultrasound Curriculum for 1st-Year Medical Students.

PubMed

Nelson, Bret P; Hojsak, Joanne; Dei Rossi, Elizabeth; Karani, Reena; Narula, Jagat

2017-01-01

Point-of-care ultrasound has been a novel addition to undergraduate medical education at a few medical schools. The impact is not fully understood, and few rigorous assessments of educational outcomes exist. This study assessed the impact of a point-of-care ultrasound curriculum on image acquisition, interpretation, and student and faculty perceptions of the course. All 142 first-year medical students completed a curriculum on ultrasound physics and instrumentation, cardiac, thoracic, and abdominal imaging. A flipped classroom model of preclass tutorials and tests augmenting live, hands-on scanning sessions was incorporated into the physical examination course. Students and faculty completed surveys on impressions of the curriculum, and all students under-went competency assessments with standardized patients. The curriculum was a mandatory part of the physical examination course and was taught by experienced clinician-sonographers as well as faculty who do not routinely perform sonography in their clinical practice. Students and faculty agreed that the physical examination course was the right time to introduce ultrasound (87% and 80%). Students demonstrated proper use of the ultrasound machine functions (M score = 91.55), and cardiac, thoracic, and abdominal system assessments (M score = 80.35, 79.58, and 71.57, respectively). Students and faculty valued the curriculum, and students demonstrated basic competency in performance and interpretation of ultrasound. Further study is needed to determine how to best incorporate this emerging technology into a robust learning experience for medical students.

Ultrasound-guided injection of triamcinolone and bupivacaine in the management of De Quervain's disease.

PubMed

Jeyapalan, Kanagaratnam; Choudhary, Surabhi

2009-11-01

The aim of this study was to describe the technique and usefulness of ultrasound-guided intrasynovial injection of triamcinolone and bupivacaine in treatment of de Quervain's disease. A total of 17 patients with symptomatic De Quervain's disease were included in this study. The procedure involved confirmation of diagnosis with ultrasound followed by guided injection of a mixture of 20 mg of triamcinolone (40 mg/ml) and 1 ml of 0.5% bupivacaine. Ultrasound guidance with a high resolution 15-Mhz footprint probe was used for injection into the first dorsal extensor compartment tendon sheath (E1). The response to ultrasound-guided injection was ascertained at the post procedure outpatient clinic appointment according to the follow-up clinic notes. There were 14 female and 3 male patients aged 29 to 74 years. Mean duration of symptoms was 8.9 months. One patient had an atypical septum in the first extensor compartment and the extensor pollicis brevis alone was involved. The mean post-injection follow-up was at 6.75 weeks. One patient was lost to follow-up. Fifteen out of 16 patients had significant symptomatic relief (93.75%). There were no immediate or delayed complications. Recurrence of symptoms was seen in 3 (20%) patients. Ultrasound-guided injection of triamcinolone and bupivacaine is safe and useful in controlling symptoms of De Quervain's disease. Correct needle placement with ultrasound guidance avoids intratendinous injection as well as local complications like fat atrophy and depigmentation.

AUGMENTATION OF MUSCLE BLOOD FLOW BY ULTRASOUND CAVITATION IS MEDIATED BY ATP AND PURINERGIC SIGNALING

PubMed Central

Belcik, J. Todd; Davidson, Brian P.; Xie, Aris; Wu, Melinda D.; Yadava, Mrinal; Qi, Yue; Liang, Sherry; Chon, Chae Ryung; Ammi, Azzdine Y.; Field, Joshua; Harmann, Leanne; Chilian, William M.; Linden, Joel; Lindner, Jonathan R.

2017-01-01

Background Augmentation of tissue blood flow by therapeutic ultrasound is thought to rely on convective shear. Microbubble contrast agents that undergo ultrasound-mediated cavitation markedly amplify these effects. We hypothesized that purinergic signalling is responsible for shear-dependent increases in muscle perfusion during therapeutic cavitation. Methods Unilateral exposure of the proximal hindlimb of mice (with or without ischemia produced by iliac ligation) to therapeutic ultrasound (1.3 MHz, mechanical index 1.3) was performed for ten minutes after intravenous injection of 2×108 lipid microbubbles. Microvascular perfusion was evaluated by low-power contrast ultrasound perfusion imaging. In vivo muscle ATP release and in vitro ATP release from endothelial cells or erythrocytes were assessed by a luciferin-luciferase assay. Purinergic signalling pathways were assessed by studying interventions that either (1) accelerated ATP degradation; (2) inhibited P2Y receptors, adenosine receptors, or KATP channels; or (3) inhibited downstream signalling pathways involving endothelial nitric oxide synthase (eNOS) or prostanoid production (indomethacin). Augmentation in muscle perfusion by ultrasound cavitation was assessed in a proof-of-concept clinical trial in 12 subjects with stable sickle cell disease (SCD). Results Therapeutic ultrasound cavitation increased muscle perfusion by 7-fold in normal mice, reversed tissue ischemia for up to 24 hrs in the murine model of peripheral artery disease, and doubled muscle perfusion in patients with SCD. Augmentation in flow extended well beyond the region of ultrasound exposure. Ultrasound cavitation produced a nearly 40-fold focal and sustained increase in ATP, the source of which included both endothelial cells and erythrocytes. Inhibitory studies indicated that ATP was a critical mediator of flow augmentation that acts primarily through either P2Y receptors or through adenosine produced by ectonucleotidase activity. Combined indomethacin and inhibition of eNOS abolished the effects of therapeutic ultrasound, indicating downstream signalling through both NO and prostaglandins. Conclusions Therapeutic ultrasound using microbubble cavitation to increase muscle perfusion relies on shear-dependent increases in ATP which can act through a diverse portfolio of purinergic signalling pathways. These events can reverse hindlimb ischemia in mice for >24 hours, and increase muscle blood flow in patients with sickle cell disease. Clinical Trial Registration NCT01566890 (https://clinicaltrials.gov/ct2/show/NCT01566890) PMID:28174191

Augmentation of Muscle Blood Flow by Ultrasound Cavitation Is Mediated by ATP and Purinergic Signaling.

PubMed

Belcik, J Todd; Davidson, Brian P; Xie, Aris; Wu, Melinda D; Yadava, Mrinal; Qi, Yue; Liang, Sherry; Chon, Chae Ryung; Ammi, Azzdine Y; Field, Joshua; Harmann, Leanne; Chilian, William M; Linden, Joel; Lindner, Jonathan R

2017-03-28

Augmentation of tissue blood flow by therapeutic ultrasound is thought to rely on convective shear. Microbubble contrast agents that undergo ultrasound-mediated cavitation markedly amplify these effects. We hypothesized that purinergic signaling is responsible for shear-dependent increases in muscle perfusion during therapeutic cavitation. Unilateral exposure of the proximal hindlimb of mice (with or without ischemia produced by iliac ligation) to therapeutic ultrasound (1.3 MHz, mechanical index 1.3) was performed for 10 minutes after intravenous injection of 2×10 8 lipid microbubbles. Microvascular perfusion was evaluated by low-power contrast ultrasound perfusion imaging. In vivo muscle ATP release and in vitro ATP release from endothelial cells or erythrocytes were assessed by a luciferin-luciferase assay. Purinergic signaling pathways were assessed by studying interventions that (1) accelerated ATP degradation; (2) inhibited P2Y receptors, adenosine receptors, or K ATP channels; or (3) inhibited downstream signaling pathways involving endothelial nitric oxide synthase or prostanoid production (indomethacin). Augmentation in muscle perfusion by ultrasound cavitation was assessed in a proof-of-concept clinical trial in 12 subjects with stable sickle cell disease. Therapeutic ultrasound cavitation increased muscle perfusion by 7-fold in normal mice, reversed tissue ischemia for up to 24 hours in the murine model of peripheral artery disease, and doubled muscle perfusion in patients with sickle cell disease. Augmentation in flow extended well beyond the region of ultrasound exposure. Ultrasound cavitation produced an ≈40-fold focal and sustained increase in ATP, the source of which included both endothelial cells and erythrocytes. Inhibitory studies indicated that ATP was a critical mediator of flow augmentation that acts primarily through either P2Y receptors or adenosine produced by ectonucleotidase activity. Combined indomethacin and inhibition of endothelial nitric oxide synthase abolished the effects of therapeutic ultrasound, indicating downstream signaling through both nitric oxide and prostaglandins. Therapeutic ultrasound using microbubble cavitation to increase muscle perfusion relies on shear-dependent increases in ATP, which can act through a diverse portfolio of purinergic signaling pathways. These events can reverse hindlimb ischemia in mice for >24 hours and increase muscle blood flow in patients with sickle cell disease. URL: http://clinicaltrials.gov. Unique identifier: NCT01566890. © 2017 American Heart Association, Inc.

Acoustic Characterization of a Vessel-on-a-Chip Microfluidic System for Ultrasound-Mediated Drug Delivery.

PubMed

Beekers, Ines; van Rooij, Tom; Verweij, Martin D; Versluis, Michel; de Jong, Nico; Trietsch, Sebastiaan J; Kooiman, Klazina

2018-04-01

Ultrasound in the presence of gas-filled microbubbles can be used to enhance local uptake of drugs and genes. To study the drug delivery potential and its underlying physical and biological mechanisms, an in vitro vessel model should ideally include 3-D cell culture, perfusion flow, and membrane-free soft boundaries. Here, we propose an organ-on-a-chip microfluidic platform to study ultrasound-mediated drug delivery: the OrganoPlate. The acoustic propagation into the OrganoPlate was determined to assess the feasibility of controlled microbubble actuation, which is required to study the microbubble-cell interaction for drug delivery. The pressure field in the OrganoPlate was characterized non-invasively by studying experimentally the well-known response of microbubbles and by simulating the acoustic wave propagation in the system. Microbubble dynamics in the OrganoPlate were recorded with the Brandaris 128 ultrahigh-speed camera (17 million frames/s) and a control experiment was performed in an OptiCell, an in vitro monolayer cell culture chamber that is conventionally used to study ultrasound-mediated drug delivery. When insonified at frequencies between 1 and 2 MHz, microbubbles in the OrganoPlate experienced larger oscillation amplitudes resulting from higher local pressures. Microbubbles responded similarly in both systems when insonified at frequencies between 2 and 4 MHz. Numerical simulations performed with a 3-D finite-element model of ultrasound propagation into the OrganoPlate and the OptiCell showed the same frequency-dependent behavior. The predictable and homogeneous pressure field in the OrganoPlate demonstrates its potential to develop an in vitro 3-D cell culture model, well suited to study ultrasound-mediated drug delivery.

Neonatal respiratory distress syndrome: Chest X-ray or lung ultrasound? A systematic review

PubMed Central

Culpan, Anne-Marie; Watts, Catriona; Munyombwe, Theresa; Wolstenhulme, Stephen

2017-01-01

Background and aim Neonatal respiratory distress syndrome is a leading cause of morbidity in preterm new-born babies (<37 weeks gestation age). The current diagnostic reference standard includes clinical testing and chest radiography with associated exposure to ionising radiation. The aim of this review was to compare the diagnostic accuracy of lung ultrasound against the reference standard in symptomatic neonates of ≤42 weeks gestation age. Methods A systematic search of literature published between 1990 and 2016 identified 803 potentially relevant studies. Six studies met the review inclusion criteria and were retrieved for analysis. Quality assessment was performed before data extraction and meta-analysis. Results Four prospective cohort studies and two case control studies included 480 neonates. All studies were of moderate methodological quality although heterogeneity was evident across the studies. The pooled sensitivity and specificity of lung ultrasound were 97% (95% confidence interval [CI] 94–99%) and 91% (CI: 86–95%) respectively. False positive diagnoses were made in 16 cases due to pneumonia (n = 8), transient tachypnoea (n = 3), pneumothorax (n = 1) and meconium aspiration syndrome (n = 1); the diagnoses of the remaining three false positive results were not specified. False negatives diagnoses occurred in nine cases, only two were specified as air-leak syndromes. Conclusions Lung ultrasound was highly sensitive for the detection of neonatal respiratory distress syndrome although there is potential to miss co-morbid air-leak syndromes. Further research into lung ultrasound diagnostic accuracy for neonatal air-leak syndrome and economic modelling for service integration is required before lung ultrasound can replace chest radiography as the imaging component of the reference standard. PMID:28567102

Disruption of Prostate Microvasculature by Combining Microbubble-Enhanced Ultrasound and Prothrombin

PubMed Central

Liu, Yongliang; Qiao, Lu; Gao, Wenhong; Zhang, Weiguo; Liu, Zheng

2016-01-01

Previous studies have shown a unique method to disrupt tumor vasculature using pulsed, high-pressure amplitude therapeutic ultrasound combined with microbubbles. In this study, we attempted to destroy the prostate vasculature of canine prostates using microbubble-enhanced ultrasound (MEUS) and prothrombin. The prostates of 43 male mongrel canines were surgically exposed. Twenty-two prostates were treated using MEUS (n = 11) or MEUS and prothrombin (PMEUS, n = 11). The other 21 prostates, which were treated using microbubbles (n = 7), ultrasound (n = 7) or prothrombin (n = 7) only, served as the controls. Prothrombin was intravenously infused at 20 IU/kg. MEUS was induced using a therapeutic ultrasound device at a peak negative pressure of 4.47 MPa and a microbubble injection. Contrast-enhanced ultrasound was performed to assess the blood perfusion of the prostates. Then, the prostate tissue was harvested immediately after treatment and at 48 hours later for pathological examination. The contrast-enhanced ultrasound peak value of the prostate decreased significantly from 36.2 ± 5.6 to 27.1 ± 6.3 after treatment in the PMEUS group, but it remained unchanged in the other groups. Histological examination found severe microvascular rupture, hemorrhage and thrombosis in both MEUS- and PMEUS-treated prostates immediately after treatment, while disruption in the PMEUS group was more severe than in the MEUS group. Forty-eight hours after treatment, massive necrosis and infiltration of white blood cells occurred in the PMEUS group. This study demonstrated that PMEUS disrupted the normal microvasculature of canine prostates and induced massive necrosis. PMEUS could potentially become a new noninvasive method used for the treatment of benign prostatic hyperplasia. PMID:27643992

Non-Weight-Bearing and Weight-Bearing Ultrasonography of Select Foot Muscles in Young, Asymptomatic Participants: A Descriptive and Reliability Study.

PubMed

Battaglia, Patrick J; Mattox, Ross; Winchester, Brett; Kettner, Norman W

The primary aim of this study was to determine the reliability of diagnostic ultrasound imaging for select intrinsic foot muscles using both non-weight-bearing and weight-bearing postures. Our secondary aim was to describe the change in muscle cross-sectional area (CSA) and dorsoplantar thickness when bearing weight. An ultrasound examination was performed with a linear ultrasound transducer operating between 9 and 12 MHz. Long-axis and short-axis ultrasound images of the abductor hallucis, flexor digitorum brevis, and quadratus plantae were obtained in both the non-weight-bearing and weight-bearing postures. Two examiners independently collected ultrasound images to allow for interexaminer and intraexaminer reliability calculation. The change in muscle CSA and dorsoplantar thickness when bearing weight was also studied. There were 26 participants (17 female) with a mean age of 25.5 ± 3.8 years and a mean body mass index of 28.0 ± 7.8 kg/m 2 . Inter-examiner reliability was excellent when measuring the muscles in short axis (intraclass correlation coefficient >0.75) and fair to good in long axis (intraclass correlation coefficient >0.4). Intraexaminer reliability was excellent for the abductor hallucis and flexor digitorum brevis and ranged from fair to good to excellent for the quadratus plantae. Bearing weight did not reduce interexaminer or intraexaminer reliability. All muscles exhibited a significant increase in CSA when bearing weight. This is the first report to describe weight-bearing diagnostic ultrasound of the intrinsic foot muscles. Ultrasound imaging is reliable when imaging these muscles bearing weight. Furthermore, muscle CSA increases in the weight-bearing posture. Copyright © 2016. Published by Elsevier Inc.

Spectrophotometer and ultrasound evaluation of late toxicity following breast-cancer radiotherapy.

PubMed

Yoshida, E J; Chen, H; Torres, M A; Curran, W J; Liu, T

2011-10-01

Radiation-induced normal-tissue toxicities are common, complex, and distressing side effects that affect 90% of patients receiving breast-cancer radiotherapy and 40% of patients post radiotherapy. In this study, the authors investigated the use of spectrophotometry and ultrasound to quantitatively measure radiation-induced skin discoloration and subcutaneous-tissue fibrosis. The study's purpose is to determine whether skin discoloration correlates with the development of fibrosis in breast-cancer radiotherapy. Eighteen breast-cancer patients were enrolled in our initial study. All patients were previously treated with a standard course of radiation, and the median follow-up time was 22 months. The treated and untreated breasts were scanned with a spectrophotometer and an ultrasound. Two spectrophotometer parameters-melanin and erythema indices-were used to quantitatively assess skin discoloration. Two ultrasound parameters-skin thickness and Pearson coefficient of the hypodermis-were used to quantitatively assess severity of fibrosis. These measurements were correlated with clinical assessments (RTOG late morbidity scores). Significant measurement differences between the treated and contralateral breasts were observed among all patients: 27.3% mean increase in skin thickness (p < 0.001), 34.1% mean decrease in Pearson coefficient (p < 0.001), 27.3% mean increase in melanin (p < 0.001), and 22.6% mean increase in erythema (p < 0.001). All parameters except skin thickness correlated with RTOG scores. A moderate correlation exists between melanin and erythema; however, spectrophotometer parameters do not correlate with ultrasound parameters. Spectrophotometry and quantitative ultrasound are objective tools that assess radiation-induced tissue injury. Spectrophotometer parameters did not correlate with those of quantitative ultrasound suggesting that skin discoloration cannot be used as a marker for subcutaneous fibrosis. These tools may prove useful for the reduction of radiation morbidities and improvement of patient quality of life.

Regeneration of Full-Thickness Rotator Cuff Tendon Tear After Ultrasound-Guided Injection With Umbilical Cord Blood-Derived Mesenchymal Stem Cells in a Rabbit Model.

PubMed

Park, Gi-Young; Kwon, Dong Rak; Lee, Sang Chul

2015-11-01

Rotator cuff tendon tear is one of the most common causes of chronic shoulder pain and disability. In this study, we investigated the therapeutic effects of ultrasound-guided human umbilical cord blood (UCB)-derived mesenchymal stem cell (MSC) injection to regenerate a full-thickness subscapularis tendon tear in a rabbit model by evaluating the gross morphology and histology of the injected tendon and motion analysis of the rabbit's activity. At 4 weeks after ultrasound-guided UCB-derived MSC injection, 7 of the 10 full-thickness subscapularis tendon tears were only partial-thickness tears, and 3 remained full-thickness tendon tears. The tendon tear size and walking capacity at 4 weeks after UCB-derived MSC injection under ultrasound guidance were significantly improved compared with the same parameters immediately after tendon tear. UCB-derived MSC injection under ultrasound guidance without surgical repair or bioscaffold resulted in the partial healing of full-thickness rotator cuff tendon tears in a rabbit model. Histology revealed that UCB-derived MSCs induced regeneration of rotator cuff tendon tear and that the regenerated tissue was predominantly composed of type I collagens. In this study, ultrasound-guided injection of human UCB-derived MSCs contributed to regeneration of the full-thickness rotator cuff tendon tear without surgical repair. The results demonstrate the effectiveness of local injection of MSCs into the rotator cuff tendon. The results of this study suggest that ultrasound-guided umbilical cord blood-derived mesenchymal stem cell injection may be a useful conservative treatment for full-thickness rotator cuff tendon tear repair. ©AlphaMed Press.

Regeneration of Full-Thickness Rotator Cuff Tendon Tear After Ultrasound-Guided Injection With Umbilical Cord Blood-Derived Mesenchymal Stem Cells in a Rabbit Model

PubMed Central

Park, Gi-Young; Lee, Sang Chul

2015-01-01

Rotator cuff tendon tear is one of the most common causes of chronic shoulder pain and disability. In this study, we investigated the therapeutic effects of ultrasound-guided human umbilical cord blood (UCB)-derived mesenchymal stem cell (MSC) injection to regenerate a full-thickness subscapularis tendon tear in a rabbit model by evaluating the gross morphology and histology of the injected tendon and motion analysis of the rabbit’s activity. At 4 weeks after ultrasound-guided UCB-derived MSC injection, 7 of the 10 full-thickness subscapularis tendon tears were only partial-thickness tears, and 3 remained full-thickness tendon tears. The tendon tear size and walking capacity at 4 weeks after UCB-derived MSC injection under ultrasound guidance were significantly improved compared with the same parameters immediately after tendon tear. UCB-derived MSC injection under ultrasound guidance without surgical repair or bioscaffold resulted in the partial healing of full-thickness rotator cuff tendon tears in a rabbit model. Histology revealed that UCB-derived MSCs induced regeneration of rotator cuff tendon tear and that the regenerated tissue was predominantly composed of type I collagens. In this study, ultrasound-guided injection of human UCB-derived MSCs contributed to regeneration of the full-thickness rotator cuff tendon tear without surgical repair. The results demonstrate the effectiveness of local injection of MSCs into the rotator cuff tendon. Significance The results of this study suggest that ultrasound-guided umbilical cord blood-derived mesenchymal stem cell injection may be a useful conservative treatment for full-thickness rotator cuff tendon tear repair. PMID:26371340

Intraoperative ultrasound for prediction of hepatocellular carcinoma biological behaviour: Prospective comparison with pathology.

PubMed

Santambrogio, Roberto; Cigala, Claudia; Barabino, Matteo; Maggioni, Marco; Scifo, Giovanna; Bruno, Savino; Bertolini, Emanuela; Opocher, Enrico; Bulfamante, Gaetano

2018-02-01

Preoperative prediction of both microinvasive hepatocellular carcinoma and histological grade of hepatocellular carcinoma is pivotal to treatment planning and prognostication. The aim of this study was to evaluate whether some intraoperative ultrasound features correlate with both the presence of same histological patterns and differentiation grade of hepatocellular carcinoma on the histological features of the primary resected tumour. All patients with single, small hepatocellular carcinoma that underwent hepatic resection were included in this prospective double-blind study: the intraoperative ultrasound patterns of nodule were registered and compared with similar histological features. A total of 179 patients were enclosed in this study: 97 (54%) patients (34% in HCC ≤2 cm) had a microinvasive hepatocellular carcinoma at ultrasound examination, while 82 (46%) patients (41% in HCC ≤2 cm) at histological evaluation. Statistical analysis showed that diameters ≤2 cm, presence of satellites and microinvasive hepatocellular carcinoma at ultrasound examination were the variables with the strongest association with the histological findings. In the multivariate analysis, the vascular microinfiltration and infiltrative hepatocellular carcinoma aspect were independent predictors for grading. In patients with cirrhosis and hepatocellular carcinoma, the prevalence of microinvasive hepatocellular carcinoma is high, even in cases of HCC ≤2 cm. Intraoperative ultrasound findings strongly correlated with histopathological criteria in detecting microinvasive patterns and are useful to predict neoplastic differentiation. The knowledge of these features prior to treatment are highly desired (this can be obtained by an intraoperative ultrasound examination), as they could help in providing optimal management of patients with hepatocellular carcinoma. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Use of Ultrasound Elastography in the Assessment of the Musculoskeletal System.

PubMed

Paluch, Łukasz; Nawrocka-Laskus, Ewa; Wieczorek, Janusz; Mruk, Bartosz; Frel, Małgorzata; Walecki, Jerzy

2016-01-01

This article presents possible applications of ultrasound elastography in musculoskeletal imaging based on the available literature, as well as the possibility of extending indications for the use of elastography in the future. Ultrasound elastography (EUS) is a new method that shows structural changes in tissues following application of physical stress. Elastography techniques have been widely used to assess muscles and tendons in vitro since the early parts of the twentieth century. Only recently with the advent of new technology and creation of highly specialized ultrasound devices, has elastography gained widespread use in numerous applications. The authors performed a search of the Medline/PubMed databases for original research and reviewed publications on the application of ultrasound elastography for musculoskeletal imaging. All publications demonstrate possible uses of ultrasound elastography in examinations of the musculoskeletal system. The most widely studied areas include the muscles, tendons and rheumatic diseases. There are also reports on the employment in vessel imaging. The main limitation of elastography as a technique is above all the variability of applied pressure during imaging, which is operator-dependent. It would therefore be reasonable to provide clear guidelines on the technique applied, as well as clear indications for performing the test. It is important to develop methods for creating artifact-free, closed-loop, compression-decompression cycles. The main advantages include cost-effectiveness, short duration of the study, non-invasive nature of the procedure, as well as a potentially broader clinical availability. There are no clear guidelines with regard to indications as well as examination techniques. Ultrasound elastography is a new and still poorly researched method. We conclude, however, that it can be widely used in the examinations of musculoskeletal system. Therefore, it is necessary to conduct large, multi-center studies to determine the methodology, indications and technique of examination.

Noncontact modal analysis of a pipe organ reed using airborne ultrasound stimulated vibrometry

NASA Astrophysics Data System (ADS)

Huber, Thomas M.; Fatemi, Mostafa; Kinnick, Randall R.; Greenleaf, James F.

2004-05-01

The goal of this experiment was to excite and measure, in a noncontact manner, the vibrational modes of the reed from a reed organ pipe. To perform ultrasound stimulated excitation, two ultrasound beams in air of different frequencies were directed at the reed; the audio-range beat frequency between these ultrasound beams induced vibrations. The resulting vibrational deflection shapes were measured with a scanning vibrometer. The modes of any relatively small object can be studied in air using this technique. For a 36 mm by 7 mm clamped brass reed cantilever, displacements and velocites of 5 μ and 4 mm/s could be imparted at the fundamental frequency of 145 Hz. Using the same ultrasound transducer, excitation across the entire range of audio frequencies was obtained, which was not possible using audio excitation with a speaker. Since the beam was focused on the reed, ultrasound stimulated excitation eliminated background effects observed during mechanical shaker excitation, such as vibrations of clamps and supports. We will discuss the results obtained using single, dual, and confocal ultrasound transducers in AM and unmodulated CW modes, along with results obtained using a mechanical shaker and audio excitation using a speaker.

Ultrasound elastography: the new frontier in direct measurement of muscle stiffness.

PubMed

Brandenburg, Joline E; Eby, Sarah F; Song, Pengfei; Zhao, Heng; Brault, Jeffrey S; Chen, Shigao; An, Kai-Nan

2014-11-01

The use of brightness-mode ultrasound and Doppler ultrasound in physical medicine and rehabilitation has increased dramatically. The continuing evolution of ultrasound technology has also produced ultrasound elastography, a cutting-edge technology that can directly measure the mechanical properties of tissue, including muscle stiffness. Its real-time and direct measurements of muscle stiffness can aid the diagnosis and rehabilitation of acute musculoskeletal injuries and chronic myofascial pain. It can also help monitor outcomes of interventions affecting muscle in neuromuscular and musculoskeletal diseases, and it can better inform the functional prognosis. This technology has implications for even broader use of ultrasound in physical medicine and rehabilitation practice, but more knowledge about its uses and limitations is essential to its appropriate clinical implementation. In this review, we describe different ultrasound elastography techniques for studying muscle stiffness, including strain elastography, acoustic radiation force impulse imaging, and shear-wave elastography. We discuss the basic principles of these techniques, including the strengths and limitations of their measurement capabilities. We review the current muscle research, discuss physiatric clinical applications of these techniques, and note directions for future research. Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Tissue mimicking simulations for temporal enhanced ultrasound-based tissue typing

NASA Astrophysics Data System (ADS)

Bayat, Sharareh; Imani, Farhad; Gerardo, Carlos D.; Nir, Guy; Azizi, Shekoofeh; Yan, Pingkun; Tahmasebi, Amir; Wilson, Storey; Iczkowski, Kenneth A.; Lucia, M. Scott; Goldenberg, Larry; Salcudean, Septimiu E.; Mousavi, Parvin; Abolmaesumi, Purang

2017-03-01

Temporal enhanced ultrasound (TeUS) is an imaging approach where a sequence of temporal ultrasound data is acquired and analyzed for tissue typing. Previously, in a series of in vivo and ex vivo studies we have demonstrated that, this approach is effective for detecting prostate and breast cancers. Evidences derived from our experiments suggest that both ultrasound-signal related factors such as induced heat and tissue-related factors such as the distribution and micro-vibration of scatterers lead to tissue typing information in TeUS. In this work, we simulate mechanical micro-vibrations of scatterers in tissue-mimicking phantoms that have various scatterer densities reflecting benign and cancerous tissue structures. Finite element modeling (FEM) is used for this purpose where the vertexes are scatterers representing cell nuclei. The initial positions of scatterers are determined by the distribution of nuclei segmented from actual digital histology scans of prostate cancer patients. Subsequently, we generate ultrasound images of the simulated tissue structure using the Field II package resulting in a temporal enhanced ultrasound. We demonstrate that the micro-vibrations of scatterers are captured by temporal ultrasound data and this information can be exploited for tissue typing.

[Use of lung ultrasound as a prognostic tool in outpatients with heart failure].

PubMed

Tojo Villanueva, María Del Carmen; Fernández López, María; Canora Lebrato, Jesús; Satué Bartolomé, José Ángel; San Martín Prado, Alberto; Zapatero Gaviria, Antonio

2016-07-01

To assess the prognostic value of lung ultrasound for patients with chronic heart failure. Prospective observational cohort study, in which a lung ultrasound was performed on 54 patients at a heart failure outpatient consultation. Ultrasonography was classified as positive or negative for ultrasound interstitial syndrome depending on the number of B lines observed. Patients were followed up for six months; considering emergency visits, readmissions and deaths due to heart failure as markers of poor prognosis. 53.7% (29) of the patients had ultrasound interstitial syndrome. Among them, 48.3% (14) were readmitted, compared to 16% (4) of those without the syndrome (P=.012). Considering any of the events previously described as end points (readmissions, emergencies and deaths), we found that in the group of patients with ultrasound interstitial syndrome, 55.2% (16) had at least one of these complications, compared to 20% (5) of participants without the syndrome (P=.008). Lung ultrasound in the outpatient setting is useful in predicting which patients are at increased risk of heart failure decompensation in the mid-term. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.

Steering Microbubbles in Physiologically Realistic Flows Using the Bjerknes Force

NASA Astrophysics Data System (ADS)

Clark, Alicia; Aliseda, Alberto

2017-11-01

Ultrasound contrast agents (UCAs) are lipid-coated microbubbles that are used to increase contrast in ultrasound imaging due to their ability to scatter sound. Additionally, UCAs can be used in conjunction with ultrasound in medical applications such as targeted drug delivery and thrombolysis. These applications utilize the Bjerknes force, an ultrasound-induced force caused by the phase difference between the incoming ultrasound pressure wave and the microbubble volume oscillations. The dynamics of microbubbles under ultrasound excitation have been studied thoroughly in stagnant fluid baths; however, understanding of the fundamental physics of microbubbles in physiologically realistic flows is lacking. An in vitroexperiment that reproduces the dynamics (Reynolds and Womersley numbers) of a medium-sized blood vessel was used to explore the behavior of microbubbles. Using Lagrangian tracking, the trajectory of each individual bubble was reconstructed using information obtained from high speed imaging. The balance of hydrodynamic forces (lift, drag, added mass, etc.) against the primary Bjerknes force was analyzed. The results show that an increase in ultrasound pulse repetition frequency leads to a linear increase in the Bjerknes force and the increase in the force is quadratic with the amplitude of the excitation.

Evaluation of trainees' ability to perform obstetrical ultrasound using simulation: challenges and opportunities.

PubMed

Chalouhi, Gihad E; Bernardi, Valeria; Gueneuc, Alexandra; Houssin, Isabelle; Stirnemann, Julien J; Ville, Yves

2016-04-01

Evaluation of trainee's ability in obstetrical ultrasound is a time-consuming process, which requires involving patients as volunteers. With the use of obstetrical ultrasound simulators, virtual reality could help in assessing competency and evaluating trainees in this field. The objective of the study was to test the validity of an obstetrical ultrasound simulator as a tool for evaluating trainees following structured training by comparing scores obtained on obstetrical ultrasound simulator with those obtained on volunteers and by assessing correlations between scores of images and of dexterity given by 2 blinded examiners. Trainees, taking the 2013 French national examination for the practice of obstetrical ultrasound were asked to obtain standardized ultrasound planes both on volunteer pregnant women and on an obstetrical ultrasound simulator. These planes included measurements of biparietal diameter, abdominal circumference, and femur length as well as reference planes for cardiac 4-chamber and outflow tracts, kidneys, stomach/diaphragm, spine, and face. Images were stored and evaluated subsequently by 2 national examiners who scored each picture according to previously established quality criteria. Dexterity was also evaluated and subjectively scored between 0 and 10. The Raghunathan's modification of Pearson, Filon's z, Spearman's rank correlation, and analysis of variance tests were used to assess correlations between the scores by the 2 examiners and scores of dexterity and also to compare the final scores between the 2 different methods. We evaluated 29 trainees. The mean dexterity scores in simulation (6.5 ± 2.0) and real examination (5.9 ± 2.3) were comparable (P = .31). Scores with an obstetrical ultrasound simulator were significantly higher than those obtained on volunteers (P = .027). Nevertheless, there was a good correlation between the scores of the 2 examiners judging on simulation (R = 0.888) and on volunteers (R = 0.873) (P = .81). An obstetrical ultrasound simulator is as good a method as volunteer-based examination for evaluating practical skills in trainees following structured training in obstetrical ultrasound. The threshold for success/failure should, however, be adapted as candidates obtain higher scores on the simulator. Advantages of the obstetrical ultrasound simulator include the absence of location and time constraints without the need to involve volunteers or to interfere with the running of ultrasound clinics. However, an obstetrical ultrasound simulator still lacks the ability to evaluate the trainees' ability to interact with patients. Copyright © 2016 Elsevier Inc. All rights reserved.

Improved Visualization of Intracranial Vessels with Intraoperative Coregistration of Rotational Digital Subtraction Angiography and Intraoperative 3D Ultrasound

PubMed Central

Podlesek, Dino; Meyer, Tobias; Morgenstern, Ute; Schackert, Gabriele; Kirsch, Matthias

2015-01-01

Introduction Ultrasound can visualize and update the vessel status in real time during cerebral vascular surgery. We studied the depiction of parent vessels and aneurysms with a high-resolution 3D intraoperative ultrasound imaging system during aneurysm clipping using rotational digital subtraction angiography as a reference. Methods We analyzed 3D intraoperative ultrasound in 39 patients with cerebral aneurysms to visualize the aneurysm intraoperatively and the nearby vascular tree before and after clipping. Simultaneous coregistration of preoperative subtraction angiography data with 3D intraoperative ultrasound was performed to verify the anatomical assignment. Results Intraoperative ultrasound detected 35 of 43 aneurysms (81%) in 39 patients. Thirty-nine intraoperative ultrasound measurements were matched with rotational digital subtraction angiography and were successfully reconstructed during the procedure. In 7 patients, the aneurysm was partially visualized by 3D-ioUS or was not in field of view. Post-clipping intraoperative ultrasound was obtained in 26 and successfully reconstructed in 18 patients (69%) despite clip related artefacts. The overlap between 3D-ioUS aneurysm volume and preoperative rDSA aneurysm volume resulted in a mean accuracy of 0.71 (Dice coefficient). Conclusions Intraoperative coregistration of 3D intraoperative ultrasound data with preoperative rotational digital subtraction angiography is possible with high accuracy. It allows the immediate visualization of vessels beyond the microscopic field, as well as parallel assessment of blood velocity, aneurysm and vascular tree configuration. Although spatial resolution is lower than for standard angiography, the method provides an excellent vascular overview, advantageous interpretation of 3D-ioUS and immediate intraoperative feedback of the vascular status. A prerequisite for understanding vascular intraoperative ultrasound is image quality and a successful match with preoperative rotational digital subtraction angiography. PMID:25803318

A Microfluidics-based Pulpal Arteriole Blood Flow Phantom for Validation of Doppler Ultrasound Devices in Pulpal Blood Flow Velocity Measurement.

PubMed

Kim, Dohyun; Park, Sung-Ho

2016-11-01

Recently, Doppler ultrasound has been used for the measurement of pulpal blood flow in human teeth. However, the reliability of this method has not been verified. In this study, we developed a model to simulate arteriole blood flow within the dental pulp by using microfluidics. This arteriole simulator, or flow phantom, was used to determine the reliability of measurements obtained by using a Doppler ultrasound device. A microfluidic chip was fabricated by using the soft lithography technique, and blood-mimicking fluid was pumped through the channel by a microfluidic system. A Doppler ultrasound device was used for the measurement of flow velocity. The peak, mean, and minimal flow velocities obtained from the phantom and the Doppler ultrasound device were compared by using linear regression analysis and Pearson correlation coefficient. Bland-Altman analyses were performed to evaluate the velocity differences between the flow generated by the phantom and the flow measurements made with the Doppler ultrasound device. The microfluidic system was able to generate the flow profiles as intended, and the fluid flow could be monitored and controlled by the software program. There were excellent linear correlations between the peak, mean, and minimal flow velocities of the phantom and those of the Doppler ultrasound device (r = 0.94-0.996, P < .001). However, the velocities were overestimated by the Doppler ultrasound device. This phantom provides opportunities for research and education involving the Doppler ultrasound technique in dentistry. Although Doppler ultrasound can be an effective tool for the measurement of pulpal blood flow velocity, it is essential to validate and calibrate the device before clinical use. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Is there subclinical enthesitis in early psoriatic arthritis? A clinical comparison with power doppler ultrasound.

PubMed

Freeston, J E; Coates, L C; Helliwell, P S; Hensor, E M A; Wakefield, R J; Emery, P; Conaghan, P G

2012-10-01

Enthesitis is a recognized feature of spondylarthritides (SpA), including psoriatic arthritis (PsA). Previously, ultrasound imaging has highlighted the presence of subclinical enthesitis in established SpA, but there are little data on ultrasound findings in early PsA. The aim of our study was to compare ultrasound and clinical examination (CE) for the detection of entheseal abnormalities in an early PsA cohort. Forty-two patients with new-onset PsA and 10 control subjects underwent CE of entheses for tenderness and swelling, as well as gray-scale (GS) and power Doppler (PD) ultrasound of a standard set of entheses. Bilateral elbow lateral epicondyles, Achilles tendons, and plantar fascia were assessed by both CE and ultrasound, the latter scored using a semiquantitative (SQ) scale. Inferior patellar tendons were assessed by ultrasound alone. A GS SQ score of >1 and/or a PD score of >0 was used to describe significant ultrasound entheseal abnormality. A total of 24 (57.1%) of 42 patients in the PsA group and 0 (0%) of 10 controls had clinical evidence of at least 1 tender enthesis. In the PsA group, for sites assessed by both CE and ultrasound, 4% (7 of 177) of nontender entheses had a GS score >1 and/or a PD score >0 compared to 24% (9 of 37) of tender entheses. CE overestimated activity in 28 (13%) of 214 of entheses. All the nontender ultrasound-abnormal entheses were in the lower extremity. The prevalence of subclinical enthesitis in this early PsA cohort was low. CE may overestimate active enthesitis. The few subclinically inflamed entheses were in the lower extremity, where mechanical stress is likely to be more significant. Copyright © 2012 by the American College of Rheumatology.

Improved visualization of intracranial vessels with intraoperative coregistration of rotational digital subtraction angiography and intraoperative 3D ultrasound.

PubMed

Podlesek, Dino; Meyer, Tobias; Morgenstern, Ute; Schackert, Gabriele; Kirsch, Matthias

2015-01-01

Ultrasound can visualize and update the vessel status in real time during cerebral vascular surgery. We studied the depiction of parent vessels and aneurysms with a high-resolution 3D intraoperative ultrasound imaging system during aneurysm clipping using rotational digital subtraction angiography as a reference. We analyzed 3D intraoperative ultrasound in 39 patients with cerebral aneurysms to visualize the aneurysm intraoperatively and the nearby vascular tree before and after clipping. Simultaneous coregistration of preoperative subtraction angiography data with 3D intraoperative ultrasound was performed to verify the anatomical assignment. Intraoperative ultrasound detected 35 of 43 aneurysms (81%) in 39 patients. Thirty-nine intraoperative ultrasound measurements were matched with rotational digital subtraction angiography and were successfully reconstructed during the procedure. In 7 patients, the aneurysm was partially visualized by 3D-ioUS or was not in field of view. Post-clipping intraoperative ultrasound was obtained in 26 and successfully reconstructed in 18 patients (69%) despite clip related artefacts. The overlap between 3D-ioUS aneurysm volume and preoperative rDSA aneurysm volume resulted in a mean accuracy of 0.71 (Dice coefficient). Intraoperative coregistration of 3D intraoperative ultrasound data with preoperative rotational digital subtraction angiography is possible with high accuracy. It allows the immediate visualization of vessels beyond the microscopic field, as well as parallel assessment of blood velocity, aneurysm and vascular tree configuration. Although spatial resolution is lower than for standard angiography, the method provides an excellent vascular overview, advantageous interpretation of 3D-ioUS and immediate intraoperative feedback of the vascular status. A prerequisite for understanding vascular intraoperative ultrasound is image quality and a successful match with preoperative rotational digital subtraction angiography.

Combined photothermal therapy and magneto-motive ultrasound imaging using multifunctional nanoparticles

NASA Astrophysics Data System (ADS)

Mehrmohammadi, Mohammad; Ma, Li L.; Chen, Yun-Sheng; Qu, Min; Joshi, Pratixa; Chen, Raeanna M.; Johnston, Keith P.; Emelianov, Stanislav

2010-02-01

Photothermal therapy is a laser-based non-invasive technique for cancer treatment. Photothermal therapy can be enhanced by employing metal nanoparticles that absorb the radiant energy from the laser leading to localized thermal damages. Targeting of nanoparticles leads to more efficient uptake and localization of photoabsorbers thus increasing the effectiveness of the treatment. Moreover, efficient targeting can reduce the required dosage of photoabsorbers; thereby reducing the side effects associated with general systematic administration of nanoparticles. Magnetic nanoparticles, due to their small size and response to an external magnetic field gradient have been proposed for targeted drug delivery. In this study, we investigate the applicability of multifunctional nanoparticles (e.g., magneto-plasmonic nanoparticles) and magneto-motive ultrasound imaging for image-guided photothermal therapy. Magneto-motive ultrasound imaging is an ultrasound based imaging technique capable of detecting magnetic nanoparticles indirectly by utilizing a high strength magnetic field to induce motion within the magnetically labeled tissue. The ultrasound imaging is used to detect the internal tissue motion. Due to presence of the magnetic component, the proposed multifunctional nanoparticles along with magneto-motive ultrasound imaging can be used to detect the presence of the photo absorbers. Clearly the higher concentration of magnetic carriers leads to a monotonic increase in magneto-motive ultrasound signal. Thus, magnetomotive ultrasound can determine the presence of the hybrid agents and provide information about their location and concentration. Furthermore, the magneto-motive ultrasound signal can indicate the change in tissue elasticity - a parameter that is expected to change significantly during the photothermal therapy. Therefore, a comprehensive guidance and assessment of the photothermal therapy may be feasible through magneto-motive ultrasound imaging and magnetoplasmonic nanoparticles.

[Physical principles and general considerations].

PubMed

Alfageme Roldán, F; Mollet Sánchez, J; Cerezo López, E

2015-11-01

Cutaneous ultrasound is based on the application of the physical properties of ultrasound to the skin and cutaneous adnexae. Knowledge of ultrasound semiology, artifacts and the application of Doppler examination allows deeper study of the biology and diseases of the skin and its adnexae. Copyright © 2015 Academia Española de Dermatología y Venereología. Published by Elsevier España, S.L.U. All rights reserved.

Monitoring stimulated cycles during in vitro fertilization treatment with ultrasound only--preliminary results.

PubMed

Wiser, Amir; Gonen, Ofer; Ghetler, Yehudit; Shavit, Tal; Berkovitz, Arie; Shulman, Adrian

2012-06-01

To evaluate if monitoring patients by ultrasound (US) only during in vitro fertilization (IVF) treatment is safe. Randomized prospective study. Patients undergoing their first IVF treatment were randomized into two groups. The ultrasound only group (study group) was monitored by US for follicle size and endometrial thickness without blood tests. In this group, only one blood test was taken before human chorionic gonadotropin (hCG) injection, to ensure a safe level of estradiol (E(2)) regarding ovarian hyperstimulation syndrome (OHSS) risk. The control group was monitored by ultrasound plus serum estradiol and progesterone concentration at each visit. Clinical pregnancy rate. No differences were found between the groups in the parameters of IVF treatment, induction days, number of ampoules, E(2) level of hCG, as well as embryo quality. The clinical pregnancy rate was not statistically different between the groups, 57.5% vs. 40.0%, respectively (p = 0.25). No OHSS cases were found among the study or control groups. Ultrasound as a single monitoring tool for IVF cycles is reliable, safe, patient friendly, and reduces treatment expenses. In an era of cost effectiveness awareness, this regimen should be considered for routine management in IVF programs.

Manipulation of Microbubble Clusters Using Focused Ultrasound

NASA Astrophysics Data System (ADS)

Matsuzaki, Hironobu; Osaki, Taichi; Kawaguchi, Kei; Unga, Johan; Ichiyanagi, Mitsuhisa; Azuma, Takashi; Suzuki, Ryo; Maruyama, Kazuo; Takagi, Shu

2017-11-01

In recent years, microbubbles (MBs) are expected to be utilized for the ultrasound drug delivery system (DDS). For the MB-DDS, it is important to establish a method of controlling bubbles and bubble clusters using ultrasound field. The objective of this study is to clarify behaviors of bubble clusters with various physical conditions. MBs in the ultrasound field are subjected to the primary Bjerknes force. The force traps MBs at the focal region of the focused ultrasound field. The trapped MBs form a bubble cluster at the region. A bubble cluster continues growing with absorbing surrounding bubbles until it reaches a maximum size beyond which it disappears from the focal region. In the present study, two kinds of MBs are used for the experiment. One is Sonazoid with average diameter of 2.6 um and resonant frequency of 5 MHz. The other is developed by Teikyo Univ., with average diameter of 1.5 um and presumed resonant frequency of 4 MHz. The bubble cluster's behaviors are analyzed using the high-speed camera. Sonazoid clusters have larger critical size than the other in every frequency, and its cluster size is inversely proportional to the ultrasound frequency, while Teikyo-bubble clusters have different tendency. These results are discussed in the presentation.

Ultrasound-mediated microbubble enhancement of radiation therapy studied using three-dimensional high-frequency power Doppler ultrasound.

PubMed

Kwok, Sheldon J J; El Kaffas, Ahmed; Lai, Priscilla; Al Mahrouki, Azza; Lee, Justin; Iradji, Sara; Tran, William Tyler; Giles, Anoja; Czarnota, Gregory J

2013-11-01

Tumor responses to high-dose (>8 Gy) radiation therapy are tightly connected to endothelial cell death. In the study described here, we investigated whether ultrasound-activated microbubbles can locally enhance tumor response to radiation treatments of 2 and 8 Gy by mechanically perturbing the endothelial lining of tumors. We evaluated vascular changes resulting from combined microbubble and radiation treatments using high-frequency 3-D power Doppler ultrasound in a breast cancer xenograft model. We compared treatment effects and monitored vasculature damage 3 hours, 24 hours and 7 days after treatment delivery. Mice treated with 2 Gy radiation and ultrasound-activated microbubbles exhibited a decrease in vascular index to 48 ± 10% at 24 hours, whereas vascular indices of mice treated with 2 Gy radiation alone or microbubbles alone were relatively unchanged at 95 ± 14% and 78 ± 14%, respectively. These results suggest that ultrasound-activated microbubbles enhance the effects of 2 Gy radiation through a synergistic mechanism, resulting in alterations of tumor blood flow. This novel therapy may potentiate lower radiation doses to preferentially target endothelial cells, thus reducing effects on neighboring normal tissue and increasing the efficacy of cancer treatments. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

Aptamer-conjugated and drug-loaded acoustic droplets for ultrasound theranosis.

PubMed

Wang, Chung-Hsin; Kang, Shih-Tsung; Lee, Ya-Hsuan; Luo, Yun-Ling; Huang, Yu-Fen; Yeh, Chih-Kuang

2012-02-01

Tumor therapy requires multi-functional treatment strategies with specific targeting of therapeutics to reduce general toxicity and increase efficacy. In this study we fabricated and functionally tested aptamer-conjugated and doxorubicin (DOX)-loaded acoustic droplets comprising cores of liquid perfluoropentane compound and lipid-based shell materials. Conjugation of sgc8c aptamers provided the ability to specifically target CCRF-CEM cells for both imaging and therapy. High-intensity focused ultrasound (HIFU) was introduced to trigger targeted acoustic droplet vaporization (ADV) which resulted in both mechanical cancer cell destruction by inertial cavitation and chemical treatment through localized drug release. HIFU insonation showed a 56.8% decrease in cell viability with aptamer-conjugated droplets, representing a 4.5-fold increase in comparison to non-conjugated droplets. In addition, the fully-vaporized droplets resulted in the highest DOX uptake by cancer cells, compared to non-vaporized or partially vaporized droplets. Optical studies clearly illustrated the transient changes that occurred upon ADV of droplet-targeted CEM cells, and B-mode ultrasound imaging revealed contrast enhancement by ADV in ultrasound images. In conclusion, our fabricated droplets functioned as a hybrid chemical and mechanical strategy for the specific destruction of cancer cells upon ultrasound-mediated ADV, while simultaneously providing ultrasound imaging capability. Copyright © 2011 Elsevier Ltd. All rights reserved.

Therapeutic ultrasound for acute ankle sprains.

PubMed

van den Bekerom, Michel Pj; van der Windt, Daniëlle Awm; Ter Riet, Gerben; van der Heijden, Geert J; Bouter, Lex M

2011-06-15

Ultrasound is used in the treatment of a wide variety of musculoskeletal disorders, which include acute ankle sprains. This is an update of a Cochrane review first published in 1999, and previously updated in 2004. To evaluate the effects of ultrasound therapy in the treatment of acute ankle sprains. We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (September 2010), the Cochrane Central Register of Controlled Trials (The Cochrane Library 2010, Issue 3), MEDLINE (1966 to September 2010), EMBASE (1983 to September 2010), CINAHL (1982 to 2004), and PEDro - the Physiotherapy Evidence Database (accessed 01/06/09). We also searched the Cochrane Rehabilitation and Related Therapies Field database, reference lists of articles, and contacted colleagues.The WHO International Clinical Trials Registry Platform was searched for ongoing trials. Randomised or quasi-randomised trials were included if the following conditions were met: at least one study group was treated with therapeutic ultrasound; participants had acute lateral ankle sprains; and outcome measures included general improvement, pain, swelling, functional disability, or range of motion. Two authors independently performed study selection, and assessed the risk of bias and extracted data. Risk ratios and risk differences together with 95% confidence intervals were calculated for dichotomous outcomes and mean differences together with 95% confidence intervals for continuous outcome measures. Limited pooling of data was undertaken where there was clinical homogeneity in terms of participants, treatments, outcomes, and follow-up time points. Six trials were included, involving 606 participants. Five trials included comparisons of ultrasound therapy with sham ultrasound; and three trials included single comparisons of ultrasound with three other treatments. The assessment of risk of bias was hampered by poor reporting of trial methods and results. None of the five placebo-controlled trials (sham ultrasound) demonstrated statistically significant differences between true and sham ultrasound therapy for any outcome measure at one to four weeks of follow-up. The pooled risk ratio for general improvement at one week was 1.04 (random-effects model, 95% confidence interval 0.92 to 1.17) for active versus sham ultrasound. The differences between intervention groups were generally small, between zero and six per cent, for most dichotomous outcomes. The evidence from the five small placebo-controlled trials included in this review does not support the use of ultrasound in the treatment of acute ankle sprains. The potential treatment effects of ultrasound appear to be generally small and of probably of limited clinical importance, especially in the context of the usually short-term recovery period for these injuries. However, the available evidence is insufficient to rule out the possibility that there is an optimal dosage schedule for ultrasound therapy that may be of benefit.

Neuromuscular ultrasound in patients with carpal tunnel syndrome and normal nerve conduction studies.

PubMed

Aseem, Fazila; Williams, Jessica W; Walker, Francis O; Cartwright, Michael S

2017-06-01

Nerve conduction studies (NCS) are sensitive for carpal tunnel syndrome (CTS), but a small proportion of patients with clinical CTS have normal NCS. This retrospective study was designed to assess the neuromuscular ultrasound findings in a group of CTS patients. The electronic medical record was reviewed by a neurologist to identify patients who had a diagnosis of CTS with normal NCS, including either mixed median-ulnar comparison or transcarpal sensory studies, and complete neuromuscular ultrasound evaluation for CTS. Fourteen individuals (22 wrists) met all criteria. A total of 92.3% had median nerve cross-sectional area enlargement at the wrist (mean 16.3 mm 2 ), 100% had increased wrist-to-forearm median nerve area ratio (mean 2.4), 82.4% had decreased median nerve echogenicity, 75.0% had decreased median nerve mobility, and 7.1% had increased median nerve vascularity. A large proportion of patients with clinical CTS but normal NCS have abnormal neuromuscular ultrasound findings. Muscle Nerve 55: 913-915, 2017. © 2016 Wiley Periodicals, Inc.

Factors Predictive of Improved Abdominal Ultrasound Visualization after Oral Administration of Simethicone.

PubMed

Marsico, Maria; Gabbani, Tommaso; Casseri, Tommaso; Biagini, Maria Rosa

2016-11-01

Ultrasonography is a non-invasive, accurate and low-cost technique used to study the upper abdomen, but it has reduced reliability in the study of the pancreas and retroperitoneum. Simethicone is a well-known emulsifying agent that has been used to improve ultrasonographic visualization. The aim of this study was to identify anthropometric parameters that are able to predict a good response to simethicone in improving ultrasonographic visualization of abdominal structures. One hundred twenty-seven patients were recruited. After basal examination, their anthropometric parameters were collected. Patients with an incomplete upper abdominal examination because of gastrointestinal gas have greater body mass index, waist circumference and abdominal wall thickness. In our study, the best anthropometric parameter for identifying patients with poor visualization at abdominal ultrasound examination is waist circumference. Using a cutoff of 84 cm, we can identify patients with poor visibility at abdominal ultrasound examination (group B) with a sensitivity of 90%. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Lung ultrasound accurately detects pneumothorax in a preterm newborn lamb model.

PubMed

Blank, Douglas A; Hooper, Stuart B; Binder-Heschl, Corinna; Kluckow, Martin; Gill, Andrew W; LaRosa, Domenic A; Inocencio, Ishmael M; Moxham, Alison; Rodgers, Karyn; Zahra, Valerie A; Davis, Peter G; Polglase, Graeme R

2016-06-01

Pneumothorax is a common emergency affecting extremely preterm. In adult studies, lung ultrasound has performed better than chest x-ray in the diagnosis of pneumothorax. The purpose of this study was to determine the efficacy of lung ultrasound (LUS) examination to detect pneumothorax using a preterm animal model. This was a prospective, observational study using newborn Border-Leicester lambs at gestational age = 126 days (equivalent to gestational age = 26 weeks in humans) receiving mechanical ventilation from birth to 2 h of life. At the conclusion of the experiment, LUS was performed, the lambs were then euthanised and a post-mortem exam was immediately performed. We used previously published ultrasound techniques to identify pneumothorax. Test characteristics of LUS to detect pneumothorax were calculated, using the post-mortem exam as the 'gold standard' test. Nine lambs (18 lungs) were examined. Four lambs had a unilateral pneumothorax, all of which were identified by LUS with no false positives. This was the first study to use post-mortem findings to test the efficacy of LUS to detect pneumothorax in a newborn animal model. Lung ultrasound accurately detected pneumothorax, verified by post-mortem exam, in premature, newborn lambs. © 2016 Paediatrics and Child Health Division (The Royal Australasian College of Physicians).

Doppler ultrasound-based measurement of tendon velocity and displacement for application toward detecting user-intended motion.

PubMed

Stegman, Kelly J; Park, Edward J; Dechev, Nikolai

2012-07-01

The motivation of this research is to non-invasively monitor the wrist tendon's displacement and velocity, for purposes of controlling a prosthetic device. This feasibility study aims to determine if the proposed technique using Doppler ultrasound is able to accurately estimate the tendon's instantaneous velocity and displacement. This study is conducted with a tendon mimicking experiment consisting of two different materials: a commercial ultrasound scanner, and a reference linear motion stage set-up. Audio-based output signals are acquired from the ultrasound scanner, and are processed with our proposed Fourier technique to obtain the tendon's velocity and displacement estimates. We then compare our estimates to an external reference system, and also to the ultrasound scanner's own estimates based on its proprietary software. The proposed tendon motion estimation method has been shown to be repeatable, effective and accurate in comparison to the external reference system, and is generally more accurate than the scanner's own estimates. After establishing this feasibility study, future testing will include cadaver-based studies to test the technique on the human arm tendon anatomy, and later on live human test subjects in order to further refine the proposed method for the novel purpose of detecting user-intended tendon motion for controlling wearable prosthetic devices.

Application of ultrasound in the dissolution of potential antiophidian compounds from two ethanolics extracts of two species of Heliconias.

PubMed

Estrada, G Sebastián; Jiménez, Silvia L; Alarcon, P Juan C; Vargas, Leidy J

2010-06-01

This study evaluates the favorable effects of using ultrasound during the dissolution process of ethanolic extracts of Heliconia psittacorum and Heliconia rostrata (Heliconiaceae), a family of plants reported to have antiophidic activities. The extracts were subjected to an ultrasound treatment before incubation with venom, and carbohydrate and protein contents were calculated. The ultrasound-treated extracts delayed the clotting effect of venom by up to 45.59 s compared to the positive control (venom). The metabolites content increased to 296.6% and 61.6% in protein and carbohydrate content, respectively. Ultrasound increases the amount of primary and secondary metabolites (potentially antiophidics) released from the extract into the media, and thereby enhances the anticoagulant activity of these plants against the Bothrops asper (mapaná X) venom. (c) 2010 Elsevier B.V. All rights reserved.

The Sound Games: Introducing Gamification into Stanford's Orientation on Emergency Ultrasound.

PubMed

Lobo, Viveta; Stromberg, Andrew Q; Rosston, Peter

2017-09-18

Point-of-care ultrasound is a critical component of graduate medical training in emergency medicine. Innovation in ultrasound teaching methods is greatly needed to keep up with a changing medical landscape. A field-wide trend promoting simulation and technology-enhanced learning is underway in an effort to improve patient care, as well as patient safety. In an effort to both motivate students and increase their skill retention, training methods are shifting towards a friendly competition model and are gaining popularity nationwide. In line with this emerging trend, Stanford incorporated the Sound Games - an educational ultrasound event with a distinctly competitive thread - within its existing two-day point-of-care ultrasound orientation course for emergency medicine interns. In this study, we demonstrate successful implementation of the orientation program, significant learning gains in participants, and overall student satisfaction with the course.

Pulsed Magneto-motive Ultrasound Imaging Using Ultrasmall Magnetic Nanoprobes

PubMed Central

Mehrmohammadi, Mohammad; Oh, Junghwan; Mallidi, Srivalleesha; Emelianov, Stanislav Y.

2011-01-01

Nano-sized particles are widely regarded as a tool to study biologic events at the cellular and molecular levels. However, only some imaging modalities can visualize interaction between nanoparticles and living cells. We present a new technique, pulsed magneto-motive ultrasound imaging, which is capable of in vivo imaging of magnetic nanoparticles in real time and at sufficient depth. In pulsed magneto-motive ultrasound imaging, an external high-strength pulsed magnetic field is applied to induce the motion within the magnetically labeled tissue and ultrasound is used to detect the induced internal tissue motion. Our experiments demonstrated a sufficient contrast between normal and iron-laden cells labeled with ultrasmall magnetic nanoparticles. Therefore, pulsed magneto-motive ultrasound imaging could become an imaging tool capable of detecting magnetic nanoparticles and characterizing the cellular and molecular composition of deep-lying structures. PMID:21439255

Ultrasound-Guided 50% Ethyl Alcohol Injection for Patients With Malleolar and Olecranon Bursitis: A Prospective Pilot Study

PubMed Central

Hong, Ji Seong; Lee, Jin Hyung

2016-01-01

Objective To evaluate the feasibility and effect of ultrasound-guided ethyl alcohol injection on malleolar and olecranon synovial proliferative bursitis. Methods Twenty-four patients received ultrasound-guided 50% diluted ethyl alcohol injection at the site of synovial proliferative bursitis after aspiration of the free fluid. Results Swelling and symptoms significantly decreased in 13 of the 24 patients without any complications. Eleven patients had partial improvement in swelling and symptoms. Conclusion Ultrasound-guided alcohol injection could be an alternative therapeutic option before surgery in patients with chronic intractable malleolar and olecranon synovial proliferative bursitis. PMID:27152282

Neuromuscular ultrasound of cranial nerves.

PubMed

Tawfik, Eman A; Walker, Francis O; Cartwright, Michael S

2015-04-01

Ultrasound of cranial nerves is a novel subdomain of neuromuscular ultrasound (NMUS) which may provide additional value in the assessment of cranial nerves in different neuromuscular disorders. Whilst NMUS of peripheral nerves has been studied, NMUS of cranial nerves is considered in its initial stage of research, thus, there is a need to summarize the research results achieved to date. Detailed scanning protocols, which assist in mastery of the techniques, are briefly mentioned in the few reference textbooks available in the field. This review article focuses on ultrasound scanning techniques of the 4 accessible cranial nerves: optic, facial, vagus and spinal accessory nerves. The relevant literatures and potential future applications are discussed.

Four-dimensional ultrasound current source density imaging of a dipole field

NASA Astrophysics Data System (ADS)

Wang, Z. H.; Olafsson, R.; Ingram, P.; Li, Q.; Qin, Y.; Witte, R. S.

2011-09-01

Ultrasound current source density imaging (UCSDI) potentially transforms conventional electrical mapping of excitable organs, such as the brain and heart. For this study, we demonstrate volume imaging of a time-varying current field by scanning a focused ultrasound beam and detecting the acoustoelectric (AE) interaction signal. A pair of electrodes produced an alternating current distribution in a special imaging chamber filled with a 0.9% NaCl solution. A pulsed 1 MHz ultrasound beam was scanned near the source and sink, while the AE signal was detected on remote recording electrodes, resulting in time-lapsed volume movies of the alternating current distribution.