Use of ultrasound scanning and body condition score to evaluate composition traits in mature beef cows

USDA-ARS?s Scientific Manuscript database

The experiment was designed to validate the use of ultrasound to evaluate body composition in mature beef cows. Both precision and accuracy of measurement were assessed. Cull cows (n = 87) selected for highly variable fatness were used. Two experienced ultrasound technicians scanned and assigned ...

Refixation of Osteochondral Fractures by an Ultrasound-Activated Pin System - An Ovine In Vivo Examination Using CT and Scanning Electron Microscope.

PubMed

H, Neumann; A P, Schulz; S, Breer; A, Unger; B, Kienast

2015-01-01

Osteochondral injuries, if not treated appropriately, often lead to severe osteoarthritis of the affected joint. Without refixation of the osteochondral fragment, human cartilage only repairs these defects imperfectly. All existing refixation systems for chondral defects have disadvantages, for instance bad MRI quality in the postoperative follow-up or low anchoring forces. To address the problem of reduced stability in resorbable implants, ultrasound-activated pins were developed. By ultrasound-activated melting of the tip of these implants a higher anchoring is assumed. Aim of the study was to investigate, if ultrasound-activated pins can provide a secure refixation of osteochondral fractures comparing to conventional screw and conventional, resorbable pin osteosynthesis. CT scans and scanning electron microscopy should proovegood refixation results with no further tissue damage by the melting of the ultrasound-activated pins in comparison to conventional osteosynthesis. Femoral osteochondral fragments in sheep were refixated with ultrasound-activated pins (SonicPin™), Ethipins(®) and screws (Asnis™). The quality of the refixated fragments was examined after three month of full weight bearing by CT scans and scanning electron microscopy of the cartilage surface. The CT examination found almost no statistically significant difference in the quality of refixation between the three different implants used. Concerning the CT morphology, ultrasound-activated pins demonstrated at least the same quality in refixation of osteochondral fragments as conventional resorbable pins or screws. The scanning electron microscopy showed no major surface damage by the three implants, especially any postulated cartilage damage induced by the heat of the ultrasound-activated pin. The screws protruded above the cartilage surface, which may affect the opposingtibial surface. Using CT scans and scanning electron microscopy, the SonicPin™, the Ethipin(®) and screws were at least

[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.

A scanned focused ultrasound device for hyperthermia: numerical simulation and prototype implementation

NASA Astrophysics Data System (ADS)

Meaney, Paul M.; Raynolds, Timothy; Geimer, Shireen D.; Potwin, Lincoln; Paulsen, Keith D.

2004-07-01

We are developing a scanned focused ultrasound system for hyperthermia treatment of breast cancer. Focused ultrasound has significant potential as a therapy delivery device because it can focus sufficient heating energy below the skin surface with minimal damage to intervening tissue. However, as a practical therapy system, the focal zone is generally quite small and requires either electronic (in the case of a phased array system) or mechanical steering (for a fixed bowl transducer) to cover a therapeutically useful area. We have devised a simple automated steering system consisting of a focused bowl transducer supported by three vertically movable rods which are connected to computer controlled linear actuators. This scheme is particularly attractive for breast cancer hyperthermia where the support rods can be fed through the base of a liquid coupling tank to treat tumors within the breast while coupled to our noninvasive microwave thermal imaging system. A MATLAB routine has been developed for controlling the rod motion such that the beam focal point scans a horizontal spiral and the subsequent heating zone is cylindrical. In coordination with this effort, a 3D finite element thermal model has been developed to evaluate the temperature distributions from the scanned focused heating. In this way, scanning protocols can be optimized to deliver the most uniform temperature rise to the desired location.

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…

Refixation of Osteochondral Fractures by an Ultrasound-Activated Pin System – An Ovine In Vivo Examination Using CT and Scanning Electron Microscope

PubMed Central

H, Neumann; A.P, Schulz; S, Breer; A, Unger; B, Kienast

2015-01-01

Background: Osteochondral injuries, if not treated appropriately, often lead to severe osteoarthritis of the affected joint. Without refixation of the osteochondral fragment, human cartilage only repairs these defects imperfectly. All existing refixation systems for chondral defects have disadvantages, for instance bad MRI quality in the postoperative follow-up or low anchoring forces. To address the problem of reduced stability in resorbable implants, ultrasound-activated pins were developed. By ultrasound-activated melting of the tip of these implants a higher anchoring is assumed. Aim of the study was to investigate, if ultrasound-activated pins can provide a secure refixation of osteochondral fractures comparing to conventional screw and conventional, resorbable pin osteosynthesis. CT scans and scanning electron microscopy should proovegood refixation results with no further tissue damage by the melting of the ultrasound-activated pins in comparison to conventional osteosynthesis. Methods: Femoral osteochondral fragments in sheep were refixated with ultrasound-activated pins (SonicPin™), Ethipins® and screws (Asnis™). The quality of the refixated fragments was examined after three month of full weight bearing by CT scans and scanning electron microscopy of the cartilage surface. Results: The CT examination found almost no statistically significant difference in the quality of refixation between the three different implants used. Concerning the CT morphology, ultrasound-activated pins demonstrated at least the same quality in refixation of osteochondral fragments as conventional resorbable pins or screws. The scanning electron microscopy showed no major surface damage by the three implants, especially any postulated cartilage damage induced by the heat of the ultrasound-activated pin. The screws protruded above the cartilage surface, which may affect the opposingtibial surface. Conclusion: Using CT scans and scanning electron microscopy, the Sonic

Ultrasound line-by-line scanning method of spatial-temporal active cavitation mapping for high-intensity focused ultrasound.

PubMed

Ding, Ting; Zhang, Siyuan; Fu, Quanyou; Xu, Zhian; Wan, Mingxi

2014-01-01

This paper presented an ultrasound line-by-line scanning method of spatial-temporal active cavitation mapping applicable in a liquid or liquid filled tissue cavities exposed by high-intensity focused ultrasound (HIFU). Scattered signals from cavitation bubbles were obtained in a scan line immediately after one HIFU exposure, and then there was a waiting time of 2 s long enough to make the liquid back to the original state. As this pattern extended, an image was built up by sequentially measuring a series of such lines. The acquisition of the beamformed radiofrequency (RF) signals for a scan line was synchronized with HIFU exposure. The duration of HIFU exposure, as well as the delay of the interrogating pulse relative to the moment while HIFU was turned off, could vary from microseconds to seconds. The feasibility of this method was demonstrated in tap-water and a tap-water filled cavity in the tissue-mimicking gelatin-agar phantom as capable of observing temporal evolutions of cavitation bubble cloud with temporal resolution of several microseconds, lateral and axial resolution of 0.50 mm and 0.29 mm respectively. The dissolution process of cavitation bubble cloud and spatial distribution affected by cavitation previously generated were also investigated. Although the application is limited by the requirement for a gassy fluid (e.g. tap water, etc.) that allows replenishment of nuclei between HIFU exposures, the technique may be a useful tool in spatial-temporal cavitation mapping for HIFU with high precision and resolution, providing a reference for clinical therapy. Copyright © 2013 Elsevier B.V. All rights reserved.

Factors affecting feasibility and quality of second-trimester ultrasound scans in obese pregnant women.

PubMed

Fuchs, F; Houllier, M; Voulgaropoulos, A; Levaillant, J-M; Colmant, C; Bouyer, J; Senat, M-V

2013-01-01

To evaluate the feasibility of completing in one session a second-trimester ultrasound scan in obese pregnant women, to compare the quality of images obtained with those of non-obese women and to analyze factors that can improve the completion rate. This prospective study, from 2009 to 2011, included all obese pregnant women (prepregnancy body mass index (BMI) > 30 kg/m2) who had an ultrasound examination at 20-24 weeks in our department, and a control group of pregnant women with normal BMI (20-24.9 kg/m2) who had the same examination. A single operator reviewed the standardized ultrasound images (three biometric and six to assess key anatomical features) required under French guidelines, to assess their presence, evaluate the quality of all images and score the quality of the six anatomical images. Each image was assessed according to between four and six criteria, each worth one point. We sought excellent quality, defined as the frequency of maximum points for a given image type. The factors associated with completing the scan in one session were evaluated with multivariate logistic regression. The obese group included 223 women and the control group 60; a complete scan in one session was achieved in 70.4% and 81.7% of these, respectively (P = 0.08). The completion rate for each image type was at least 95% in the control group and 90% in the obese group, except for diaphragm and right outflow tract images. Significant factors associated with completing the scan in the multivariate model were: having 10 additional minutes for the scan (P = 0.03), moving the fetus so that the back was in posterior or lateral position (P = 0.01), more experienced sonographer (P = 0.03) and thinner maternal abdominal wall thickness (P = 0.01). Overall, the excellence rate varied from 35% to 92% in the normal BMI group and from 18% to 58% in the obese group, and was significantly lower in the latter for all images except abdominal circumference (P�

Investigation into the quantitative and qualitative characteristics of choroidal melanoma through magnetic resonance imaging and B-scan ultrasound

PubMed Central

Papayiannis, Vassilis; Tsaousis, Konstantinos T; Kouskouras, Constantinos A; Haritanti, Afroditi; Diakonis, Vasilios F; Tsinopoulos, Ioannis T

2017-01-01

Objective To investigate the homogeneity and vascularity of choroidal melanoma through magnetic resonance imaging (MRI) and brightness modulation (B-mode) ultrasound scan and their correlation with dimensions of tumor, as well as to measure the sensitivity of both modalities in retinal detachment (RD) detection. Materials and methods This retrospective chart review included patients diagnosed with choroidal melanoma. All these patients underwent MRI scans using T2-weighted (T2-WI) and T1-weighted (T1-WI) sequences, before and after an intravenous injection of paramagnetic contrast material. The patients were also examined using a B-mode ultrasound scan, and the results from both modalities were compared (tumor homogeneity, tumor height, tumor base diameter, and tumor vascularity). Results Forty-two patients (mean age=65.33±12.51 years) with choroidal melanoma were included in the study. Homogeneity was confirmed in 16 patients through ultrasound scan, in 19 patients through T1-WI sequence, in 21 patients through T2-WI sequence, and in 25 patients through T1-WI sequence + contrast (gadolinium). Patients with homogenous tumors presented with lower (P=0.0045) mean height than that of those with nonhomogenous tumors, whereas no statistically significant difference was found for base diameter measurements (P=0.056). Patients with tumors of high vascularity presented with greater mean height (P=0.000638) and greater mean base diameter compared with those with tumors of low vascularity (P=0.019543). RD was detected in 26 patients through T1-WI sequence, in 13 patients through T2-WI sequence, in 26 patients through T1-WI sequence + contrast, and in 32 patients through ultrasound scan, which proved to be the most sensitive modality. Conclusion The height of choroidal melanoma was positively correlated with tumor’s homogeneity. Melanomas of greater height were found to be less homogenous, due to increased degeneration and higher occurrence of intratumoral hemorrhage. In

Tissue ablation accelerated by peripheral scanning mode with high-intensity focused ultrasound: a study on isolated porcine liver perfusion.

PubMed

Bu, Rui; Yin, Li; Yang, Han; Wang, Qi; Wu, Feng; Zou, Jian Zhong

2013-08-01

The aims of this study were to investigate the feasibility of accelerated tissue ablation using a peripheral scanning mode with high-intensity focused ultrasound (HIFU) and to explore the effect of flow rate on total energy consumption of the target tissues. Using a model of isolated porcine liver perfusion via the portal vein and hepatic artery, we conducted a scanning protocol along the periphery of the target tissues using linear-scanned HIFU to carefully adjust the varying focal depth, generator power, scanning velocity and line-by-line interval over the entire ablation range. Porcine livers were divided into four ablation groups: group 1, n = 12, with dual-vessel perfusion; group 2, n = 11, with portal vein perfusion alone; group 3, n = 10, with hepatic artery perfusion alone; and group 4, n = 11, control group with no-flow perfusion. The samples were cut open consecutively at a thickness of 3 mm, and the actual ablation ranges were calculated along the periphery of the target tissues after triphenyl tetrazolium chloride staining. Total energy consumption was calculated as the sum of the energy requirements at various focal depths in each group. On the basis of the pre-supposed scanning protocol, the peripheral region of the target tissue formed a complete coagulation necrosis barrier in each group with varying dose combinations, and the volume of the peripheral necrotic area did not differ significantly among the four groups (p > 0.05). Furthermore, total energy consumption in each group significantly decreased with the corresponding decrease in flow rate (p < 0.01). This study revealed that the complete peripheral necrosis barrier within the target tissues can defined using linear-scanned HIFU in an isolated porcine liver perfusion model. Additionally, the flow rate in the major hepatic vessels may play an important role in the use of the peripheral ablation mode, and this novel mode of ablation may enhance the therapeutic efficacy and tolerability of the

Abdominal ultrasound (image)

MedlinePlus

Abdominal ultrasound is a scanning technique used to image the interior of the abdomen. Like the X-ray, MRI, ... it has its place as a diagnostic tool. Ultrasound scans use high frequency sound waves to produce ...

Laser Ultrasound Spectroscopy Scanning for 3D Printed Parts

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

Brennan, Guendalyn Kendra

One of the challenges of additive manufacturing is quality control due to the possibility of unseen flaws in the final product. The current methods of inspection are lacking in detail, too slow for practical use, or unable to validate internal structure. This report examines the use of laser ultrasound spectroscopy in layer by layer scans of 3D printed parts as they are created. The result is fast and detailed quality control. An additional advantage of this method is the ability to cancel a print as soon as a defect is detected, therefore saving materials and time. This technique, though simplemore » in concept, has been a challenge to implement. I discuss tweaking the 3D printer configuration, and finding the optimal settings for laser scanning small parts made of ABS plastic, as well as the limits of how small of a detail the laser can detect. These settings include the frequency of the ultrasonic transducer, the speed of the laser, and the distance from the laser to the part.« less

Etiology of congenital hypothyroidism using thyroglobulin and ultrasound combination.

PubMed

Beltrão, Cristine B; Juliano, Adriana G; Chammas, Maria C; Watanabe, Tomoco; Sapienza, Marcelo T; Marui, Suemi

2010-01-01

Methods currently employed to establish the etiology of congenital hypothyroidism include thyroid ultrasound and scintigraphic exams. Thyroglobulin is a protein almost exclusively secreted by thyroid tissue and indirectly reflects the amount of follicular cells. Even though thyroglobulin is easy to measure, it has been not frequently used because of discordant results to distinguish mainly athyreosis and ectopy (dysgenesis). Knowing the differences in inheritance and prognosis of thyroid dysgenesis and dyshormonogenesis, it is important to define the etiology of CH, combining tools that are easy, fast and available in most medical centers. Our objective was to evaluate and compare color Doppler ultrasound and serum thyroglobulin with radionuclide scan to define the etiology of congenital hypothyroidism. We evaluated 38 children above 3 years-old off-treatment that performed serum thyroglobulin by immunofluorometric assay, color Doppler ultrasound and radionuclide study. On color Doppler ultrasound, 11 patients had athyreosis, 5 ectopic glands, being 1 associated to hemiagenesis. Twenty one had topic thyroid (3 goiters, 10 normal, 8 hypoplastic). Hemiagenesis and cystic lesion were not revealed by radionuclide scan. We observed substantial agreement between color Doppler ultrasound and radionuclide scan (kappa=0.745, p<0.0001). Serum thyroglobulin in athyreosis ranged from <1.0 to 18.7 micro g/L. Patients with ectopic glands showed wider thyroglobulin range (4.5 to 123 micro g/L, median 28.4 micro g/L). Only one patient showed thyroglobulin deficiency. By using color Doppler ultrasound and serum thyroglobulin levels as valuable combined tools, we established the etiology of congenital hypothyroidism limiting excessive and harmful exams in children, like radionuclide scan.

The ultrasound brain helmet: feasibility study of multiple simultaneous 3D scans of cerebral vasculature.

PubMed

Smith, Stephen W; Ivancevich, Nikolas M; Lindsey, Brooks D; Whitman, John; Light, Edward; Fronheiser, Matthew; Nicoletto, Heather A; Laskowitz, Daniel T

2009-02-01

We describe early stage experiments to test the feasibility of an ultrasound brain helmet to produce multiple simultaneous real-time three-dimensional (3D) scans of the cerebral vasculature from temporal and suboccipital acoustic windows of the skull. The transducer hardware and software of the Volumetrics Medical Imaging (Durham, NC, USA) real-time 3D scanner were modified to support dual 2.5 MHz matrix arrays of 256 transmit elements and 128 receive elements which produce two simultaneous 64 degrees pyramidal scans. The real-time display format consists of two coronal B-mode images merged into a 128 degrees sector, two simultaneous parasagittal images merged into a 128 degrees x 64 degrees C-mode plane and a simultaneous 64 degrees axial image. Real-time 3D color Doppler scans from a skull phantom with latex blood vessel were obtained after contrast agent injection as a proof of concept. The long-term goal is to produce real-time 3D ultrasound images of the cerebral vasculature from a portable unit capable of internet transmission thus enabling interactive 3D imaging, remote diagnosis and earlier therapeutic intervention. We are motivated by the urgency for rapid diagnosis of stroke due to the short time window of effective therapeutic intervention.

Feasibility of rotational scan ultrasound imaging by an angled high frequency transducer for the posterior segment of the eye.

PubMed

Paeng, Dong-Guk; Chang, Jin Ho; Chen, Ruimin; Humayun, Mark S; Shung, K Kirk

2009-03-01

High frequency ultrasound over 40 MHz has been used to image the anterior segment of the eye, but it is not suitable for the posterior segment due to the frequency dependent attenuation of ultrasound and thus the limitation of penetration depth. This paper proposes a novel scan method to image the posterior segment of the eye with an angled high frequency (beyond 40 MHz) ultrasound needle transducer. In this method, the needle transducer is inserted into the eye through a small incision hole (approximately 1 mm in diameter) and rotated around the axial direction to form a cone-shaped imaging plane, allowing the spatial information of retinal vessels and diagnosis of their occlusion to be displayed. The feasibility of this novel technique was tested with images of a wire phantom, a polyimide tube, and an excised pig eye obtained by manually rotating a 40-MHz PMN-PT needle transducer with a beveled tip of 45 degrees . From the results, we believe that rotational scan imaging will help expand the minimally invasive applications of high frequency ultrasound to other areas due to the capability of increased closeness of an angled needle transducer to structures of interest buried in other tissues.

Ultrasound for fetal assessment in early pregnancy

PubMed Central

Whitworth, Melissa; Bricker, Leanne; Neilson, James P; Dowswell, Therese

2014-01-01

Background Diagnostic ultrasound is a sophisticated electronic technology, which utilises pulses of high frequency sound to produce an image. Diagnostic ultrasound examination may be employed in a variety of specific circumstances during pregnancy such as after clinical complications, or where there are concerns about fetal growth. Because adverse outcomes may also occur in pregnancies without clear risk factors, assumptions have been made that routine ultrasound in all pregnancies will prove beneficial by enabling earlier detection and improved management of pregnancy complications. Routine screening may be planned for early pregnancy, late gestation, or both. The focus of this review is routine early pregnancy ultrasound. Objectives To assess whether routine early pregnancy ultrasound for fetal assessment (i.e. its use as a screening technique) influences the diagnosis of fetal malformations, multiple pregnancies, the rate of clinical interventions, and the incidence of adverse fetal outcome when compared with the selective use of early pregnancy ultrasound (for specific indications). Search methods We searched the Cochrane Pregnancy and Childbirth Group’s Trials Register (September 2009). Selection criteria Published, unpublished, and ongoing randomised controlled trials that compared outcomes in women who experienced routine versus selective early pregnancy ultrasound (i.e. less than 24 weeks’ gestation). We have included quasi-randomised trials. Data collection and analysis Two review authors independently extracted data for each included study. We used the Review Manager software to enter and analyse data. Main results Routine/revealed ultrasound versus selective ultrasound/concealed: 11 trials including 37505 women. Ultrasound for fetal assessment in early pregnancy reduces the failure to detect multiple pregnancy by 24 weeks’ gestation (risk ratio (RR) 0.07, 95% confidence interval (CI) 0.03 to 0.17). Routine scan is associated with a reduction in

Consensus-based identification of factors related to false-positives in ultrasound scanning of synovitis and tenosynovitis.

PubMed

Ikeda, Kei; Narita, Akihiro; Ogasawara, Michihiro; Ohno, Shigeru; Kawahito, Yutaka; Kawakami, Atsushi; Ito, Hiromu; Matsushita, Isao; Suzuki, Takeshi; Misaki, Kenta; Ogura, Takehisa; Kamishima, Tamotsu; Seto, Yohei; Nakahara, Ryuichi; Kaneko, Atsushi; Nakamura, Takayuki; Henmi, Mihoko; Fukae, Jun; Nishida, Keiichiro; Sumida, Takayuki; Koike, Takao

2016-01-01

We aimed to identify causes of false-positives in ultrasound scanning of synovial/tenosynovial/bursal inflammation and provide corresponding imaging examples. We first performed systematic literature review to identify previously reported causes of false-positives. We next determined causes of false-positives and corresponding example images for educational material through Delphi exercises and discussion by 15 experts who were an instructor and/or a lecturer in the 2013 advanced course for musculoskeletal ultrasound organized by Japan College of Rheumatology Committee for the Standardization of Musculoskeletal Ultrasonography. Systematic literature review identified 11 articles relevant to sonographic false-positives of synovial/tenosynovial inflammation. Based on these studies, 21 candidate causes of false-positives were identified in the consensus meeting. Of these items, 11 achieved a predefined consensus (≥ 80%) in Delphi exercise and were classified as follows: (I) Gray-scale assessment [(A) non-specific synovial findings and (B) normal anatomical structures which can mimic synovial lesions due to either their low echogenicity or anisotropy]; (II) Doppler assessment [(A) Intra-articular normal vessels and (B) reverberation)]. Twenty-four corresponding examples with 49 still and 23 video images also achieved consensus. Our study provides a set of representative images that can help sonographers to understand false-positives in ultrasound scanning of synovitis and tenosynovitis.

Obstetric Ultrasound

PubMed Central

Nicholson, Stuart F.; Nimrod, Carl A.

1988-01-01

This article addresses the current indications for an obstetric ultrasound and describes the findings that it is reasonable to expect when reading an ultrasound report. The authors discuss several common obstetrical problems focussing the attention on the usefulness of the imaging information. Finally, they provide a glimpse into the future direction of obstetric ultrasound by discussing vaginal scanning, Doppler assessment of fetal blood flow, and routine ultrasound in pregnancy. PMID:21253229

Feasibility of Rotational Scan Ultrasound Imaging by an Angled High Frequency Transducer for the Posterior Segment of the Eye

PubMed Central

Paeng, Dong-Guk; Chang, Jin Ho; Chen, Ruimin; Humayun, Mark S.; Shung, K. Kirk

2009-01-01

High frequency ultrasound over 40 MHz has been used to image the anterior segment of the eye, but it is not suitable for the posterior segment due to the frequency-dependent attenuation of ultrasound and thus the limitation of penetration depth. This paper proposes a novel scan method to image the posterior segment of the eye with an angled high frequency (beyond 40 MHz) ultrasound needle transducer. In this method, the needle transducer is inserted into the eye through a small incision hole (∼1 mm in diameter) and rotated around the axial direction to form a cone-shaped imaging plane, allowing the spatial information of retinal vessels and diagnosis of their occlusion to be displayed. The feasibility of this novel technique was tested with images of a wire phantom, a polyimide tube, and an excised pig eye obtained by manually rotating a 40-MHz PMN-PT needle transducer with a beveled tip of 45°. From the results, we believe that rotational scan imaging will help expand the minimally invasive applications of high frequency ultrasound to other areas due to the capability of increased closeness of an angled needle transducer to structures of interest buried in other tissues. PMID:19411226

Fincke performs an ultrasound bone scan on Padalka using the ADUM in the U.S. Lab during Expedition 9

NASA Image and Video Library

2004-08-10

ISS009-E-17439 (10 August 2004) --- Astronaut Edward M. (Mike) Fincke (foreground), Expedition 9 NASA ISS science officer and flight engineer, performs an ultrasound bone scan on cosmonaut Gennady I. Padalka, commander representing Russia's Federal Space Agency. The two are using the Advanced Diagnostic Ultrasound in Micro-G (ADUM) in the Destiny laboratory of the International Space Station (ISS). The ADUM keyboard, flat screen display and front control panel are visible at right.

Automated ultrasound scanning on a dual-modality breast imaging system: coverage and motion issues and solutions.

PubMed

Sinha, Sumedha P; Goodsitt, Mitchell M; Roubidoux, Marilyn A; Booi, Rebecca C; LeCarpentier, Gerald L; Lashbrook, Christine R; Thomenius, Kai E; Chalek, Carl L; Carson, Paul L

2007-05-01

We are developing an automated ultrasound imaging-mammography system wherein a digital mammography unit has been augmented with a motorized ultrasound transducer carriage above a special compression paddle. Challenges of this system are acquiring complete coverage of the breast and minimizing motion. We assessed these problems and investigated methods to increase coverage and stabilize the compressed breast. Visual tracings of the breast-to-paddle contact area and breast periphery were made for 10 patients to estimate coverage area. Various motion artifacts were evaluated in 6 patients. Nine materials were tested for coupling the paddle to the breast. Fourteen substances were tested for coupling the transducer to the paddle in lateral-to-medial and medial-to-lateral views and filling the gap between the peripheral breast and paddle. In-house image registration software was used to register adjacent ultrasound sweeps. The average breast contact area was 56%. The average percentage of the peripheral air gap filled with ultrasound gel was 61%. Shallow patient breathing proved equivalent to breath holding, whereas speech and sudden breathing caused unacceptable artifacts. An adhesive spray that preserves image quality was found to be best for coupling the breast to the paddle and minimizing motion. A highly viscous ultrasound gel proved most effective for coupling the transducer to the paddle for lateral-to-medial and medial-to-lateral views and for edge fill-in. The challenges of automated ultrasound scanning in a multimodality breast imaging system have been addressed by developing methods to fill in peripheral gaps, minimize patient motion, and register and reconstruct multisweep ultrasound image volumes.

Optical detection of ultrasound using an apertureless near-field scanning optical microscopy system

NASA Astrophysics Data System (ADS)

Ahn, Phillip; Zhang, Zhen; Sun, Cheng; Balogun, Oluwaseyi

2013-01-01

Laser ultrasonics techniques are power approaches for non-contact generation and detection of high frequency ultrasound on a local scale. In these techniques, optical diffraction limits the spatial information that can be accessed from a measurement. In order to improve the lateral spatial resolution, we incorporate an apertureless near-field scanning optical microscope (aNSOM) into laser ultrasonics setup for local detection of laser generated ultrasound. The aNSOM technique relies on the measurement of a weak backscattered near-field light intensity resulting from the oblique illumination of a nanoscale probe-tip positioned close to a sample surface. We enhance the optical near-field intensity by coupling light to surface plasmon polaritons (SPPs) on the shaft of an atomic force microscopy (AFM) cantilever. The SPPs propagate down the AFM shaft, localize at the tip apex, and are backscattered to the far-field when the separation distance between the probe tip and the sample surface is comparable to the probe-tip radius. The backscattered near-field intensity is dynamically modulated when an ultrasonic wave arrives at the sample surface leading to a transient change in the tip-sample separation distance. We present experimental results detailing measurement of broadband and narrowband laser generated ultrasound in solids with frequencies reaching up to 180 MHz range.

Gallbladder radionuclide scan

MedlinePlus

... Gallbladder scan; Biliary scan; Cholescintigraphy; HIDA; Hepatobiliary nuclear imaging scan ... test results. This test is combined with other imaging (such as CT or ultrasound). After the gallbladder ...

Focused Ultrasound Surgery for Uterine Fibroids

MedlinePlus

... ultrasound surgery, your doctor may perform a pelvic magnetic resonance imaging (MRI) scan before treatment. Focused ultrasound surgery — also called magnetic resonance-guided focused ultrasound surgery or focused ultrasound ...

Transvaginal ultrasound (image)

MedlinePlus

Transvaginal ultrasound is a method of imaging the genital tract in females. A hand held probe is inserted directly ... vaginal cavity to scan the pelvic structures, while ultrasound pictures are viewed on a monitor. The test ...

Evaluation of diagnostic value of CT scan, physical examination and ultrasound based on pathological findings in patients with pelvic masses.

PubMed

Firoozabadi, Razieh Dehghani; Karimi Zarchi, Mojgan; Mansurian, Hamid Reza; Moghadam, Bita Rafiei; Teimoori, Soraya; Naseri, Ali

2011-01-01

Because benign and malignant cervical and ovarian masses occur with different percentages in different age groups, the importance of primary diagnosis and selection of a suitable surgical procedure is underlined. Diagnosis of pelvic masses is carried out using ultrasound, physical examination, CT scan and MRI. The objective of this study is to evaluate the diagnostic value of CT scan in pelvic masses in comparison with physical examination-ultrasound based on pathology of the lesion in patients undergoing laparotomic surgery. This analytic-descriptive study focused on age, sonographic findings, physical examinations, CT scan and pathological findings in 139 patients with pelvic mass, gathered with questionnaires and statistically analayzed using the SPSS software programme. Of 139 patients with pelvic mass (patients aged from 17 to 75 years old), 62 (44%) cases were diagnosed as benign and 77 (55.4%) as malignant; among them malignant tratoma serocyst adenocarsinoma with 33 (23.7%) cases and benign myoma with 21 (15.2%) cases comprised the most frequent cases. The sensitivity and specificity of sonography-physical examination were 51.9% and 87.9% respectively and the sensitivity and specificity of CT scan images were 79.2% and 91.6% respectively. It was shown that CT scan images were more consistant with pathological findings in predicting appropriate surgical procedures than do sonography-physical examinations. The sensitivity of CT scan is far higher than that of sonography-physical examination in the diagnosis of pelvic mass malignancy.

The ultrasound brain helmet: early human feasibility study of multiple simultaneous 3D scans of cerebral vasculature

NASA Astrophysics Data System (ADS)

Lindsey, Brooks D.; Ivancevich, Nikolas M.; Whitman, John; Light, Edward; Fronheiser, Matthew; Nicoletto, Heather A.; Laskowitz, Daniel T.; Smith, Stephen W.

2009-02-01

We describe early stage experiments to test the feasibility of an ultrasound brain helmet to produce multiple simultaneous real-time 3D scans of the cerebral vasculature from temporal and suboccipital acoustic windows of the skull. The transducer hardware and software of the Volumetrics Medical Imaging real-time 3D scanner were modified to support dual 2.5 MHz matrix arrays of 256 transmit elements and 128 receive elements which produce two simultaneous 64° pyramidal scans. The real-time display format consists of two coronal B-mode images merged into a 128° sector, two simultaneous parasagittal images merged into a 128° × 64° C-mode plane, and a simultaneous 64° axial image. Real-time 3D color Doppler images acquired in initial clinical studies after contrast injection demonstrate flow in several representative blood vessels. An offline Doppler rendering of data from two transducers simultaneously scanning via the temporal windows provides an early visualization of the flow in vessels on both sides of the brain. The long-term goal is to produce real-time 3D ultrasound images of the cerebral vasculature from a portable unit capable of internet transmission, thus enabling interactive 3D imaging, remote diagnosis and earlier therapeutic intervention. We are motivated by the urgency for rapid diagnosis of stroke due to the short time window of effective therapeutic intervention.

Non-invasive transcranial ultrasound therapy based on a 3D CT scan: protocol validation and in vitro results

NASA Astrophysics Data System (ADS)

Marquet, F.; Pernot, M.; Aubry, J.-F.; Montaldo, G.; Marsac, L.; Tanter, M.; Fink, M.

2009-05-01

A non-invasive protocol for transcranial brain tissue ablation with ultrasound is studied and validated in vitro. The skull induces strong aberrations both in phase and in amplitude, resulting in a severe degradation of the beam shape. Adaptive corrections of the distortions induced by the skull bone are performed using a previous 3D computational tomography scan acquisition (CT) of the skull bone structure. These CT scan data are used as entry parameters in a FDTD (finite differences time domain) simulation of the full wave propagation equation. A numerical computation is used to deduce the impulse response relating the targeted location and the ultrasound therapeutic array, thus providing a virtual time-reversal mirror. This impulse response is then time-reversed and transmitted experimentally by a therapeutic array positioned exactly in the same referential frame as the one used during CT scan acquisitions. In vitro experiments are conducted on monkey and human skull specimens using an array of 300 transmit elements working at a central frequency of 1 MHz. These experiments show a precise refocusing of the ultrasonic beam at the targeted location with a positioning error lower than 0.7 mm. The complete validation of this transcranial adaptive focusing procedure paves the way to in vivo animal and human transcranial HIFU investigations.

A-scan ultrasound system for real-time puncture safety assessment during percutaneous nephrolithotomy

NASA Astrophysics Data System (ADS)

Rodrigues, Pedro L.; Rodrigues, Nuno F.; Fonseca, Jaime C.; von Krüger, M. A.; Pereira, W. C. A.; Vilaça, João. L.

2015-03-01

Background: Kidney stone is a major universal health problem, affecting 10% of the population worldwide. Percutaneous nephrolithotomy is a first-line and established procedure for disintegration and removal of renal stones. Its surgical success depends on the precise needle puncture of renal calyces, which remains the most challenging task for surgeons. This work describes and tests a new ultrasound based system to alert the surgeon when undesirable anatomical structures are in between the puncture path defined through a tracked needle. Methods: Two circular ultrasound transducers were built with a single 3.3-MHz piezoelectric ceramic PZT SN8, 25.4 mm of radius and resin-epoxy matching and backing layers. One matching layer was designed with a concave curvature to work as an acoustic lens with long focusing. The A-scan signals were filtered and processed to automatically detect reflected echoes. Results: The transducers were mapped in water tank and tested in a study involving 45 phantoms. Each phantom mimics different needle insertion trajectories with a percutaneous path length between 80 and 150 mm. Results showed that the beam cross-sectional area oscillates around the ceramics radius and it was possible to automatically detect echo signals in phantoms with length higher than 80 mm. Conclusions: This new solution may alert the surgeon about anatomical tissues changes during needle insertion, which may decrease the need of X-Ray radiation exposure and ultrasound image evaluation during percutaneous puncture.

Immersion ultrasonography: simultaneous A-scan and B-scan.

PubMed

Coleman, D J; Dallow, R L; Smith, M E

1979-01-01

In eyes with opaque media, ophthalmic ultrasound provides a unique source of information that can dramatically affect the course of patient management. In addition, when an ocular abnormality can be visualized, ultrasonography provides information that supplements and complements other diagnostic testing. It provides documentation and differentiation of abnormal states, such as vitreous hemorrhage and intraocular tumor, as well as differentiation of orbital tumors from inflammatory causes of exophthalmos. Additional capabilities of ultrasound are biometric determinations for calculation of intraocular lens implant powers and drug-effectiveness studies. Maximal information is derived from ultrasonography when A-scan and B-scan techniques are employed simultaneously. Flexibility of electronics, variable-frequency transducers, and the use of several different manual scanning patterns aid in detection and interpretation of results. The immersion system of ultrasonography provides these features optimally.

Determining Directions of Ultrasound in Solids

NASA Technical Reports Server (NTRS)

Generazio, Edward R.; Roth, Don J.

1987-01-01

Ultrasound shadows cast by grooves. Improved method for determining direction of ultrasound in materials is shadow method using Scanning laser acoustic microscopy (SLAM). Direction of ultrasound calculated from dimensions of groove and portion of surface groove shields from ultrasound. Method has variety of applications in nontraditional quality-control applications.

Breast ultrasound tomography with two parallel transducer arrays

NASA Astrophysics Data System (ADS)

Huang, Lianjie; Shin, Junseob; Chen, Ting; Lin, Youzuo; Gao, Kai; Intrator, Miranda; Hanson, Kenneth

2016-03-01

Breast ultrasound tomography is an emerging imaging modality to reconstruct the sound speed, density, and ultrasound attenuation of the breast in addition to ultrasound reflection/beamforming images for breast cancer detection and characterization. We recently designed and manufactured a new synthetic-aperture breast ultrasound tomography prototype with two parallel transducer arrays consisting of a total of 768 transducer elements. The transducer arrays are translated vertically to scan the breast in a warm water tank from the chest wall/axillary region to the nipple region to acquire ultrasound transmission and reflection data for whole-breast ultrasound tomography imaging. The distance of these two ultrasound transducer arrays is adjustable for scanning breasts with different sizes. We use our breast ultrasound tomography prototype to acquire phantom and in vivo patient ultrasound data to study its feasibility for breast imaging. We apply our recently developed ultrasound imaging and tomography algorithms to ultrasound data acquired using our breast ultrasound tomography system. Our in vivo patient imaging results demonstrate that our breast ultrasound tomography can detect breast lesions shown on clinical ultrasound and mammographic images.

Comparison of the biometric formulas used for applanation A-scan ultrasound biometry.

PubMed

Özcura, Fatih; Aktaş, Serdar; Sağdık, Hacı Murat; Tetikoğlu, Mehmet

2016-10-01

The purpose of the study was to compare the accuracy of various biometric formulas for predicting postoperative refraction determined using applanation A-scan ultrasound. This retrospective comparative study included 485 eyes that underwent uneventful phacoemulsification with intraocular lens (IOL) implantation. Applanation A-scan ultrasound biometry and postoperative manifest refraction were obtained in all eyes. Biometric data were entered into each of the five IOL power calculation formulas: SRK-II, SRK/T, Holladay I, Hoffer Q, and Binkhorst II. All eyes were divided into three groups according to axial length: short (≤22.0 mm), average (22.0-25.0 mm), and long (≥25.0 mm) eyes. The postoperative spherical equivalent was calculated and compared with the predicted refractive error using each biometric formula. The results showed that all formulas had significantly lower mean absolute error (MAE) in comparison with Binkhorst II formula (P < 0.01). The lowest MAE was obtained with the SRK-II for average (0.49 ± 0.40 D) and short (0.67 ± 0.54 D) eyes and the SRK/T for long (0.61 ± 0.50 D) eyes. The highest postoperative hyperopic shift was seen with the SRK-II for average (46.8 %), short (28.1 %), and long (48.4 %) eyes. The highest postoperative myopic shift was seen with the Holladay I for average (66.4 %) and long (71.0 %) eyes and the SRK/T for short eyes (80.6 %). In conclusion, the SRK-II formula produced the lowest MAE in average and short eyes and the SRK/T formula produced the lowest MAE in long eyes. The SRK-II has the highest postoperative hyperopic shift in all eyes. The highest postoperative myopic shift is with the Holladay I for average and long eyes and SRK/T for short eyes.

Ultrasound

MedlinePlus

... reflect off body structures. A computer receives the waves and uses them to create a picture. Unlike with an x-ray or CT scan, this test does not use ionizing radiation. The test is done in the ultrasound ...

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

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.

Office-based ultrasound screening for abdominal aortic aneurysm

PubMed Central

Blois, Beau

2012-01-01

Abstract Objective To assess the efficacy of an office-based, family physician–administered ultrasound examination to screen for abdominal aortic aneurysm (AAA). Design A prospective observational study. Consecutive patients were approached by nonphysician staff. Setting Rural family physician offices in Grand Forks and Revelstoke, BC. Participants The Canadian Society for Vascular Surgery screening recommendations for AAA were used to help select patients who were at risk of AAA. All men 65 years of age or older were included. Women 65 years of age or older were included if they were current smokers or had diabetes, hypertension, a history of coronary artery disease, or a family history of AAA. Main outcome measures A focused “quick screen,” which measured the maximal diameter of the abdominal aorta using point-of-care ultrasound technology, was performed in the office by a resident physician trained in emergency ultrasonography. Each patient was then booked for a criterion standard scan (ie, a conventional abdominal ultrasound scan performed by a technician and interpreted by a radiologist). The maximal abdominal aortic diameter measured by ultrasound in the office was compared with that measured by the criterion standard method. The time to screen each patient was recorded. Results Forty-five patients were included in data analysis; 62% of participants were men. The mean age was 73 years. The mean pairwise difference between the office-based ultrasound scan and the criterion standard scan was not statistically significant. The mean absolute difference between the 2 scans was 0.20 cm (95% CI 0.15 to 0.25 cm). Correlation between the scans was 0.81. The office-based ultrasound scan had both a sensitivity and a specificity of 100%. The mean time to screen each patient was 212 seconds (95% CI 194 to 230 seconds). Conclusion Abdominal aortic aneurysm screening can be safely performed in the office by family physicians who are trained to use point

Office-based ultrasound screening for abdominal aortic aneurysm.

PubMed

Blois, Beau

2012-03-01

To assess the efficacy of an office-based, family physician–administered ultrasound examination to screen for abdominal aortic aneurysm (AAA). A prospective observational study. Consecutive patients were approached by nonphysician staff. Rural family physician offices in Grand Forks and Revelstoke, BC. The Canadian Society for Vascular Surgery screening recommendations for AAA were used to help select patients who were at risk of AAA. All men 65 years of age or older were included. Women 65 years of age or older were included if they were current smokers or had diabetes, hypertension, a history of coronary artery disease, or a family history of AAA. A focused “quick screen”, which measured the maximal diameter of the abdominal aorta using point-of-care ultrasound technology, was performed in the office by a resident physician trained in emergency ultrasonography. Each patient was then booked for a criterion standard scan (i.e., a conventional abdominal ultrasound scan performed by a technician and interpreted by a radiologist). The maximal abdominal aortic diameter measured by ultrasound in the office was compared with that measured by the criterion standard method. The time to screen each patient was recorded. Forty-five patients were included in data analysis; 62% of participants were men. The mean age was 73 years. The mean pairwise difference between the office-based ultrasound scan and the criterion standard scan was not statistically significant. The mean absolute difference between the 2 scans was 0.20 cm (95% CI 0.15 to 0.25 cm). Correlation between the scans was 0.81. The office-based ultrasound scan had both a sensitivity and a specificity of 100%. The mean time to screen each patient was 212 seconds (95% CI 194 to 230 seconds). Abdominal aortic aneurysm screening can be safely performed in the office by family physicians who are trained to use point-of- care ultrasound technology. The screening test can be completed within the time constraints of a

Ultrasound scans and dual energy CT identify tendons as preferred anatomical location of MSU crystal depositions in gouty joints.

PubMed

Yuan, Yuan; Liu, Chang; Xiang, Xi; Yuan, Tong-Ling; Qiu, Li; Liu, Yi; Luo, Yu-Bin; Zhao, Y; Herrmann, Martin

2018-05-01

The present study was performed to localize the articular deposition of monosodium urate (MSU) crystal in joints. We compare the detection efficiencies of dual-energy CT (DECT) and ultrasound scans. Analyses by DECT and ultrasound were performed with 184 bilateral joints of the lower limbs of 54 consecutive gout patients. All joints were categorized into (1) knee, (2) ankle, (3) MTP1, and (4) MTP2, and sorted into those with and those without detectable MSU deposition. The comparison of the positive rate between DECT and ultrasound and the agreement was performed using the McNemar test and the Cohen's κ coefficient, respectively. Next, we listed the MSU crystal deposition as assessed by ultrasound between the DECT-positive and -negative joints according to their interior structure. We included tendons, synovia, cartilage, subcutaneous tissue, etc. RESULTS: Among all joints, the percentages with MSU crystal deposition detected by DECT (99/184, 53.8%) and ultrasound (106/184, 57.6%) were comparable (P = 0.530 > 0.05). For MTP1 (21/34, 61.8%; 12/34, 35.3%; P < 0.05) and MTP2-5 (17/34, 50.0%; 10/34, 29.4%, P < 0.05), ultrasound and DECT were more efficient, respectively. The data concordance in 46 of 50 joints (92.00%; κ = 0.769, P < 0.05) for knee; and 27 of 34 joints (79.41%; κ = 0.588, P < 0.05) for MTP2-5 and suggested that tendons were the most frequent anatomical location of MSU crystal deposition. The tendons are the most frequent anatomical location of MSU crystal depositions. The concordance rate of knee joints and MTP2-5 joints shows good agreement between DECT and ultrasound depending on the location.

Medical Imaging with Ultrasound: Some Basic Physics.

ERIC Educational Resources Information Center

Gosling, R.

1989-01-01

Discussed are medical applications of ultrasound. The physics of the wave nature of ultrasound including its propagation and production, return by the body, spatial and contrast resolution, attenuation, image formation using pulsed echo ultrasound techniques, measurement of velocity and duplex scanning are described. (YP)

[Ultrasound duplex scanning of head and neck vessels with the aim of preoperational preparation of the patients with inherent microtia of the III degree].

PubMed

Chkadua, T Z; Kuz'mina, I V; Ramazanova, Iu I

2010-01-01

For surgical treatment of patients with inherent microtia of the III degree we use one stage method of otoplasty with silicone implant and parietotemporal fascial flap. In order to receive most full picture of the status of superficial temporal artery and its branches the additional diagnostic study is necessary. Method of ultrasound duplex scanning let to study any vessel in real time regimen under monitor screen control. Received by us results of ultrasound duplex scanning of superficial temporal artery branches in patients with inherent microtia of the III degree let us to conclude about the status of the vessel wall, to determine diameter and vessel occlusion, to evaluate and measure blood flow parameters. It is diagnostically necessary criteria for answering the question about flap vitality and in such a way let to avoid possible complications.

Morphological and ultrasound findings in the placenta of diabetic pregnancy.

PubMed

Berceanu, Costin; Tetileanu, Adrian Victor; Ofiţeru, Anca Maria; Brătilă, Elvira; Mehedinţu, Claudia; Voicu, Nicoleta Loredana; Szasz, Florin Adrian; Berceanu, Sabina; Vlădăreanu, Simona; Navolan, Dan Bogdan

2018-01-01

The purpose of this study is to analyze the morphological, histological, immunohistochemical and ultrasound findings in the placenta of maternal type 1 and gestational diabetes, to compare the pathological changes of the placental structure in the two types of metabolic disruptions, but also to establish correlations with the expression of these findings, influenced by different associated conditions. This multicenter study includes 53 pregnancies, of which 37 with pregestational and 16 with gestational diabetes. All cases undergone specific obstetric ultrasound assessment and detailed placental scan. There were assessed 49 singleton and four twin pregnancies, all of which having live births as fetal outcome. Maternal preexisting hypertension, preeclampsia and obesity were the main associated conditions. Placental ultrasound scan revealed increased placental thickness even from the second trimester, with significant increases in the first half, and placentomegaly at the end of the third trimester. Macroscopic analysis of the placentas and umbilical cords has shown that the placentas of women with diabetes are heavier, and abnormal cord insertion has been also found. Gross analysis of maternal and fetal surfaces of the placentas revealed certain changes in both metabolic conditions. We observed 14 types of placental pathological findings in pregestational and 11 in gestational diabetes. In diabetic placenta, it is not appropriate to discuss about specific changes, but rather about a pathological diabetic pattern, influenced by associated conditions. Preconceptional and first trimester glycemic control is the key element, and euglycemia throughout pregnancy is a purpose whose accomplishment depends the maternal-fetal outcome.

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.

FE6 during Sprint Ultrasound Scans

NASA Image and Video Library

2013-11-22

ISS038-E-007119 (21 Nov. 2013) --- Japan Aerospace Exploration Agency astronaut Koichi Wakata, Expedition 38 flight engineer, wears ultrasound gear around his legs while performing the Integrated Resistance and Aerobic Training Study (Sprint) experiment in the Columbus laboratory of the International Space Station. Sprint evaluates the use of high intensity, low volume exercise training to minimize loss of muscle, bone, and cardiovascular function in station crew members during long-duration missions.

Automated kidney detection for 3D ultrasound using scan line searching

NASA Astrophysics Data System (ADS)

Noll, Matthias; Nadolny, Anne; Wesarg, Stefan

2016-04-01

Ultrasound (U/S) is a fast and non-expensive imaging modality that is used for the examination of various anatomical structures, e.g. the kidneys. One important task for automatic organ tracking or computer-aided diagnosis is the identification of the organ region. During this process the exact information about the transducer location and orientation is usually unavailable. This renders the implementation of such automatic methods exceedingly challenging. In this work we like to introduce a new automatic method for the detection of the kidney in 3D U/S images. This novel technique analyses the U/S image data along virtual scan lines. Here, characteristic texture changes when entering and leaving the symmetric tissue regions of the renal cortex are searched for. A subsequent feature accumulation along a second scan direction produces a 2D heat map of renal cortex candidates, from which the kidney location is extracted in two steps. First, the strongest candidate as well as its counterpart are extracted by heat map intensity ranking and renal cortex size analysis. This process exploits the heat map gap caused by the renal pelvis region. Substituting the renal pelvis detection with this combined cortex tissue feature increases the detection robustness. In contrast to model based methods that generate characteristic pattern matches, our method is simpler and therefore faster. An evaluation performed on 61 3D U/S data sets showed, that in 55 cases showing none or minor shadowing the kidney location could be correctly identified.

Chest wall segmentation in automated 3D breast ultrasound scans.

PubMed

Tan, Tao; Platel, Bram; Mann, Ritse M; Huisman, Henkjan; Karssemeijer, Nico

2013-12-01

In this paper, we present an automatic method to segment the chest wall in automated 3D breast ultrasound images. Determining the location of the chest wall in automated 3D breast ultrasound images is necessary in computer-aided detection systems to remove automatically detected cancer candidates beyond the chest wall and it can be of great help for inter- and intra-modal image registration. We show that the visible part of the chest wall in an automated 3D breast ultrasound image can be accurately modeled by a cylinder. We fit the surface of our cylinder model to a set of automatically detected rib-surface points. The detection of the rib-surface points is done by a classifier using features representing local image intensity patterns and presence of rib shadows. Due to attenuation of the ultrasound signal, a clear shadow is visible behind the ribs. Evaluation of our segmentation method is done by computing the distance of manually annotated rib points to the surface of the automatically detected chest wall. We examined the performance on images obtained with the two most common 3D breast ultrasound devices in the market. In a dataset of 142 images, the average mean distance of the annotated points to the segmented chest wall was 5.59 ± 3.08 mm. Copyright © 2012 Elsevier B.V. All rights reserved.

Comparative study of lesions created by high-intensity focused ultrasound using sequential discrete and continuous scanning strategies.

PubMed

Fan, Tingbo; Liu, Zhenbo; Zhang, Dong; Tang, Mengxing

2013-03-01

Lesion formation and temperature distribution induced by high-intensity focused ultrasound (HIFU) were investigated both numerically and experimentally via two energy-delivering strategies, i.e., sequential discrete and continuous scanning modes. Simulations were presented based on the combination of Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation and bioheat equation. Measurements were performed on tissue-mimicking phantoms sonicated by a 1.12-MHz single-element focused transducer working at an acoustic power of 75 W. Both the simulated and experimental results show that, in the sequential discrete mode, obvious saw-tooth-like contours could be observed for the peak temperature distribution and the lesion boundaries, with the increasing interval space between two adjacent exposure points. In the continuous scanning mode, more uniform peak temperature distributions and lesion boundaries would be produced, and the peak temperature values would decrease significantly with the increasing scanning speed. In addition, compared to the sequential discrete mode, the continuous scanning mode could achieve higher treatment efficiency (lesion area generated per second) with a lower peak temperature. The present studies suggest that the peak temperature and tissue lesion resulting from the HIFU exposure could be controlled by adjusting the transducer scanning speed, which is important for improving the HIFU treatment efficiency.

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

Anterior segment biometry with 2 imaging technologies: very-high-frequency ultrasound scanning versus optical coherence tomography.

PubMed

Piñero, David P; Plaza, Ana Belén; Alió, Jorge L

2008-01-01

To determine the interchangeability of 2 anterior segment imaging systems: a very-high-frequency (VHF) ultrasound scanning system (Artemis 2, Ultralink LLC) and an optical coherence tomography (OCT) system (Visante, Zeiss). Vissum Instituto Oftalmologico de Alicante, Alicante, Spain. This study comprised 20 eyes without pathology or previous surgery. The anterior chamber depth (ACD), central corneal thickness (CCT), angle-to-angle distance (ATA), and the iridocorneal angle size (IAS) at the 0-degree and 180-degree positions were measured with 2 imaging techniques: VHF ultrasound scanning and OCT. Analysis of agreement and interchangeability was performed by the Bland and Altman method. In addition, each measurement was performed 3 times consecutively to determine intrasession repeatability by means of the coefficient of variation (CV) and the intraclass correlation coefficient (ICC). No statistically significant differences were found between imaging techniques in ACD, CCT, or ATA (P>.40). The ranges of agreement were 0.20 mm, 16.11 mum, and 0.80 mm for ACD, CCT, and ATA, respectively. Regarding IAS, no statistically significant differences were found in the nasal (P = .78) or temporal (P = .63) measurements between devices. However, the range of agreement for nasal (14.3 degrees) and temporal (14.90 degrees) values was relevant, indicating the 2 techniques cannot be used interchangeably for IAS measurement. Excellent intrasession repeatability scores were obtained (CV and ICC). The Artemis 2 and the Visante OCT systems provide equivalent and repeatable measurements of the ACD, CCT, and ATA and can be used interchangeably for these purposes.

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.

Investigation of Human Nail Microstructure with Ultrasound

NASA Astrophysics Data System (ADS)

Maeva, A. R.; Bakulin, E. Y.; Denisova, L. A.; Maev, R. Gr.

Investigation of a human fingernail and the extraction of the data on its microstructure and elastic properties is important in three main aspects. First of all, various diseases of the nail can be differentiated more precisely; second of all, it is possible to non-invasively track during time the effects of a cosmetic product upon the nail; third of all, because various processes in the organism have a strong influence upon the nail plate growth, the monitoring of the nail morphology and its mechanical properties may be used as additional information for the diagnosis of a number of medical disorders, such as systemic sclerosis, psoriasis, chronic hand eczema, anemia etc. The aim of the present study was to carry out a detailed ultrasound investigation in the high-frequency range (25-50 MHz) of a human nail including micro-anatomical structure imaging and ultrasound velocity evaluation, using B-scans obtained with a scanning acoustic microscope. On the images, exact topology of the nail, nail matrix and the underlying bone have been revealed. Additionally, a certain type of inclined internal layering along the nails of some individuals has been found, which was not reported in previous ultrasonic studies of the nail.

Sonographic physical diagnosis 101: teaching senior medical students basic ultrasound scanning skills using a compact ultrasound system.

PubMed

Angtuaco, Teresita L; Hopkins, Robert H; DuBose, Terry J; Bursac, Zoran; Angtuaco, Michael J; Ferris, Ernest J

2007-06-01

This project was designed to test the feasibility of introducing ultrasound to senior medical students as a primary diagnostic tool in the evaluation of patients. Specifically, its aim was to determine if it is possible for medical students untrained in sonography to gain basic competence in performing abdominal ultrasound with limited didactic and hands-on instructions. Registered sonographers provided the students with hands-on instructions on the use of a compact ultrasound system. They were likewise shown how to evaluate specific organs and perform measurements. The results of the student measurements and those obtained by the sonographers were compared. There was close correlation between the results obtained by sonographers and students on both normal and abnormal findings. This supports the concept that medical students can be taught basic ultrasound skills with limited didactic and hands-on instructions with the potential of using these skills in the patient clinics as an adjunct to routine physical diagnosis.

Accuracy, repeatability, and reproducibility of Artemis very high-frequency digital ultrasound arc-scan lateral dimension measurements

PubMed Central

Reinstein, Dan Z.; Archer, Timothy J.; Silverman, Ronald H.; Coleman, D. Jackson

2008-01-01

Purpose To determine the accuracy, repeatability, and reproducibility of measurement of lateral dimensions using the Artemis (Ultralink LLC) very high-frequency (VHF) digital ultrasound (US) arc scanner. Setting London Vision Clinic, London, United Kingdom. Methods A test object was measured first with a micrometer and then with the Artemis arc scanner. Five sets of 10 consecutive B-scans of the test object were performed with the scanner. The test object was removed from the system between each scan set. One expert observer and one newly trained observer separately measured the lateral dimension of the test object. Two-factor analysis of variance was performed. The accuracy was calculated as the average bias of the scan set averages. The repeatability and reproducibility coefficients were calculated. The coefficient of variation (CV) was calculated for repeatability and reproducibility. Results The test object was measured to be 10.80 mm wide. The mean lateral dimension bias was 0.00 mm. The repeatability coefficient was 0.114 mm. The reproducibility coefficient was 0.026 mm. The repeatability CV was 0.38%, and the reproducibility CV was 0.09%. There was no statistically significant variation between observers (P = .0965). There was a statistically significant variation between scan sets (P = .0036) attributed to minor vertical changes in the alignment of the test object between consecutive scan sets. Conclusion The Artemis VHF digital US arc scanner obtained accurate, repeatable, and reproducible measurements of lateral dimensions of the size commonly found in the anterior segment. PMID:17081860

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

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.

A 100-200 MHz ultrasound biomicroscope.

PubMed

Knspik, D A; Starkoski, B; Pavlin, C J; Foster, F S

2000-01-01

The development of higher frequency ultrasound imaging systems affords a unique opportunity to visualize living tissue at the microscopic level. This work was undertaken to assess the potential of ultrasound imaging in vivo using the 100-200 MHz range. Spherically focused lithium niobate transducers were fabricated. The properties of a 200 MHz center frequency device are described in detail. This transducer showed good sensitivity with an insertion loss of 18 dB at 200 MHz. Resolution of 14 /spl mu/m in the lateral direction and 12 /spl mu/m in the axial direction was achieved with f/1.14 focusing. A linear mechanical scan system and a scan converter were used to generate B-scan images at a frame rate up to 12 frames per second. System performance in B-mode imaging is limited by frequency dependent attenuation in tissues. An alternative technique, zone-focus image collection, was investigated to extend depth of field. Images of coronary arteries, the eye, and skin are presented along with some preliminary correlations with histology. These results demonstrate the feasibility of ultrasound biomicroscopy In the 100-200 MHz range. Further development of ultrasound backscatter imaging at frequencies up to and above 200 MHz will contribute valuable information about tissue microstructure.

[Ultrasound findings in rhabdomyolysis].

PubMed

Carrillo-Esper, Raúl; Galván-Talamantes, Yazmin; Meza-Ayala, Cynthia Margarita; Cruz-Santana, Julio Alberto; Bonilla-Reséndiz, Luis Ignacio

Rhabdomyolysis is defined as skeletal muscle necrosis. Ultrasound assessment has recently become a useful tool for the diagnosis and monitoring of muscle diseases, including rhabdomyolysis. A case is presented on the ultrasound findings in a patient with rhabdomyolysis. To highlight the importance of ultrasound as an essential part in the diagnosis in rhabdomyolysis, to describe the ultrasound findings, and review the literature. A 30 year-old with post-traumatic rhabdomyolysis of both thighs. Ultrasound was performed using a Philips Sparq model with a high-frequency linear transducer (5-10MHz), in low-dimensional scanning mode (2D), in longitudinal and transverse sections at the level of both thighs. The images obtained showed disorganisation of the orientation of the muscle fibres, ground glass image, thickening of the muscular fascia, and the presence of anechoic areas. Ultrasound is a useful tool in the evaluation of rhabdomyolysis. Copyright © 2015 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.

Non-stationary blind deconvolution of medical ultrasound scans

NASA Astrophysics Data System (ADS)

Michailovich, Oleg V.

2017-03-01

In linear approximation, the formation of a radio-frequency (RF) ultrasound image can be described based on a standard convolution model in which the image is obtained as a result of convolution of the point spread function (PSF) of the ultrasound scanner in use with a tissue reflectivity function (TRF). Due to the band-limited nature of the PSF, the RF images can only be acquired at a finite spatial resolution, which is often insufficient for proper representation of the diagnostic information contained in the TRF. One particular way to alleviate this problem is by means of image deconvolution, which is usually performed in a "blind" mode, when both PSF and TRF are estimated at the same time. Despite its proven effectiveness, blind deconvolution (BD) still suffers from a number of drawbacks, chief among which stems from its dependence on a stationary convolution model, which is incapable of accounting for the spatial variability of the PSF. As a result, virtually all existing BD algorithms are applied to localized segments of RF images. In this work, we introduce a novel method for non-stationary BD, which is capable of recovering the TRF concurrently with the spatially variable PSF. Particularly, our approach is based on semigroup theory which allows one to describe the effect of such a PSF in terms of the action of a properly defined linear semigroup. The approach leads to a tractable optimization problem, which can be solved using standard numerical methods. The effectiveness of the proposed solution is supported by experiments with in vivo ultrasound data.

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.

Lung ultrasound training: curriculum implementation and learning trajectory among respiratory therapists.

PubMed

See, K C; Ong, V; Wong, S H; Leanda, R; Santos, J; Taculod, J; Phua, J; Teoh, C M

2016-01-01

Guidelines recommend teaching of lung ultrasound for critical care, though little information exists on how much training is required for independent practice, especially for non-physician trainees. We thus aimed to elucidate a threshold number of cases above which competency for independent practice may be attained for respiratory therapists (RTs). We conducted a prospective audit of lung ultrasound training between July 2014 and April 2015 in our 20-bed medical intensive care unit. Following theoretical instruction and self-learning, trainees acquired images from 12 lung zones under direct supervision and classified images into six patterns. Assistance during image acquisition and correct interpretation of ultrasound images were recorded. Eleven ultrasound-naïve RTs scanned an average of 15 patients each (170 patients in total). Among supervisor-adjudicated lung ultrasound findings, 35.5% were abnormal. Blinded verification of the adjudicated findings was done for the first 92 patients (1104 images), with an agreement of 95.4%. As RTs scanned more patients, there was a significant decrease in the proportion of images requiring supervisor assistance (Cuzick's P < 0.001), and a significant increase in the proportion of correctly identified images (Cuzick's P = 0.008). After trainees performed at least ten scans, less than 2% of images required assistance with acquisition and less than 5% were wrongly interpreted. Our training method allowed RTs to independently perform lung ultrasound after at least ten directly supervised scans. Given that RTs are likely to have less ultrasound knowledge and less clinical know-how compared to physicians, we believe that the same threshold number of scans may be also safely applied to the latter.

Effects of introducing routinely ultrasound scanning during Ante Natal Care (ANC) clinics on number of visits of ANC and facility delivery: a cohort study.

PubMed

Mbuyita, Selemani; Tillya, Robert; Godfrey, Ritha; Kinyonge, Iddajovana; Shaban, Josephine; Mbaruku, Godfrey

2015-01-01

Many countries have integrated antenatal care as an essential part of routine maternal health services. The importance of this service cannot be overemphasized as many women's lives are usually saved particularly through early detection of pregnancy related complications. However, while many women would attend at least one visit for ante natal care (ANC), completion of recommended number of visits (4+) has been a challenge of many health systems particularly in developing countries like Tanzania. We conducted a cohort study to include ultrasound scanning using a portable hand-held Vscan to test whether by integrating it in routine ANC clinics at dispensary and health centre levels would promote number of ANC visits by women. Health providers rendering ANC services in selected facilities were trained on how to use the simple technology of ultrasound scanning. Women living in catchment areas of the respective selected facilities were eligible to inclusion to the study when consented. A baseline status of the ANC attendance in the study area was established through baseline household and facility surveys. A total of 257 women consented and received the study treatment. Our results showed that, there was no a slight change between baseline (97.2 %) and endline (97.4 %) results among women attending ANC clinics at least once. However, there was a significant change in percentage of women attending ANC clinic four times or more (27.2 % during baseline and 60.3 %; p = 0001). We conclude that, introduction of the simplified ultrasound scanning technology at lowest levels of care has an effect to improving ANC attendance in terms of number of visits and motivate facility delivery.

Routine preoperative colour Doppler duplex ultrasound scanning in anterolateral thigh flaps.

PubMed

Lichte, Johanna; Teichmann, Jan; Loberg, Christina; Kloss-Brandstätter, Anita; Bartella, Alexander; Steiner, Timm; Modabber, Ali; Hölzle, Frank; Lethaus, Bernd

2016-10-01

The anterolateral thigh flap (ALT) is often used to reconstruct the head and neck and depends on one or more skin perforators, which often present with variable anatomy. The aim of this study was to localise and evaluate the precise position of these perforators preoperatively with colour Doppler duplex ultrasound scanning (US). We detected 74 perforators in 30 patients. The mean duration of examination with colour Doppler was 29 (range 13-51) minutes. Adequate perforators and their anatomical course could be detected preoperatively extremely accurately (p<0.001). The mean difference between the preoperatively marked, and the real, positions was 6.3 (range 0-16) mm. There was a highly significant correlation between the accuracy of the prediction and the body mass index of the patient (0.75; p<0.001). Neither the age nor the sex of the patient correlated with the accuracy of the prediction. Colour Doppler duplex US used preoperatively to localise perforators in ALT flaps is reliable and could be adopted as standard procedure. Copyright © 2016 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

[Efficacy and problems of bladder volume measurement using portable three dimensional ultrasound scanning device--in particular, on measuring bladder volume lower than 100ml].

PubMed

Oh-Oka, Hitoshi; Nose, Ryuichiro

2005-09-01

Using a portable three dimensional ultrasound scanning device (The Bladder Scan BVI6100, Diagnostic Ultrasound Corporation), we examined measured values of bladder volume, especially focusing on volume lower than 100 ml. A total of 100 patients (male: 66, female: 34) were enrolled in the study. We made a comparison study between the measured value (the average of three measurements of bladder urine volume after a trial in male and female modes) using BVI6100, and the actual measured value of the sample obtained by urethral catheterization in each patient. We examined the factors which could increase the error rate. We also introduced the effective techniques to reduce measurement errors. The actual measured values in all patients correlated well with the average value of three measurements after a trial in a male mode of the BVI6100. The correlation coefficient was 0.887, the error rate was--4.6 +/- 24.5%, and the average coefficient of variation was 15.2. It was observed that the measurement result using the BVI6100 is influenced by patient side factors (extracted edges between bladder wall and urine, thickened bladder wall, irregular bladder wall, flattened rate of bladder, mistaking prostate for bladder in male, mistaking bladder for uterus in a female mode, etc.) or examiner side factors (angle between BVI and abdominal wall, compatibility between abdominal wall and ultrasound probe, controlling deflection while using probe, etc). When appropriate patients are chosen and proper measurement is performed, BVI6100 provides significantly higher accuracy in determining bladder volume, compared with existing abdominal ultrasound methods. BVI6100 is a convenient and extremely effective device also for the measurement of bladder urine over 100 ml.

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

SonoNet: Real-Time Detection and Localisation of Fetal Standard Scan Planes in Freehand Ultrasound.

PubMed

Baumgartner, Christian F; Kamnitsas, Konstantinos; Matthew, Jacqueline; Fletcher, Tara P; Smith, Sandra; Koch, Lisa M; Kainz, Bernhard; Rueckert, Daniel

2017-11-01

Identifying and interpreting fetal standard scan planes during 2-D ultrasound mid-pregnancy examinations are highly complex tasks, which require years of training. Apart from guiding the probe to the correct location, it can be equally difficult for a non-expert to identify relevant structures within the image. Automatic image processing can provide tools to help experienced as well as inexperienced operators with these tasks. In this paper, we propose a novel method based on convolutional neural networks, which can automatically detect 13 fetal standard views in freehand 2-D ultrasound data as well as provide a localization of the fetal structures via a bounding box. An important contribution is that the network learns to localize the target anatomy using weak supervision based on image-level labels only. The network architecture is designed to operate in real-time while providing optimal output for the localization task. We present results for real-time annotation, retrospective frame retrieval from saved videos, and localization on a very large and challenging dataset consisting of images and video recordings of full clinical anomaly screenings. We found that the proposed method achieved an average F1-score of 0.798 in a realistic classification experiment modeling real-time detection, and obtained a 90.09% accuracy for retrospective frame retrieval. Moreover, an accuracy of 77.8% was achieved on the localization task.

Detection of an embolized central venous catheter fragment with endobronchial ultrasound.

PubMed

Dhillon, Samjot Singh; Harris, Kassem; Alraiyes, Abdul H; Picone, Anthony L

2018-01-01

An 84-year-old woman underwent Convex-probe Endobronchial Ultrasound (CP-EBUS) for 18 F-fluorodeoxyglucose avid subcarinal lymphadenopathy on Positron Emission Tomogram (PET) scan. Endobronchial ultrasound-guided transbronchial needle aspiration of the subcarinal lymph node revealed squamous cell lung carcinoma. A small hyperechoic rounded density was noted inside the lumen of the azygous vein. Based on chest computed tomography findings and her clinical history, this was felt to be a broken fragment of a peripherally inserted central catheter, which was placed for intravenous antibiotics, a few months prior to this presentation. To the best of our knowledge, this is the first ever CP-EBUS description of a broken fragment of central venous catheter. © 2016 John Wiley & Sons Ltd.

[Contrast-enhanced Ultrasound in Diagnostic Imaging of Muscle Injuries: Perfusion Imaging in the Early Arterial Phase].

PubMed

Hotfiel, T; Carl, H D; Swoboda, B; Engelhardt, M; Heinrich, M; Strobel, D; Wildner, D

2016-03-01

Ultrasound is a standard procedure widely used in the diagnostic investigation of muscle injuries and widely described in the literature. Its advantages include rapid availability, cost effectiveness and the possibility to perform a real-time dynamic examination with the highest possible spatial resolution. In the diagnostic work-up of minor lesions (muscle stiffness, muscle strain), plain ultrasound has so far been inferior to MRI. The case presented by us is an example of the possibilities offered by contrast-enhanced ultrasound (CEUS) in the imaging of muscle injuries compared with plain B-mode image ultrasound and MRI imaging of the affected region. This case report is about a high-performance football player who sustained a muscle injury. He underwent an ultrasound examination (S 2000, 9L4 Probe, Siemens, Germany), which was performed simultaneously in the conventional and contrast-enhanced mode at the level of the lesion. An intravenous bolus injection of 4.8 ml of intravascular contrast agent (SonoVue(®), Bracco, Italy) was given via a cubital intravenous line. After that, the distribution of contrast agent was visualised in the early arterial phase. In addition, a plain magnetic resonance imaging scan of both thighs was performed for reference. On conventional ultrasound, the lesion was not clearly distinguishable from neighbouring tissue, whereas contrast-enhanced ultrasound demonstrated a well delineated, circumscribed area of impaired perfusion with hypoenhancement compared with the surrounding muscles at the clinical level of the lesion in the arterial wash-in phase (0-30 sec, after intravenous administration). The MRI scan revealed an edema signal with perifascial fluid accumulation in the corresponding site. The use of intravascular contrast agent enabled the sensitive detection of a minor injury by ultrasound for the first time. An intramuscular edema seen in the MRI scan showed a functional arterial perfusion impairment on ultrasound, which was

Generation of ultrasound in materials using continuous-wave lasers.

PubMed

Caron, James N; DiComo, Gregory P; Nikitin, Sergei

2012-03-01

Generating and detecting ultrasound is a standard method of nondestructive evaluation of materials. Pulsed lasers are used to generate ultrasound remotely in situations that prohibit the use of contact transducers. The scanning rate is limited by the repetition rates of the pulsed lasers, ranging between 10 and 100 Hz for lasers with sufficient pulse widths and energies. Alternately, a high-power continuous-wave laser can be scanned across the surface, creating an ultrasonic wavefront. Since generation is continuous, the scanning rate can be as much as 4 orders of magnitude higher than with pulsed lasers. This paper introduces the concept, comparing the theoretical scanning speed with generation by pulsed laser. © 2012 Optical Society of America

Ultrasound diagnostic of mesonephric paraovarian cyst - case report

PubMed Central

Bohîlțea, RE; Cîrstoiu, MM; Turcan, N; Ionescu, CA

2016-01-01

Paraovarian cysts are a rare pathology, constituting 10-20% of the adnexal masses. The origin can be represented by paramesonephric ducts (Hydatid cysts of Morgagni), vestiges of mesonephric ducts also represented by mesothelium, or neoplastic (cystadenomas or cystadenofibromas) that are mostly benign. Borderline or malignant paraovarian tumors are encountered less often. This article presents a case of paraovarian cyst in a 37-year-old patient, with a history of 2 pregnancies, completed by cesarean. The patient sought medical attention for an asymptomatic voluminous ovarian cyst, detected in a routine ultrasound scan. Laboratory tests and tumor markers were within normal limits. Transvaginal ultrasound and color Doppler revealed a cystic adnexal mass with 10 cm transonic, smooth, homogeneous content, avascular walls with no internal papillary projections, with a “hyperechoic line” sign of delimitation from the ovarian capsule, mostly visible when the adnexa was mobilized. The diagnostic and curative laparoscopic surgery was successful, followed by a quick recovery. The histopathological exam confirmed the benignity and the origin of the paraovarian cyst. The case was discussed in the context of the literature review concerning this pathology, drawing attention to the real possibility of differentiating ovarian from paraovarian cysts by ultrasound. PMID:27974934

The role of ultrasound in the management of flexor tendon injuries.

PubMed

Jeyapalan, K; Bisson, M A; Dias, J J; Griffin, Y; Bhatt, R

2008-08-01

The use of ultrasound scanning to establish tendon pathologies was assessed retrospectively in 17 patients in 18 digits. The ultrasound scan demonstrated four patterns: (1) normal intact tendons in four, (2) ruptured tendons in three, (3) tendons in continuity but attenuated in five and (4) tendons in continuity but thickened with fibrosis and decreased movement representing adhesions in five patients. Surgery was undertaken in only three cases, confirming the ultrasound diagnosis in two. Surgery was offered to all three patients with ruptures but was declined by two. Ultrasound imaging helped to avoid surgery in 14 cases by excluding flexor tendon re-ruptures. This allowed on-going mobilisation, leading to recovery of function.

Ultrasound variants of autoimmune thyroiditis in children and adolescents and their clinical implication in relation to papillary thyroid carcinoma development.

PubMed

Januś, D; Wójcik, M; Drabik, G; Wyrobek, Ł; Starzyk, J B

2018-03-01

The prevalence of autoimmune thyroiditis (AIT) and papillary thyroid carcinoma (PTC) is rising in children and adolescents, and the coincidence of AIT and PTC is as high as 6.3-43%. To investigate the ultrasound manifestation of AIT in relation to PTC development in paediatric patients. 179 paediatric patients (133 females), mean (SD) age: 13.9 (3.03) years diagnosed with AIT and referred for ultrasound evaluation. Eight patients were diagnosed with PTC (6 females). Retrospective analysis of thyroid ultrasound scans of patients diagnosed with AIT. Thyroid and autoimmune status was assessed based on TSH, fT4, fT3 and increased aTPO and/or aTG and/or TRAB levels. In patients with PTC, total thyroidectomy was performed. Analysis of thyroid US scans revealed that the following five ultrasound variants of AIT were observed in 179 patients: the most common in 35.2%-diffuse thyroiditis with hypoechogenic background and normoechogenic parenchyma, in 30.2%-diffuse thyroiditis with irregular background, in 18.9% nodular variant with normoechogenic background, in 11.7%-micronodulations and in 3.9%-diffuse hypoechogenic background. Eight cases of PTC were diagnosed in nodular variant of AIT with normoechogenic irregular background. Patients with AIT and nodular variant with normoechogenic irregular background of the thyroid gland on US scans are in the risk group of developing PTC and should be followed up with regular neck US assessment.

Three-dimensional ultrasonic scanning.

PubMed

Fredfeldt, K E; Holm, H H; Pedersen, J F

1984-01-01

Simple experiments which form the basis for a true 3-D demonstration of sectional images are presented and a method for genuine 3-D display of dynamic ultrasound images is described. Eight ultrasound images are recorded with a slightly different angulation of the transducer. The images are extracted from the video signal from a conventional ultrasound scanner and stored in eight digital memories. After recording, each image is displayed on an oscilloscope screen, which is viewed via a fast oscillating mirror. The position of the mirror determines which of the eight images are to be displayed and thereby ensures a correct spatial relationship of the images, resulting in a true 3-D scan presentation.

Focused ultrasound in ophthalmology

PubMed Central

Silverman, Ronald H

2016-01-01

The use of focused ultrasound to obtain diagnostically significant information about the eye goes back to the 1950s. This review describes the historical and technological development of ophthalmic ultrasound and its clinical application and impact. Ultrasound, like light, can be focused, which is crucial for formation of high-resolution, diagnostically useful images. Focused, single-element, mechanically scanned transducers are most common in ophthalmology. Specially designed transducers have been used to generate focused, high-intensity ultrasound that through thermal effects has been used to treat glaucoma (via ciliodestruction), tumors, and other pathologies. Linear and annular transducer arrays offer synthetic focusing in which precise timing of the excitation of independently addressable array elements allows formation of a converging wavefront to create a focus at one or more programmable depths. Most recently, linear array-based plane-wave ultrasound, in which the array emits an unfocused wavefront and focusing is performed solely on received data, has been demonstrated for imaging ocular anatomy and blood flow. While the history of ophthalmic ultrasound extends back over half-a-century, new and powerful technologic advances continue to be made, offering the prospect of novel diagnostic capabilities. PMID:27757007

Focused ultrasound in ophthalmology.

PubMed

Silverman, Ronald H

2016-01-01

The use of focused ultrasound to obtain diagnostically significant information about the eye goes back to the 1950s. This review describes the historical and technological development of ophthalmic ultrasound and its clinical application and impact. Ultrasound, like light, can be focused, which is crucial for formation of high-resolution, diagnostically useful images. Focused, single-element, mechanically scanned transducers are most common in ophthalmology. Specially designed transducers have been used to generate focused, high-intensity ultrasound that through thermal effects has been used to treat glaucoma (via ciliodestruction), tumors, and other pathologies. Linear and annular transducer arrays offer synthetic focusing in which precise timing of the excitation of independently addressable array elements allows formation of a converging wavefront to create a focus at one or more programmable depths. Most recently, linear array-based plane-wave ultrasound, in which the array emits an unfocused wavefront and focusing is performed solely on received data, has been demonstrated for imaging ocular anatomy and blood flow. While the history of ophthalmic ultrasound extends back over half-a-century, new and powerful technologic advances continue to be made, offering the prospect of novel diagnostic capabilities.

Real-time 3-D contrast-enhanced transcranial ultrasound and aberration correction.

PubMed

Ivancevich, Nikolas M; Pinton, Gianmarco F; Nicoletto, Heather A; Bennett, Ellen; Laskowitz, Daniel T; Smith, Stephen W

2008-09-01

Contrast-enhanced (CE) transcranial ultrasound (US) and reconstructed 3-D transcranial ultrasound have shown advantages over traditional methods in a variety of cerebrovascular diseases. We present the results from a novel ultrasound technique, namely real-time 3-D contrast-enhanced transcranial ultrasound. Using real-time 3-D (RT3D) ultrasound and microbubble contrast agent, we scanned 17 healthy volunteers via a single temporal window and nine via the suboccipital window and report our detection rates for the major cerebral vessels. In 71% of subjects, both of our observers identified the ipsilateral circle of Willis from the temporal window, and in 59% we imaged the entire circle of Willis. From the suboccipital window, both observers detected the entire vertebrobasilar circulation in 22% of subjects, and in 44%, the basilar artery. After performing phase aberration correction on one subject, we were able to increase the diagnostic value of the scan, detecting a vessel not present in the uncorrected scan. These preliminary results suggest that RT3D CE transcranial US and RT3D CE transcranial US with phase aberration correction have the potential to greatly impact the field of neurosonology.

Real-Time 3D Contrast-Enhanced Transcranial Ultrasound and Aberration Correction

PubMed Central

Ivancevich, Nikolas M.; Pinton, Gianmarco F.; Nicoletto, Heather A.; Bennett, Ellen; Laskowitz, Daniel T.; Smith, Stephen W.

2008-01-01

Contrast-enhanced (CE) transcranial ultrasound (US) and reconstructed 3D transcranial ultrasound have shown advantages over traditional methods in a variety of cerebrovascular diseases. We present the results from a novel ultrasound technique, namely real-time 3D contrast-enhanced transcranial ultrasound. Using real-time 3D (RT3D) ultrasound and micro-bubble contrast agent, we scanned 17 healthy volunteers via a single temporal window and 9 via the sub-occipital window and report our detection rates for the major cerebral vessels. In 71% of subjects, both of our observers identified the ipsilateral circle of Willis from the temporal window, and in 59% we imaged the entire circle of Willis. From the sub-occipital window, both observers detected the entire vertebrobasilar circulation in 22% of subjects, and in 44% the basilar artery. After performing phase aberration correction on one subject, we were able to increase the diagnostic value of the scan, detecting a vessel not present in the uncorrected scan. These preliminary results suggest that RT3D CE transcranial US and RT3D CE transcranial US with phase aberration correction have the potential to greatly impact the field of neurosonology. PMID:18395321

Isolated splenic tuberculosis diagnosed by endoscopic ultrasound-guided fine needle aspiration.

PubMed

Nasa, Mukesh; Choudhary, Narendra S; Guleria, Mridula; Puri, Rajesh

2017-04-01

Our patient was a 48-year-old female, who presented with history of persistent low-grade fever and weight loss. The CT scan of the abdomen revealed multiple hypodense lesions in spleen. No primary focus of infection was detected in any other organs. Endoscopic ultrasound-guided fine needle aspiration of splenic lesion revealed granulomatous inflammation. The patient was started on anti-tuberculous therapy. There is a diagnostic possibility of splenic tuberculosis even in immunocompetent individuals and we chose a combination anti-tuberculous therapy as the first line treatment with consideration of splenectomy depending on the response. Copyright © 2016 Tuberculosis Association of India. Published by Elsevier B.V. All rights reserved.

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.

Comparison of central corneal thickness measurement using ultrasonic pachymetry, rotating Scheimpflug camera, and scanning-slit topography.

PubMed

Sedaghat, Mohammad Reza; Daneshvar, Ramin; Kargozar, Abbas; Derakhshan, Akbar; Daraei, Mona

2010-12-01

To evaluate and compare central corneal thickness measurements using rotating Scheimpflug camera, scanning-slit topography, and ultrasound pachymetry in virgin, healthy corneas. Prospective, observational, cross-sectional study. Central corneal thickness in 157 healthy eyes of 157 patients without ocular abnormalities other than refractive errors was measured, in a sequential order, once with rotating Scheimpflug camera and scanning-slit topography and 3 times with ultrasound pachymetry as the last part of examination. All measurements were performed by a single experienced examiner. The results from scanning-slit topography are given with and without correction for "acoustic correction factor" of 0.92. The average measurements of central corneal thickness by rotating Scheimpflug imaging, scanning-slit pachymetry, and ultrasound were 537.15 ± 32.98 μm, 542.06 ± 39.04 μm, and 544.07 ± 34.75 μm, respectively. The mean differences between modalities were 6.92 μm between rotating Scheimpflug and ultrasound (P < .0001), 2.01 μm between corrected scanning-slit and ultrasound (P = .204), and 4.91 μm between corrected scanning-slit and rotating Scheimpflug imaging (P = .001). According to Bland-Altman analysis, highest agreement was between ultrasonic and rotating Scheimpflug pachymetry. In the assessment of normal corneas, rotating Scheimpflug topography measures central corneal thickness values with higher agreement to ultrasound pachymetry. Copyright © 2010 Elsevier Inc. All rights reserved.

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

Hand ultrasound: a high-fidelity simulation of lung sliding.

PubMed

Shokoohi, Hamid; Boniface, Keith

2012-09-01

Simulation training has been effectively used to integrate didactic knowledge and technical skills in emergency and critical care medicine. In this article, we introduce a novel model of simulating lung ultrasound and the features of lung sliding and pneumothorax by performing a hand ultrasound. The simulation model involves scanning the palmar aspect of the hand to create normal lung sliding in varying modes of scanning and to mimic ultrasound features of pneumothorax, including "stratosphere/barcode sign" and "lung point." The simple, reproducible, and readily available simulation model we describe demonstrates a high-fidelity simulation surrogate that can be used to rapidly illustrate the signs of normal and abnormal lung sliding at the bedside. © 2012 by the Society for Academic Emergency Medicine.

Duplex ultrasound surveillance after carotid artery endarterectomy.

PubMed

Al Shakarchi, Julien; Lowry, Danielle; Nath, Jay; Khawaja, Aurangzaib Z; Inston, Nicholas; Tiwari, Alok

2016-06-01

After carotid endarterectomy (CEA), patients have been regularly followed up by duplex ultrasound imaging. However, the evidence for long-term follow-up is not clear, especially if the results from an early duplex scan are normal. This study assessed and systematically reviewed the evidence base for long-term surveillance after CEA and a normal early scan. Electronic databases were searched for studies assessing duplex surveillance after CEA in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The primary outcome for this study was the incidence of restenosis after a normal early scan. The secondary outcome was the number of reinterventions after a normal early scan. The review included seven studies that reported 2317 procedures. Of those patients with a normal early scan, 2.8% (95% confidence interval, 0.7%-6%) developed a restenosis, and 0.4% (95% confidence interval, 0%-0.9%) underwent a reintervention for their restenosis during the follow-up period. This review confirms that routine postoperative duplex ultrasound surveillance after CEA is not necessary if the early duplex scan is normal. Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Comparison of the biometric values obtained by two different A-mode ultrasound devices (Eye Cubed vs. PalmScan): a transversal, descriptive, and comparative study.

PubMed

Velez-Montoya, Raul; Shusterman, Eugene Mark; López-Miranda, Miriam Jessica; Mayorquin-Ruiz, Mariana; Salcedo-Villanueva, Guillermo; Quiroz-Mercado, Hugo; Morales-Cantón, Virgilio

2010-03-24

To assess the reliability of the measurements obtained with the PalmScan, when compared with another standardized A-mode ultrasound device, and assess the consistency and correlation between the two methods. Transversal, descriptive, and comparative study. We recorded the axial length (AL), anterior chamber depth (ACD) and lens thickness (LT) obtained with two A-mode ultrasounds (PalmScan A2000 and Eye Cubed) using an immersion technique. We compared the measurements with a two-sample t-test. Agreement between the two devices was assessed with Bland-Altman plots and 95% limits of agreement. 70 eyes of 70 patients were enrolled in this study. The measurements with the Eye Cubed of AL and ACD were shorter than the measurements taken by the PalmScan. The differences were not statistically significant regarding AL (p < 0.4) but significant regarding ACD (p < 0.001). The highest agreement between the two devices was obtained during LT measurement. The PalmScan measurements were shorter, but not statistically significantly (p < 0.2). The values of AL and LT, obtained with both devices are not identical, but within the limits of agreement. The agreement is not affected by the magnitude of the ocular dimensions (but only between range of 20 mm to 27 mm of AL and 3.5 mm to 5.7 mm of LT). A correction of about 0.5 D could be considered if an intraocular lens is being calculated. However due to the large variability of the results, the authors recommend discretion in using this conversion factor, and to adjust the power of the intraocular lenses based upon the personal experience of the surgeon.

3D ultrasound-based patient positioning for radiotherapy

NASA Astrophysics Data System (ADS)

Wang, Michael H.; Rohling, Robert N.; Archip, Neculai; Clark, Brenda G.

2006-03-01

A new 3D ultrasound-based patient positioning system for target localisation during radiotherapy is described. Our system incorporates the use of tracked 3D ultrasound scans of the target anatomy acquired using a dedicated 3D ultrasound probe during both the simulation and treatment sessions, fully automatic 3D ultrasound-toultrasound registration, and OPTOTRAK IRLEDs for registering simulation CT to ultrasound data. The accuracy of the entire radiotherapy treatment process resulting from the use of our system, from simulation to the delivery of radiation, has been validated on a phantom. The overall positioning error is less than 5mm, which includes errors from estimation of the irradiated region location in the phantom.

Synergetic effects of ultrasound and slightly acidic electrolyzed water against Staphylococcus aureus evaluated by flow cytometry and electron microscopy.

PubMed

Li, Jiao; Ding, Tian; Liao, Xinyu; Chen, Shiguo; Ye, Xingqian; Liu, Donghong

2017-09-01

This study evaluated the synergetic effects of ultrasound and slightly acidic electrolyzed water (SAEW) on the inactivation of Staphylococcus aureus using flow cytometry and electron microscopy. The individual ultrasound treatment for 10min only resulted in 0.36logCFU/mL reductions of S. aureus, while the SAEW treatment alone for 10min resulted in 3.06logCFU/mL reductions. The log reductions caused by combined treatment were enhanced to 3.68logCFU/mL, which were greater than the sum of individual treatments. This phenomenon was referred to as synergistic effects. FCM analysis distinguished live and dead cells as well as revealed dynamic changes in the physiological states of S. aureus after different treatments. The combined treatment greatly reduced the number of viable but nonculturable (VBNC) bacteria to 0.07%; in contrast, a single ultrasound treatment for 10min induced the formation of VBNC cells to 45.75%. Scanning and transmission electron microscopy analysis revealed that greater damage to the appearance and ultrastructure of S. aureus were achieved after combined ultrasound-SAEW treatment compared to either treatment alone. These results indicated that combining ultrasound with SAEW is a promising sterilization technology with potential uses for environmental remediation and food preservation. Copyright © 2016 Elsevier B.V. All rights reserved.

Non-Contact Inspection of Composites Using Air-Coupled Ultrasound

NASA Astrophysics Data System (ADS)

Peters, J.; Kommareddy, V.; Liu, Z.; Fei, D.; Hsu, D.

2003-03-01

Conventional ultrasonic tests are conducted using water as a transmitting medium. Water coupled ultrasound cannot be applied to certain water-sensitive or porous materials and is more difficult to use in the field. In contrast, air-coupled ultrasound is non-contact and has clear advantages over water-coupled testing. The technology of air-coupled ultrasound has gained maturity in recent years. Some systems have become commercially available and researchers are pursuing several different modalities of air-coupled transduction. This paper reports our experience of applying air-coupled ultrasound to the inspection of flaws, damage, and normal internal structures of composite parts. Through-transmission C-scans at 400 kHz using a focused receiver has resolution sufficient to image honeycomb cells in the sandwich core. With the transmitter and receiver on the same side of a laminate. Lamb waves were generated and used for the imaging of substructures. Air-coupled scan results are presented for flaw detection and damage in aircraft composite structures.

Ultrasound-guided thermocouple placement for cryosurgery.

PubMed

Abramovits, W; Pruiksma, R; Bose, S

1996-09-01

Although cryosurgical methods have high cure rates, imprecise estimates of both skin lesion depth and destructive temperature front location result in subjective technique in skin malignancy treatments. We evaluated the possibility of newer ultrasound equipment to assist in the precise placement of thermocouples in human skin. DermaScan C ver. 3 ultrasonographic equipment fitted with a sharp focus probe with a frequency of 20 MHz and a scan length of 12.1 mm was used to locate thermocouples with 27- and 30-gauge needles. We successfully and reproducibly located thermocouples and thin needles, and accurately measured their distance from the skin surface. Ultrasound is a useful method for the accurate placement of thermocouples, and needles as thin as 30 gauge for monitoring in cryosurgery.

Real-time registration of video with ultrasound using stereo disparity

NASA Astrophysics Data System (ADS)

Wang, Jihang; Horvath, Samantha; Stetten, George; Siegel, Mel; Galeotti, John

2012-02-01

Medical ultrasound typically deals with the interior of the patient, with the exterior left to the original medical imaging modality, direct human vision. For the human operator scanning the patient, the view of the external anatomy is essential for correctly locating the ultrasound probe on the body and making sense of the resulting ultrasound images in their proper anatomical context. The operator, after all, is not expected to perform the scan with his eyes shut. Over the past decade, our laboratory has developed a method of fusing these two information streams in the mind of the operator, the Sonic Flashlight, which uses a half silvered mirror and miniature display mounted on an ultrasound probe to produce a virtual image within the patient at its proper location. We are now interested in developing a similar data fusion approach within the ultrasound machine itself, by, in effect, giving vision to the transducer. Our embodiment of this concept consists of an ultrasound probe with two small video cameras mounted on it, with software capable of locating the surface of an ultrasound phantom using stereo disparity between the two video images. We report its first successful operation, demonstrating a 3D rendering of the phantom's surface with the ultrasound data superimposed at its correct relative location. Eventually, automated analysis of these registered data sets may permit the scanner and its associated computational apparatus to interpret the ultrasound data within its anatomical context, much as the human operator does today.

Role of B-scan ultrasonography in pre-operative cataract patients.

PubMed

Qureshi, Manzoor A; Laghari, Khalida

2010-01-01

To visualize the posterior portion of eye globe in dense cataract patients with B scan ultrasound, and to find out any posterior segment lesion in such pre-operative cases. We performed diagnostic B-scan ultrasound on 750 cataract patients before surgery. This was a prospective diagnostic study which was conducted in the Department of Opthalmology, Liaquat University Eye Hospital, Hyderabad Sind, Pakistan from January 2007 to July 2007. Detailed history and some basic eye examination techniques, like slit lamp and tonometry were done in two groups of patients, traumatic (71) and non traumatic(679). Patients in the age range of 1 to 79 years of both sexes were included. Patients having already posterior segment lesions and those who had previous history of ocular surgery were excluded from the study. An ultrasound machine Nidek Echo Scan Model US-3300 with a probe of direct contact was used. Out of 750 patients, 90 patients had posterior segment lesions. Among traumatic group of 71 patients, 39 (55%) had positive posterior segment lesions, while in the non traumatic group of 679 patients, only 51 (7%) cases had positive posterior segment lesions. Out of the 90 positive cases, 25 (3%) had retinal detachment, 14 (2%) had posterior vitreous detachment, 24 (3%) had vitreous hemorrhage, 12 (2%) were asteroid hyolosis, while posterior staphyloma and intra-ocular foreign body were found with the frequency of 9 (1.2%) and 6 (1%), respectively. We concluded that two dimensional B-scan ultrasound can be one of the diagnostic tool for the detection of hidden posterior segment lesions and can be performed routinely in pre-operative cataract patients, as this would help in surgical planning. In cases, where a two dimensional B-scan is not sufficient or helpful. a three dimensional ultrasound would be justified.

[Comparative Study on Evaluating the Bladder Volume between BladderScan BVI9400 and Ultrasound System iU22].

PubMed

Luo, Huanli; Wang, Ying; Li, Fang; Ling, Yun; Yang, Dingyi; Jin, Fu

2015-07-01

To evaluate the accuracy of the latest BladderScan BVI9400 on measuring bladder volume. Two bladder phantoms were selected for investigating the accuracy of BVI9400. 341 patients with the iU22 ultrasound examinations were followed by BVI 9400. The difference and correlation between BVI9400 and iU22 were contrastively analyzed. The relative difference between results from BVI9400 and phantom volume was 2.5% and 1.36%. There was a strong correlation for patients between BVI9400 and iU22 (R = 0.96, P < 0.001). The relative difference between BVI9400 and iU22 decreased with the increasing of bladder volume and had no significant difference with patient's gender (P > 0.1). BladderScan BVI9400 had the ability of high accuracy and good stability of measured data. In view of quick and conveniences, BVI9400 could be as auxiliary equipment on pelvic tumor to evaluate whether the bladder volume during fractional radiotherapy was consistency with that during CT positioning.

Ultrasound physics and instrumentation for pathologists.

PubMed

Lieu, David

2010-10-01

Interest in pathologist-performed ultrasound-guided fine-needle aspiration is increasing. Educational courses discuss clinical ultrasound and biopsy techniques but not ultrasound physics and instrumentation. To review modern ultrasound physics and instrumentation to help pathologists understand the basis of modern ultrasound. A review of recent literature and textbooks was performed. Ultrasound physics and instrumentation are the foundations of clinical ultrasound. The key physical principle is the piezoelectric effect. When stimulated by an electric current, certain crystals vibrate and produce ultrasound. A hand-held transducer converts electricity into ultrasound, transmits it into tissue, and listens for reflected ultrasound to return. The returning echoes are converted into electrical signals and used to create a 2-dimensional gray-scale image. Scanning at a high frequency improves axial resolution but has low tissue penetration. Electronic focusing moves the long-axis focus to depth of the object of interest and improves lateral resolution. The short-axis focus in 1-dimensional transducers is fixed, which results in poor elevational resolution away from the focal zone. Using multiple foci improves lateral resolution but degrades temporal resolution. The sonographer can adjust the dynamic range to change contrast and bring out subtle masses. Contrast resolution is limited by processing speed, monitor resolution, and gray-scale perception of the human eye. Ultrasound is an evolving field. New technologies include miniaturization, spatial compound imaging, tissue harmonics, and multidimensional transducers. Clinical cytopathologists who understand ultrasound physics, instrumentation, and clinical ultrasound are ready for the challenges of cytopathologist-performed ultrasound-guided fine-needle aspiration and core-needle biopsy in the 21st century.

Clinical experience with real-time ultrasound

NASA Astrophysics Data System (ADS)

Chimiak, William J.; Wolfman, Neil T.; Covitz, Wesley

1995-05-01

After testing the extended multimedia interface (EMMI) product which is an asynchronous transmission mode (ATM) user to network interface (UNI) of AT&T at the Society for Computer Applications in Radiology conference in Winston-Salem, the Department of Radiology together with AT&T are implementing a tele-ultrasound system to combine real- time ultrasound with the static imaging features of more traditional digital ultrasound systems. Our current ultrasound system archives digital images to an optical disk system. Static images are sent using our digital radiology systems. This could be transferring images from one digital imaging and communications (DICOM)-compliant machine to another, or the current image transfer methodologies. The prototype of a live ultrasound system using the EMMI demonstrated the feasibility of doing live ultrasound. We now are developing the scenarios using a mix of the two methodologies. Utilizing EMMI technology, radiologists at the BGSM review at a workstation both static images and real-time scanning done by a technologist on patients at a remote site in order to render on-line primary diagnosis. Our goal is to test the feasibility of operating an ultrasound laboratory at a remote site utilizing a trained technologist without the necessity of having a full-time radiologist at that site. Initial plans are for a radiologist to review an initial set of static images on a patient taken by the technologist. If further scanning is required, the EMMI is used to transmit real-time imaging and audio using the audio input of a standard microphone system and the National Television Standards Committee (NTSC) output of the ultrasound equipment from the remote site to the radiologist in the department review station. The EMMI digitally encodes this data and places it in an ATM format. This ATM data stream goes to the GCNS2000 and then to the other EMMI where the ATM data stream is decoded into the live studies and voice communication which are then

Reconstruction of three-dimensional ultrasound images based on cyclic Savitzky-Golay filters

NASA Astrophysics Data System (ADS)

Toonkum, Pollakrit; Suwanwela, Nijasri C.; Chinrungrueng, Chedsada

2011-01-01

We present a new algorithm for reconstructing a three-dimensional (3-D) ultrasound image from a series of two-dimensional B-scan ultrasound slices acquired in the mechanical linear scanning framework. Unlike most existing 3-D ultrasound reconstruction algorithms, which have been developed and evaluated in the freehand scanning framework, the new algorithm has been designed to capitalize the regularity pattern of the mechanical linear scanning, where all the B-scan slices are precisely parallel and evenly spaced. The new reconstruction algorithm, referred to as the cyclic Savitzky-Golay (CSG) reconstruction filter, is an improvement on the original Savitzky-Golay filter in two respects: First, it is extended to accept a 3-D array of data as the filter input instead of a one-dimensional data sequence. Second, it incorporates the cyclic indicator function in its least-squares objective function so that the CSG algorithm can simultaneously perform both smoothing and interpolating tasks. The performance of the CSG reconstruction filter compared to that of most existing reconstruction algorithms in generating a 3-D synthetic test image and a clinical 3-D carotid artery bifurcation in the mechanical linear scanning framework are also reported.

Lung Ultrasound for Diagnosing Pneumothorax in the Critically Ill Neonate.

PubMed

Raimondi, Francesco; Rodriguez Fanjul, Javier; Aversa, Salvatore; Chirico, Gaetano; Yousef, Nadya; De Luca, Daniele; Corsini, Iuri; Dani, Carlo; Grappone, Lidia; Orfeo, Luigi; Migliaro, Fiorella; Vallone, Gianfranco; Capasso, Letizia

2016-08-01

To evaluate the accuracy of lung ultrasound for the diagnosis of pneumothorax in the sudden decompensating patient. In an international, prospective study, sudden decompensation was defined as a prolonged significant desaturation (oxygen saturation <65% for more than 40 seconds) and bradycardia or sudden increase of oxygen requirement by at least 50% in less than 10 minutes with a final fraction of inspired oxygen ≥0.7 to keep stable saturations. All eligible patients had an ultrasound scan before undergoing a chest radiograph, which was the reference standard. Forty-two infants (birth weight = 1531 ± 812 g; gestational age = 31 ± 3.5 weeks) were enrolled in 6 centers; pneumothorax was detected in 26 (62%). Lung ultrasound accuracy in diagnosing pneumothorax was as follows: sensitivity 100%, specificity 100%, positive predictive value 100%, and negative predictive value 100%. Clinical evaluation of pneumothorax showed sensitivity 84%, specificity 56%, positive predictive value 76%, and negative predictive value 69%. After sudden decompensation, a lung ultrasound scan was performed in an average time of 5.3 ± 5.6 minutes vs 19 ± 11.7 minutes required for a chest radiography. Emergency drainage was performed after an ultrasound scan but before radiography in 9 cases. Lung ultrasound shows high accuracy in detecting pneumothorax in the critical infant, outperforming clinical evaluation and reducing time to imaging diagnosis and drainage. Copyright © 2016 Elsevier Inc. All rights reserved.

Point of Care Ultrasound Diagnosis of Empyema.

PubMed

Nelson, Mathew; Stankard, Brendon; Greco, Jeffrey; Okumura, Yoshito

2016-08-01

Emergency ultrasonography is an efficient and cost effective tool for patients who are in respiratory distress. Chest radiographs can yield limited information for these patients. Computed tomography scans have long been the criterion standard for advanced imaging in patients with respiratory complaints, but point of care ultrasound (POCUS) can be performed at bedside, does not expose the patient to radiation, and at times may provide more information than a computed tomography scan. A 60-year-old man with a medical history of hypertension presented to the emergency department complaining of a productive cough associated with fever, weakness, and progressively worsening dyspnea on exertion over the previous 1 to 2 weeks. The physical examination was remarkable for rhonchi in the right upper lobe and diminished breath sounds throughout the right lung. POCUS was performed, and the results revealed severe atelectasis and hepatization of the right lung parenchyma with visualized air bronchograms. Complex hypoechoic material with a posterior spine sign was noted, which increased concern for complex consolidation and effusion. The diagnosis of pneumonia with empyema was made. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: POCUS has become a much more commonly used imaging modality within many emergency departments. Ultrasound is more sensitive than chest radiographs for identifying pathologies such as pneumothorax and simple effusions. This case shows how well POCUS can diagnose empyema even in the setting of diagnostic uncertainty of computed tomographic imaging. Copyright © 2016 Elsevier Inc. All rights reserved.

Accuracy assessment of high frequency 3D ultrasound for digital impression-taking of prepared teeth

NASA Astrophysics Data System (ADS)

Heger, Stefan; Vollborn, Thorsten; Tinschert, Joachim; Wolfart, Stefan; Radermacher, Klaus

2013-03-01

Silicone based impression-taking of prepared teeth followed by plaster casting is well-established but potentially less reliable, error-prone and inefficient, particularly in combination with emerging techniques like computer aided design and manufacturing (CAD/CAM) of dental prosthesis. Intra-oral optical scanners for digital impression-taking have been introduced but until now some drawbacks still exist. Because optical waves can hardly penetrate liquids or soft-tissues, sub-gingival preparations still need to be uncovered invasively prior to scanning. High frequency ultrasound (HFUS) based micro-scanning has been recently investigated as an alternative to optical intra-oral scanning. Ultrasound is less sensitive against oral fluids and in principal able to penetrate gingiva without invasively exposing of sub-gingival preparations. Nevertheless, spatial resolution as well as digitization accuracy of an ultrasound based micro-scanning system remains a critical parameter because the ultrasound wavelength in water-like media such as gingiva is typically smaller than that of optical waves. In this contribution, the in-vitro accuracy of ultrasound based micro-scanning for tooth geometry reconstruction is being investigated and compared to its extra-oral optical counterpart. In order to increase the spatial resolution of the system, 2nd harmonic frequencies from a mechanically driven focused single element transducer were separated and corresponding 3D surface models were calculated for both fundamentals and 2nd harmonics. Measurements on phantoms, model teeth and human teeth were carried out for evaluation of spatial resolution and surface detection accuracy. Comparison of optical and ultrasound digital impression taking indicate that, in terms of accuracy, ultrasound based tooth digitization can be an alternative for optical impression-taking.

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.

Advanced Ultrasound Technologies for Diagnosis and Therapy.

PubMed

Rix, Anne; Lederle, Wiltrud; Theek, Benjamin; Lammers, Twan; Moonen, Chrit; Schmitz, Georg; Kiessling, Fabian

2018-05-01

Ultrasound is among the most rapidly advancing imaging techniques. Functional methods such as elastography have been clinically introduced, and tissue characterization is improved by contrast-enhanced scans. Here, novel superresolution techniques provide unique morphologic and functional insights into tissue vascularization. Functional analyses are complemented by molecular ultrasound imaging, to visualize markers of inflammation and angiogenesis. The full potential of diagnostic ultrasound may become apparent by integrating these multiple imaging features in radiomics approaches. Emerging interest in ultrasound also results from its therapeutic potential. Various applications of tumor ablation with high-intensity focused ultrasound are being clinically evaluated, and its performance strongly benefits from the integration into MRI. Additionally, oscillating microbubbles mediate sonoporation to open biologic barriers, thus improving the delivery of drugs or nucleic acids that are coadministered or coformulated with microbubbles. This article provides an overview of recent developments in diagnostic and therapeutic ultrasound, highlighting multiple innovation tracks and their translational potential. © 2018 by the Society of Nuclear Medicine and Molecular Imaging.

Is Ultrasound a Valid and Reliable Imaging Modality for Airway Evaluation?: An Observational Computed Tomographic Validation Study Using Submandibular Scanning of the Mouth and Oropharynx.

PubMed

Abdallah, Faraj W; Yu, Eugene; Cholvisudhi, Phantila; Niazi, Ahtsham U; Chin, Ki J; Abbas, Sherif; Chan, Vincent W

2017-01-01

Ultrasound (US) imaging of the airway may be useful in predicting difficulty of airway management (DAM); but its use is limited by lack of proof of its validity and reliability. We sought to validate US imaging of the airway by comparison to CT-scan, and to assess its inter- and intra-observer reliability. We used submandibular sonographic imaging of the mouth and oropharynx to examine how well the ratio of tongue thickness to oral cavity height correlates with the ratio of tongue volume to oral cavity volume, an established tomographic measure of DAM. A cohort of 34 patients undergoing CT-scan was recruited. Study standardized assessments included CT-measured ratios of tongue volume to oropharyngeal cavity volume; tongue thickness to oral cavity height; and US-measured ratio of tongue thickness to oral cavity height. Two sonographers independently performed US imaging of the airway before and after CT-scan. Our findings indicate that the US-measured ratio of tongue thickness to oral cavity height highly correlates with the CT-measured ratio of tongue volume to oral cavity volume. US measurements also demonstrated strong inter- and intra-observer reliability. This study suggests that US is a valid and reliable tool for imaging the oral and oropharyngeal parts of the airway, as well as for measuring the volumetric relationship between the tongue and oral cavity, and may therefore be a useful predictor of DAM. © 2016 by the American Institute of Ultrasound in Medicine.

A Guide to Analysing Tongue Motion from Ultrasound Images

ERIC Educational Resources Information Center

Stone, Maureen

2005-01-01

This paper is meant to be an introduction to and general reference for ultrasound imaging for new and moderately experienced users of the instrument. The paper consists of eight sections. The first explains how ultrasound works, including beam properties, scan types and machine features. The second section discusses image quality, including the…

Identification of nanoparticles and nanosystems in biological matrices with scanning probe microscopy.

PubMed

Angeloni, Livia; Reggente, Melania; Passeri, Daniele; Natali, Marco; Rossi, Marco

2018-04-17

Identification of nanoparticles and nanosystems into cells and biological matrices is a hot research topic in nanobiotechnologies. Because of their capability to map physical properties (mechanical, electric, magnetic, chemical, or optical), several scanning probe microscopy based techniques have been proposed for the subsurface detection of nanomaterials in biological systems. In particular, atomic force microscopy (AFM) can be used to reveal stiff nanoparticles in cells and other soft biomaterials by probing the sample mechanical properties through the acquisition of local indentation curves or through the combination of ultrasound-based methods, like contact resonance AFM (CR-AFM) or scanning near field ultrasound holography. Magnetic force microscopy can detect magnetic nanoparticles and other magnetic (bio)materials in nonmagnetic biological samples, while electric force microscopy, conductive AFM, and Kelvin probe force microscopy can reveal buried nanomaterials on the basis of the differences between their electric properties and those of the surrounding matrices. Finally, scanning near field optical microscopy and tip-enhanced Raman spectroscopy can visualize buried nanostructures on the basis of their optical and chemical properties. Despite at a still early stage, these methods are promising for detection of nanomaterials in biological systems as they could be truly noninvasive, would not require destructive and time-consuming specific sample preparation, could be performed in vitro, on alive samples and in water or physiological environment, and by continuously imaging the same sample could be used to dynamically monitor the diffusion paths and interaction mechanisms of nanomaterials into cells and biological systems. This article is categorized under: Diagnostic Tools > In Vivo Nanodiagnostics and Imaging Nanotechnology Approaches to Biology > Nanoscale Systems in Biology. © 2018 Wiley Periodicals, Inc.

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.

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.

Comparison of the measurements of a novel optical biometry: Nidek AL-Scan with Sirius and a ultrasound biometry.

PubMed

Çağlar, Çağatay; Kocamış, Sücattin İlker; Demir, Emre; Durmuş, Mustafa

2017-06-01

To investigate the accuracy of the measurements of Nidek AL-Scan by comparing with Sirius (CSO, Florence, Italy), a corneal tomography which also employs the Scheimpflug principle, and a commonly used device, ultrasound biometry (UB) (Aviso A/B, Quantel Medical, MT, USA). Right eyes of 85 healthy volunteers (58 women 27 men) with a mean age of 39.24 ± 14.37 years (range 15-68) were enrolled into this comparative prospective study. Average K 2.4, average K 3.3, CCT (central corneal thickness), WTW (white to white distance), ACD (anterior chamber depth) and AL (axial length) were obtained from the AL-Scan and compared with average SimK, CCT, WTW (horizontal anterior chamber diameter) and ACD obtained from Sirius and also compared with ACD and AL obtained from UB. The statistically significant difference was found between all of the measurements (p < 0.001) except the average keratometry values (K2.4, K3.3, SimK) (p = 0.083). There was a perfect correlation between keratometry, CCT and AL measurements of the devices (ICC = 0.977, 0.954, 0.923, respectively) and there was a strong correlation between the WTW measurements of AL-Scan and Sirius (ICC = 0.865). While ACD parameter of AL-Scan and UB showed a perfect correlation (ICC = 0.977), there was a moderate correlation between AL-Scan and Sirius and also between UB and Sirius (ICC = 0.608 and 0.664, respectively). There was a high correlation between the all measurements, besides ACD, of AL-Scan and Sirius and they can be used interchangeably for average keratometry and WTW confidently. However, ACD and CCT have a broader 95 % LoA (-0.039 to 0.744 and -24.985 to 3.691, respectively). In addition, AL-Scan and UB were in good agreement regarding ACD, while differences in AL measurements of UB and AL-Scan were clinically important (95 % LoA = -0.091 to 0.703). Furthermore, UB and Sirius have a moderate agreement regarding ACD (95 % LoA = -0.047 to 0.680).

Longitudinal Ultrasound Education Track Curriculum Implemented Within an Emergency Medicine Residency Program.

PubMed

Boulger, Creagh; Adams, Daniel Z; Hughes, Daralee; Bahner, David P; King, Andrew

2017-06-01

Emergency Medicine residency programs offer ultrasound-focused curricula to address Accreditation Council for Graduate Medical Education (ACGME) milestones. Although some programs offer advanced clinical tracks in ultrasound, no standard curriculum exists. We sought to establish a well-defined ultrasound track curriculum to allow interested residents to develop advanced clinical skills and scholarship within this academic niche. The curriculum involves a greater number of clinical scans, ultrasound-focused scholarly and quality improvement projects, enhanced faculty-driven ultrasound focused didactics, and participation at a national ultrasound conference to receive certification. Successful ultrasound scholarly tracks can provide residents with the potential to obtain fellowships or competency beyond ACGME requirements. © 2017 by the American Institute of Ultrasound in Medicine.

Ultrasound Thermal Imaging and its application to Rayleigh-Bénard convection in mercury

NASA Astrophysics Data System (ADS)

Xu, Hongzhou; Andereck, C. David

2003-11-01

We have developed Ultrasound Thermal Imaging (UTI), a non-intrusive ultrasound technique for internal temperature measurement of opaque fluids, and have applied UTI to low Rayleigh number buoyancy driven convection in mercury. UTI relies upon the variation of sound speed with temperature of the fluid. An array of ultrasound transducers scanned electronically along the sidewall of a convection cell with aspect ratio of 6 yields a map of the thermal field over the chamber. The chamber has stainless steel sidewalls and molybdenum covered copper plates at the top and bottom. As the Rayleigh number increases slowly from zero, the data reveal the formation of a roll cell pattern and transitions between different cellular states. Based on standard deviation distributions of the temperature profile at the cell's mid-depth, the critical temperature difference agrees well with the theoretically predicted value. The heat flux through the horizontal mercury layer was determined by thermistors mounted at the exit and entrance of the internal channel in each copper plate through which flows warm/cool constant temperature water. Nusselt numbers and other experimental results will also be presented.

Implementation of a rotational ultrasound biomicroscopy system equipped with a high-frequency angled needle transducer--ex vivo ultrasound imaging of porcine ocular posterior tissues.

PubMed

Bok, Tae-Hoon; Kim, Juho; Bae, Jinho; Lee, Chong Hyun; Paeng, Dong-Guk

2014-09-24

The mechanical scanning of a single element transducer has been mostly utilized for high-frequency ultrasound imaging. However, it requires space for the mechanical motion of the transducer. In this paper, a rotational scanning ultrasound biomicroscopy (UBM) system equipped with a high-frequency angled needle transducer is designed and implemented in order to minimize the space required. It was applied to ex vivo ultrasound imaging of porcine posterior ocular tissues through a minimal incision hole of 1 mm in diameter. The retina and sclera for the one eye were visualized in the relative rotating angle range of 270°~330° and at a distance range of 6~7 mm, whereas the tissues of the other eye were observed in relative angle range of 160°~220° and at a distance range of 7.5~9 mm. The layer between retina and sclera seemed to be bent because the distance between the transducer tip and the layer was varied while the transducer was rotated. Certin features of the rotation system such as the optimal scanning angle, step angle and data length need to be improved for ensure higher accuracy and precision. Moreover, the focal length should be considered for the image quality. This implementation represents the first report of a rotational scanning UBM system.

Ultrasound contrast agent fabricated from microbubbles containing instant adhesives, and its ultrasound imaging ability

NASA Astrophysics Data System (ADS)

Makuta, T.; Tamakawa, Y.

2012-04-01

Non-invasive surgery techniques and drug delivery system with acoustic characteristics of ultrasound contrast agent have been studied intensively in recent years. Ultrasound contrast agent collapses easily under the blood circulating and the ultrasound irradiating because it is just a stabilized bubble without solid-shell by surface adsorption of surfactant or lipid. For improving the imaging stability, we proposed the fabrication method of the hollow microcapsule with polymer shell, which can be fabricated just blowing vapor of commonly-used instant adhesive (Cyanoacrylate monomer) into water as microbubbles. Therefore, the cyanoacrylate vapor contained inside microbubble initiates polymerization on the gasliquid interface soon after microbubbles are generated in water. Consequently, hollow microspheres coated by cyanoacrylate thin film are generated. In this report, we revealed that diameter distributions of microbubbles and microcapsules were approximately same and most of them were less than 10 μm, that is, smaller than blood capillary. In addition, we also revealed that hollow microcapsules enhanced the acoustic signal especially in the harmonic contrast imaging and were broken or agglomerated under the ultrasound field. As for the yield of hollow microcapsules, we revealed that sodium dodecyl sulfate addition to water phase instead of deoxycolic acid made the fabrication yield increased.

In vivo visualization of robotically implemented synthetic tracked aperture ultrasound (STRATUS) imaging system using curvilinear array

NASA Astrophysics Data System (ADS)

Zhang, Haichong K.; Aalamifar, Fereshteh; Boctor, Emad M.

2016-04-01

Synthetic aperture for ultrasound is a technique utilizing a wide aperture in both transmit and receive to enhance the ultrasound image quality. The limitation of synthetic aperture is the maximum available aperture size limit determined by the physical size of ultrasound probe. We propose Synthetic-Tracked Aperture Ultrasound (STRATUS) imaging system to overcome the limitation by extending the beamforming aperture size through ultrasound probe tracking. With a setup involving a robotic arm, the ultrasound probe is moved using the robotic arm, while the positions on a scanning trajectory are tracked in real-time. Data from each pose are synthesized to construct a high resolution image. In previous studies, we have demonstrated the feasibility through phantom experiments. However, various additional factors such as real-time data collection or motion artifacts should be taken into account when the in vivo target becomes the subject. In this work, we build a robot-based STRATUS imaging system with continuous data collection capability considering the practical implementation. A curvilinear array is used instead of a linear array to benefit from its wider capture angle. We scanned human forearms under two scenarios: one submerged the arm in the water tank under 10 cm depth, and the other directly scanned the arm from the surface. The image contrast improved 5.51 dB, and 9.96 dB for the underwater scan and the direct scan, respectively. The result indicates the practical feasibility of STRATUS imaging system, and the technique can be potentially applied to the wide range of human body.

Evaluation of the validity and reliability of A-scan ultrasound biometry with a single use disposable cover.

PubMed

Cass, K; Thompson, C M; Tromans, C; Wood, I C J

2002-03-01

The UK Medical Devices Agency has suggested that ophthalmic practitioners should, where practicable and not compromising clinical outcome, restrict corneal contact devices to single patient use to minimise a remote theoretical risk of transmission of new variant Creutzfeldt-Jakob disease (vCJD). This study reports on a modified technique of ultrasound A-scan biometry that complies with the MDA recommendations. The right eyes of 37 consecutive hospital patients had a series of biometry readings taken with a Humphrey 820 A-scan instrument with a plane wave transducer use d conventionally and with the addition of a disposable latex cover. Intrasessional repeatability of axial length measurements was similar for conventional readings--mean difference 0.027 mm, 95% confidence intervals (CI) +/- 0.44 mm and those taken with a disposable cover (0.028 mm, CI +/- 0.38). Intersessional repeatability was equivalent with (0.002 mm, CI +.- 0.51) and without a cover (0.03 mm, CI +/- 0.51). Readings with a cover were not significantly different from those without (paired t test; p >0.05), but tended to be greater (mean difference 0.085 mm, CI +/- 0.60). These findings suggest that corneal contact biometry with a disposable cover is a viable and theoretically safer alternative to the conventional technique.

Ultrasound and the IRB

ERIC Educational Resources Information Center

Epstein, Melissa A.

2005-01-01

The purpose of this paper is to assist researchers in writing their research protocols and subject consent forms so that both the Institutional Review Board (IRB) and subjects are assured of the minimal risk associated with diagnostic B-scan ultrasound as it is used in speech research. There have been numerous epidemiological studies on fetal…

A Dual-Modality System for Both Multi-Color Ultrasound-Switchable Fluorescence and Ultrasound Imaging

PubMed Central

Kandukuri, Jayanth; Yu, Shuai; Cheng, Bingbing; Bandi, Venugopal; D’Souza, Francis; Nguyen, Kytai T.; Hong, Yi; Yuan, Baohong

2017-01-01

Simultaneous imaging of multiple targets (SIMT) in opaque biological tissues is an important goal for molecular imaging in the future. Multi-color fluorescence imaging in deep tissues is a promising technology to reach this goal. In this work, we developed a dual-modality imaging system by combining our recently developed ultrasound-switchable fluorescence (USF) imaging technology with the conventional ultrasound (US) B-mode imaging. This dual-modality system can simultaneously image tissue acoustic structure information and multi-color fluorophores in centimeter-deep tissue with comparable spatial resolutions. To conduct USF imaging on the same plane (i.e., x-z plane) as US imaging, we adopted two 90°-crossed ultrasound transducers with an overlapped focal region, while the US transducer (the third one) was positioned at the center of these two USF transducers. Thus, the axial resolution of USF is close to the lateral resolution, which allows a point-by-point USF scanning on the same plane as the US imaging. Both multi-color USF and ultrasound imaging of a tissue phantom were demonstrated. PMID:28165390

Irregular or absent periods--what can an ultrasound scan tell you?

PubMed

Khalid, Asma

2004-02-01

Transvaginal ultrasonography has increased our appreciation of the physiological changes in the ovary and endometrium that occur during the normal menstrual cycle. It has become a primary investigative tool in women with irregular or absent periods. Its usefulness in cases of primary amenorrhoea to assess anatomy is also undisputed although it may have limitations in terms of its specificity. However, the interpretation of ultrasound images in women with irregular menses or secondary amenorrhoea is not entirely straightforward. This is particularly true in the diagnosis of polycystic ovary syndrome, a condition of uncertain aetiology, which may present with oligoamenorrhoea. This chapter aims to discuss the benefits and limitations of ultrasound while taking into account the broad overlap between normal and abnormal physiology, some of which has still to be elucidated.

Clot retraction affects the extent of ultrasound-enhanced thrombolysis in an ex vivo porcine thrombosis model

PubMed Central

Sutton, Jonathan T.; Ivancevich, Nikolas M.; Perrin, Stephen R.; Vela, Deborah C.; Holland, Christy K.

2013-01-01

Using an FDA-approved contrast agent (Definity®) and thrombolytic drug (rt-PA), we investigated ultrasound-enhanced thrombolysis in two whole-blood clot models. Porcine venous blood was collected from donor hogs and coagulated in two different materials. This method produced clots with differing compositional properties, as determined by routine scanning electron microscopy and histology. Clots were deployed in an ex vivo porcine thrombolysis model, while an intermittent ultrasound scheme previously developed to maximize stable cavitation was applied and acoustic emissions were detected. Exposure of clots to 3.15 μg/mL rt-PA promoted lysis in both clot models, compared to exposure to plasma alone. However, in the presence of rt-PA, Definity®, and ultrasound, only unretracted clots experienced significant enhancement of thrombolysis compared to treatment with rt-PA. In these clots, microscopy studies revealed loose erythrocyte aggregates, a significantly less extensive fibrin network, and a higher porosity, which may facilitate increase penetration of thrombolytics by cavitation. PMID:23453629

Diagnostic and interventional musculoskeletal ultrasound: part 1. Fundamentals.

PubMed

Smith, Jay; Finnoff, Jonathan T

2009-01-01

Musculoskeletal ultrasound involves the use of high-frequency sound waves to image soft tissues and bony structures in the body for the purposes of diagnosing pathology or guiding real-time interventional procedures. Recently, an increasing number of physicians have integrated musculoskeletal ultrasound into their practices to facilitate patient care. Technological advancements, improved portability, and reduced costs continue to drive the proliferation of ultrasound in clinical medicine. This increased interest creates a need for education pertaining to all aspects of musculoskeletal ultrasound. The primary purpose of this article is to review diagnostic ultrasound technology and its potential clinical applications in the evaluation and treatment of patients with neurologic and musculoskeletal disorders. After reviewing this article, physicians should be able to (1) list the advantages and disadvantages of ultrasound compared with other available imaging modalities, (2) describe how ultrasound machines produce images using sound waves, (3) discuss the steps necessary to acquire and optimize an ultrasound image, (4) understand the different ultrasound appearances of tendons, nerves, muscles, ligaments, blood vessels, and bones, and (5) identify multiple applications for diagnostic and interventional musculoskeletal ultrasound in musculoskeletal practice. Part 1 of this 2-part article reviews the fundamentals of clinical ultrasonographic imaging, including relevant physics, equipment, training, image optimization, and scanning principles for diagnostic and interventional purposes.

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.

A 3D freehand ultrasound system for multi-view reconstructions from sparse 2D scanning planes.

PubMed

Yu, Honggang; Pattichis, Marios S; Agurto, Carla; Beth Goens, M

2011-01-20

A significant limitation of existing 3D ultrasound systems comes from the fact that the majority of them work with fixed acquisition geometries. As a result, the users have very limited control over the geometry of the 2D scanning planes. We present a low-cost and flexible ultrasound imaging system that integrates several image processing components to allow for 3D reconstructions from limited numbers of 2D image planes and multiple acoustic views. Our approach is based on a 3D freehand ultrasound system that allows users to control the 2D acquisition imaging using conventional 2D probes.For reliable performance, we develop new methods for image segmentation and robust multi-view registration. We first present a new hybrid geometric level-set approach that provides reliable segmentation performance with relatively simple initializations and minimum edge leakage. Optimization of the segmentation model parameters and its effect on performance is carefully discussed. Second, using the segmented images, a new coarse to fine automatic multi-view registration method is introduced. The approach uses a 3D Hotelling transform to initialize an optimization search. Then, the fine scale feature-based registration is performed using a robust, non-linear least squares algorithm. The robustness of the multi-view registration system allows for accurate 3D reconstructions from sparse 2D image planes. Volume measurements from multi-view 3D reconstructions are found to be consistently and significantly more accurate than measurements from single view reconstructions. The volume error of multi-view reconstruction is measured to be less than 5% of the true volume. We show that volume reconstruction accuracy is a function of the total number of 2D image planes and the number of views for calibrated phantom. In clinical in-vivo cardiac experiments, we show that volume estimates of the left ventricle from multi-view reconstructions are found to be in better agreement with clinical

Effects and mechanism of ultrasound pretreatment on rapeseed protein enzymolysis.

PubMed

Jin, Jian; Ma, Haile; Wang, Weiwei; Luo, Min; Wang, Bei; Qu, Wenjuan; He, Ronghai; Owusu, John; Li, Yunliang

2016-03-15

The disadvantages which stem from the use of traditional enzymolysis of protein has necessitated the need to employ sweeping frequency and pulsed ultrasound (SFPU) in the pretreatment of rapeseed protein prior to proteolysis in order to bring about improvement in enzymolysis efficiency. Further, in order to determine the mechanism of ultrasound-accelerated enzymolysis of RP, the effects of SFPU on the kinetics, thermodynamics, molecular conformation and microstructure of RP were investigated. Kinetic studies showed that SFPU pretreatment on RP improved enzymolysis by decreasing the apparent constant KM significantly (P < 0.05) by 32.8% and reducing the thermodynamic parameters Ea , ΔH and ΔS by 16.6%, 17.7% and 9.2% respectively. Fluorescence spectra revealed that SFPU pretreatment induced molecular unfolding, causing more hydrophobic groups and regions inside the molecules to be exposed to the outside. Circular dichroism analysis indicated that SFPU pretreatment decreased the α-helix content by 16.1% and increased the random coil content by 3.6%. In addition, scanning electron microscopy showed that SFPU pretreatment increased the specific surface area of RP. Ultrasound pretreatment is an efficient method in RP proteolysis to produce peptides through its impact on the molecular conformation and microstructure of proteins. © 2015 Society of Chemical Industry.

[Evidence of lacrimal plugs via high resolution ultrasound].

PubMed

Tost, Frank H W; Darman, Jacques

2003-07-01

The practical value of high-frequency ultrasound (transducer frequency of 20 MHz) for studying lacrimal plugs positioned into canaliculi was proved. Twelve patients with twenty intracanalicular plugs and two punctum plugs were examined via high-frequency B-scan ultrasonography using 20 MHz transducer (model I3 Sacramento, USA). Detection and localisation of the intracanalicular plugs was made by a 20 MHz sector scanner. The ultrasound examinations were performed 1 - 24 month after the placement of lacrimal plugs. After patient's head positioning, the high-frequency ultrasound investigation was done via immersion fluid (2 % methylcellulose). All patients with dry eye treated by lacrimal plug implant showed echographic structure in the lacrimal canaliculus. In transversal echograms it was possible to image both canaliculi together when the lids were half-closed. Contrary to the normal state, it was not necessary to inject viscous fluid into the canaliculus. High-resolution ultrasound was able to differentiate the normal canaliculus from the findings after plug placement. The echograms can vary from one plug type to another. Highly reflective structures were found after the placement of silicone intracanalicular plugs, e. g. HERRICK-Plug. In contrast, the ultrasonic image taken through acrylic polymer intracanalicular plugs showed homogeneous small reflective inner structure, e. g. SMART-Plug. However, smooth and flat acoustic interface between acrylic polymer plug and the lacrimal canaliculus produced strong echoes. 20 MHz ultrasound seems to be well suited for the detection and localisation of intracanalicular plugs. By use of 20 MHz ultrasound scans it is possible to get high-quality images of the intracanalicular plug and around lacrimal canaliculus. Compared with UBM, the depth of penetration is much higher with negligible resolution. On the whole, we believe that 20 MHz ultrasound can become a useful tool for evaluating the placement of intracanalicular plugs

Automatic Cataract Hardness Classification Ex Vivo by Ultrasound Techniques.

PubMed

Caixinha, Miguel; Santos, Mário; Santos, Jaime

2016-04-01

To demonstrate the feasibility of a new methodology for cataract hardness characterization and automatic classification using ultrasound techniques, different cataract degrees were induced in 210 porcine lenses. A 25-MHz ultrasound transducer was used to obtain acoustical parameters (velocity and attenuation) and backscattering signals. B-Scan and parametric Nakagami images were constructed. Ninety-seven parameters were extracted and subjected to a Principal Component Analysis. Bayes, K-Nearest-Neighbours, Fisher Linear Discriminant and Support Vector Machine (SVM) classifiers were used to automatically classify the different cataract severities. Statistically significant increases with cataract formation were found for velocity, attenuation, mean brightness intensity of the B-Scan images and mean Nakagami m parameter (p < 0.01). The four classifiers showed a good performance for healthy versus cataractous lenses (F-measure ≥ 92.68%), while for initial versus severe cataracts the SVM classifier showed the higher performance (90.62%). The results showed that ultrasound techniques can be used for non-invasive cataract hardness characterization and automatic classification. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

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

Ultrasound diagnosis of bilateral cataracts in a fetus with possible cerebro-ocular congential muscular dystrophy during the routine second trimester anomaly scan

PubMed Central

Wimalasundera, Ruwan; Holder, Susan

2015-01-01

The finding of bilateral congenital cataracts in the fetus is rare. We report bilateral congenital cataracts detected during the routine second trimester anomaly scan, which subsequently were found to be associated with other congenital anomalies and the parents opted for a termination of pregnancy. At post-mortem, Muscle–Eye Brain disease or Walker–Warburg Syndrome was considered likely, which are autosomal recessive congenital muscular dystrophy disorders associated with cerebral, cerebellar, muscle and eye anomalies. On ultrasound, bilateral cataracts appear as echogenic, solid areas within the fetal orbits. The examination of the fetal face and orbits plays an important role in confirming fetal well-being antenatally. We propose that it should become a routine part of the structural survey of fetal anatomy during the obstetric anomaly scan. This is especially important in pregnancies previously affected by fetal cataracts or pregnancies at risk of rare genetic syndromes. PMID:27433255

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

The utility of neck ultrasound and sestamibi scans in patients with secondary and tertiary hyperparathyroidism.

PubMed

Alkhalili, Eyas; Tasci, Yunus; Aksoy, Erol; Aliyev, Shamil; Soundararajan, Saranya; Taskin, Eren; Siperstein, Allan; Berber, Eren

2015-03-01

Secondary hyperparathyroidism (SHPT) and tertiary hyperparathyroidism (THPT) are disease entities in patients with chronic kidney disease that are caused by parathyroid hyperplasia. The role of preoperative localization studies in patients undergoing parathyroidectomy for these conditions remains poorly defined. To evaluate the utility of surgeon-performed neck ultrasound (US) as well as sestamibi scans in the localization of parathyroid glands in patients with SHPT/THPT. A retrospective analysis of patients with SHPT/THPT who underwent parathyroidectomy at a single institution. Results of preoperative localization studies were compared to intraoperative findings. One hundred and three patients underwent parathyroidectomy for SHPT/THPT. All patients underwent surgeon-performed neck US, while 92 (89%) underwent sestamibi scans. US failed to localize any of the parathyroids in 4 patients (3.8%), while sestamibi was negative in 11 (12%). Forty-seven ectopic glands were identified in 38 patients in whom sestamibi was performed. In five patients (13%), ectopic glands were identified by both modalities, by US only in 6 (16%), by sestamibi only in 8 (21%), and by neither study in 19 patients (50%). US showed new thyroid nodules in 19 patients (18.4 %), leading to lobectomy or thyroidectomy at the time of parathyroidectomy in 16 patients (15.5%). Pathology showed malignancy in 7 patients (6.8%). US and MIBI offer little benefit in localizing ectopic glands and rarely change the conduct of a standard four-gland exploration. Although there was a benefit of US in the assessment of thyroid nodules, in only 8.7% of patients was sestamibi of benefit in identifying ectopic glands.

Virtual Guidance Ultrasound: A Tool to Obtain Diagnostic Ultrasound for Remote Environments

NASA Technical Reports Server (NTRS)

Caine,Timothy L.; Martin David S.; Matz, Timothy; Lee, Stuart M. C.; Stenger, Michael B.; Platts, Steven H.

2012-01-01

Astronauts currently acquire ultrasound images on the International Space Station with the assistance of real-time remote guidance from an ultrasound expert in Mission Control. Remote guidance will not be feasible when significant communication delays exist during exploration missions beyond low-Earth orbit. For example, there may be as much as a 20- minute delay in communications between the Earth and Mars. Virtual-guidance, a pre-recorded audio-visual tutorial viewed in real-time, is a viable modality for minimally trained scanners to obtain diagnostically-adequate images of clinically relevant anatomical structures in an autonomous manner. METHODS: Inexperienced ultrasound operators were recruited to perform carotid artery (n = 10) and ophthalmic (n = 9) ultrasound examinations using virtual guidance as their only instructional tool. In the carotid group, each each untrained operator acquired two-dimensional, pulsed, and color Doppler of the carotid artery. In the ophthalmic group, operators acquired representative images of the anterior chamber of the eye, retina, optic nerve, and nerve sheath. Ultrasound image quality was evaluated by independent imaging experts. RESULTS: Eight of the 10 carotid studies were judged to be diagnostically adequate. With one exception the quality of all the ophthalmic images were adequate to excellent. CONCLUSION: Diagnostically-adequate carotid and ophthalmic ultrasound examinations can be obtained by untrained operators with instruction only from an audio/video tutorial viewed in real time while scanning. This form of quick-response-guidance, can be developed for other ultrasound examinations, represents an opportunity to acquire important medical and scientific information for NASA flight surgeons and researchers when trained medical personnel are not present. Further, virtual guidance will allow untrained personnel to autonomously obtain important medical information in remote locations on Earth where communication is

Non-Contact Laser Based Ultrasound Evaluation of Canned Foods

NASA Astrophysics Data System (ADS)

Shelton, David

2005-03-01

Laser-Based Ultrasound detection was used to measure the velocity of compression waves transmitted through canned foods. Condensed broth, canned pasta, and non-condensed soup were evaluated in these experiments. Homodyne adaptive optics resulted in measurements that were more accurate than the traditional heterodyne method, as well as yielding a 10 dB gain in signal to noise. A-Scans measured the velocity of ultrasound sent through the center of the can and were able to distinguish the quantity of food stuff in its path, as well as distinguish between meat and potato. B-Scans investigated the heterogeneity of the sample’s contents. The evaluation of canned foods was completely non-contact and would be suitable for continuous monitoring in production. These results were verified by conducting the same experiments with a contact piezo transducer. Although the contact method yields a higher signal to noise ratio than the non-contact method, Laser-Based Ultrasound was able to detect surface waves the contact transducer could not.

Integration of a Low-Cost Introductory Ultrasound Curriculum Into Existing Procedural Skills Education for Preclinical Medical Students.

PubMed

Maloney, Lauren; Zach, Kristen; Page, Christopher; Tewari, Neera; Tito, Matthew; Seidman, Peggy

2017-02-01

We evaluated integration of an introductory ultrasound curriculum into our existing mandatory procedural skills program for preclinical medical students. Phantoms consisting of olives, pimento olives, and grapes embedded in opaque gelatin were developed. Four classes encouraged progressive refinement of phantom-scanning and object identification skills. Students improved their ability to identify hidden objects, although each object type achieved a statistically significant improvement in correct identification at different time points. The total phantom cost per student was $0.76. Our results suggest that short repeated experiences scanning simple, low-cost ultrasound phantoms confer basic ultrasound skills. © 2016 by the American Institute of Ultrasound in Medicine.

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.

Trained simulated ultrasound patients: medical students as models, learners, and teachers.

PubMed

Blickendorf, J Matthew; Adkins, Eric J; Boulger, Creagh; Bahner, David P

2014-01-01

Medical educators must develop ultrasound education programs to ensure that future physicians are prepared to face the changing demands of clinical practice. It can be challenging to find human models for hands-on scanning sessions. This article outlines an educational model from a large university medical center that uses medical students to fulfill the need for human models. During the 2011-2012 academic year, medical students from The Ohio State University College of Medicine served as trained simulated ultrasound patients (TSUP) for hands-on scanning sessions held by the college and many residency programs. The extracurricular program is voluntary and coordinated by medical students with faculty supervision. Students receive a longitudinal didactic and hands-on ultrasound education program as an incentive for serving as a TSUP. The College of Medicine and 7 residency programs used the program, which included 47 second-year and 7 first-year student volunteers. Participation has increased annually because of the program's ease, reliability, and cost savings in providing normal anatomic models for ultrasound education programs. A key success of this program is its inherent reproducibility, as a new class of eager students constitutes the volunteer pool each year. The TSUP program is a feasible and sustainable method of fulfilling the need for normal anatomic ultrasound models while serving as a valuable extracurricular ultrasound education program for medical students. The program facilitates the coordination of ultrasound education programs by educators at the undergraduate and graduate levels.

Intelligent scanning: automated standard plane selection and biometric measurement of early gestational sac in routine ultrasound examination.

PubMed

Zhang, Ling; Chen, Siping; Chin, Chien Ting; Wang, Tianfu; Li, Shengli

2012-08-01

To assist radiologists and decrease interobserver variability when using 2D ultrasonography (US) to locate the standardized plane of early gestational sac (SPGS) and to perform gestational sac (GS) biometric measurements. In this paper, the authors report the design of the first automatic solution, called "intelligent scanning" (IS), for selecting SPGS and performing biometric measurements using real-time 2D US. First, the GS is efficiently and precisely located in each ultrasound frame by exploiting a coarse to fine detection scheme based on the training of two cascade AdaBoost classifiers. Next, the SPGS are automatically selected by eliminating false positives. This is accomplished using local context information based on the relative position of anatomies in the image sequence. Finally, a database-guided multiscale normalized cuts algorithm is proposed to generate the initial contour of the GS, based on which the GS is automatically segmented for measurement by a modified snake model. This system was validated on 31 ultrasound videos involving 31 pregnant volunteers. The differences between system performance and radiologist performance with respect to SPGS selection and length and depth (diameter) measurements are 7.5% ± 5.0%, 5.5% ± 5.2%, and 6.5% ± 4.6%, respectively. Additional validations prove that the IS precision is in the range of interobserver variability. Our system can display the SPGS along with biometric measurements in approximately three seconds after the video ends, when using a 1.9 GHz dual-core computer. IS of the GS from 2D real-time US is a practical, reproducible, and reliable approach.

Clinical Utility of High-Frequency Musculoskeletal Ultrasonography in Foot and Ankle Pathology: How Ultrasound Imaging Influences Diagnosis and Management.

PubMed

Delzell, Patricia B; Tritle, Benjamin A; Bullen, Jennifer A; Chiunda, Stella; Forney, Michael C

The use of high-frequency (high-resolution) musculoskeletal ultrasonography is increasing and has shown promising utility in many areas of medicine. The utility of musculoskeletal ultrasonography for foot and ankle complaints has not been widely investigated, however. Although some conditions of the foot and ankle are easily diagnosed by physical examination, others can have nonspecific examination findings, making optimal treatment decisions difficult. We hypothesized that high-resolution musculoskeletal ultrasound scanning of the foot and ankle can affect the diagnosis and/or treatment for patients presenting with foot or ankle complaints. Retrospectively, the cases of 98 patients who had undergone musculoskeletal ultrasound scanning of the foot or ankle were reviewed. The pre-ultrasound clinical diagnosis and treatment were compared with the post-ultrasound diagnosis and treatment. In 64% of the patients, the diagnosis or treatment changed after the ultrasound examination. In 43% of patients, both the diagnosis and the treatment changed after ultrasound scanning. For those patients for whom the diagnosis and treatment were unchanged after the ultrasound examination, the ultrasound findings were concordant with the pre-ultrasound clinical diagnosis for 100% of the patients. These results suggest that in a large proportion of patients, high-resolution musculoskeletal ultrasonography of the foot or ankle can facilitate appropriate diagnosis and management. Copyright © 2017 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Evaluation of the validity and reliability of A-scan ultrasound biometry with a single use disposable cover

PubMed Central

Cass, K; Thompson, C M; Tromans, C; Wood, I C J

2002-01-01

Background: The UK Medical Devices Agency has suggested that ophthalmic practitioners should, where practicable and not compromising clinical outcome, restrict corneal contact devices to single patient use to minimise a remote theoretical risk of transmission of new variant Creutzfeldt-Jakob disease (vCJD). This study reports on a modified technique of ultrasound A-scan biometry that complies with the MDA recommendations. Methods: The right eyes of 37 consecutive hospital patients had a series of biometry readings taken with a Humphrey 820 A-scan instrument with a plane wave transducer use d conventionally and with the addition of a disposable latex cover. Results: Intrasessional repeatability of axial length measurements was similar for conventional readings—mean difference 0.027 mm, 95% confidence intervals (CI) ± 0.44 mm and those taken with a disposable cover (0.028 mm, CI ± 0.38). Intersessional repeatability was equivalent with (0.002 mm, CI ± 0.51) and without a cover (0.03 mm, CI ± 0.51). Readings with a cover were not significantly different from those without (paired t test; p >0.05), but tended to be greater (mean difference 0.085 mm, CI ± 0.60). Conclusions: These findings suggest that corneal contact biometry with a disposable cover is a viable and theoretically safer alternative to the conventional technique. PMID:11864896

Ultrasound imaging in the management of bleeding and pain in early pregnancy.

PubMed

Knez, Jure; Day, Andrea; Jurkovic, Davor

2014-07-01

Bleeding and pain are experienced by 20% of women during the first trimester of pregnancy. Although most pregnancies complicated by pain and bleeding tend to progress normally, these symptoms are distressing for woman, and they are also associated with an increased risk of miscarriage and ectopic pregnancy. Ultrasound is the first and often the only diagnostic modality that is used to determine location of early pregnancy and to assess its health. Ultrasound is an accurate, safe, painless and relatively inexpensive diagnostic tool, which all contributed to its widespread use in early pregnancy. Pain and bleeding in early pregnancy are sometimes caused by concomitant gynaecological, gastrointestinal, and urological problems, which could also be detected on ultrasound scan. In women with suspected intra-abdominal bleeding, ultrasound scan can be used to detect the presence of blood and provide information about the extent of bleeding. In this chapter, we comprehensively review the use of ultrasound in the diagnosis and management of early pregnancy complications. We include information about the diagnosis of gynaecological and other pelvic abnormalities, which could cause pain or bleeding in pregnancy. We also provide a summary of the current views on the safety of ultrasound in early pregnancy. Copyright © 2014 Elsevier Ltd. All rights reserved.

Pulmonary Capillary Hemorrhage Induced by Different Imaging Modes of Diagnostic Ultrasound.

PubMed

Miller, Douglas L; Dong, Zhihong; Dou, Chunyan; Raghavendran, Krishnan

2018-05-01

The induction of pulmonary capillary hemorrhage (PCH) is a well-established non-thermal biological effect of pulsed ultrasound in animal models. Typically, research has been done using laboratory pulsed ultrasound systems with a fixed beam and, recently, by B-mode diagnostic ultrasound. In this study, a GE Vivid 7 Dimension ultrasound machine with 10 L linear array probe was used at 6.6 MHz to explore the relative PCH efficacy of B-mode imaging, M-mode (fixed beam), color angio mode Doppler imaging and pulsed Doppler mode (fixed beam). Anesthetized rats were scanned in a warmed water bath, and thresholds were determined by scanning at different power steps, 2 dB apart, in different groups of six rats. Exposures were performed for 5 min, except for a 15-s M-mode group. Peak rarefactional pressure amplitude thresholds were 1.5 MPa for B-mode and 1.1 MPa for angio Doppler mode. For the non-scanned modes, thresholds were 1.1 MPa for M-mode and 0.6 MPa for pulsed Doppler mode with its relatively high duty cycle (7.7 × 10 -3 vs. 0.27 × 10 -3 for M-mode). Reducing the duration of M-mode to 15 s (from 300 s) did not significantly reduce PCH (area, volume or depth) for some power settings, but the threshold was increased to 1.4 MPa. Pulmonary sonographers should be aware of this unique adverse bio-effect of diagnostic ultrasound and should consider reduced on-screen mechanical index settings for potentially vulnerable patients. Copyright © 2018 World Federation for Ultrasound in Medicine and Biology. Published by Elsevier Inc. All rights reserved.

High-Speed Digital Scan Converter for High-Frequency Ultrasound Sector Scanners

PubMed Central

Chang, Jin Ho; Yen, Jesse T.; Shung, K. Kirk

2008-01-01

This paper presents a high-speed digital scan converter (DSC) capable of providing more than 400 images per second, which is necessary to examine the activities of the mouse heart whose rate is 5–10 beats per second. To achieve the desired high-speed performance in cost-effective manner, the DSC developed adopts a linear interpolation algorithm in which two nearest samples to each object pixel of a monitor are selected and only angular interpolation is performed. Through computer simulation with the Field II program, its accuracy was investigated by comparing it to that of bilinear interpolation known as the best algorithm in terms of accuracy and processing speed. The simulation results show that the linear interpolation algorithm is capable of providing an acceptable image quality, which means that the difference of the root mean square error (RMSE) values of the linear and bilinear interpolation algorithms is below 1 %, if the sample rate of the envelope samples is at least four times higher than the Nyquist rate for the baseband component of echo signals. The designed DSC was implemented with a single FPGA (Stratix EP1S60F1020C6, Altera Corporation, San Jose, CA) on a DSC board that is a part of a high-speed ultrasound imaging system developed. The temporal and spatial resolutions of the implemented DSC were evaluated by examining its maximum processing time with a time stamp indicating when an image is completely formed and wire phantom testing, respectively. The experimental results show that the implemented DSC is capable of providing images at the rate of 400 images per second with negligible processing error. PMID:18430449

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…

Implementation of a Rotational Ultrasound Biomicroscopy System Equipped with a High-Frequency Angled Needle Transducer — Ex Vivo Ultrasound Imaging of Porcine Ocular Posterior Tissues

PubMed Central

Bok, Tae-Hoon; Kim, Juho; Bae, Jinho; Lee, Chong Hyun; Paeng, Dong-Guk

2014-01-01

The mechanical scanning of a single element transducer has been mostly utilized for high-frequency ultrasound imaging. However, it requires space for the mechanical motion of the transducer. In this paper, a rotational scanning ultrasound biomicroscopy (UBM) system equipped with a high-frequency angled needle transducer is designed and implemented in order to minimize the space required. It was applied to ex vivo ultrasound imaging of porcine posterior ocular tissues through a minimal incision hole of 1 mm in diameter. The retina and sclera for the one eye were visualized in the relative rotating angle range of 270° ∼ 330° and at a distance range of 6 ∼ 7 mm, whereas the tissues of the other eye were observed in relative angle range of 160° ∼ 220° and at a distance range of 7.5 ∼ 9 mm. The layer between retina and sclera seemed to be bent because the distance between the transducer tip and the layer was varied while the transducer was rotated. Certin features of the rotation system such as the optimal scanning angle, step angle and data length need to be improved for ensure higher accuracy and precision. Moreover, the focal length should be considered for the image quality. This implementation represents the first report of a rotational scanning UBM system. PMID:25254305

Co-registered photoacoustic, thermoacoustic, and ultrasound mouse imaging

NASA Astrophysics Data System (ADS)

Reinecke, Daniel R.; Kruger, Robert A.; Lam, Richard B.; DelRio, Stephen P.

2010-02-01

We have constructed and tested a prototype test bed that allows us to form 3D photoacoustic CT images using near-infrared (NIR) irradiation (700 - 900 nm), 3D thermoacoustic CT images using microwave irradiation (434 MHz), and 3D ultrasound images from a commercial ultrasound scanner. The device utilizes a vertically oriented, curved array to capture the photoacoustic and thermoacoustic data. In addition, an 8-MHz linear array fixed in a horizontal position provides the ultrasound data. The photoacoustic and thermoacoustic data sets are co-registered exactly because they use the same detector. The ultrasound data set requires only simple corrections to co-register its images. The photoacoustic, thermoacoustic, and ultrasound images of mouse anatomy reveal complementary anatomic information as they exploit different contrast mechanisms. The thermoacoustic images differentiate between muscle, fat and bone. The photoacoustic images reveal the hemoglobin distribution, which is localized predominantly in the vascular space. The ultrasound images provide detailed information about the bony structures. Superposition of all three images onto a co-registered hybrid image shows the potential of a trimodal photoacoustic-thermoacoustic-ultrasound small-animal imaging system.

Impact of ultrasound video transfer on the practice of ultrasound

NASA Astrophysics Data System (ADS)

Duerinckx, Andre J.; Hayrapetian, Alek S.; Grant, Edward G.; Valentino, Daniel J.; Rahbar, Darius; Kiszonas, Mike; Franco, Ricky; Melany, Michelle; Narin, Sherelle L.; Ragavendra, Nagesh

1996-05-01

Sonography can be highly dependent on real-time imaging and as such is highly physician intensive. Such situations arise mostly during complicated ultrasound radiology studies or echocardiology examinations. Under those circumstances it would be of benefit to transmit real-time images beyond the immediate area of the ultrasound laboratory when a physician is not on location. We undertook this study to determine if both static and dynamic image transfer to remote locations might be accomplished using an ultrafast ATM network and PACS. Image management of the local image files was performed by a commercial PACS from AGFA corporation. The local network was Ethernet based, and the global network was based on Asynchronous Transfer Mode (ATM, rates up to 100 Mbits/sec). Real-time image transfer involved two teaching hospitals, one of which had 2 separate ultrasound facilities. Radiologists consulted with technologists via telephone while the examinations were being performed. The applications of ATM network providing real time video for ultrasound imaging in a clinical environment and its potential impact on health delivery and clinical teaching. This technology increased technologist and physician productivity due to the elimination of commute time for physicians and waiting time for technologists and patients. Physician confidence in diagnosis increased compared to reviewing static images alone. This system provided instant access for radiologists to real-time scans from remote sites. Image quality and frame rate were equivalent to the original. The system increased productivity by allowing physicians to monitor studies at multiple sites simultaneously.

Naturally Inspired Peptide Leads: Alanine Scanning Reveals an Actin‐Targeting Thiazole Analogue of Bisebromoamide

PubMed Central

Johnston, Heather J.; Boys, Sarah K.; Makda, Ashraff; Carragher, Neil O.

2016-01-01

Abstract Systematic alanine scanning of the linear peptide bisebromoamide (BBA), isolated from a marine cyanobacterium, was enabled by solid‐phase peptide synthesis of thiazole analogues. The analogues have comparable cytotoxicity (nanomolar) to that of BBA, and cellular morphology assays indicated that they target the actin cytoskeleton. Pathway inhibition in human colon tumour (HCT116) cells was explored by reverse phase protein array (RPPA) analysis, which showed a dose‐dependent response in IRS‐1 expression. Alanine scanning reveals a structural dependence to the cytotoxicity, actin targeting and pathway inhibition, and allows a new readily synthesised lead to be proposed. PMID:27304907

Standards of ultrasound imaging of the adrenal glands

PubMed Central

Jakubowski, Wiesław S.; Dobruch-Sobczak, Katarzyna; Kasperlik-Załuska, Anna A.

2015-01-01

Adrenal glands are paired endocrine glands located over the upper renal poles. Adrenal pathologies have various clinical presentations. They can coexist with the hyperfunction of individual cortical zones or the medulla, insufficiency of the adrenal cortex or retained normal hormonal function. The most common adrenal masses are tumors incidentally detected in imaging examinations (ultrasound, tomography, magnetic resonance imaging), referred to as incidentalomas. They include a range of histopathological entities but cortical adenomas without hormonal hyperfunction are the most common. Each abdominal ultrasound scan of a child or adult should include the assessment of the suprarenal areas. If a previously non-reported, incidental solid focal lesion exceeding 1 cm (incidentaloma) is detected in the suprarenal area, computed tomography or magnetic resonance imaging should be conducted to confirm its presence and for differentiation and the tumor functional status should be determined. Ultrasound imaging is also used to monitor adrenal incidentaloma that is not eligible for a surgery. The paper presents recommendations concerning the performance and assessment of ultrasound examinations of the adrenal glands and their pathological lesions. The article includes new ultrasound techniques, such as tissue harmonic imaging, spatial compound imaging, three-dimensional ultrasound, elastography, contrast-enhanced ultrasound and parametric imaging. The guidelines presented above are consistent with the recommendations of the Polish Ultrasound Society. PMID:26807295

Emergency ultrasound in the detection of pediatric long-bone fractures.

PubMed

Barata, Isabel; Spencer, Robert; Suppiah, Ara; Raio, Christopher; Ward, Mary Frances; Sama, Andrew

2012-11-01

Long-bone fractures represent one of the most commonly sustained injuries following trauma and account for nearly 4% of emergency department visits in the United States each year. These fractures are associated with a significant risk of bleeding and neurovascular compromise. Delays in their identification and treatment can lead to loss of limb and even death. Although emergency physicians currently rely predominantly on radiography for the examination of long-bone injuries, emergency ultrasound has several advantages over radiography and may be useful in the identification of long-bone fractures. Ultrasound is rapid, noninvasive, and cost-effective. Unlike radiography, ultrasound does not expose children to ionizing radiation, which has been linked to cancer. The goal of this study was to assess the agreement between emergency physicians' and radiologists' final assessments of suspected long-bone fractures using emergency ultrasound and radiography, respectively, in the pediatric population. This is a prospective study involving a convenience sample of pediatric patients (<18 years of age) who presented to the emergency department of a university-affiliated, level I trauma center between March 2008 and January 2009 with at least 1 suspected long-bone fracture. Suspected fractures were characterized by swelling, erythema, and localized pain. Patients who had a history of fracture, extremity deformity, orthopedic hardware in the traumatized area, or an open fracture were excluded from this study. Each investigator received limited, focused training in the use of ultrasonography for fracture identification and localization. This training consisted of a brief didactic session and video review of normal and fractured long-bones. A total of 53 subjects (mean age, 10.2 [SD, 3.8] years; 56.6% were male) were enrolled, which corresponded to 98 ultrasound examinations. Sixty-nine scans (70.4%) involved bones of the upper extremity, and 29 (29.6%) the lower extremity

Nanobubble-Affibody: Novel ultrasound contrast agents for targeted molecular ultrasound imaging of tumor.

PubMed

Yang, Hengli; Cai, Wenbin; Xu, Lei; Lv, Xiuhua; Qiao, Youbei; Li, Pan; Wu, Hong; Yang, Yilin; Zhang, Li; Duan, Yunyou

2015-01-01

Nanobubbles (NBs), as novel ultrasound contrast agents (UCAs), have attracted increasing attention in the field of molecular ultrasound imaging for tumors. However, the preparation of uniform-sized NBs is considered to be controversial, and poor tumor selectivity in in vivo imaging has been reported. In this study, we fabricated uniform nano-sized NBs (478.2 ± 29.7 nm with polydispersity index of 0.164 ± 0.044, n = 3) using a thin-film hydration method by controlling the thickness of phospholipid films; we then conjugated the NBs with Affibody molecules to produce nano-sized UCAs referred to as NB-Affibody with specific affinity to human epidermal growth factor receptor type 2 (HER2)-overexpressing tumors. NB-Affibody presented good ultrasound enhancement, demonstrating a peak intensity of 104.5 ± 2.1 dB under ultrasound contrast scanning. Ex vivo experiments further confirmed that the NB-Affibody conjugates were capable of targeting HER2-expressing tumor cells in vivo with high affinity. The newly prepared nano-sized NB-Affibody conjugates were observed to be novel targeted UCAs for efficient and safe specific molecular imaging and may have potential applications in early cancer quantitative diagnosis and targeted therapy in the future. Copyright © 2014 Elsevier Ltd. All rights reserved.

[Evaluation of the diagnosis of subclinical endometritis in dairy cattle using ultrasound].

PubMed

Lenz, Mirjam; Drillich, Marc; Heuwieser, Wolfgang

2007-01-01

The aim of this study was to determine signs of subclinical endometritis found by ultrasound that are associated with reduced fertility in dairy cows. The maximum diameter of the uterine lumen was determined by ultrasound in 324 cows without clinical signs of endometritis after evaluation of the genital tract 21 to 27 days postpartum. Cows were classified into healthy or with subclinical endometritis by three threshold values for the maximum uterine lumen diameter of 0.2 cm, 0.5 cm or 0.8 cm. Examinations by rectal palpation and ultrasound as well as classifications were repeated 14 days later. In addition, ovaries were scanned by ultrasound to determine the stage of the estrous cycle. In a subgroup of 103 cows the echotexture of the uterus and its contents was evaluated. In these cows the diagnosis of subclinical endometritis was performed by a scoring system. The diameter of the uterine lumen was significantly affected by stage of the estrous cycle at the time of examination. However, no effects were found for the stage of the cycle at the time of examination on subsequent reproductive performance. A uterine lumen with a maximum diameter of more than 0.2 cm showed a significant negative association with conception rate and proportion of cows pregnant. Classification based on higher threshold values did not reveal an association with reproductive performance. Echogenic content in the uterus also decreased reproductive performance. A classification based on the echotexture of the uterus and its contents revealed significant differences between healthy cows and cows with subclinical endometritis regarding the proportion of cows inseminated and pregnant. The results of this study showed that the diagnostic of bovine endometritis should be broadend by ultrasonography. The definition of subclinical endometritis diagnosed by means of ultrasonography has to be evaluated in further studies.

A cMUT probe for ultrasound-guided focused ultrasound targeted therapy.

PubMed

Gross, Dominique; Coutier, Caroline; Legros, Mathieu; Bouakaz, Ayache; Certon, Dominique

2015-06-01

Ultrasound-mediated targeted therapy represents a promising strategy in the arsenal of modern therapy. Capacitive micromachined ultrasonic transducer (cMUT) technology could overcome some difficulties encountered by traditional piezoelectric transducers. In this study, we report on the design, fabrication, and characterization of an ultrasound-guided focused ultrasound (USgFUS) cMUT probe dedicated to preclinical evaluation of targeted therapy (hyperthermia, thermosensitive liposomes activation, and sonoporation) at low frequency (1 MHz) with simultaneous ultrasonic imaging and guidance (15 to 20 MHz). The probe embeds two types of cMUT arrays to perform the modalities of targeted therapy and imaging respectively. The wafer-bonding process flow employed for the manufacturing of the cMUTs is reported. One of its main features is the possibility of implementing two different gap heights on the same wafer. All the design and characterization steps of the devices are described and discussed, starting from the array design up to the first in vitro measurements: optical (microscopy) and electrical (impedance) measurements, arrays' electroacoustic responses, focused pressure field mapping (maximum peak-to-peak pressure = 2.5 MPa), and the first B-scan image of a wire-target phantom.

Clot retraction affects the extent of ultrasound-enhanced thrombolysis in an ex vivo porcine thrombosis model.

PubMed

Sutton, Jonathan T; Ivancevich, Nikolas M; Perrin, Stephen R; Vela, Deborah C; Holland, Christy K

2013-05-01

We investigated ultrasound-enhanced thrombolysis in two whole-blood clot models using a Food and Drug Administration-approved contrast agent (Definity, Lantheus Medical Imaging; Billerica, MA USA) and thrombolytic drug (recombinant tissue-type plasminogen activator [rt-PA]) (Genentech; South San Francisco, CA USA). Porcine venous blood was collected from donor hogs and coagulated in vials made of two different materials. This method produced clots with differing compositional properties, as determined by routine scanning electron microscopy and histology. Clots were deployed in an ex vivo porcine thrombosis model, and exposed to an intermittent ultrasound scheme previously developed to maximize stable cavitation while acoustic emissions were detected. Exposure to 3.15 μg/mL rt-PA promoted lysis in both clot models, compared with exposure to plasma alone. However, only unretracted clots experienced significant enhancement of thrombolysis in the presence of rt-PA, Definity, and ultrasound, compared with treatment with rt-PA. In these clots, microscopy revealed loose erythrocyte aggregates, a significantly less extensive fibrin network and a higher porosity, which may facilitate increased penetration of thrombolytics by cavitation. Copyright © 2013 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Assessment of the accuracy of AortaScan for detection of abdominal aortic aneurysm (AAA).

PubMed

Abbas, A; Smith, A; Cecelja, M; Waltham, M

2012-02-01

AortaScan AMI 9700 is a portable 3D ultrasound device that automatically measures the maximum diameter of the abdominal aorta without the need for a trained sonographer. It is designed to rapidly diagnose or exclude an AAA and may have particular use in screening programs. Our objective was to determine its accuracy to detect AAA. Subjects from our AAA screening and surveillance programs were examined. The aorta was scanned using the AortaScan and computed tomography (CT). Ninety-one subjects underwent imaging (44 AAA on conventional ultrasound surveillance and 47 controls). The largest measurement obtained by AortaScan was compared against the CT-aortic measurement. The mean aortic diameter was 2.8 cm. The CT scan confirmed the diagnosis of AAA in 43 subjects. There was one false positive measurement on conventional ultrasound. AortaScan missed the diagnosis of AAA in eight subjects. There were thirteen false positive measurements. The sensitivity, specificity, positive and negative predictive values were 81%, 72%, 72% and 81% respectively. A device to detect AAA without the need for a trained operator would have potential in a community-based screening programme. The AortaScan, however, lacks adequate sensitivity and significant technical improvement is necessary before it could be considered a replacement for trained screening personnel. Copyright © 2011 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

Raster-scan optoacoustic angiography reveals 3D microcirculatory changes during cuffed occlusion

NASA Astrophysics Data System (ADS)

Subochev, Pavel; Orlova, Anna; Smolina, Ekaterina; Kirillov, Aleksey; Shakhova, Natalia; Turchin, Ilya

2018-04-01

Acoustic resolution photoacoustic microscopy at the optical wavelength of 532 nm was used to investigate the functional reaction of blood vessels of healthy human skin during cuffed venous occlusion. The high bandwidth of the polyvinilidene difluoride detector provided the opportunity for raster-scan optoacoustic angiography of both the superficial and deep plexuses at the high resolution of 35/50 microns (axial/lateral). A reversible increase of blood supply in the microcirculatory bed during occlusion was revealed.

Evaluation of targeting errors in ultrasound-assisted radiotherapy

PubMed Central

Wang, Michael; Rohling, Robert; Duzenli, Cheryl; Clark, Brenda; Archip, Neculai

2014-01-01

A method for validating the start-to-end accuracy of a 3D ultrasound-based patient positioning system for radiotherapy is described. A radiosensitive polymer gel is used to record the actual dose delivered to a rigid phantom after being positioned using 3D ultrasound guidance. Comparison of the delivered dose with the treatment plan allows accuracy of the entire radiotherapy treatment process, from simulation to 3D ultrasound guidance, and finally delivery of radiation, to be evaluated. The 3D ultrasound patient positioning system has a number of features for achieving high accuracy and reducing operator dependence. These include using tracked 3D ultrasound scans of the target anatomy acquired using a dedicated 3D ultrasound probe during both the simulation and treatment sessions, automatic 3D ultrasound-to-ultrasound registration, and use of infra-red LED (IRED) markers of the optical position sensing system for registering simulation CT to ultrasound data. The mean target localization accuracy of this system was 2.5mm for four target locations inside the phantom, compared to 1.6mm obtained using the conventional patient positioning method of laser alignment. Since the phantom is rigid, this represents the best possible set-up accuracy of the system. Thus, these results suggest that 3D ultrasound-based target localization is practically feasible and potentially capable of increasing the accuracy of patient positioning for radiotherapy in sites where day-to-day organ shifts are greater than 1mm in magnitude. PMID:18723271

A 3D Freehand Ultrasound System for Multi-view Reconstructions from Sparse 2D Scanning Planes

PubMed Central

2011-01-01

Background A significant limitation of existing 3D ultrasound systems comes from the fact that the majority of them work with fixed acquisition geometries. As a result, the users have very limited control over the geometry of the 2D scanning planes. Methods We present a low-cost and flexible ultrasound imaging system that integrates several image processing components to allow for 3D reconstructions from limited numbers of 2D image planes and multiple acoustic views. Our approach is based on a 3D freehand ultrasound system that allows users to control the 2D acquisition imaging using conventional 2D probes. For reliable performance, we develop new methods for image segmentation and robust multi-view registration. We first present a new hybrid geometric level-set approach that provides reliable segmentation performance with relatively simple initializations and minimum edge leakage. Optimization of the segmentation model parameters and its effect on performance is carefully discussed. Second, using the segmented images, a new coarse to fine automatic multi-view registration method is introduced. The approach uses a 3D Hotelling transform to initialize an optimization search. Then, the fine scale feature-based registration is performed using a robust, non-linear least squares algorithm. The robustness of the multi-view registration system allows for accurate 3D reconstructions from sparse 2D image planes. Results Volume measurements from multi-view 3D reconstructions are found to be consistently and significantly more accurate than measurements from single view reconstructions. The volume error of multi-view reconstruction is measured to be less than 5% of the true volume. We show that volume reconstruction accuracy is a function of the total number of 2D image planes and the number of views for calibrated phantom. In clinical in-vivo cardiac experiments, we show that volume estimates of the left ventricle from multi-view reconstructions are found to be in better

The ScanTrainer obstetrics and gynaecology ultrasound virtual reality training simulator: A cost model to determine the cost viability of replacing clinical training with simulation training.

PubMed

Carolan-Rees, G; Ray, A F

2015-05-01

The aim of this study was to produce an economic cost model comparing the use of the Medaphor ScanTrainer virtual reality training simulator for obstetrics and gynaecology ultrasound to achieve basic competence, with the traditional training method. A literature search and survey of expert opinion were used to identify resources used in training. An executable model was produced in Excel. The model showed a cost saving for a clinic using the ScanTrainer of £7114 per annum. The uncertainties of the model were explored and it was found to be robust. Threshold values for the key drivers of the model were identified. Using the ScanTrainer is cost saving for clinics with at least two trainees per year to train, if it would take at least six lists to train them using the traditional training method and if a traditional training list has at least two fewer patients than a standard list.

Soft tissue-preserving computer-aided impression: a novel concept using ultrasonic 3D-scanning.

PubMed

Vollborn, Thorsten; Habor, Daniel; Pekam, Fabrice Chuembou; Heger, Stefan; Marotti, Juliana; Reich, Sven; Wolfart, Stefan; Tinschert, Joachim; Radermacher, Klaus

2014-01-01

Subgingival preparations are often affected by blood and saliva during impression taking, regardless of whether one is using compound impression techniques or intraoral digital scanning methods. The latter are currently based on optical principles and therefore also need clean and dry surfaces. In contrast, ultrasonic waves are able to non-invasively penetrate gingiva, saliva, and blood, leading to decisive advantages, as cleaning and drying of the oral cavity becomes unnecessary. In addition, the application of ultrasound may facilitate the detection of subgingival structures without invasive manipulation, thereby reducing the risk of secondary infection and treatment time, and increasing patient comfort. Ultrasound devices commonly available for medical application and for the testing of materials are only suitable to a limited extent, as their resolution, precision, and design do not fulfill the requirements for intraoral scanning. The aim of this article is to describe the development of a novel ultrasound technology that enables soft tissue-preserving digital impressions of preparations for the CAD/CAM-based production of dental prostheses. The concept and development of the high-resolution ultrasound technique and the corresponding intraoral scanning system, as well as the integration into the CAD/CAM process chain, is presented.

High resolution three-dimensional robotic synthetic tracked aperture ultrasound imaging: feasibility study

NASA Astrophysics Data System (ADS)

Zhang, Haichong K.; Fang, Ting Yun; Finocchi, Rodolfo; Boctor, Emad M.

2017-03-01

Three dimensional (3D) ultrasound imaging is becoming a standard mode for medical ultrasound diagnoses. Conventional 3D ultrasound imaging is mostly scanned either by using a two dimensional matrix array or by motorizing a one dimensional array in the elevation direction. However, the former system is not widely assessable due to its cost, and the latter one has limited resolution and field-of-view in the elevation axis. Here, we propose a 3D ultrasound imaging system based on the synthetic tracked aperture approach, in which a robotic arm is used to provide accurate tracking and motion. While the ultrasound probe is moved by a robotic arm, each probe position is tracked and can be used to reconstruct a wider field-of-view as there are no physical barriers that restrict the elevational scanning. At the same time, synthetic aperture beamforming provides a better resolution in the elevation axis. To synthesize the elevational information, the single focal point is regarded as the virtual element, and forward and backward delay-andsum are applied to the radio-frequency (RF) data collected through the volume. The concept is experimentally validated using a general ultrasound phantom, and the elevational resolution improvement of 2.54 and 2.13 times was measured at the target depths of 20 mm and 110 mm, respectively.

Ultrasound for the Anesthesiologists: Present and Future

PubMed Central

Terkawi, Abdullah S.; Karakitsos, Dimitrios; Elbarbary, Mahmoud; Blaivas, Michael; Durieux, Marcel E.

2013-01-01

Ultrasound is a safe, portable, relatively inexpensive, and easily accessible imaging modality, making it a useful diagnostic and monitoring tool in medicine. Anesthesiologists encounter a variety of emergent situations and may benefit from the application of such a rapid and accurate diagnostic tool in their routine practice. This paper reviews current and potential applications of ultrasound in anesthesiology in order to encourage anesthesiologists to learn and use this useful tool as an adjunct to physical examination. Ultrasound-guided peripheral nerve blockade and vascular access represent the most popular ultrasound applications in anesthesiology. Ultrasound has recently started to substitute for CT scans and fluoroscopy in many pain treatment procedures. Although the application of airway ultrasound is still limited, it has a promising future. Lung ultrasound is a well-established field in point-of-care medicine, and it could have a great impact if utilized in our ORs, as it may help in rapid and accurate diagnosis in many emergent situations. Optic nerve sheath diameter (ONSD) measurement and transcranial color coded duplex (TCCD) are relatively new neuroimaging modalities, which assess intracranial pressure and cerebral blood flow. Gastric ultrasound can be used for assessment of gastric content and diagnosis of full stomach. Focused transthoracic (TTE) and transesophageal (TEE) echocardiography facilitate the assessment of left and right ventricular function, cardiac valve abnormalities, and volume status as well as guiding cardiac resuscitation. Thus, there are multiple potential areas where ultrasound can play a significant role in guiding otherwise blind and invasive interventions, diagnosing critical conditions, and assessing for possible anatomic variations that may lead to plan modification. We suggest that ultrasound training should be part of any anesthesiology training program curriculum. PMID:24348179

Evaluating Thin Compression Paddles for Mammographically Compatible Ultrasound

PubMed Central

Booi, Rebecca C.; Krücker, Jochen F.; Goodsitt, Mitchell M.; O’Donnell, Matthew; Kapur, Ajay; LeCarpentier, Gerald L.; Roubidoux, Marilyn A.; Fowlkes, J. Brian; Carson, Paul L.

2007-01-01

We are developing a combined digital mammography/3D ultrasound system to improve detection and/or characterization of breast lesions. Ultrasound scanning through a mammographic paddle could significantly reduce signal level, degrade beam focusing, and create reverberations. Thus, appropriate paddle choice is essential for accurate sonographic lesion detection and assessment with this system. In this study, we characterized ultrasound image quality through paddles of varying materials (lexan, polyurethane, TPX, mylar) and thicknesses (0.25–2.5 mm). Analytical experiments focused on lexan and TPX, which preliminary results demonstrated were most competitive. Spatial and contrast resolution, sidelobe and range lobe levels, contrast and signal strength were compared with no-paddle images. When the beamforming of the system was corrected to account for imaging through the paddle, the TPX 2.5 mm paddle performed the best. Test objects imaged through this paddle demonstrated ≤ 15% reduction in spatial resolution, ≤ 7.5 dB signal loss, ≤ 3 dB contrast loss, and range lobe levels ≥ 35 dB below signal maximum over 4 cm. TPX paddles < 2.5 mm could also be used with this system, depending on imaging goals. In 10 human subjects with cysts, small CNR losses were observed but were determined to be statistically insignificant. Radiologists concluded that 75% of cysts in through-paddle scans were at least as detectable as in their corresponding direct-contact scans. (Email: rbooi@umich.edu) PMID:17280765

Non-invasive assessment of bone quantity and quality in human trabeculae using scanning ultrasound imaging

NASA Astrophysics Data System (ADS)

Xia, Yi

Fractures and associated bone fragility induced by osteoporosis and osteopenia are widespread health threat to current society. Early detection of fracture risk associated with bone quantity and quality is important for both the prevention and treatment of osteoporosis and consequent complications. Quantitative ultrasound (QUS) is an engineering technology for monitoring bone quantity and quality of humans on earth and astronauts subjected to long duration microgravity. Factors currently limiting the acceptance of QUS technology involve precision, accuracy, single index and standardization. The objective of this study was to improve the accuracy and precision of an image-based QUS technique for non-invasive evaluation of trabecular bone quantity and quality by developing new techniques and understanding ultrasound/tissue interaction. Several new techniques have been developed in this dissertation study, including the automatic identification of irregular region of interest (iROI) in bone, surface topology mapping (STM) and mean scattering spacing (MSS) estimation for evaluating trabecular bone structure. In vitro results have shown that (1) the inter- and intra-observer errors in QUS measurement were reduced two to five fold by iROI compared to previous results; (2) the accuracy of QUS parameter, e.g., ultrasound velocity (UV) through bone, was improved 16% by STM; and (3) the averaged trabecular spacing can be estimated by MSS technique (r2=0.72, p<0.01). The measurement errors of BUA and UV introduced by the soft tissue and cortical shells in vivo can be quantified by developed foot model and simplified cortical-trabecular-cortical sandwich model, which were verified by the experimental results. The mechanisms of the errors induced by the cortical and soft tissues were revealed by the model. With developed new techniques and understanding of sound-tissue interaction, in vivo clinical trail and bed rest study were preformed to evaluate the performance of QUS in

Defining the reliability of sonoanatomy identification by novices in ultrasound-guided pediatric ilioinguinal and iliohypogastric nerve blockade.

PubMed

Ford, Simon; Dosani, Maryam; Robinson, Ashley J; Campbell, G Claire; Ansermino, J Mark; Lim, Joanne; Lauder, Gillian R

2009-12-01

The ilioinguinal (II)/iliohypogastric (IH) nerve block is a safe, frequently used block that has been improved in efficacy and safety by the use of ultrasound guidance. We assessed the frequency with which pediatric anesthesiologists with limited experience with ultrasound-guided regional anesthesia could correctly identify anatomical structures within the inguinal region. Our primary outcome was to compare the frequency of correct identification of the transversus abdominis (TA) muscle with the frequency of correct identification of the II/IH nerves. We used 2 ultrasound machines with different capabilities to assess a potential equipment effect on success of structure identification and time taken for structure identification. Seven pediatric anesthesiologists with <6 mo experience with ultrasound-guided regional anesthesia performed a total of 127 scans of the II region in anesthetized children. The muscle planes and the II and IH nerves were identified and labeled. The ultrasound images were reviewed by a blinded expert to mark accuracy of structure identification and time taken for identification. Two ultrasound machines (Sonosite C180plus and Micromaxx, both from Sonosite, Bothell, WA) were used. There was no difference in the frequency of correct identification of the TA muscle compared with the II/IH nerves (chi(2) test, TA versus II, P = 0.45; TA versus IH, P = 0.50). Ultrasound machine selection did show a nonsignificant trend in improving correct II/IH nerve identification (II nerve chi(2) test, P = 0.02; IH nerve chi(2) test, P = 0.04; Bonferroni corrected significance 0.17) but not for the muscle planes (chi(2) test, P = 0.83) or time taken (1-way analysis of variance, P = 0.07). A curve of improving accuracy with number of scans was plotted, with reliability of TA recognition occurring after 14-15 scans and II/IH identification after 18 scans. We have demonstrated that although there is no difference in the overall accuracy of muscle plane versus II

Reliability of Achilles Tendon Moment Arm Measured In Vivo Using Freehand Three-Dimensional Ultrasound.

PubMed

Obst, Steven J; Barber, Lee; Miller, Ashton; Barrett, Rod S

2017-08-01

This study investigated reliability of freehand three-dimensional ultrasound (3DUS) measurement of in vivo human Achilles tendon (AT) moment arm. Sixteen healthy adults were scanned on 2 separate occasions by a single investigator. 3DUS scans were performed over the free AT, medial malleolus, and lateral malleolus with the ankle passively positioned in maximal dorsiflexion, mid dorsiflexion, neutral, mid plantar flexion and maximal plantar flexion. 3D reconstructions of the AT, medial malleolus, and lateral malleolus were created from manual segmentation of the ultrasound images and used to geometrically determine the AT moment arm using both a straight (straight AT MA ) and curved (curved AT MA ) tendon line-of-action. Both methods were reliable within- and between-session (intra-class correlation coefficients > 0.92; coefficient of variation < 2.5 %) and revealed that AT moment arm increased by ∼ 7 mm from maximal dorsiflexion (∼ 41mm) to maximal plantar flexion (∼ 48 mm). Failing to account for tendon curvature led to a small overestimation (< 2 mm) of AT moment arm that was most pronounced in ankle plantar flexion, but was less than the minimal detectable change of the method and could be disregarded.

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.

Noninvasive detection of intimal xanthoma using combined ultrasound, strain rate and photoacoustic imaging.

PubMed

Graf, Iulia M; Kim, Seungsoo; Wang, Bo; Smalling, Richard; Emelianov, Stanislav

2012-03-01

The structure, composition and mechanics of carotid artery are good indicators of early progressive atherosclerotic lesions. The combination of three imaging modalities (ultrasound, strain rate and photoacoustic imaging) which could provide corroborative information about the named arterial properties could enhance the characterization of intimal xanthoma. The experiments were performed using a New Zealand white rabbit model of atherosclerosis. The aorta excised from an atherosclerotic rabbit was scanned ex vivo using the three imaging techniques: (1) ultrasound imaging of the longitudinal section: standard ultrasound B-mode (74Hz frame rate); (2) strain rate imaging: the artery was flushed with blood and a 1.5Hz physiologic pulsation was induced, while the ultrasound data were recorded at higher frame rate (296Hz); (3) photoacoustic imaging: the artery was irradiated with nanosecond pulsed laser light of low fluence in the 1210-1230nm wavelength range and the photoacoustic data was recorded at 10Hz frame rate. Post processing algorithms based on cross-correlation and optical absorption variation were implemented to derive strain rate and spectroscopic photoacoustic images, respectively. Based on the spatio-temporal variation in displacement of different regions within the arterial wall, strain rate imaging reveals differences in tissue mechanical properties. Additionally, spectroscopic photoacoustic imaging can spatially resolve the optical absorption properties of arterial tissue and identify the location of lipid pools. The study demonstrates that ultrasound, strain rate and photoacoustic imaging can be used to simultaneously evaluate the structure, the mechanics and the composition of atherosclerotic lesions to improve the assessment of plaque vulnerability. Copyright © 2011 Elsevier B.V. All rights reserved.

Impact of the introduction of emergency ultrasound to one large UK emergency department: the REBUS study.

PubMed

Kwok, T'ng Choong; Johnson, Sue; Reed, Matthew James

2013-02-01

Firstly, to detail the experiences of one UK training region in establishing an emergency ultrasound (EU) training programme and secondly, to report the initial 30 months of EU scanning experience. Prospective study of all documented emergency department (ED) ultrasound scans. Results were extracted from written paper reports and/or electronically saved images. Details of scan date, time, type of scan, grade of operator, supervision status (whether supervised by a level 1 competent scanner) and whether the scan was clinical (performed or supervised by a level 1 operator) or training, were recorded. EU scans were reviewed for quality (internal quality assurance) and for diagnostic accuracy (external quality assurance). Between 14 January 2009 and 4 July 2011, 626 scans were performed by 41 operators. 263 (42%) scans were completed outside of normal working hours (09:00 to 17:00). There were 251 abdominal aorta and inferior vena cava scans (40% of all scans) and 198 focused assessment with sonography in trauma scans (32%). The number of scans performed by each operator varied widely. 87 scans (14%) were supervised but the majority (459; 73%) were not. 484 (77%) scans were for training purposes, 124 (20%) were clinical scans and the majority (401; 63%) were performed by either speciality registrars (ST4-6) or specialist registrars (SpR). When the three commonest types of scans performed were analysed, eight false positives and 11 false negatives were identified. Only seven of these were deemed of poor quality and none led to poor patient outcome. Since the acquisition of our ED ultrasound machine and the development of a quality assured training programme, on average 20 scans per month have been performed in the ED, with no known adverse patient outcomes.

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

Monitoring radiofrequency ablation with ultrasound Nakagami imaging.

PubMed

Wang, Chiao-Yin; Geng, Xiaonan; Yeh, Ta-Sen; Liu, Hao-Li; Tsui, Po-Hsiang

2013-07-01

Radiofrequency ablation (RFA) is a widely used alternative modality in the treatment of liver tumors. Ultrasound B-mode imaging is an important tool to guide the insertion of the RFA electrode into the tissue. However, it is difficult to visualize the ablation zone because RFA induces the shadow effect in a B-scan. Based on the randomness of ultrasonic backscattering, this study proposes ultrasound Nakagami imaging, which is a well-established method for backscattered statistics analysis, as an approach to complement the conventional B-scan for evaluating the ablation region. Porcine liver samples (n = 6) were ablated using a RFA system and monitored by employing an ultrasound scanner equipped with a 7.5 MHz linear array transducer. During the stages of ablation (0-12 min) and postablation (12-24 min), the raw backscattered data were acquired at a sampling rate of 30 MHz for B-mode, Nakagami imaging, and polynomial approximation of Nakagami imaging. The contrast-to-noise ratio (CNR) was also calculated to compare the image contrasts of the B-mode and Nakagami images. The results demonstrated that the Nakagami image has the ability to visualize changes in the backscattered statistics in the ablation zone, including the shadow region during RFA. The average Nakagami parameter increased from 0.2 to 0.6 in the ablation stage, and then decreased to approximately 0.3 at the end of the postablation stage. Moreover, the CNR of the Nakagami image was threefold that of the B-mode image, showing that the Nakagami image has a better image contrast for monitoring RFA. Specifically, the use of the polynomial approximation equips the Nakagami image with an enhanced ability to estimate the range of the ablation region. This study demonstrated that ultrasound Nakagami imaging based on the analysis of backscattered statistics has the ability to visualize the RFA-induced ablation zone, even if the shadow effect exists in the B-scan.

Cone and Rod Loss in Stargardt Disease Revealed by Adaptive Optics Scanning Light Ophthalmoscopy

PubMed Central

Song, Hongxin; Rossi, Ethan A.; Latchney, Lisa; Bessette, Angela; Stone, Edwin; Hunter, Jennifer J.; Williams, David R.; Chung, Mina

2015-01-01

Importance Stargardt disease (STGD1) is characterized by macular atrophy and flecks in the retinal pigment epithelium. The causative ABCA4 gene encodes a protein localizing to photoreceptor outer segments. The pathologic steps by which ABCA4 mutations lead to clinically detectable retinal pigment epithelium changes remain unclear. We investigated early STGD1 using adaptive optics scanning light ophthalmoscopy. Observations Adaptive optics scanning light ophthalmoscopy imaging of 2 brothers with early STGD1 and their unaffected parents was compared with conventional imaging. Cone and rod spacing were increased in both patients (P <.001) with a dark cone appearance. No foveal cones were detected in the older brother. In the younger brother, foveal cones were enlarged with low density (peak cone density, 48.3 × 103 cones/mm2). The ratio of cone to rod spacing was increased in both patients, with greater divergence from normal approaching the foveal center, indicating that cone loss predominates centrally and rod loss increases peripherally. Both parents had normal photoreceptor mosaics. Genetic testing revealed 3 disease-causing mutations. Conclusions and Relevance This study provides in vivo images of rods and cones in STGD1. Although the primary clinical features of STGD1 are retinal pigment epithelial lesions, adaptive optics scanning light ophthalmoscopy reveals increased cone and rod spacing in areas that appear normal in conventional images, suggesting that photoreceptor loss precedes clinically detectable retinal pigment epithelial disease in STGD1. PMID:26247787

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.

Remotely supported prehospital ultrasound: A feasibility study of real-time image transmission and expert guidance to aid diagnosis in remote and rural communities.

PubMed

Eadie, Leila; Mulhern, John; Regan, Luke; Mort, Alasdair; Shannon, Helen; Macaden, Ashish; Wilson, Philip

2017-01-01

Introduction Our aim is to expedite prehospital assessment of remote and rural patients using remotely-supported ultrasound and satellite/cellular communications. In this paradigm, paramedics are remotely-supported ultrasound operators, guided by hospital-based specialists, to record images before receiving diagnostic advice. Technology can support users in areas with little access to medical imaging and suboptimal communications coverage by connecting to multiple cellular networks and/or satellites to stream live ultrasound and audio-video. Methods An ambulance-based demonstrator system captured standard trauma and novel transcranial ultrasound scans from 10 healthy volunteers at 16 locations across the Scottish Highlands. Volunteers underwent brief scanning training before receiving expert guidance via the communications link. Ultrasound images were streamed with an audio/video feed to reviewers for interpretation. Two sessions were transmitted via satellite and 21 used cellular networks. Reviewers rated image and communication quality, and their utility for diagnosis. Transmission latency and bandwidth were recorded, and effects of scanner and reviewer experience were assessed. Results Appropriate views were provided in 94% of the simulated trauma scans. The mean upload rate was 835/150 kbps and mean latency was 114/2072 ms for cellular and satellite networks, respectively. Scanning experience had a significant impact on time to achieve a diagnostic image, and review of offline scans required significantly less time than live-streamed scans. Discussion This prehospital ultrasound system could facilitate early diagnosis and streamlining of treatment pathways for remote emergency patients, being particularly applicable in rural areas worldwide with poor communications infrastructure and extensive transport times.

The role of ultrasound in controlling the liquid-liquid phase separation and nucleation of vanillin polymorphs I and II

NASA Astrophysics Data System (ADS)

Parimaladevi, P.; Supriya, S.; Srinivasan, K.

2018-02-01

The influence of ultrasound on liquid-liquid phase separation (LLPS) and polymorphism of vanillin in aqueous solution has been investigated for the first time by varying the ultrasonic parameters such as power, pulse rate and insonation time at ambient condition. Results reveal that the application of ultrasound controls the impact of LLPS and accelerates the nucleation of vanillin within a short period at lower levels of ultrasonic process parameters, and also enhances the quality of the nucleated crystals. Moreover, the application of ultrasound induces the nucleation of rare and metastable polymorph of vanillin Form II in aqueous solution. But, at higher levels of power, pulse rate and insonation time, the rate of LLPS is found increased and the quality of the crystals becomes deteriorated. Morphology of the nucleated polymorphs were identified through optical microscopy and confirmed by optical goniometry. The internal structure and thermal stability of the grown stable Form I and metastable Form II of vanillin were confirmed through powder X-ray diffraction (PXRD) and differential scanning calorimetry (DSC) analyses. Further, results suggest that the ultrasound has profound effect in controlling the LLPS and nucleation of vanillin polymorphs in aqueous solution.

M-Mode Ultrasound Reveals Earlier Gluteus Minimus Activity in Individuals With Chronic Hip Pain During a Step-down Task.

PubMed

Dieterich, Angela V; Deshon, Louise; Strauss, Geoffrey R; McKay, Jan; Pickard, Christine M

2016-04-01

Controlled laboratory study. The hip abductor muscles are important hip joint stabilizers. Hip joint pain may alter muscle recruitment. Motion-mode (M-mode) ultrasound enables noninvasive measurements of the onset of deep and superficial muscle motion, which is associated with activation onset. To compare (1) the onset of superficial and deep gluteus medius and gluteus minimus muscle motion relative to the instant of peak ground reaction force and (2) the level of swing-phase muscle motion during step-down between subjects with chronic hip pain and controls using M-mode ultrasound. Thirty-five subjects with anterior, nontraumatic hip pain for more than 6 months (mean ± SD age, 54 ± 9 years) and 35 controls (age, 57 ± 7 years) were scanned on the lateral hip of the leading leg during frontal step-down onto a force platform using M-mode ultrasound. Computerized motion detection with the Teager-Kaiser energy operator was applied on the gluteus minimus and the deep and superficial gluteus medius to determine the time lag between muscle motion onset and instant of peak ground reaction force and the level of gluteus minimus motion during the swing phase. Time lags and motion levels were averaged per subject, and t tests were used to determine between-group differences. In participants with hip pain, gluteus minimus motion onset was 103 milliseconds earlier (P = .002) and superficial gluteus medius motion was 70 milliseconds earlier (P = .047) than those in healthy control participants. The level of gluteus minimus swing-phase motion was higher with pain (P = .006). Increased gluteus minimus motion during the swing phase and earlier gluteus minimus and superficial gluteus medius motion in individuals with hip pain suggest an overall increase of muscle activity, possibly a protective behavior.

Ultrasound image filtering using the mutiplicative model

NASA Astrophysics Data System (ADS)

Navarrete, Hugo; Frery, Alejandro C.; Sanchez, Fermin; Anto, Joan

2002-04-01

Ultrasound images, as a special case of coherent images, are normally corrupted with multiplicative noise i.e. speckle noise. Speckle noise reduction is a difficult task due to its multiplicative nature, but good statistical models of speckle formation are useful to design adaptive speckle reduction filters. In this article a new statistical model, emerging from the Multiplicative Model framework, is presented and compared to previous models (Rayleigh, Rice and K laws). It is shown that the proposed model gives the best performance when modeling the statistics of ultrasound images. Finally, the parameters of the model can be used to quantify the extent of speckle formation; this quantification is applied to adaptive speckle reduction filter design. The effectiveness of the filter is demonstrated on typical in-vivo log-compressed B-scan images obtained by a clinical ultrasound system.

Passive cavitation imaging with ultrasound arrays

PubMed Central

Salgaonkar, Vasant A.; Datta, Saurabh; Holland, Christy K.; Mast, T. Douglas

2009-01-01

A method is presented for passive imaging of cavitational acoustic emissions using an ultrasound array, with potential application in real-time monitoring of ultrasound ablation. To create such images, microbubble emissions were passively sensed by an imaging array and dynamically focused at multiple depths. In this paper, an analytic expression for a passive image is obtained by solving the Rayleigh–Sommerfield integral, under the Fresnel approximation, and passive images were simulated. A 192-element array was used to create passive images, in real time, from 520-kHz ultrasound scattered by a 1-mm steel wire. Azimuthal positions of this target were accurately estimated from the passive images. Next, stable and inertial cavitation was passively imaged in saline solution sonicated at 520 kHz. Bubble clusters formed in the saline samples were consistently located on both passive images and B-scans. Passive images were also created using broadband emissions from bovine liver sonicated at 2.2 MHz. Agreement was found between the images and source beam shape, indicating an ability to map therapeutic ultrasound beams in situ. The relation between these broadband emissions, sonication amplitude, and exposure conditions are discussed. PMID:20000921

Passive cavitation imaging with ultrasound arrays.

PubMed

Salgaonkar, Vasant A; Datta, Saurabh; Holland, Christy K; Mast, T Douglas

2009-12-01

A method is presented for passive imaging of cavitational acoustic emissions using an ultrasound array, with potential application in real-time monitoring of ultrasound ablation. To create such images, microbubble emissions were passively sensed by an imaging array and dynamically focused at multiple depths. In this paper, an analytic expression for a passive image is obtained by solving the Rayleigh-Sommerfield integral, under the Fresnel approximation, and passive images were simulated. A 192-element array was used to create passive images, in real time, from 520-kHz ultrasound scattered by a 1-mm steel wire. Azimuthal positions of this target were accurately estimated from the passive images. Next, stable and inertial cavitation was passively imaged in saline solution sonicated at 520 kHz. Bubble clusters formed in the saline samples were consistently located on both passive images and B-scans. Passive images were also created using broadband emissions from bovine liver sonicated at 2.2 MHz. Agreement was found between the images and source beam shape, indicating an ability to map therapeutic ultrasound beams in situ. The relation between these broadband emissions, sonication amplitude, and exposure conditions are discussed.

Robot-assisted ultrasound imaging: overview and development of a parallel telerobotic system.

PubMed

Monfaredi, Reza; Wilson, Emmanuel; Azizi Koutenaei, Bamshad; Labrecque, Brendan; Leroy, Kristen; Goldie, James; Louis, Eric; Swerdlow, Daniel; Cleary, Kevin

2015-02-01

Ultrasound imaging is frequently used in medicine. The quality of ultrasound images is often dependent on the skill of the sonographer. Several researchers have proposed robotic systems to aid in ultrasound image acquisition. In this paper we first provide a short overview of robot-assisted ultrasound imaging (US). We categorize robot-assisted US imaging systems into three approaches: autonomous US imaging, teleoperated US imaging, and human-robot cooperation. For each approach several systems are introduced and briefly discussed. We then describe a compact six degree of freedom parallel mechanism telerobotic system for ultrasound imaging developed by our research team. The long-term goal of this work is to enable remote ultrasound scanning through teleoperation. This parallel mechanism allows for both translation and rotation of an ultrasound probe mounted on the top plate along with force control. Our experimental results confirmed good mechanical system performance with a positioning error of < 1 mm. Phantom experiments by a radiologist showed promising results with good image quality.

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

Venous catheterization with ultrasound navigation

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

Kasatkin, A. A., E-mail: ant-kasatkin@yandex.ru; Nigmatullina, A. R.; Urakov, A. L., E-mail: ant-kasatkin@yandex.ru

By ultrasound scanning it was determined that respiratory movements made by chest of healthy and sick person are accompanied by respiratory chest rise of internal jugular veins. During the exhalation of an individual diameter of his veins increases and during the breath it decreases down to the complete disappearing if their lumen. Change of the diameter of internal jugular veins in different phases can influence significantly the results of vein puncture and cauterization in patients. The purpose of this research is development of the method increasing the efficiency and safety of cannulation of internal jugular veins by the ultrasound visualization.more » We suggested the method of catheterization of internal jugular veins by the ultrasound navigation during the execution of which the puncture of venous wall by puncture needle and the following conduction of J-guide is carried out at the moment of patient’s exhalation. This method decreases the risk of complications development during catheterization of internal jugular vein due to exclusion of perforating wound of vein and subjacent tissues and anatomical structures.« less

Venous catheterization with ultrasound navigation

NASA Astrophysics Data System (ADS)

Kasatkin, A. A.; Urakov, A. L.; Nigmatullina, A. R.

2015-11-01

By ultrasound scanning it was determined that respiratory movements made by chest of healthy and sick person are accompanied by respiratory chest rise of internal jugular veins. During the exhalation of an individual diameter of his veins increases and during the breath it decreases down to the complete disappearing if their lumen. Change of the diameter of internal jugular veins in different phases can influence significantly the results of vein puncture and cauterization in patients. The purpose of this research is development of the method increasing the efficiency and safety of cannulation of internal jugular veins by the ultrasound visualization. We suggested the method of catheterization of internal jugular veins by the ultrasound navigation during the execution of which the puncture of venous wall by puncture needle and the following conduction of J-guide is carried out at the moment of patient's exhalation. This method decreases the risk of complications development during catheterization of internal jugular vein due to exclusion of perforating wound of vein and subjacent tissues and anatomical structures.

Development of ultrasound focusing discrete array for air-coupled ultrasound generation

NASA Astrophysics Data System (ADS)

Korobov, Alexander I.; Izosimova, Maria Y.; Toschov, Sergey A.

2010-01-01

The technique and results of synthesis of ultrasound focusing discrete arrays for air-coupled ultrasound generation are presented. One of the arrays is an antenna 22 cm in diameter. It consists of 60 transmitters of Murata Company. The resonant frequency of each transmitter is 40 kHz, diameter is 16 mm. The transmitters were placed in first four Fresnel zones. Each of the zones was emitting with anti-phases. Position data and pressure field in focus were calculated using Rayleigh integral. Parameters of made array were measured using method of air-coupled vibrometry with laser scanning vibrometer. Measured parameters (operating frequency is 40 ± 1 kHz, focal distance is 308 mm, size of focal spot is 16.3 mm, and pressure in focus is about 150 dB) are in good agreement with calculated data. The examples of use of designed arrays for noncontact non-destructive diagnostics of some structural materials are reported. Work supported by RFBR.

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

Ultrasound in the Diagnosis & Management of Pleural Effusions

PubMed Central

Soni, Nilam J.; Franco, Ricardo; Velez, Maria I.; Schnobrich, Daniel; Dancel, Ria; Restrepo, Marcos I.; Mayo, Paul H.

2015-01-01

We review the literature on the use of point-of-care ultrasound to evaluate and manage pleural effusions. Point-of-care ultrasound is more sensitive than physical exam and chest radiography to detect and characterize pleural fluid, and avoids many negative aspects of computerized tomography (CT). Additionally, point-of-care ultrasound can be used to assess pleural fluid volume and character, revealing possible underlying pathologies and guiding management. Thoracentesis performed with ultrasound guidance has lower risk of pneumothorax and bleeding complications. Future research should focus on the clinical-effectiveness of point-of-care ultrasound in the routine management of pleural effusions and how new technologies may expand its clinical utility. PMID:26218493

Photoacoustic and ultrasound imaging of cancellous bone tissue.

PubMed

Yang, Lifeng; Lashkari, Bahman; Tan, Joel W Y; Mandelis, Andreas

2015-07-01

We used ultrasound (US) and photoacoustic (PA) imaging modalities to characterize cattle trabecular bones. The PA signals were generated with an 805-nm continuous wave laser used for optimally deep optical penetration depth. The detector for both modalities was a 2.25-MHz US transducer with a lateral resolution of ~1 mm at its focal point. Using a lateral pixel size much larger than the size of the trabeculae, raster scanning generated PA images related to the averaged values of the optical and thermoelastic properties, as well as density measurements in the focal volume. US backscatter yielded images related to mechanical properties and density in the focal volume. The depth of interest was selected by time-gating the signals for both modalities. The raster scanned PA and US images were compared with microcomputed tomography (μCT) images averaged over the same volume to generate similar spatial resolution as US and PA. The comparison revealed correlations between PA and US modalities with the mineral volume fraction of the bone tissue. Various features and properties of these modalities such as detectable depth, resolution, and sensitivity are discussed.

High frequency ultrasound: a new frontier for ultrasound.

PubMed

Shung, K; Cannata, Jonathan; Qifa Zhou, Member; Lee, Jungwoo

2009-01-01

High frequency ultrasonic imaging is considered by many to be the next frontier in ultrasonic imaging because higher frequencies yield much improved spatial resolution by sacrificing the depth of penetration. It has many clinical applications including visualizing blood vessel wall, anterior segments of the eye and skin. Another application is small animal imaging. Ultrasound is especially attractive in imaging the heart of a small animal like mouse which has a size in the mm range and a heart beat rate faster than 600 BPM. A majority of current commercial high frequency scanners often termed "ultrasonic backscatter microscope or UBM" acquire images by scanning single element transducers at frequencies between 50 to 80 MHz with a frame rate lower than 40 frames/s, making them less suitable for this application. High frequency linear arrays and linear array based ultrasonic imaging systems at frequencies higher than 30 MHz are being developed. The engineering of such arrays and development of high frequency imaging systems has been proven to be highly challenging. High frequency ultrasound may find other significant biomedical applications. The development of acoustic tweezers for manipulating microparticles is such an example.

Emergency ultrasound-based algorithms for diagnosing blunt abdominal trauma.

PubMed

Stengel, Dirk; Bauwens, Kai; Rademacher, Grit; Ekkernkamp, Axel; Güthoff, Claas

2013-07-31

Ultrasonography is regarded as the tool of choice for early diagnostic investigations in patients with suspected blunt abdominal trauma. Although its sensitivity is too low for definite exclusion of abdominal organ injury, proponents of ultrasound argue that ultrasound-based clinical pathways enhance the speed of primary trauma assessment, reduce the number of computed tomography scans and cut costs. To assess the effects of trauma algorithms that include ultrasound examinations in patients with suspected blunt abdominal trauma. We searched the Cochrane Injuries Group's Specialised Register, CENTRAL (The Cochrane Library), MEDLINE (OvidSP), EMBASE (OvidSP), CINAHL (EBSCO), publishers' databases, controlled trials registers and the Internet. Bibliographies of identified articles and conference abstracts were searched for further elligible studies. Trial authors were contacted for further information and individual patient data. The searches were updated in February 2013. randomised controlled trials (RCTs) and quasi-randomised trials (qRCTs). patients with blunt torso, abdominal or multiple trauma undergoing diagnostic investigations for abdominal organ injury. diagnostic algorithms comprising emergency ultrasonography (US). diagnostic algorithms without ultrasound examinations (for example, primary computed tomography [CT] or diagnostic peritoneal lavage [DPL]). mortality, use of CT and DPL, cost-effectiveness, laparotomy and negative laparotomy rates, delayed diagnoses, and quality of life. Two authors independently selected trials for inclusion, assessed methodological quality and extracted data. Where possible, data were pooled and relative risks (RRs), risk differences (RDs) and weighted mean differences, each with 95% confidence intervals (CIs), were calculated by fixed- or random-effects modelling, as appropriate. We identified four studies meeting our inclusion criteria. Overall, trials were of moderate methodological quality. Few trial authors responded to

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.

Electronic screening in stacked graphene flakes revealed by scanning tunneling microscopy

NASA Astrophysics Data System (ADS)

Feng, Xiaofeng; Salmeron, Miquel

2013-02-01

Electronic doping and screening effects in stacked graphene flakes on Ru and Cu substrates have been observed using scanning tunneling microscopy (STM). The screening affects the apparent STM height of each flake in successive layers reflecting the density of states near the Fermi level and thus the doping level. It is revealed in this way that the strong doping of the first graphene layer on Ru(0001) is attenuated in the second one, and almost eliminated in the third and fourth layers. Similar effect is also observed in graphene flakes on Cu(111). In contrast, the strong doping effect is suppressed immediately by a water layer intercalated between the graphene and Ru.

Portable Bladder Ultrasound

PubMed Central

2006-01-01

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

Ultrasound imaging diagnostics: healthcare risks for urologists.

PubMed

Martino, Tilde; Massaro, Tommaso; Martino, Paolo; Martino, Pasquale

2010-12-01

The objectives of this study are: 1) assessing if Ultrasound (US) used during US scans can represent a risk for the healthcare of urologists; 2) verifying the frequency of Carpal Tunnel Syndrome (CTS) symptoms and musculoskeletal disorders (MSD), trying to assess the possible correlation with job load and US scanning procedures; 3) assessing the role of individual factors like age, gender and physical activity in determining such disorders. A group of 35 voluntary urologists carrying out ultrasound scans were selected: 13 were working for the 1 degrees Teaching Hospital Urology, 11 for the 2 degrees Teaching Hospital Urology, 2 for the Hospitalization Urology of the Policlinico of Bari and 9 for Urology of Public Corporation Di Venere of Bari. A questionnaire, divided in two parts, was administered to the sample: the first aimed at collecting demographic data and at describing the operators' workload and the second focused on the possible presence of CTS and MSD symptoms. 32 urologists over 35 performed more than 5 scans per week and more than 5 scans per day. On average the specialists were carrying out this activity since 18 years wheras for post-graduate students, this time was about 4 years. Twenty-six subjects (74%) showed no symptoms, 8 subjects (23%) showed from 1 to 4 symptoms which can be associated to the presence of CTS; only one subject presents more than 5 symptoms. As regards MSD, 6 urologists (17%) did not present disorders, 24 subjects (69%) showed from 1 to 4 symptoms and 5 subjects (14%) presented more than 5 symptoms. The use of US scan examination is completely safe both for the healthcare of the patients and the operator. For what concerns healthcare risks, it is highly recommended to adopt a correct posture when performing the examination and to use the provided chair.

Strain measurement of abdominal aortic aneurysm with real-time 3D ultrasound speckle tracking.

PubMed

Bihari, P; Shelke, A; Nwe, T H; Mularczyk, M; Nelson, K; Schmandra, T; Knez, P; Schmitz-Rixen, T

2013-04-01

Abdominal aortic aneurysm rupture is caused by mechanical vascular tissue failure. Although mechanical properties within the aneurysm vary, currently available ultrasound methods assess only one cross-sectional segment of the aorta. This study aims to establish real-time 3-dimensional (3D) speckle tracking ultrasound to explore local displacement and strain parameters of the whole abdominal aortic aneurysm. Validation was performed on a silicone aneurysm model, perfused in a pulsatile artificial circulatory system. Wall motion of the silicone model was measured simultaneously with a commercial real-time 3D speckle tracking ultrasound system and either with laser-scan micrometry or with video photogrammetry. After validation, 3D ultrasound data were collected from abdominal aortic aneurysms of five patients and displacement and strain parameters were analysed. Displacement parameters measured in vitro by 3D ultrasound and laser scan micrometer or video analysis were significantly correlated at pulse pressures between 40 and 80 mmHg. Strong local differences in displacement and strain were identified within the aortic aneurysms of patients. Local wall strain of the whole abdominal aortic aneurysm can be analysed in vivo with real-time 3D ultrasound speckle tracking imaging, offering the prospect of individual non-invasive rupture risk analysis of abdominal aortic aneurysms. Copyright © 2013 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

Face and content validity of the virtual reality simulator 'ScanTrainer®'.

PubMed

Alsalamah, Amal; Campo, Rudi; Tanos, Vasilios; Grimbizis, Gregoris; Van Belle, Yves; Hood, Kerenza; Pugh, Neil; Amso, Nazar

2017-01-01

Ultrasonography is a first-line imaging in the investigation of women's irregular bleeding and other gynaecological pathologies, e.g. ovarian cysts and early pregnancy problems. However, teaching ultrasound, especially transvaginal scanning, remains a challenge for health professionals. New technology such as simulation may potentially facilitate and expedite the process of learning ultrasound. Simulation may prove to be realistic, very close to real patient scanning experience for the sonographer and objectively able to assist the development of basic skills such as image manipulation, hand-eye coordination and examination technique. The aim of this study was to determine the face and content validity of a virtual reality simulator (ScanTrainer®, MedaPhor plc, Cardiff, Wales, UK) as reflective of real transvaginal ultrasound (TVUS) scanning. A questionnaire with 14 simulator-related statements was distributed to a number of participants with differing levels of sonography experience in order to determine the level of agreement between the use of the simulator in training and real practice. There were 36 participants: novices ( n  = 25) and experts ( n  = 11) who rated the simulator. Median scores of face validity statements between experts and non-experts using a 10-point visual analogue scale (VAS) ratings ranged between 7.5 and 9.0 ( p  > 0.05) indicated a high level of agreement. Experts' median scores of content validity statements ranged from 8.4 to 9.0. The findings confirm that the simulator has the feel and look of real-time scanning with high face validity. Similarly, its tutorial structures and learning steps confirm the content validity.

Estimating cardiac fiber orientations in pig hearts using registered ultrasound and MR image volumes

NASA Astrophysics Data System (ADS)

Dormer, James D.; Meng, Yuguang; Zhang, Xiaodong; Jiang, Rong; Wagner, Mary B.; Fei, Baowei

2017-03-01

Heart fiber mechanics can be important predictors in current and future cardiac function. Accurate knowledge of these mechanics could enable cardiologists to provide a diagnosis before conditions progress. Magnetic resonance diffusion tensor imaging (MR-DTI) has been used to determine cardiac fiber orientations. Ultrasound is capable of providing anatomical information in real time, enabling a physician to quickly adjust parameters to optimize image scans. If known fiber orientations from a template heart measured using DTI can be accurately deformed onto a cardiac ultrasound volume, fiber orientations could be estimated for the patient without the need for a costly MR scan while still providing cardiologists valuable information about the heart mechanics. In this study, we apply the method to pig hearts, which are a close representation of human heart anatomy. Experiments from pig hearts show that the registration method achieved an average Dice similarity coefficient (DSC) of 0.819 +/- 0.050 between the ultrasound and deformed MR volumes and that the proposed ultrasound-based method is able to estimate the cardiac fiber orientation in pig hearts.

Photoacoustic micro-imaging of focused ultrasound induced blood-brain-barrier opening in a rat model

NASA Astrophysics Data System (ADS)

Wang, Po-Hsun; Hsu, Po-Hung; Liu, Hao-Li; Wang, Churng-Ren Chris; Li, Meng-Lin

2010-02-01

Blood brain barrier (BBB) prevents most of the drug from transmitting into the brain tissue and decreases the treatment performance for brain disease. One of the methods to overcome the difficulty of drug delivery is to locally increase the permeability of BBB with high-intensity focused ultrasound. In this study, we have investigated the feasibility of photoacoustic microscopy of focused-ultrasound induced BBB opening in a rat model in vivo with gold nanorods (AuNRs) as a contrast agent. This study takes advantage of the strong near-infrared absorption of AuNRs and their extravasation tendency from BBB opening foci due to their nano-scale size. Before the experiments, craniotomy was performed on rats to provide a path for focused ultrasound beam. Localized BBB opening at the depth of about 3 mm from left cortex of rat brains was achieved by delivering 1.5 MHz focused ultrasound energy into brain tissue in the presence of microbubbles. PEGylated AuNRs with a peak optical absorption at ~800 nm were then intravenously administered. Pre-scan prior to BBB disruption and AuNR injection was taken to mark the signal background. After injection, the distribution of AuNRs in rat brains was monitored up to 2 hours. Experimental results show that imaging AuNRs reveals BBB disruption area in left brains while there are no changes observed in the right brains. From our results, photoacoustic imaging plus AuNRs shows the promise as a novel monitoring strategy in identifying the location and variation of focused-ultrasound BBB-opening in a rat model.

A single FPGA-based portable ultrasound imaging system for point-of-care applications.

PubMed

Kim, Gi-Duck; Yoon, Changhan; Kye, Sang-Bum; Lee, Youngbae; Kang, Jeeun; Yoo, Yangmo; Song, Tai-kyong

2012-07-01

We present a cost-effective portable ultrasound system based on a single field-programmable gate array (FPGA) for point-of-care applications. In the portable ultrasound system developed, all the ultrasound signal and image processing modules, including an effective 32-channel receive beamformer with pseudo-dynamic focusing, are embedded in an FPGA chip. For overall system control, a mobile processor running Linux at 667 MHz is used. The scan-converted ultrasound image data from the FPGA are directly transferred to the system controller via external direct memory access without a video processing unit. The potable ultrasound system developed can provide real-time B-mode imaging with a maximum frame rate of 30, and it has a battery life of approximately 1.5 h. These results indicate that the single FPGA-based portable ultrasound system developed is able to meet the processing requirements in medical ultrasound imaging while providing improved flexibility for adapting to emerging POC applications.

Nde of Lumber and Natural Fiber Based Products with Air Coupled Ultrasound

NASA Astrophysics Data System (ADS)

Hsu, David K.; Utrata, David; Kuo, Monlin

2010-02-01

Due to the porous nature of wood and natural fiber based products, conventional fluid or gel coupled ultrasonic inspection is unsuitable. Air-coupled ultrasonic transmission scanning, being non-contact, is ideally suited for inspecting lumber, wood and natural fiber based products. We report here several successful applications of air-coupled ultrasound for the inspection of wood. Air-coupled ultrasonic scan at 120 kHz can easily detect "sinker-stock" lumber in which bacterial damage of ray tissue cells had occurred during anaerobic pond storage. Channels in ash lumber board caused by insect bore were imaged in transmission scan. Delamination and material inhomogeneities were mapped out in manufactured wood and natural fiber products including medium density fiberboards, compression molded shredded waste wood with formaldehyde resin, and acoustic panels molded with kenaf fibers. The study has demonstrated some of the capabilities of air-coupled ultrasound in the NDE of forest products.

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; ...

Intracardiac ultrasound scanner using a micromachine (MEMS) actuator.

PubMed

Zara, J M; Bobbio, S M; Goodwin-Johansson, S; Smith, S W

2000-01-01

Catheter-based intracardiac ultrasound offers the potential for improved guidance of interventional cardiac procedures. The objective of this research is the development of catheter-based mechanical sector scanners incorporating high frequency ultrasound transducers operating at frequencies up to 20 MHz. The authors' current transducer assembly consists of a single 1.75 mm by 1.75 mm, 20 MHz, PZT element mounted on a 2 mm by 2 mm square, 75 mum thick polyimide table that pivots on 3-mum thick gold plated polyimide hinges. The hinges also serve as the electrical connections to the transducer. This table-mounted transducer is tilted using a miniature linear actuator to produce a sector scan. This linear actuator is an integrated force array (IFA), which is an example of a micromachine, i.e., a microelectromechanical system (MEMS). The IFA is a thin (2.2 mum) polyimide membrane, which consists of a network of hundreds of thousands of micron scale deformable capacitors made from pairs of metallized polyimide plates. IFAs contract with an applied voltage of 30-120 V and have been shown to produce strains as large as 20% and forces of up to 8 dynes. The prototype transducer and actuator assembly was fabricated and interfaced with a GagePCI analog to digital conversion board digitizing 12 bit samples at a rate of 100 MSamples/second housed in a personal computer to create a single channel ultrasound scanner. The deflection of the table transducer in a low viscosity insulating fluid (HFE 7100, 3M) is up to +/-10 degrees at scan rates of 10-60 Hz. Software has been developed to produce real-time sector scans on the PC monitor.

Value of delayed duplex ultrasound assessment after endothermal ablation of the great saphenous vein.

PubMed

Ryer, Evan J; Elmore, James R; Garvin, Robert P; Cindric, Matthew C; Dove, James T; Kekulawela, Stephanie; Franklin, David P

2016-08-01

Endothermal ablation (ETA) of the great saphenous vein (GSV) is associated with a small but definite risk of endothermal heat-induced thrombosis (EHIT) extending into the common femoral vein. Follow-up duplex ultrasound imaging to detect EHIT after ETA is considered standard of care, although the exact timing of duplex ultrasound imaging to detect EHIT after ETA remains unclear. We hypothesized that an additional duplex ultrasound assessment 1 week after ETA would not identify a significant number of patients with EHIT and would significantly increase health care costs. This was a retrospective review of consecutive ETA GSV procedures from 2007 to 2014. All patients were evaluated with duplex ultrasound imaging on postprocedure day 1, and 79% of patients underwent a second ultrasound assessment 1 week postprocedure. EHIT was considered present when proximal GSV closure progressed to level ≥4, based on a six-tier classification system. From January 1, 2007, until December 31, 2014, 842 patients underwent GSV ETA. Patients with EHIT were more likely to have had a prior deep venous thrombosis (DVT; P = .002) and a larger GSV (P = .006). Forty-three procedures (5.1%) were classified as having EHIT requiring anticoagulation, based on a level ≥4 proximal closure level. Of the 43 patients with EHIT, 20 (47%) were found on the initial ultrasound assessment performed 24 hours postprocedure, but 19 patients (44%) with EHIT would not have been identified with a single postoperative ultrasound scan performed 24 hours after intervention. These 19 patients had a level ≤3 closure level at the duplex ultrasound scan performed 24 hours postprocedure and progressed to EHIT on the delayed duplex ultrasound scan. Lastly, thrombotic complications in four patients (9%), representing three late DVT and one DVT/pulmonary embolism presenting to another hospital, would not have been identified regardless of the postoperative surveillance strategy. Maximum GSV diameter was the

Syrian Women’s Perceptions and Experiences of Ultrasound Screening in Pregnancy: Implications for Antenatal Policy

PubMed Central

Bashour, Hyam; Hafez, Raghda; Abdulsalam, Asmaa

2006-01-01

Ultrasound scanning is firmly embedded in antenatal maternity care around the world. This paper reports on a qualitative study carried out in 2003 of 30 Syrian women’s perceptions and experiences of routine ultrasound in pregnancy. It was part of a larger study of the experiences of pregnancy and childbirth of 500 women from Damascus and its suburbs who had recently given birth to healthy newborns. The women had had multiple scans during pregnancy and accepted its use uncritically nearly all the time. The scans gave them reassurance that the baby was healthy, the pregnancy was progressing well and allowed them to learn the sex of the baby. The women also reacted positively to the antenatal educational messages that were conveyed using scans. However, we found the excessive use of this technology worrying. We believe private doctors, who attend 80% of pregnant women, use ultrasound primarily to attract women to their clinics and increase their income. We recommend that maternity care in Syria should be better regulated; that women and their doctors should be made aware of the essential components of antenatal care; that national guidelines for antenatal care should be developed and that Syrian women should be empowered to ask questions about pregnancy and childbirth and the care they receive. PMID:16035608

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

Release of indomethacin from ultrasound dry granules containing lactose-based excipients.

PubMed

Cavallari, Cristina; Albertini, Beatrice; Rodriguez, Lorenzo; Rabasco, Antonio M; Fini, Adamo

2005-01-20

Physical mixtures were prepared containing indomethacin and beta-lactose and alpha-lactose-based excipients (Ludipress and Cellactose). The mixtures were compacted with the aid of ultrasound, obtaining tablets, which were milled and sieved. Granules thus obtained were examined by optical microscopy and differential scanning calorimetry. The intense yellow color of the granules and the absence of indomethacin peak in thermograms suggest important modifications of indomethacin physical state; the drug thus modified appears to be spread on the excipient particle surface as a thin film, giving a lustrous appearance. No influence of ultrasound was observed on phase transition concerning lactose; only loss of water was important under high energy ultrasound. Dissolution profiles suggest an increased release of the drug from the systems treated with ultrasound at high energy, with respect to a traditional compaction; while no difference could be evidenced among the three excipients that, however, appear all suitable for this ultrasound-aided direct compression process.

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.

Transvaginal ultrasound

MedlinePlus

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

Short- and long-term effects on the ciliary body and the aqueous outflow pathways of high-intensity focused ultrasound cyclocoagulation.

PubMed

Aptel, Florent; Béglé, Aurélie; Razavi, Arash; Romano, Fabrice; Charrel, Thomas; Chapelon, Jean-Yves; Denis, Philippe; Lafon, Cyril

2014-09-01

Several physical methods can be used to coagulate the ciliary body and decrease intra-ocular pressure in patients with glaucoma. The study described here investigated the short- and long-term effects of high-intensity focused ultrasound (HIFU) cyclocoagulation on the aqueous humor production structures and outflow pathways. Thirty-four rabbit eyes were sonicated with a ring-shaped probe containing six miniaturized HIFU transducers. Light, scanning electron and transmission electron microscopy and corrosion casts were performed. In the affected regions, the epithelium of the ciliary processes was degenerated or necrotic and sloughed off. Examinations performed several months afterward revealed involution of the ciliary processes. Vascular corrosion cast revealed focal interruption of the ciliary body microvasculature. In most animals, a sustained fluid space was seen between the sclera, the ciliary body and the choroid, likely indicating an increase in the aqueous outflow by the uveoscleral pathway. These results suggest that HIFU cyclocoagulation has a dual effect on aqueous humor dynamics. Copyright © 2014 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Training Midwives to Perform Basic Obstetric Point-of-Care Ultrasound in Rural Areas Using a Tablet Platform and Mobile Phone Transmission Technology-A WFUMB COE Project.

PubMed

Vinayak, Sudhir; Sande, Joyce; Nisenbaum, Harvey; Nolsøe, Christian Pállson

2017-10-01

pregnancies and diagnoses on the basis of reports generated by the midwives. Only 1 discrepancy was found in the midwives' reports. Scan results versus actual outcomes revealed 2 discrepancies in the 20 patients identified as high risk. In conclusion, we found that it is valuable to train midwives in POCUS to use an ultrasound tablet device and transmit images and reports via the internet to radiologists for review of accuracy. This focus on the identification of high-risk patients can be valuable in a remote healthcare facility. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Development of a Mechanical Scanning Device With High-Frequency Ultrasound Transducer for Ultrasonic Capsule Endoscopy.

PubMed

Wang, Xingying; Seetohul, Vipin; Chen, Ruimin; Zhang, Zhiqiang; Qian, Ming; Shi, Zhehao; Yang, Ge; Mu, Peitian; Wang, Congzhi; Huang, Zhihong; Zhou, Qifa; Zheng, Hairong; Cochran, Sandy; Qiu, Weibao

2017-09-01

Wireless capsule endoscopy has opened a new era by enabling remote diagnostic assessment of the gastrointestinal tract in a painless procedure. Video capsule endoscopy is currently commercially available worldwide. However, it is limited to visualization of superficial tissue. Ultrasound (US) imaging is a complementary solution as it is capable of acquiring transmural information from the tissue wall. This paper presents a mechanical scanning device incorporating a high-frequency transducer specifically as a proof of concept for US capsule endoscopy (USCE), providing information that may usefully assist future research. A rotary solenoid-coil-based motor was employed to rotate the US transducer with sectional electronic control. A set of gears was used to convert the sectional rotation to circular rotation. A single-element focused US transducer with 39-MHz center frequency was used for high-resolution US imaging, connected to an imaging platform for pulse generation and image processing. Key parameters of US imaging for USCE applications were evaluated. Wire phantom imaging and tissue phantom imaging have been conducted to evaluate the performance of the proposed method. A porcine small intestine specimen was also used for imaging evaluation in vitro. Test results demonstrate that the proposed device and rotation mechanism are able to offer good image resolution ( [Formula: see text]) of the lumen wall, and they, therefore, offer a viable basis for the fabrication of a USCE device.

Endocavity Ultrasound Probe Manipulators

PubMed Central

Stoianovici, Dan; Kim, Chunwoo; Schäfer, Felix; Huang, Chien-Ming; Zuo, Yihe; Petrisor, Doru; Han, Misop

2014-01-01

We developed two similar structure manipulators for medical endocavity ultrasound probes with 3 and 4 degrees of freedom (DoF). These robots allow scanning with ultrasound for 3-D imaging and enable robot-assisted image-guided procedures. Both robots use remote center of motion kinematics, characteristic of medical robots. The 4-DoF robot provides unrestricted manipulation of the endocavity probe. With the 3-DoF robot the insertion motion of the probe must be adjusted manually, but the device is simpler and may also be used to manipulate external-body probes. The robots enabled a novel surgical approach of using intraoperative image-based navigation during robot-assisted laparoscopic prostatectomy (RALP), performed with concurrent use of two robotic systems (Tandem, T-RALP). Thus far, a clinical trial for evaluation of safety and feasibility has been performed successfully on 46 patients. This paper describes the architecture and design of the robots, the two prototypes, control features related to safety, preclinical experiments, and the T-RALP procedure. PMID:24795525

Building and assessing anatomically relevant phantoms for neonatal transcranial ultrasound

NASA Astrophysics Data System (ADS)

Memoli, G.; Gatto, M.; Sadhoo, N.; Gélat, P.; Harris, R. A.; Shaw, A.

2011-02-01

This study describes the design and construction of a clinically relevant phantom to survey the temperature increase caused by ultrasound equipment, as currently used in neonatal head-scanning in the UK. The phantom is an ellipsoid of bone-mimic material, filled with brain-mimic; a circular hole in the external surface mimicks the fontanel, through which most clinically relevant scans are made. Finite-element simulations were used to identify possible hot spots and decide the most effective thermocouple positions within the phantom to investigate temperature rise during a typical scan. Novel materials were purposively designed to simulate key acoustic and thermal properties. Three Dimensional Printing (3DP) was employed for the fabrication of the skull phantom, and a specific strategy was successfully pursued to embed a thermocouple within the 3DP skull phantom during the manufacturing process. An in-process Non-Destructive Analysis (NDA) was used to assess the correct position of the deposited thermocouple inside the fabricated skull phantom. The temperature increase in the phantom for a typical trans-fontanellar scan is also presented here. The current phantom will be used in a hospital survey in the UK and, in its final design, will allow for a more reliable evaluation of ultrasound heating than is currently possible.

Ultrasound diagnosis of ectopic pregnancy

PubMed Central

2015-01-01

Abstract Ectopic pregnancy (EP) remains the number one cause of first trimester maternal death. Traditionally, laparoscopy has been the gold standard for diagnosis of EP. The advent of high‐resolution transvaginal scan (TVS) means more clinically stable women with EPs are diagnosed earlier, well before surgery becomes necessary in many cases. Early diagnosis by TVS is therefore potentially life saving and can reduce surgical morbidity by allowing elective surgery or even non‐surgical conservative treatment options. Combining transabdominal and transvaginal scanning confers no benefit over transvaginal scanning alone. Reports that reads “…empty uterus, ectopic pregnancy cannot be excluded” should be a thing of the past. Diagnosis of EP should be based upon the positive identification of an adnexal mass using TVS rather than the absence of an intra‐uterine gestational sac. A systematic approach to scanning the early pregnancy pelvis will diagnose the vast majority of EPs at the initial scan. Ultrasound, and in particular TVS, is fast becoming the new gold standard for diagnosis of all types of EP. In modern management, laparoscopy should be seen as the operative tool of choice while TVS the diagnostic tool of choice. PMID:28191110

Ultrasound

MedlinePlus

... community Home > Pregnancy > Prenatal care > Ultrasound during pregnancy Ultrasound during pregnancy E-mail to a friend Please ... you. What are some reasons for having an ultrasound? Your provider uses ultrasound to do several things, ...

Ultrasound diagnosis of penile fracture.

PubMed

Nomura, Jason T; Sierzenski, Paul R

2010-04-01

Rupture of the corpus cavernosum, penile fracture, is an uncommon occurrence. Diagnosis is straightforward when classical historical and physical examination findings are present. However, atypical presentations can make the diagnosis difficult. Review the literature supporting use of ultrasound for the diagnosis of penile fracture. Review of the ultrasonographic findings in patients with penile fracture. A 32-year-old man presented with penile ecchymosis after sex but lacking several historical and physical examination elements for a diagnosis of penile fracture. Ultrasound performed by the treating physician revealed rupture of the tunica albuginea and presence of a hematoma, leading to a diagnosis of penile fracture. Ultrasound is a simple, efficient, and non-invasive imaging method to assist in the diagnosis of penile fracture. Copyright 2010 Elsevier Inc. All rights reserved.

Evaluation of uterine ultrasound imaging in cervical radiotherapy; a comparison of autoscan and conventional probe

PubMed Central

Cooper, David T; Behrens, Claus F

2016-01-01

Objective: In cervical radiotherapy, it is essential that the uterine position is correctly determined prior to treatment delivery. The aim of this study was to evaluate an autoscan ultrasound (A-US) probe, a motorized transducer creating three-dimensional (3D) images by sweeping, by comparing it with a conventional ultrasound (C-US) probe, where manual scanning is required to acquire 3D images. Methods: Nine healthy volunteers were scanned by seven operators, using the Clarity® system (Elekta, Stockholm, Sweden). In total, 72 scans, 36 scans from the C-US and 36 scans from the A-US probes, were acquired. Two observers delineated the uterine structure, using the software-assisted segmentation in the Clarity workstation. The data of uterine volume, uterine centre of mass (COM) and maximum uterine lengths, in three orthogonal directions, were analyzed. Results: In 53% of the C-US scans, the whole uterus was captured, compared with 89% using the A-US. F-test on 36 scans demonstrated statistically significant differences in interobserver COM standard deviation (SD) when comparing the C-US with the A-US probe for the inferior–superior (p < 0.006), left–right (p < 0.012) and anteroposterior directions (p < 0.001). The median of the interobserver COM distance (Euclidean distance for 36 scans) was reduced from 8.5 (C-US) to 6.0 mm (A-US). An F-test on the 36 scans showed strong significant differences (p < 0.001) in the SD of the Euclidean interobserver distance when comparing the C-US with the A-US scans. The average Dice coefficient when comparing the two observers was 0.67 (C-US) and 0.75 (A-US). The predictive interval demonstrated better interobserver delineation concordance using the A-US probe. Conclusion: The A-US probe imaging might be a better choice of image-guided radiotherapy system for correcting for daily uterine positional changes in cervical radiotherapy. Advances in knowledge: Using a novel A-US probe might reduce the uncertainty in

Evaluation of uterine ultrasound imaging in cervical radiotherapy; a comparison of autoscan and conventional probe.

PubMed

Baker, Mariwan; Cooper, David T; Behrens, Claus F

2016-10-01

In cervical radiotherapy, it is essential that the uterine position is correctly determined prior to treatment delivery. The aim of this study was to evaluate an autoscan ultrasound (A-US) probe, a motorized transducer creating three-dimensional (3D) images by sweeping, by comparing it with a conventional ultrasound (C-US) probe, where manual scanning is required to acquire 3D images. Nine healthy volunteers were scanned by seven operators, using the Clarity(®) system (Elekta, Stockholm, Sweden). In total, 72 scans, 36 scans from the C-US and 36 scans from the A-US probes, were acquired. Two observers delineated the uterine structure, using the software-assisted segmentation in the Clarity workstation. The data of uterine volume, uterine centre of mass (COM) and maximum uterine lengths, in three orthogonal directions, were analyzed. In 53% of the C-US scans, the whole uterus was captured, compared with 89% using the A-US. F-test on 36 scans demonstrated statistically significant differences in interobserver COM standard deviation (SD) when comparing the C-US with the A-US probe for the inferior-superior (p < 0.006), left-right (p < 0.012) and anteroposterior directions (p < 0.001). The median of the interobserver COM distance (Euclidean distance for 36 scans) was reduced from 8.5 (C-US) to 6.0 mm (A-US). An F-test on the 36 scans showed strong significant differences (p < 0.001) in the SD of the Euclidean interobserver distance when comparing the C-US with the A-US scans. The average Dice coefficient when comparing the two observers was 0.67 (C-US) and 0.75 (A-US). The predictive interval demonstrated better interobserver delineation concordance using the A-US probe. The A-US probe imaging might be a better choice of image-guided radiotherapy system for correcting for daily uterine positional changes in cervical radiotherapy. Using a novel A-US probe might reduce the uncertainty in interoperator variability during ultrasound scanning.

Standards of the Polish Ultrasound Society - update. Ultrasound examination of the kidneys, ureters and urinary bladder.

PubMed

Tyloch, Janusz F; Woźniak, Magdalena Maria; Wieczorek, Andrzej Paweł

2013-09-01

The paper presents the principles of performing proper ultrasound examinations of the urinary tract. The following are discussed: preparation of patients, type of optimal apparatus, technique of examination and conditions which its description should fulfill. Urinary track examination in adults and in children constitutes an integral part of each abdominal examination. Such examinations should be performed with fasting patients or several hours after the last meal, with filled urinary bladder. Ultrasound examinations in children and infants are performed using transducers with the frequency of 5.0-9.0 MHz and in adults - with the frequency of 2.0-6.0 MHz. Doppler options are desirable since they improve diagnostic capacity of sonography in terms of differentiation between renal focal lesions. Renal examinations are performed with the patients in the supine position. The right kidney is examined in the right hypochondriac region using the liver as the ultrasound "window." The left kidney is examined in the left hypochondriac region, preferably in the posterior axillary line. Ultrasound examinations of the upper segment of the ureters are performed after renal examination when the pelvicalyceal system is dilated. A condition necessary for a proper examination of the perivesical portion of the ureter is full urinary bladder. The scans of the urinary bladder are performed in transverse, longitudinal and oblique planes when the bladder is filled. The description should include patient's personal details, details of the referring unit, of the unit in which the examination is performed, examining physician's details, type of ultrasound apparatus and transducers as well as the description proper.

Pediatric Lung Abscess: Immediate Diagnosis by Point-of-Care Ultrasound.

PubMed

Kraft, Clara; Lasure, Benjamin; Sharon, Melinda; Patel, Paulina; Minardi, Joseph

2018-06-01

The diagnosis of lung abscess can be difficult to make and often requires imaging beyond plain chest x-ray. The decision to further image with computed tomography should be weighed against the risks of radiation exposure, especially in pediatric patients. In addition, the cost and potential impact on length of stay from obtaining computed tomography scans should be considered. In this report, we describe a case of lung abscess made immediately using point-of-care ultrasound in the emergency department. To our knowledge, there are no previous cases describing lung abscess diagnosed by point-of-care ultrasound. This case report aims to describe a case of pediatric lung abscess, review the ultrasound findings, and discuss relevant literature on the topic.

A PILOT STUDY OF DIAGNOSTIC NEUROMUSCULAR ULTRASOUND IN BELL'S PALSY

PubMed Central

TAWFIK, EMAN A.; WALKER, FRANCIS O.; CARTWRIGHT, MICHAEL S.

2015-01-01

Background and purpose Neuromuscular ultrasound of the cranial nerves is an emerging field which may help in the assessment of cranial neuropathies. The aim of this study was to evaluate the role of neuromuscular ultrasound in Bell's palsy. A second objective was to assess the possibility of any associated vagus nerve abnormality. Methods Twenty healthy controls and 12 Bell's palsy patients were recruited. The bilateral facial nerves, vagus nerves, and frontalis muscles were scanned using an 18 MHz linear array transducer. Facial nerve diameter, vagus nerve cross-sectional area, and frontalis thickness were measured. Results Mean facial nerve diameter was 0.8 ± 0.2 mm in controls and 1.1 ± 0.3 mm in patients group. The facial nerve diameter was significantly larger in patients than controls (p = 0.006, 95% CI for the difference between groups of 0.12-0.48), with a significant side-to-side difference in patients as well (p = 0.004, 95% CI for side-to-side difference of 0.08-0.52). ROC curve analysis of the absolute facial nerve diameter revealed a sensitivity of 75 % and a specificity of 70 %. No significant differences in vagus nerve cross-sectional area or frontalis thickness were detected between patients and controls. Conclusions Ultrasound can detect facial nerve enlargement in Bell's palsy and may have a role in assessment, or follow-up, of Bell's palsy and other facial nerve disorders. The low sensitivity of the current technique precludes its routine use for diagnosis, however, this study demonstrates its validity and potential for future research. PMID:26076910

Ultrasound-Diagnosed Tibia Stress Fracture: A Case Report.

PubMed

Amoako, Adae; Abid, Ayesha; Shadiack, Anthony; Monaco, Robert

2017-01-01

Stress fractures are a frequent cause of lower extremity pain in athletes, and especially in runners. Plain imaging has a low sensitivity. Magnetic resonance imaging (MRI) or bone scan scintigraphy is the criterion standard, but expensive. We present the case of a young female distance runner with left shin pain. Plain radiography was unremarkable. Ultrasound showed focal hyperechoic elevation of the periosteum with irregularity over the distal tibia and increased flow on Doppler. These findings were consistent with a distal tibia stress fracture and confirmed by MRI. Examination of our case will highlight the utility of considering an ultrasound for diagnosis of tibial stress fracture.

Ultrasound-Diagnosed Tibia Stress Fracture: A Case Report

PubMed Central

Amoako, Adae; Abid, Ayesha; Shadiack, Anthony; Monaco, Robert

2017-01-01

Stress fractures are a frequent cause of lower extremity pain in athletes, and especially in runners. Plain imaging has a low sensitivity. Magnetic resonance imaging (MRI) or bone scan scintigraphy is the criterion standard, but expensive. We present the case of a young female distance runner with left shin pain. Plain radiography was unremarkable. Ultrasound showed focal hyperechoic elevation of the periosteum with irregularity over the distal tibia and increased flow on Doppler. These findings were consistent with a distal tibia stress fracture and confirmed by MRI. Examination of our case will highlight the utility of considering an ultrasound for diagnosis of tibial stress fracture. PMID:28469488

Analysing Normal and Partial Glossectomee Tongues Using Ultrasound

ERIC Educational Resources Information Center

Bressmann, Tim; Uy, Catherine; Irish, Jonathan C.

2005-01-01

The present study aimed at identifying underlying parameters that govern the shape of the tongue. A functional topography of the tongue surface was developed based on three-dimensional ultrasound scans of sustained speech sounds in ten normal subjects. A principal component analysis extracted three components that explained 89.2% of the variance…

Hole filling with oriented sticks in ultrasound volume reconstruction

PubMed Central

Vaughan, Thomas; Lasso, Andras; Ungi, Tamas; Fichtinger, Gabor

2015-01-01

Abstract. Volumes reconstructed from tracked planar ultrasound images often contain regions where no information was recorded. Existing interpolation methods introduce image artifacts and tend to be slow in filling large missing regions. Our goal was to develop a computationally efficient method that fills missing regions while adequately preserving image features. We use directional sticks to interpolate between pairs of known opposing voxels in nearby images. We tested our method on 30 volumetric ultrasound scans acquired from human subjects, and compared its performance to that of other published hole-filling methods. Reconstruction accuracy, fidelity, and time were improved compared with other methods. PMID:26839907

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.

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.

Recent advances of ultrasound imaging in dentistry--a review of the literature.

PubMed

Marotti, Juliana; Heger, Stefan; Tinschert, Joachim; Tortamano, Pedro; Chuembou, Fabrice; Radermacher, Klaus; Wolfart, Stefan

2013-06-01

Ultrasonography as an imaging modality in dentistry has been extensively explored in recent years due to several advantages that diagnostic ultrasound provides. It is a non-invasive, inexpensive, painless method and unlike X-ray, it does not cause harmful ionizing radiation. Ultrasound has a promising future as a diagnostic imaging tool in all specialties in dentistry, for both hard and soft tissue detection. The aim of this review is to provide the scientific community and clinicians with an overview of the most recent advances of ultrasound imaging in dentistry. The use of ultrasound is described and discussed in the fields of dental scanning, caries detection, dental fractures, soft tissue and periapical lesions, maxillofacial fractures, periodontal bony defects, gingival and muscle thickness, temporomandibular disorders, and implant dentistry. Copyright © 2013 Elsevier Inc. All rights reserved.

Non-invasive assessment of peripheral arterial disease: Automated ankle brachial index measurement and pulse volume analysis compared to duplex scan.

PubMed

Lewis, Jane Ea; Williams, Paul; Davies, Jane H

2016-01-01

This cross-sectional study aimed to individually and cumulatively compare sensitivity and specificity of the (1) ankle brachial index and (2) pulse volume waveform analysis recorded by the same automated device, with the presence or absence of peripheral arterial disease being verified by ultrasound duplex scan. Patients (n=205) referred for lower limb arterial assessment underwent ankle brachial index measurement and pulse volume waveform recording using volume plethysmography, followed by ultrasound duplex scan. The presence of peripheral arterial disease was recorded if ankle brachial index <0.9; pulse volume waveform was graded as 2, 3 or 4; or if haemodynamically significant stenosis >50% was evident with ultrasound duplex scan. Outcome measure was agreement between the measured ankle brachial index and interpretation of pulse volume waveform for peripheral arterial disease diagnosis, using ultrasound duplex scan as the reference standard. Sensitivity of ankle brachial index was 79%, specificity 91% and overall accuracy 88%. Pulse volume waveform sensitivity was 97%, specificity 81% and overall accuracy 85%. The combined sensitivity of ankle brachial index and pulse volume waveform was 100%, specificity 76% and overall accuracy 85%. Combining these two diagnostic modalities within one device provided a highly accurate method of ruling out peripheral arterial disease, which could be utilised in primary care to safely reduce unnecessary secondary care referrals.

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

Intracranial translucency assessment at first trimester nuchal translucency ultrasound.

PubMed

Lane, Annah; Lee, Ling; Traves, Donna; Lee, Andreas

2017-04-01

The antenatal diagnosis of open spina bifida (OSB), a neural tube defect, is predominantly made at the second trimester morphology scan by ultrasound detection of structural abnormalities resulting from the associated Chiari II malformation. Evidence has emerged suggesting that these structural abnormalities can be detected earlier, by examination of the posterior fossa as part of the first trimester nuchal translucency scan. In particular, absence of the intra-cranial translucency (IT) of the fourth ventricle has shown promise as a diagnostic marker of OSB, although the sensitivity and specificity of this finding varies widely in the literature. The aim of this study is to assess the feasibility of obtaining the image of the IT at our institution as part of the routine first trimester scan. This is a prospective study of 900 obstetric patients who presented to a tertiary women's imaging centre for routine first trimester nuchal translucency screening ultrasound for the year 2014. Their risk status was that of the general population (low risk) prior to presentation. A total of 158 patients were excluded, leaving a study group of 742. Sonographers obtained a mid-sagittal view of the fetal face with particular focus on optimum viewing of the IT. All images were examined by a Radiology Registrar for presence or absence of IT. Duration of each scan was documented. The IT image was successfully acquired in 94.9% of scans. Maternal pre-pregnancy BMI and fetal lie were shown to have a statistically significant effect on success of acquisition of the IT image. No cases of OSB were diagnosed during the study. Scan times were not lengthened by the addition of the image. We consider that acquisition of an image of the IT as part of the routine first trimester nuchal translucency scan is feasible, without lengthening appointment times. © 2016 The Royal Australian and New Zealand College of Radiologists.

Lumbar epidural depth using transverse ultrasound scan and its correlation with loss of resistance technique: A prospective observational study in Indian population.

PubMed

Chauhan, Amit Kumar; Bhatia, Rohan; Agrawal, Sanjay

2018-01-01

The objective of the present study was to evaluate the skin-epidural space distance as assessed by ultrasonography and conventional loss of resistance (LOR) technique and to find the correlation of epidural depth with body mass index (BMI). Ninety-eight patients of either sex, American Society of Anesthesiology I/II, BMI <30 kg/m 2 requiring lumbar epidural for surgery were enrolled. The epidural space was assessed with a curvilinear ultrasound (US) probe, 2-5 MHz, in the transverse plane at L3-L4 intervertebral space. Thereafter, the epidural depth from skin was assessed with conventional LOR method while performing the epidural. The needle depth (ND) was measured using a sterile linear scale, and any change in the needle direction or intervertebral space was noted. The patients were demographically similar. Depth of epidural space measured by US depth (UD) was 3.96 ± 0.44 cm (range 3.18-5.44 cm) and by ND was 4.04 ± 0.52 cm (range 2.7-5.7 cm). The Pearson's correlation coefficient (r) between UD and ND was 0.935 (95% confidence interval: 0.72-0.92, r 2 = 0.874, P < 0.001), and Bland-Altman analysis revealed the 95% limits of agreement -0.494-0.652 cm. The present study demonstrates a good correlation between UD and ND and shows that the preprocedural US scan in transverse plane provides accurate needle entry site with a high success rate in single attempt for lumbar epidurals in patients with a BMI <30 kg/m 2 .

Radiographer-performed abdominal and pelvic ultrasound: its value in a urology out-patient clinic.

PubMed

Nargund, V H; Lomas, K; Sapherson, D A; Flannigan, G M; Stewart, P A

1994-04-01

To assess the efficacy of radiographer-performed ultrasound examination as a routine investigative procedure in a urological out-patient clinic. A total of 151 patients attending a District General Hospital Urological Out-patient Department underwent an ultrasound examination in the clinic. Diagnosis by ultrasound was achieved in 93% of patients. The remaining patients underwent further investigations. Two (1%) patients with normal scans had small bladder tumours. Subsequent intravenous urography in these individuals showed normal upper tracts. Abdominal and pelvic ultrasound examination performed in the urological out-patient clinic on unprepared patients was the only investigation necessary for evaluation of common problems such as non-specific urinary symptoms, recurrent urinary tract infections and bladder outlet obstruction.

What proportions of focal liver lesions detected by unenhanced ultrasound are inconclusive?

PubMed Central

Willits, Iain; Burn, Julie; Cole, Helen; Hoare, Tim

2014-01-01

In August 2012, the National Institute for Health and Care Excellence produced positive diagnostics guidance on the ultrasound contrast agent SonoVue®, but recommended further research involving an estimation of the proportion of unenhanced ultrasound scans reporting, but not characterising, focal liver lesions, particularly in cirrhotic livers. Patient records from the Radiology Information System of an acute hospital trust were progressively filtered based on categorical fields and keywords in the free text reports, to obtain ultrasound records including the liver that were appropriate for manual analysis. In total, 21,731 records referred from general practice or out-patient clinics were analysed. Patients described as having cirrhosis were analysed as a subgroup. After automatic exclusion of records considered likely to be negative, 5812 records were manually read and categorised as focal liver lesion inconclusive, benign or malignant. In the general practice cohort of 9175 records, 746 reported the presence of one or more focal liver lesions, with 18.4% (95% CI 15.7% to 21.3%) of these records mentioning an inconclusive focal liver lesion. In the out-patient cohort of 12,556 records, 1437 reported one or more focal liver lesions, and 29.4% (95% CI 26.9% to 32.0%) of these were inconclusive. Cirrhosis was reported in 10.8% of the out-patient scans that also reported a focal liver lesion, and 47.4% (95% CI 39.3% to 55.6%) of these scans had an inconclusive focal liver lesion, compared with 27.3% (95% CI 24.9% to 29.8%) that were inconclusive in non-cirrhotic livers (odds ratio 2.4; 95% CI 1.7 to 3.4). This retrospective study indicates that unenhanced ultrasound scans, in which a focal liver lesion is detected, are frequently inconclusive, with the probability of an inconclusive scan being greater in out-patient than general practice referrals. Inconclusive focal liver lesions were also reported in greater proportions of cirrhotic than non-cirrhotic livers. The

A Review on Real-Time 3D Ultrasound Imaging Technology

PubMed Central

Zeng, Zhaozheng

2017-01-01

Real-time three-dimensional (3D) ultrasound (US) has attracted much more attention in medical researches because it provides interactive feedback to help clinicians acquire high-quality images as well as timely spatial information of the scanned area and hence is necessary in intraoperative ultrasound examinations. Plenty of publications have been declared to complete the real-time or near real-time visualization of 3D ultrasound using volumetric probes or the routinely used two-dimensional (2D) probes. So far, a review on how to design an interactive system with appropriate processing algorithms remains missing, resulting in the lack of systematic understanding of the relevant technology. In this article, previous and the latest work on designing a real-time or near real-time 3D ultrasound imaging system are reviewed. Specifically, the data acquisition techniques, reconstruction algorithms, volume rendering methods, and clinical applications are presented. Moreover, the advantages and disadvantages of state-of-the-art approaches are discussed in detail. PMID:28459067

Goal-directed ultrasound in the detection of long-bone fractures

NASA Technical Reports Server (NTRS)

Marshburn, Thomas H.; Legome, Eric; Sargsyan, Ashot; Li, Shannon Melton James; Noble, Vicki A.; Dulchavsky, Scott A.; Sims, Carrie; Robinson, David

2004-01-01

BACKGROUND: New portable ultrasound (US) systems are capable of detecting fractures in the remote setting. However, the accuracy of ultrasound by physicians with minimal ultrasound training is unknown. METHODS: After one hour of standardized training, physicians with minimal US experience clinically evaluated patients presenting with pain and trauma to the upper arm or leg. The investigators then performed a long-bone US evaluation, recording their impression of fracture presence or absence. Results of the examination were compared with routine plain or computer aided radiography (CT). RESULTS: 58 patients were examined. The sensitivity and specificity of US were 92.9% and 83.3%, and of the physical examination were 78.6% and 90.0%, respectively. US provided improved sensitivity with less specificity compared with physical examination in the detection of fractures in long bones. CONCLUSION: Ultrasound scans by minimally trained clinicians may be used to rule out a long-bone fracture in patients with a medium to low probability of fracture.

A Review on Real-Time 3D Ultrasound Imaging Technology.

PubMed

Huang, Qinghua; Zeng, Zhaozheng

2017-01-01

Real-time three-dimensional (3D) ultrasound (US) has attracted much more attention in medical researches because it provides interactive feedback to help clinicians acquire high-quality images as well as timely spatial information of the scanned area and hence is necessary in intraoperative ultrasound examinations. Plenty of publications have been declared to complete the real-time or near real-time visualization of 3D ultrasound using volumetric probes or the routinely used two-dimensional (2D) probes. So far, a review on how to design an interactive system with appropriate processing algorithms remains missing, resulting in the lack of systematic understanding of the relevant technology. In this article, previous and the latest work on designing a real-time or near real-time 3D ultrasound imaging system are reviewed. Specifically, the data acquisition techniques, reconstruction algorithms, volume rendering methods, and clinical applications are presented. Moreover, the advantages and disadvantages of state-of-the-art approaches are discussed in detail.

Transabdominal contrast-enhanced ultrasound imaging of the prostate.

PubMed

Mischi, Massimo; Demi, Libertario; Smeenge, Martijn; Kuenen, Maarten P J; Postema, Arnoud W; de la Rosette, Jean J M C H; Wijkstra, Hessel

2015-04-01

Numerous age-related pathologies affect the prostate gland, the most menacing of which is prostate cancer (PCa). The diagnostic tools for prostate investigation are invasive, requiring biopsies when PCa is suspected. Novel dynamic contrast-enhanced ultrasound (DCE-US) imaging approaches have been proposed recently and appear promising for minimally invasive localization of PCa. Ultrasound imaging of the prostate is traditionally performed with a transrectal probe because the location of the prostate allows for high-resolution images using high-frequency transducers. However, DCE-US imaging requires lower frequencies to induce bubble resonance and, thus, improve contrast-to-tissue ratio. For this reason, in this study we investigate the feasibility of quantitative DCE-US imaging of the prostate via the abdomen. The study included 10 patients (age = 60.7 ± 5.7 y) referred for a needle biopsy study. After having given informed consent, patients underwent DCE-US with both transabdominal and transrectal probes. Time-intensity contrast curves were derived using both approaches and their model-fit quality was compared. Although further improvements are expected by optimization of the transabdominal settings, the results of transabdominal and transrectal DCE-US are closely comparable, confirming the feasibility of transabdominal DCE-US; transabdominal curve fitting revealed an average determination coefficient r(2) = 0.91 (r(2) > 0.75 for 78.6% of all prostate pixels) compared with r(2) = 0.91 (r(2) > 0.75 for 81.6% of all prostate pixels) by the transrectal approach. Replacing the transrectal approach with more acceptable transabdominal scanning for prostate investigation is feasible. This approach would improve patient comfort and represent a useful option for PCa localization and monitoring. Copyright © 2015 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

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

Temperature-dependent differences in the nonlinear acoustic behavior of ultrasound contrast agents revealed by high-speed imaging and bulk acoustics.

PubMed

Mulvana, Helen; Stride, Eleanor; Tang, Mengxing; Hajnal, Jo V; Eckersley, Robert

2011-09-01

Previous work by the authors has established that increasing the temperature of the suspending liquid from 20°C to body temperature has a significant impact on the bulk acoustic properties and stability of an ultrasound contrast agent suspension (SonoVue, Bracco Suisse SA, Manno, Lugano, Switzerland). In this paper the influence of temperature on the nonlinear behavior of microbubbles is investigated, because this is one of the most important parameters in the context of diagnostic imaging. High-speed imaging showed that raising the temperature significantly influences the dynamic behavior of individual microbubbles. At body temperature, microbubbles exhibit greater radial excursion and oscillate less spherically, with a greater incidence of jetting and gas expulsion, and therefore collapse, than they do at room temperature. Bulk acoustics revealed an associated increase in the harmonic content of the scattered signals. These findings emphasize the importance of conducting laboratory studies at body temperature if the results are to be interpreted for in vivo applications. Copyright © 2011 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Stereoscopic augmented reality using ultrasound volume rendering for laparoscopic surgery in children

NASA Astrophysics Data System (ADS)

Oh, Jihun; Kang, Xin; Wilson, Emmanuel; Peters, Craig A.; Kane, Timothy D.; Shekhar, Raj

2014-03-01

In laparoscopic surgery, live video provides visualization of the exposed organ surfaces in the surgical field, but is unable to show internal structures beneath those surfaces. The laparoscopic ultrasound is often used to visualize the internal structures, but its use is limited to intermittent confirmation because of the need for an extra hand to maneuver the ultrasound probe. Other limitations of using ultrasound are the difficulty of interpretation and the need for an extra port. The size of the ultrasound transducer may also be too large for its usage in small children. In this paper, we report on an augmented reality (AR) visualization system that features continuous hands-free volumetric ultrasound scanning of the surgical anatomy and video imaging from a stereoscopic laparoscope. The acquisition of volumetric ultrasound image is realized by precisely controlling a back-and-forth movement of an ultrasound transducer mounted on a linear slider. Furthermore, the ultrasound volume is refreshed several times per minute. This scanner will sit outside of the body in the envisioned use scenario and could be even integrated into the operating table. An overlay of the maximum intensity projection (MIP) of ultrasound volume on the laparoscopic stereo video through geometric transformations features an AR visualization system particularly suitable for children, because ultrasound is radiation-free and provides higher-quality images in small patients. The proposed AR representation promises to be better than the AR representation using ultrasound slice data.

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 ...

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.

Convolution neural networks for real-time needle detection and localization in 2D ultrasound.

PubMed

Mwikirize, Cosmas; Nosher, John L; Hacihaliloglu, Ilker

2018-05-01

We propose a framework for automatic and accurate detection of steeply inserted needles in 2D ultrasound data using convolution neural networks. We demonstrate its application in needle trajectory estimation and tip localization. Our approach consists of a unified network, comprising a fully convolutional network (FCN) and a fast region-based convolutional neural network (R-CNN). The FCN proposes candidate regions, which are then fed to a fast R-CNN for finer needle detection. We leverage a transfer learning paradigm, where the network weights are initialized by training with non-medical images, and fine-tuned with ex vivo ultrasound scans collected during insertion of a 17G epidural needle into freshly excised porcine and bovine tissue at depth settings up to 9 cm and [Formula: see text]-[Formula: see text] insertion angles. Needle detection results are used to accurately estimate needle trajectory from intensity invariant needle features and perform needle tip localization from an intensity search along the needle trajectory. Our needle detection model was trained and validated on 2500 ex vivo ultrasound scans. The detection system has a frame rate of 25 fps on a GPU and achieves 99.6% precision, 99.78% recall rate and an [Formula: see text] score of 0.99. Validation for needle localization was performed on 400 scans collected using a different imaging platform, over a bovine/porcine lumbosacral spine phantom. Shaft localization error of [Formula: see text], tip localization error of [Formula: see text] mm, and a total processing time of 0.58 s were achieved. The proposed method is fully automatic and provides robust needle localization results in challenging scanning conditions. The accurate and robust results coupled with real-time detection and sub-second total processing make the proposed method promising in applications for needle detection and localization during challenging minimally invasive ultrasound-guided procedures.

Whole-Body Bone Scan Findings after High-Intensity Focused Ultrasound (HIFU) Treatment.

PubMed

Seo, Ye Young; O, Joo Hyun; Sohn, Hyung Sun; Choi, Eun Kyoung; Yoo, Ik Dong; Oh, Jin Kyoung; Han, Eun Ji; Jung, Seung Eun; Kim, Sung Hoon

2011-12-01

This study aims to examine the findings of (99m)Tc-diphosphonate bone scans in cancer patients with a history of HIFU treatment. Bone scan images of patients with a history of HIFU treatment for primary or metastatic cancer from January 2006 to July 2010 were retrospectively reviewed. Cases of primary bone tumor or HIFU treatment reaching only the superficial soft tissue layer were excluded. Bone scan images of 62 patients (26 female, 36 male; mean age 57 ± 9 years) were studied. HIFU treatment was performed in the liver (n = 40), pancreas (n = 16), and breast (n = 6). Mean interval time between HIFU treatment and bone scan was 106 ± 105 days (range: 1-572 days). Of 62 scans, 43 showed diffusely decreased uptake of bone within the path of HIFU treatment: antero-axillary and/or posterior arcs of right 5th to 11th ribs in 34 cases after treatment of hepatic lesions; anterior arcs of 2nd to 5th ribs in 5 cases after treatment for breast tumors; and posterior arcs of left 9th to 11th ribs or thoraco-lumbar vertebrae in 4 cases after treatment for pancreas tumor. Of 20 patients who had bone scans more than twice, five showed recovered uptake of the radiotracer in the involved ribs in the follow-up bone scan. Of 62 bone scans in patients with a history of HIFU treatment for primary or metastatic cancer, 69% presented diffusely decreased uptake in the bone in the path of HIFU treatment.

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.

Effects of Student-Performed Point-of-Care Ultrasound on Physician Diagnosis and Management of Patients in the Emergency Department.

PubMed

Udrea, Daniel S; Sumnicht, Andrew; Lo, Deanna; Villarreal, Logan; Gondra, Stephanie; Chyan, Richard; Wisham, Audra; Dinh, Vi Am

2017-07-01

Despite the increasing integration of ultrasound training into medical education, there is an inadequate body of research demonstrating the benefits and practicality of medical student-performed point-of-care ultrasound (SP-POCUS) in the clinical setting. The primary purpose of this study was to evaluate the effects that SP-POCUS can have on physician diagnosis and management of patients in the emergency department, with a secondary purpose of evaluating the diagnostic accuracy of SP-POCUS. SP-POCUS examinations were performed in the emergency department by medical students who completed year one of a 4-year medical school curriculum with integrated ultrasound training. Scans were evaluated by an emergency physician who then completed a survey to record any changes in diagnosis and management. A total of 641 scans were performed on the 482 patients enrolled in this study. SP-POCUS resulted in a change in management in 17.3% of scans performed. For 12.4% of scans, SP-POCUS discovered a new diagnosis. SP-POCUS reduced time to disposition 33.5% of the time. Because of SP-POCUS, physicians avoided ordering an additional imaging study for 53.0% of the scans performed. There was 94.7% physician agreement with SP-POCUS diagnosis. This study showed that SP-POCUS is feasible and may potentially have a meaningful impact on physician diagnosis and management of patients in the emergency department. In addition, the implementation of SP-POCUS could serve as an ideal method of developing ultrasound skills in medical school while positively impacting patient care. Copyright © 2017 Elsevier Inc. All rights reserved.

Enhanced ultrasound for advanced diagnostics, ultrasound tomography for volume limb imaging and prosthetic fitting

NASA Astrophysics Data System (ADS)

Anthony, Brian W.

2016-04-01

Ultrasound imaging methods hold the potential to deliver low-cost, high-resolution, operator-independent and nonionizing imaging systems - such systems couple appropriate algorithms with imaging devices and techniques. The increasing demands on general practitioners motivate us to develop more usable and productive diagnostic imaging equipment. Ultrasound, specifically freehand ultrasound, is a low cost and safe medical imaging technique. It doesn't expose a patient to ionizing radiation. Its safety and versatility make it very well suited for the increasing demands on general practitioners, or for providing improved medical care in rural regions or the developing world. However it typically suffers from sonographer variability; we will discuss techniques to address user variability. We also discuss our work to combine cylindrical scanning systems with state of the art inversion algorithms to deliver ultrasound systems for imaging and quantifying limbs in 3-D in vivo. Such systems have the potential to track the progression of limb health at a low cost and without radiation exposure, as well as, improve prosthetic socket fitting. Current methods of prosthetic socket fabrication remain subjective and ineffective at creating an interface to the human body that is both comfortable and functional. Though there has been recent success using methods like magnetic resonance imaging and biomechanical modeling, a low-cost, streamlined, and quantitative process for prosthetic cup design and fabrication has not been fully demonstrated. Medical ultrasonography may inform the design process of prosthetic sockets in a more objective manner. This keynote talk presents the results of progress in this area.

Point-of-care ultrasound facilitates diagnosing a posterior shoulder dislocation.

PubMed

Mackenzie, David C; Liebmann, Otto

2013-05-01

Posterior shoulder dislocation is an uncommon disruption of the glenohumeral joint. Risk factors include seizure, electric shock, and underlying instabilities of the shoulder joint. A 27-year-old man with a history of recurrent posterior shoulder dislocation presented to the Emergency Department with sudden shoulder pain and reduced range of motion about the shoulder after abducting and internally rotating his arm. Radiographs did not show fracture or dislocation. The treating physician suspected an occult posterior shoulder dislocation, but wanted to avoid performing a computed tomography scan of the shoulder, as the patient had undergone numerous scans during the evaluation of similar complaints. Instead, a point-of-care ultrasound was performed, demonstrating posterior displacement of the humeral head relative to the glenoid rim, confirming the presence of a posterior shoulder dislocation. The patient received procedural sedation, and the shoulder was reduced with real-time ultrasound visualization. The patient tolerated the procedure well, and had decreased pain and improved range of motion. He was discharged with a sling, swathe, and orthopedic follow-up. Point-of-care ultrasound of the shoulder may be used to demonstrate posterior shoulder dislocation. This may have particular utility in the setting of non-diagnostic radiographs. Copyright © 2013. Published by Elsevier Inc.

Combination of ultrasound and rtPA enhances fibrinolysis in an In Vitro clot system

PubMed Central

Winter, Philipp; Müller-Werkmeister, Hendrik; Strand, Susanne; König, Jochem; Kempski, Oliver; Ringel, Florian; Kantelhardt, Sven R.; Keric, Naureen

2017-01-01

Background Catheter-based lysis with recombinant tissue plasminogen activator (rtPA) is a well-established therapy for spontaneous intracerebral hemorrhage (ICH). The effectiveness of this therapy can be increased with ultrasound, but the optimal conditions are not yet clearly established. Using a novel in vitro system of blood clots previously developed by our group, we investigated various parameters of intralesional sonothrombolysis using an endosonography catheter in combination with rtPA. Methods Standardized human blood clots were equipped with a drainage catheter and weighed before and after 4 treatments: control (drainage only), rtPA only, ultrasound only and the combination of rtPA+ultrasound. The effectiveness of ultrasound was further analysed in terms of optimal frequency, duration and distance to the probe. Temperature and acoustic peak rarefaction pressure (APRP) were assessed to analyse potential adverse effects and quantify lysis. Histo-morphological analysis of the treated clots was performed by H&E staining and confocal laser scanning microscopy using fluorescent fibrinogen. Results The combined treatment rtPA+ultrasound achieved the highest lysis rates with a relative weight of 30.3%±5.5% (p≤0.0001) compared to all other groups. Similar results were observed when treating aged clots. Confocal fluorescent microscopy of the treated clots revealed a rarefied fibrin mesh without cavitations. No relevant temperature increase occurred (0.53±0.75°C). The optimal insonation treatment time was 1 hour. APRP measurements showed a lysis threshold of 515.5±113.4 kPa. Application of 10 MHz achieved optimal lysis and lysis radius, while simultaneously proving to be the best frequency for morphologic imaging of the clot and surrounding tissue. Conclusions These promising data provide the basis for an individualized minimal invasive ICH therapy by rtPA and sonothrombolysis independent of ICH age. PMID:29145482

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.

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.

The management of ultrasound equipment at Sheffield Teaching Hospitals NHS Foundation Trust

PubMed Central

Peacock, M

2013-01-01

Management of ultrasound equipment at Sheffield Teaching Hospitals NHS Foundation Trust is described. The organisation and input of various stakeholders and their involvement with ultrasound equipment management and scientific ultrasound is discussed. Two important stakeholders are the Medical Equipment Management Group and the Radiation Safety Steering Committee. The Medical Equipment Management Group has a specific sub-group, the Ultrasound sub-group, and its role is to coordinate the purchase, replacement and quality assurance of ultrasound equipment in the Trust. The Radiation Safety Steering Committee has a non-ionising radiation representative and the role of this committee is to provide corporate assurance that any health and safety issues arising from the use of radiation to either patients, members of the public or staff within the Trust are being effectively managed. The Ultrasound sub-group of the Medical Equipment Management Group has successfully brought together management of all ultrasound equipment within the Trust and is in the process of fulfilling the quality assurance and training milestones set out by the Medical Equipment Management Group. Advice from the Radiation Safety Steering Committee has helped to increase awareness of ultrasound safety and good scanning practice, especially in the case of neonatal ultrasound imaging, within the Trust. In addition, the RSSC has given advice on clinical pathways for patients undergoing ionising radiation imaging while being treated by extra-corporeal shockwave lithotripsy. PMID:27433195

Ultrasound-Guided Percutaneous Tenotomy of Biceps Tendon: Technical Feasibility on Cadavers.

PubMed

Sconfienza, Luca Maria; Mauri, Giovanni; Messina, Carmelo; Aliprandi, Alberto; Secchi, Francesco; Sardanelli, Francesco; Randelli, Pietro Simone

2016-10-01

We tested the technical feasibility of ultrasound-guided percutaneous tenotomy of the long head of the biceps tendon (LHBT) in cadavers. Both shoulders of two fresh cadavers were scanned anteriorly to evaluate the extra-articular portion of the LHBT. Under ultrasound monitoring, a scalpel was advanced obliquely up to touch the superficial medial side of the LHBT, cutting it until the tendon was not visible anymore. Ultrasound evaluation was repeated after the procedure, and anatomic dissection was performed. The procedure was 100% feasible: four cuts were made to completely sever the tendon; the duration was less than 1 min. Skin incision measured 5 mm in two cases and 6 mm in two cases. Anatomic dissection confirmed complete tendon cut in all cases with proximal and distal tendon stumps very close to each other. Ultrasound-guided percutaneous LHBT tenotomy was 100% technically feasible in cadavers with a quick procedure and minimal cutaneous incision. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Synthesis of Hydroxyapatite through Ultrasound and Calcination Techniques

NASA Astrophysics Data System (ADS)

Akindoyo, John O.; Beg, M. D. H.; Ghazali, Suriati; Akindoyo, Edward O.; Jeyaratnam, Nitthiyah

2017-05-01

There is a growing demand for hydroxyapatite (HA) especially in medical applications, production of HA which is totally green is however a challenge. In this research, HA was produced from biowaste through ultrasound followed by calcination techniques. Pre-treatment of the biowaste was effectively achieved through the help of ultrasound. After calcination at 950°C, the obtained HA was characterized through Thermogravimetric (TGA) analysis, X-ray diffraction analysis (XRD) and Fourier transform infrared spectroscopy (FTIR). Spectrum of the produced HA was compared with standard HA index. The spectrum is in agreement with the standard HA as confirmed through FTIR, XRD and TGA result. Furthermore, morphological study of the HA through Field emission scanning electron microscope (FESEM) shows almost uniform spherical shape for the HA as expected. Based on the results obtained herein, combining ultrasound with calcination can help to produce pure HA with potential medical applications without the use of any organic solvent.

Robotic assisted laparoscopic partial nephrectomy using contrast‐enhanced ultrasound scan to map renal blood flow

PubMed Central

Motiwala, Aamir; Eves, Susannah; Gray, Rob; Thomas, Asha; Meiers, Isabelle; Sharif, Haytham; Motiwala, Hanif; Laniado, Marc; Karim, Omer

2016-01-01

Abstract Objective The paper describes novel real‐time ‘in situ mapping’ and ‘sequential occlusion angiography’ to facilitate selective ischaemia robotic partial nephrectomy (RPN) using intraoperative contrast enhanced ultrasound scan (CEUS). Materials and methods Data were collected and assessed for 60 patients (61 tumours) between 2009 and 2013. 31 (50.8%) tumours underwent ‘Global Ischaemia’, 27 (44.3%) underwent ‘Selective Ischaemia’ and 3 (4.9%) were removed ‘Off Clamp Zero Ischaemia’. Demographics, operative variables, complications, renal pathology and outcomes were assessed. Results Median PADUA score was 9 (range 7–10). The mean warm ischaemia time in selective ischaemia was less and statistically significant than in global ischaemia (17.1 and 21.4, respectively). Mean operative time was 163 min. Postoperative complications (n = 10) included three (5%) Clavien grade 3 or above. Malignancy was demonstrated in 47 (77%) with negative margin in 43 (91.5%) and positive margin in four (8.5%). Long‐term decrease in eGFR post selective ischaemia robotic partial nephrectomy was less compared with global ischaemia (four and eight, respectively) but not statistically significant. Conclusions This technique is safe, feasible and cost‐effective with comparable perioperative outcomes. The technical aspects elucidate the role of intraoperative CEUS to facilitate and ascertain selective ischaemia. Further work is required to demonstrate long‐term oncological outcomes. © 2016 The Authors. The International Journal of Medical Robotics and Computer Assisted Surgery published by John Wiley & Sons, Ltd. PMID:26948671

Clinical applications of very high frequency ultrasound in ophthalmology

NASA Astrophysics Data System (ADS)

Silverman, Ronald H.; Coleman, D. Jackson; Reinstein, Dan Z.; Lizzi, Frederic L.

2004-05-01

The eye is ideally suited for diagnostic imaging with very high frequency (>35 MHz) ultrasound (VHFU) because of its peripheral location and cystic structure. VHFU allows high resolution visualization of pathologies affecting the anterior segment of the eye, including tumors, cysts, foreign bodies, and corneal pathologies. We developed a series of prototype instruments suitable for ophthalmic studies using both polymer and lithium niobate transducers, with digitization of radiofrequency echo data at up to 500 MHz. While initially using linear scan geometries, we subsequently developed an arc-shaped scan matched to the curvature of the 0.5-mm-thick cornea to circumvent the effect of specular deflection of the ultrasound beam produced by the corneas curved surface. This technique allowed us to obtain data across the entire cornea and determination of the thickness of each corneal layer, including the epithelium (approximately 50 microns in thickness) and the surgically induced interface produced in LASIK, the most common form of refractive surgery. By scanning in a series of meridians, and applying optimized signal processing strategies (deconvolution, analytic signal envelope determination), corneal pachymetric maps representing the local thickness of each layer can be generated and aid in diagnosis of surgically induced defects or refractive abnormalities.

Real-time visualization of ultrasound-guided retrobulbar blockade: an imaging study.

PubMed

Luyet, C; Eichenberger, U; Moriggl, B; Remonda, L; Greif, R

2008-12-01

Retrobulbar anaesthesia allows eye surgery in awake patients. Severe complications of the blind techniques are reported. Ultrasound-guided needle introduction and direct visualization of the spread of local anaesthetic may improve quality and safety of retrobulbar anaesthesia. Therefore, we developed a new ultrasound-guided technique using human cadavers. In total, 20 blocks on both sides in 10 embalmed human cadavers were performed. Using a small curved array transducer and a long-axis approach, a 22 G short bevel needle was introduced under ultrasound guidance lateral and caudal of the eyeball until the needle tip was seen 2 mm away from the optic nerve. At this point, 2 ml of contrast dye as a substitute for local anaesthetic was injected. Immediately after the injection, the spread of the contrast dye was documented by means of CT scans performed in each cadaver. The CT scans showed the distribution of the contrast dye in the muscle cone and behind the posterior sclera in all but one case. No contrast dye was found inside the optic nerve or inside the eyeball. In one case, there could be an additional trace of contrast dye behind the orbita. Our new ultrasound-guided technique has the potential to improve safety and efficacy of the procedure by direct visualization of the needle placement and the distribution of the injected fluid. Furthermore, the precise injection near the optic nerve could lead to a reduction of the amount of the local anaesthetic needed with fewer related complications.

Ultrasound Imaging of Breastfeeding--A Window to the Inside: Methodology, Normal Appearances, and Application.

PubMed

Geddes, Donna T; Sakalidis, Vanessa S

2016-05-01

Ultrasound imaging has been employed as a noninvasive technique to explore the sucking dynamics of the breastfeeding infant over the past 40 years. Recent improvements in the resolution of ultrasound images have allowed a more detailed description of the tongue movements during sucking, identification of oral structures, and measurements of nipple position and tongue motion. Several different scanning planes can be used and each show sucking from a different perspective. Ultrasound techniques and image anatomy are described in detail in this review and provide the basis for implementation in the objective assessment of breastfeeding. © The Author(s) 2016.

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

Does Ultrasound-Enhanced Instruction of Musculoskeletal Anatomy Improve Physical Examination Skills of First-Year Medical Students?

PubMed

Walrod, Bryant J; Schroeder, Allison; Conroy, Mark J; Boucher, Laura C; Bockbrader, Marcia; Way, David P; McCamey, Kendra L; Hartz, Clinton A; Jonesco, Michael A; Bahner, David P

2018-01-01

Ultrasound imaging is commonly used to teach basic anatomy to medical students. The purpose of this study was to determine whether learning musculoskeletal anatomy with ultrasound improved performance on medical students' musculoskeletal physical examination skills. Twenty-seven first-year medical students were randomly assigned to 1 of 2 instructional groups: either shoulder or knee. Both groups received a lecture followed by hands-on ultrasound scanning on live human models of the assigned joint. After instruction, students were assessed on their ability to accurately palpate 4 anatomic landmarks: the acromioclavicular joint, the proximal long-head biceps tendon, and the medial and lateral joint lines of the knee. Performance scores were based on both accuracy and time. A total physical examination performance score was derived for each joint. Scores for instructional groups were compared by a 2-way analysis of variance with 1 repeated measure. Significant findings were further analyzed with post hoc tests. All students performed significantly better on the knee examination, irrespective of instructional group (F = 14.9; df = 1.25; P = .001). Moreover, the shoulder instruction group performed significantly better than the knee group on the overall assessment (t = -3.0; df = 25; P < .01). Post hoc analyses revealed that differences in group performance were due to the shoulder group's higher scores on palpation of the biceps tendon (t = -2.8; df = 25; P = .01), a soft tissue landmark. Both groups performed similarly on palpation of all other anatomic structures. The use of ultrasound appears to provide an educational advantage when learning musculoskeletal physical examination of soft tissue landmarks. © 2017 by the American Institute of Ultrasound in Medicine.

Endolithic algae and micrite envelope formation in Bahamian oolites as revealed by scanning electron microscopy.

NASA Technical Reports Server (NTRS)

Margolis, S.; Rex, R. W.

1971-01-01

Examination of Holocene Bahamian ooelites by scanning electron and light microscopy has revealed the morphology and orientation of aragonite crystals in the lamellar ooelitic envelope, and their modification by the boring activities of endolithic algae. The voids produced by these algae are found in progressive stages of being lined and filled with precipitated microcrystalline aragonite, which is similar to the process of micrite envelope formation in molluscan and other skeletal carbonate grains.

Podiatry Ankle Duplex Scan: Readily Learned and Accurate in Diabetes.

PubMed

Normahani, Pasha; Powezka, Katarzyna; Aslam, Mohammed; Standfield, Nigel J; Jaffer, Usman

2018-03-01

We aimed to train podiatrists to perform a focused duplex ultrasound scan (DUS) of the tibial vessels at the ankle in diabetic patients; podiatry ankle (PodAnk) duplex scan. Thirteen podiatrists underwent an intensive 3-hour long simulation training session. Participants were then assessed performing bilateral PodAnk duplex scans of 3 diabetic patients with peripheral arterial disease. Participants were assessed using the duplex ultrasound objective structured assessment of technical skills (DUOSATS) tool and an "Imaging Score". A total of 156 vessel assessments were performed. All patients had abnormal waveforms with a loss of triphasic flow. Loss of triphasic flow was accurately detected in 145 (92.9%) vessels; the correct waveform was identified in 139 (89.1%) cases. Participants achieved excellent DUOSATS scores (median 24 [interquartile range: 23-25], max attainable score of 26) as well as "Imaging Scores" (8 [8-8], max attainable score of 8) indicating proficiency in technical skills. The mean time taken for each bilateral ankle assessment was 20.4 minutes (standard deviation ±6.7). We have demonstrated that a focused DUS for the purpose of vascular assessment of the diabetic foot is readily learned using intensive simulation training.

A comparison between intrastomal 3D ultrasonography, CT scanning and findings at surgery in patients with stomal complaints.

PubMed

Näsvall, P; Wikner, F; Gunnarsson, U; Rutegård, J; Strigård, K

2014-10-01

Since there are no reliable investigative tools for imaging parastomal hernia, new techniques are needed. The aim of this study was to assess the validity of intrastomal three-dimensional ultrasonography (3D) as an alternative to CT scanning for the assessment of stomal complaints. Twenty patients with stomal complaints, indicating surgery, were examined preoperatively with a CT scan in the supine position and 3D intrastomal ultrasonography in the supine and erect positions. Comparison with findings at surgery, considered to be the true state, was made. Both imaging methods, 3D ultrasonography and CT scanning, showed high sensitivity (ultrasound 15/18, CT scan 15/18) and specificity (ultrasound 2/2, CT scan 1/2) when judged by a dedicated radiologist. Corresponding values for interpretation of CT scans in routine clinical practice was for sensitivity 17/18 and for specificity 1/2. 3D ultrasonography has a high validity and is a promising alternative to CT scanning in the supine position to distinguish a bulge from a parastomal hernia.

Investigation of Infant Brain with or without Hydrocephalous in Our Environment Using Anterior Transfontanelle Ultrasound Scan.

PubMed

Marchie, Tobechukwu T; Ayara, Charles O

2013-01-01

A prospective study aimed to suggest easy and simple reproducible ventricular site that will be basic measurement plane and normal dimension determined, correlated to sizes of infants for comparative evaluation of hydrocephalous infants and should be reproducible in follow-up. A prospective study done in University of Benin Teaching Hospital Benin, Nigeria. This study used 50 consecutive infants with Ultrasound scan (US) diagnosis of hydrocephalus and a control group of 50 US normal from 1(st) January 2007 to 30(th) June 2008. The infants were scan through the mid-patent anterior fontanelle in sagittal, and transverse planes with minor angulations to properly outline the ventricles and the position of measurement determined at the foramen of Monro of lateral ventricles and the diameter measured. The infants' weight, crown-heel length, and head circumference were measured and body mass index (BMI) calculated and correlated to lateral ventricular measurement. Data analysis was conducted using the Statistical Package for Social Sciences (SPSS Inc, USA), Version 11.0. There was no statistically sex and age-related difference. There is statistically comparative high mean weight and height and lower BMI in hydrocephalic infants as against the control group (P < 0.001). The mean head circumference for hydrocephalus was 45.6 (± 10.5 standard deviation [SD]), whereas the control group was 35.9 (± 2.7 SD) with P < 0.001. The mean diameter of the anterior horn of left and right lateral ventricles at the level of foramen of Monro in hydrocephalic subjects is 18.4 mm ± 14.3 mm and 20.1 mm ± 16.8 mm with median diameter of 14.1 mm and 15.2 mm, respectively, whereas control group is 2.5 mm ± 0.6 mm and 2.5 mm ± 0.7 mm with median diameter of 2.5 mm and 2.4 mm, respectively. Transfontanelle US was found highly useful in investigation of hydrocephalous in infant.

Feasibility of imaging superficial palmar arch using micro-ultrasound, 7T and 3T magnetic resonance imaging.

PubMed

Pruzan, Alison N; Kaufman, Audrey E; Calcagno, Claudia; Zhou, Yu; Fayad, Zahi A; Mani, Venkatesh

2017-02-28

To demonstrate feasibility of vessel wall imaging of the superficial palmar arch using high frequency micro-ultrasound, 7T and 3T magnetic resonance imaging (MRI). Four subjects (ages 22-50 years) were scanned on a micro-ultrasound system with a 45-MHz transducer (Vevo 2100, VisualSonics). Subjects' hands were then imaged on a 3T clinical MR scanner (Siemens Biograph MMR) using an 8-channel special purpose phased array carotid coil. Lastly, subjects' hands were imaged on a 7T clinical MR scanner (Siemens Magnetom 7T Whole Body Scanner) using a custom built 8-channel transmit receive carotid coil. All three imaging modalities were subjectively analyzed for image quality and visualization of the vessel wall. Results of this very preliminary study indicated that vessel wall imaging of the superficial palmar arch was feasible with a whole body 7T and 3T MRI in comparison with micro-ultrasound. Subjective analysis of image quality (1-5 scale, 1: poorest, 5: best) from B mode, ultrasound, 3T SPACE MRI and 7T SPACE MRI indicated that the image quality obtained at 7T was superior to both 3T MRI and micro-ultrasound. The 3D SPACE sequence at both 7T and 3T MRI with isotropic voxels allowed for multi-planar reformatting of images and allowed for less operator dependent results as compared to high frequency micro-ultrasound imaging. Although quantitative analysis revealed that there was no significant difference between the three methods, the 7T Tesla trended to have better visibility of the vessel and its wall. Imaging of smaller arteries at the 7T is feasible for evaluating atherosclerosis burden and may be of clinical relevance in multiple diseases.

Adaptive kernel regression for freehand 3D ultrasound reconstruction

NASA Astrophysics Data System (ADS)

Alshalalfah, Abdel-Latif; Daoud, Mohammad I.; Al-Najar, Mahasen

2017-03-01

Freehand three-dimensional (3D) ultrasound imaging enables low-cost and flexible 3D scanning of arbitrary-shaped organs, where the operator can freely move a two-dimensional (2D) ultrasound probe to acquire a sequence of tracked cross-sectional images of the anatomy. Often, the acquired 2D ultrasound images are irregularly and sparsely distributed in the 3D space. Several 3D reconstruction algorithms have been proposed to synthesize 3D ultrasound volumes based on the acquired 2D images. A challenging task during the reconstruction process is to preserve the texture patterns in the synthesized volume and ensure that all gaps in the volume are correctly filled. This paper presents an adaptive kernel regression algorithm that can effectively reconstruct high-quality freehand 3D ultrasound volumes. The algorithm employs a kernel regression model that enables nonparametric interpolation of the voxel gray-level values. The kernel size of the regression model is adaptively adjusted based on the characteristics of the voxel that is being interpolated. In particular, when the algorithm is employed to interpolate a voxel located in a region with dense ultrasound data samples, the size of the kernel is reduced to preserve the texture patterns. On the other hand, the size of the kernel is increased in areas that include large gaps to enable effective gap filling. The performance of the proposed algorithm was compared with seven previous interpolation approaches by synthesizing freehand 3D ultrasound volumes of a benign breast tumor. The experimental results show that the proposed algorithm outperforms the other interpolation approaches.

An Electro-Optic Spatial Light Modulator for Thermoelastic Generation of Programmably Focused Ultrasound.

DTIC Science & Technology

1984-12-01

The concept proposed is an electro - optic technique that would make it possible to spatially modulate a high power pulsed laser beam to thermoelastically induce focused ultrasound in a test material. Being a purely electro - optic device, the modulator, and therefore the depth at which the acoustic focus occurs, can be programmed electronically at electronic speeds. If successful, it would become possible to scan ultrasound continuously in three dimensions within the component or structure under test. (Author)

An electro-optic spatial light modulator for thermoelastic generation of programmably focused ultrasound

NASA Astrophysics Data System (ADS)

1984-12-01

The concept proposed is an electro-optic technique that would make it possible to spatially modulate a high power pulsed laser beam to thermoelastically induce focused ultrasound in a test material. Being a purely electro-optic device, the modulator, and therefore the depth at which the acoustic focus occurs, can be programmed electronically at electronic speeds. If successful, it would become possible to scan ultrasound continuously in three dimensions within the component or structure under test.

Processing ultrasound backscatter to monitor high-intensity focused ultrasound (HIFU) therapy

NASA Astrophysics Data System (ADS)

Kaczkowski, Peter J.; Anand, Ajay; Bailey, Michael R.

2005-09-01

The development of new noninvasive surgical methods such as HIFU for the treatment of cancer and internal bleeding requires simultaneous development of new sensing approaches to guide, monitor, and assess the therapy. Ultrasound imaging using echo amplitude has long been used to map tissue morphology for diagnostic interpretation by the clinician. New quantitative ultrasonic methods that rely on amplitude and phase processing for tissue characterization are being developed for monitoring of ablative therapy. We have been developing the use of full wave ultrasound backscattering for real-time temperature estimation, and to image changes in tissue backscatter spectrum as therapy progresses. Both approaches rely on differential processing of the backscatter signal in time, and precise measurement of phase differences. Noise and artifacts from motion and nonstationary speckle statistics are addressed by constraining inversions for tissue parameters with physical models. We present results of HIFU experiments with static point and scanned HIFU exposures in which temperature rise can be accurately mapped using a new heat transfer equation (HTE) model-constrained inverse approach. We also present results of a recently developed spectral imaging method that elucidates microbubble-mediated nonlinearity not visible as a change in backscatter amplitude. [Work supported by Army MRMC.

Pulse-encoded ultrasound imaging of the vitreous with an annular array.

PubMed

Silverman, Ronald H; Ketterling, Jeffrey A; Mamou, Jonathan; Lloyd, Harriet O; Filoux, Erwan; Coleman, D Jackson

2012-01-01

The vitreous body is nearly transparent both optically and ultrasonically. Conventional 10- to 12-MHz diagnostic ultrasound can detect vitreous inhomogeneities at high gain settings, but has limited resolution and sensitivity, especially outside the fixed focal zone near the retina. To improve visualization of faint intravitreal fluid/gel interfaces, the authors fabricated a spherically curved 20-MHz five-element annular array ultrasound transducer, implemented a synthetic-focusing algorithm to extend the depth-of-field, and used a pulse-encoding strategy to increase sensitivity. The authors evaluated a human subject with a recent posterior vitreous detachment and compared the annular array with conventional 10-MHz ultrasound and spectral-domain optical coherence tomography. With synthetic focusing and chirp pulse-encoding, the array allowed visualization of the formed and fluid components of the vitreous with improved sensitivity and resolution compared with the conventional B-scan. Although optical coherence tomography allowed assessment of the posterior vitreoretinal interface, the ultrasound array allowed evaluation of the entire vitreous body. Copyright 2012, SLACK Incorporated.

Ultrasound contrast agents: an overview.

PubMed

Cosgrove, David

2006-12-01

With the introduction of microbubble contrast agents, diagnostic ultrasound has entered a new era that allows the dynamic detection of tissue flow of both the macro and microvasculature. Underpinning this development is the fact that gases are compressible, and thus the microbubbles expand and contract in the alternating pressure waves of the ultrasound beam, while tissue is almost incompressible. Special software using multiple pulse sequences separates these signals from those of tissue and displays them as an overlay or on a split screen. This can be done at low acoustic pressures (MI<0.3) so that the microbubbles are not destroyed and scanning can continue in real time. The clinical roles of contrast enhanced ultrasound scanning are expanding rapidly. They are established in echocardiography to improve endocardial border detection and are being developed for myocardial perfusion. In radiology, the most important application is the liver, especially for focal disease. The approach parallels that of dynamic CT or MRI but ultrasound has the advantages of high spatial and temporal resolution. Thus, small lesions that can be indeterminate on CT can often be studied with ultrasound, and situations where the flow is very rapid (e.g., focal nodular hyperplasia where the first few seconds of arterial perfusion may be critical to making the diagnosis) are readily studied. Microbubbles linger in the extensive sinusoidal space of normal liver for several minutes whereas they wash out rapidly from metastases, which have a low vascular volume and thus appear as filling defects. The method has been shown to be as sensitive as three-phase CT. Microbubbles have clinical uses in many other applications where knowledge of the microcirculation is important (the macrocirculation can usually be assessed adequately using conventional Doppler though there are a few important situations where the signal boost given by microbubbles is useful, e.g., transcranial Doppler for evaluating

Ultrasound in twin pregnancies.

PubMed

Morin, Lucie; Lim, Kenneth

2011-06-01

To review the literature with respect to the use of diagnostic ultrasound in the management of twin pregnancies. To make recommendations for the best use of ultrasound in twin pregnancies. Reduction in perinatal mortality and morbidity and short- and long-term neonatal morbidity in twin pregnancies. Optimization of ultrasound use in twin pregnancies. Published literature was retrieved through searches of PubMed and the Cochrane Library in 2008 and 2009 using appropriate controlled vocabulary (e.g., twin, ultrasound, cervix, prematurity) and key words (e.g., acardiac, twin, reversed arterial perfusion, twin-to-twin transfusion syndrome, amniotic fluid). Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies. There were no date restrictions. Studies were restricted to those with available English or French abstracts or text. Searches were updated on a regular basis and incorporated into the guideline to September 2009. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology assessment-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies. The evidence collected was reviewed by the Diagnostic Imaging Committee of the Society of Obstetricians and Gynaecologists of Canada, with input from members of the Maternal Fetal Medicine Committee and the Genetics Committee of the SOGC. The recommendations were made according to the guidelines developed by The Canadian Task Force on Preventive Health Care (Table 1). The benefit expected from this guideline is facilitation and optimization of the use of ultrasound in twin pregnancy. SUMMARY STATEMENTS: 1. There are insufficient data to make recommendations on repeat anatomical assessments in twin pregnancies. Therefore, a complete anatomical survey at each scan may not be needed following a complete

Ultrasound

MedlinePlus

Ultrasound is a type of imaging. It uses high-frequency sound waves to look at organs and ... liver, and other organs. During pregnancy, doctors use ultrasound to view the fetus. Unlike x-rays, ultrasound ...

Enhancement of drying and rehydration characteristics of okra by ultrasound pre-treatment application

NASA Astrophysics Data System (ADS)

Tüfekçi, Senem; Özkal, Sami Gökhan

2017-07-01

Effect of ultrasound application prior to hot air drying on drying and rehydration kinetics, rehydration ratio and microstructure of okra slices were investigated. For this purpose, the selected parameters are ultrasound pre-treatment time (10, 20 and 30 min), ultrasound amplitude (55 and 100%) and the temperature of drying air (60 and 70 °C). 5 mm thick cylindrical shaped okra slices were used in the experiments. The samples were immersed in water and ultrasonic pre-treatments were done in water with ultrasonic probe connected to an ultrasonic generator with 20 kHz frequency. Pre-treated samples were dried in a tray drier with a 0.3 m/s air velocity. Ultrasound pre-treatment affected the drying rate of the okra slices significantly. Drying time of okra slices was decreased by the application of ultrasound pre-treatment. Modified Page model found to be the most suitable model for describing the drying characteristics of okra slices. Improvements in rehydration properties of the dried samples were observed due to the ultrasound pre-treatment. The influence of the ultrasound pre-treatment on microstructure was clearly observed through scanning electron microscopy images of the dried samples. As the amplitude of ultrasound increased the changes in structure of the okra tissue increased.

Ultrasound Thermal Field Imaging of Opaque Fluids

NASA Technical Reports Server (NTRS)

Andereck, C. David

1999-01-01

studying convective fluid flow in crystal growth, because particle seeding is unacceptable and flow velocities are typically too low to be resolved, and may be even lower in microgravity conditions where buoyancy forces are negligible. We will investigate a different use of ultrasound to probe the flows of opaque fluids non-intrusively and without the use of seed particles: our goal is to ultrasonically visualize the thermal field of opaque fluids with relatively high spatial resolution. The proposed technique relies upon the variation of sound speed with temperature of the fluid. A high frequency ultra-sound pulse passing through a fluid-filled chamber will traverse the chamber in a time determined by the relevant chamber dimension and the temperature of the fluid through which the pulse passes. With high time-resolution instrumentation that compares the excitation signal with the received pulse we can detect the influence of the fluid temperature on the pulse travel time. This is effectively an interferometric system, which in its optical form is an extremely sensitive approach to measuring thermal fields in fluids. Moreover, the temperature dependence of sound velocity in liquid metals is comparable to the temperature dependence of the speed of light required for accurate interferometric thermal images in transparent fluids. With an array of transducers scanned electronically a map of the thermal field over the chamber could be produced. An alternative approach would be to use the ultrasound analog of the shadowgraph technique. In the optical version, collimated light passes through the fluid, where it is focused or defocused locally by temperature field induced variations of the index of refraction. The resulting image reveals the thermal field through the spatial pattern of light intensity variations. By analogy, an ultrasound plane wave traversing an opaque fluid sample would be also locally focused or defocused depending on the speed of sound variations, giving rise

Interactive matching of ultrasound and MRI for visualization during resection of myomata

NASA Astrophysics Data System (ADS)

de Bruin, Paul W.; Vos, Frans M.; Post, Frits H.; Vossepoel, Albert M.; de Blok, Sjoerd

2002-05-01

Piecewise removal of myomata (fibroids, benign tumors) from the uterine wall is performed using a hysteroresectoscope inserted through the vagina. Only radical removal of the myoma prevents regrowth, whereas penetration of the uterine wall should be avoided. Preoperative MR (Magnetic Resonance) images show the full outline and the location of the myoma in the uterine wall. Preoperative 3D US (ultrasound) reveals the part of the myoma that protrudes into the uterine cavity, but the part located in the uterine wall is almost invisible. The images and extracted preoperative information must be registered to the preoperative situation. A pragmatic solution in the form of three point incremental matching is applied. Three patients were scanned and the matching was performed on the data. The procedure provided a good match on two patients.

Development of a c-scan photoacoutsic imaging probe for prostate cancer detection

NASA Astrophysics Data System (ADS)

Valluru, Keerthi S.; Chinni, Bhargava K.; Rao, Navalgund A.; Bhatt, Shweta; Dogra, Vikram S.

2011-03-01

Prostate cancer is the second leading cause of death in American men after lung cancer. The current screening procedures include Digital Rectal Exam (DRE) and Prostate Specific Antigen (PSA) test, along with Transrectal Ultrasound (TRUS). All suffer from low sensitivity and specificity in detecting prostate cancer in early stages. There is a desperate need for a new imaging modality. We are developing a prototype transrectal photoacoustic imaging probe to detect prostate malignancies in vivo that promises high sensitivity and specificity. To generate photoacoustic (PA) signals, the probe utilizes a high energy 1064 nm laser that delivers light pulses onto the prostate at 10Hz with 10ns duration through a fiber optic cable. The designed system will generate focused C-scan planar images using acoustic lens technology. A 5 MHz custom fabricated ultrasound sensor array located in the image plane acquires the focused PA signals, eliminating the need for any synthetic aperture focusing. The lens and sensor array design was optimized towards this objective. For fast acquisition times, a custom built 16 channel simultaneous backend electronics PCB has been developed. It consists of a low-noise variable gain amplifier and a 16 channel ADC. Due to the unavailability of 2d ultrasound arrays, in the current implementation several B-scan (depth-resolved) data is first acquired by scanning a 1d array, which is then processed to reconstruct either 3d volumetric images or several C-scan planar images. Experimental results on excised tissue using a in-vitro prototype of this technology are presented to demonstrate the system capability in terms of resolution and sensitivity.

Elasticity-based three dimensional ultrasound real-time volume rendering

NASA Astrophysics Data System (ADS)

Boctor, Emad M.; Matinfar, Mohammad; Ahmad, Omar; Rivaz, Hassan; Choti, Michael; Taylor, Russell H.

2009-02-01

Volumetric ultrasound imaging has not gained wide recognition, despite the availability of real-time 3D ultrasound scanners and the anticipated potential of 3D ultrasound imaging in diagnostic and interventional radiology. Their use, however, has been hindered by the lack of real-time visualization methods that are capable of producing high quality 3D rendering of the target/surface of interest. Volume rendering is a known visualization method, which can display clear surfaces out of the acquired volumetric data, and has an increasing number of applications utilizing CT and MRI data. The key element of any volume rendering pipeline is the ability to classify the target/surface of interest by setting an appropriate opacity function. Practical and successful real-time 3D ultrasound volume rendering can be achieved in Obstetrics and Angio applications where setting these opacity functions can be done rapidly, and reliably. Unfortunately, 3D ultrasound volume rendering of soft tissues is a challenging task due to the presence of significant amount of noise and speckle. Recently, several research groups have shown the feasibility of producing 3D elasticity volume from two consecutive 3D ultrasound scans. This report describes a novel volume rendering pipeline utilizing elasticity information. The basic idea is to compute B-mode voxel opacity from the rapidly calculated strain values, which can also be mixed with conventional gradient based opacity function. We have implemented the volume renderer using GPU unit, which gives an update rate of 40 volume/sec.

Comparison of portable and conventional ultrasound imaging in spinal curvature measurement

NASA Astrophysics Data System (ADS)

Yan, Christina; Tabanfar, Reza; Kempston, Michael; Borschneck, Daniel; Ungi, Tamas; Fichtinger, Gabor

2016-03-01

PURPOSE: In scoliosis monitoring, tracked ultrasound has been explored as a safer imaging alternative to traditional radiography. The use of ultrasound in spinal curvature measurement requires identification of vertebral landmarks, but bones have reduced visibility in ultrasound imaging and high quality ultrasound machines are often expensive and not portable. In this work, we investigate the image quality and measurement accuracy of a low cost and portable ultrasound machine in comparison to a standard ultrasound machine in scoliosis monitoring. METHODS: Two different kinds of ultrasound machines were tested on three human subjects, using the same position tracker and software. Spinal curves were measured in the same reference coordinate system using both ultrasound machines. Lines were defined by connecting two symmetric landmarks identified on the left and right transverse process of the same vertebrae, and spinal curvature was defined as the transverse process angle between two such lines, projected on the coronal plane. RESULTS: Three healthy volunteers were scanned by both ultrasound configurations. Three experienced observers localized transverse processes as skeletal landmarks and obtained transverse process angles in images obtained from both ultrasounds. The mean difference per transverse process angle measured was 3.00 +/-2.1°. 94% of transverse processes visualized in the Sonix Touch were also visible in the Telemed. Inter-observer error in the Telemed was 4.5° and 4.3° in the Sonix Touch. CONCLUSION: Price, convenience and accessibility suggest the Telemed to be a viable alternative in scoliosis monitoring, however further improvements in measurement protocol and image noise reduction must be completed before implementing the Telemed in the clinical setting.

Wetland Microtopographic Structure is Revealed with Terrestrial Laser Scanning

NASA Astrophysics Data System (ADS)

Diamond, J.; Stovall, A. E.; Mclaughlin, D. L.; Slesak, R.

2017-12-01

Wetland microtopographic structure and its function has been the subject of research for decades, and several investigations suggest that microtopography is generated by autogenic ecohydrologic processes. But due to the difficulty of capturing the true spatial variability of wetland microtopography, many of the hypotheses for self-organization have remained elusive to test. We employ a novel method of Terrestrial Laser Scanning (TLS) that reveals an unprecedented high-resolution (<0.5 cm) glimpse at the true spatial structure of wetland microtopography in 10 black ash (Fraxinus nigra) stands of northern Minnesota, USA. Here we present the first efforts to synthesize this information and show that TLS provides a good representation of real microtopographic structure, where TLS accurately measured hummock height, but occlusion of low points led to a slight negative bias. We further show that TLS can accurately locate microtopographic high points (hummocks), as well as estimate their height and area. Using these new data, we estimate distributions in both microtopographic elevation and hummock area in each wetland and relate these to monitored hydrologic regime; in doing so, we test hypotheses linking emergent microtopographic patterns to putative hydrologic controls. Finally, we discuss future efforts to enumerate consequent influences of microtopography on wetland systems (soil properties and vegetation composition).

Avoiding CT scans in children with single-suture craniosynostosis.

PubMed

Schweitzer, T; Böhm, H; Meyer-Marcotty, P; Collmann, H; Ernestus, R-I; Krauß, J

2012-07-01

During the last decades, computed tomography (CT) has become the predominant imaging technique in the diagnosis of craniosynostosis. In most craniofacial centers, at least one three-dimensional (3D) computed tomographic scan is obtained in every case of suspected craniosynostosis. However, with regard to the risk of radiation exposure particularly in young infants, CT scanning and even plain radiography should be indicated extremely carefully. Our current diagnostic protocol in the management of single-suture craniosynostosis is mainly based on careful clinical examination with regard to severity and degree of the abnormality and on ophthalmoscopic surveillance. Imaging techniques consist of ultrasound examination in young infants while routine plain radiographs are usually postponed to the date of surgery or the end of the first year. CT and magnetic resonance imaging (MRI) are confined to special diagnostic problems rarely encountered in isolated craniosynostosis. The results of this approach were evaluated retrospectively in 137 infants who were referred to our outpatient clinic for evaluation and/or treatment of suspected single suture craniosynostosis or positional deformity during a 2-year period (2008-2009). In 133 (97.1%) of the 137 infants, the diagnosis of single-suture craniosynostosis (n = 110) or positional plagiocephaly (n = 27) was achieved through clinical analysis only. Two further cases were classified by ultrasound, while the remaining two cases needed additional digital radiographs. In no case was CT scanning retrospectively considered necessary for establishing the diagnosis. Yet in 17.6% of cases, a cranial CT scan had already been performed elsewhere (n = 16) or had been definitely scheduled (n = 8). CT scanning is rarely necessary for evaluation of single-suture craniosynostosis. Taking into account that there is a quantifiable risk of developing cancer in further lifetime, every single CT scan should be carefully indicated.

Algorithms and Results of Eye Tissues Differentiation Based on RF Ultrasound

PubMed Central

Jurkonis, R.; Janušauskas, A.; Marozas, V.; Jegelevičius, D.; Daukantas, S.; Patašius, M.; Paunksnis, A.; Lukoševičius, A.

2012-01-01

Algorithms and software were developed for analysis of B-scan ultrasonic signals acquired from commercial diagnostic ultrasound system. The algorithms process raw ultrasonic signals in backscattered spectrum domain, which is obtained using two time-frequency methods: short-time Fourier and Hilbert-Huang transformations. The signals from selected regions of eye tissues are characterized by parameters: B-scan envelope amplitude, approximated spectral slope, approximated spectral intercept, mean instantaneous frequency, mean instantaneous bandwidth, and parameters of Nakagami distribution characterizing Hilbert-Huang transformation output. The backscattered ultrasound signal parameters characterizing intraocular and orbit tissues were processed by decision tree data mining algorithm. The pilot trial proved that applied methods are able to correctly classify signals from corpus vitreum blood, extraocular muscle, and orbit tissues. In 26 cases of ocular tissues classification, one error occurred, when tissues were classified into classes of corpus vitreum blood, extraocular muscle, and orbit tissue. In this pilot classification parameters of spectral intercept and Nakagami parameter for instantaneous frequencies distribution of the 1st intrinsic mode function were found specific for corpus vitreum blood, orbit and extraocular muscle tissues. We conclude that ultrasound data should be further collected in clinical database to establish background for decision support system for ocular tissue noninvasive differentiation. PMID:22654643

Comparison of Thermal Safety Practice Guidelines for Diagnostic Ultrasound Exposures.

PubMed

Harris, Gerald R; Church, Charles C; Dalecki, Diane; Ziskin, Marvin C; Bagley, Jennifer E

2016-02-01

This article examines the historical evolution of various practice guidelines designed to minimize the possibility of thermal injury during a diagnostic ultrasound examination, including those published by the American Institute of Ultrasound in Medicine, British Medical Ultrasound Society and Health Canada. The guidelines for prenatal/neonatal examinations are in general agreement, but significant differences were found for postnatal exposures. We propose sets of thermal index versus exposure time for these examination categories below which there is reasonable assurance that an examination can be conducted without risk of producing an adverse thermal effect under any scanning conditions. If it is necessary to exceed these guidelines, the occurrence of an adverse thermal event is still unlikely in most situations because of mitigating factors such as transducer movement and perfusion, but the general principle of "as low as reasonably achievable" should be followed. Some limitations of the biological effects studies underpinning the guidelines also are discussed briefly. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

In situ ultrasound imaging of silk hydrogel degradation and neovascularization.

PubMed

Leng, Xiaoping; Liu, Bin; Su, Bo; Liang, Min; Shi, Liangchen; Li, Shouqiang; Qu, Shaohui; Fu, Xin; Liu, Yue; Yao, Meng; Kaplan, David L; Wang, Yansong; Wang, Xiaoqin

2017-03-01

Ultrasound (US) is a useful technique to monitor morphological and functional changes of biomaterial implants without sacrificing the animal. Contrast-enhanced ultrasound (CEUS) along with two-dimensional (2D) US were used to characterize the biodegradation and neovascularization of silk protein (8 wt%) hydrogel implants in rats. Cylinder-shaped silk hydrogel plugs were implanted into the space between the hind limb thigh muscles in Wistar rats (n = 6). The increase of echogenicity in 2D US revealed tissue-ingrowth-accompanied gel degradation over 18 weeks. The shape and size of the implanted gels remained qualitatively unchanged until week 15, as confirmed by Bland and Altman analysis and visualization of retrieved samples. Using CEUS, neovascularization was monitored by the presence of microbubbles in the gel area, and the dynamic vascularization process was indicated by the contrast enhancement values, which showed a relatively low level (< 5 dB) during weeks 1-8 and significantly increased levels (around 20 dB at week 15 and > 35 dB at week 18), suggesting that major vascularization had occurred in the gel implants by this time point. Histological and scanning electron microscopic analysis of explants revealed time-dependent increases in the pore size of the gel matrix, the presence of endothelial and red blood cells and the number of blood vessels in the gel implants, indicating that degradation and vascularization did occur in silk gel implants during the time period. The present study demonstrates the use of US imaging for monitoring of in vivo degradation and vascularization of silk implants in a non-destructive way. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Sustained effect of simulation-based ultrasound training on clinical performance: a randomized trial

PubMed Central

Tolsgaard, M G; Ringsted, C; Dreisler, E; Nørgaard, L N; Petersen, J H; Madsen, M E; Freiesleben, N L C; Sørensen, J L; Tabor, A

2015-01-01

Objective To study the effect of initial simulation-based transvaginal sonography (TVS) training compared with clinical training only, on the clinical performance of residents in obstetrics and gynecology (Ob-Gyn), assessed 2 months into their residency. Methods In a randomized study, new Ob-Gyn residents (n = 33) with no prior ultrasound experience were recruited from three teaching hospitals. Participants were allocated to either simulation-based training followed by clinical training (intervention group; n = 18) or clinical training only (control group; n = 15). The simulation-based training was performed using a virtual-reality TVS simulator until an expert performance level was attained, and was followed by training on a pelvic mannequin. After 2 months of clinical training, one TVS examination was recorded for assessment of each resident's clinical performance (n = 26). Two ultrasound experts blinded to group allocation rated the scans using the Objective Structured Assessment of Ultrasound Skills (OSAUS) scale. Results During the 2 months of clinical training, participants in the intervention and control groups completed an average ± SD of 58 ± 41 and 63 ± 47 scans, respectively (P = 0.67). In the subsequent clinical performance test, the intervention group achieved higher OSAUS scores than did the control group (mean score, 59.1% vs 37.6%, respectively; P < 0.001). A greater proportion of the intervention group passed a pre-established pass/fail level than did controls (85.7% vs 8.3%, respectively; P < 0.001). Conclusion Simulation-based ultrasound training leads to substantial improvement in clinical performance that is sustained after 2 months of clinical training. © 2015 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology. PMID:25580809

Real-time ultrasound-guided spinal anesthesia using the SonixGPS ultrasound guidance system: a feasibility study.

PubMed

Niazi, A U; Chin, K J; Jin, R; Chan, V W

2014-08-01

Real-time ultrasound-guided neuraxial blockade remains a largely experimental technique. SonixGPS® is a new needle tracking system that displays needle tip position on the ultrasound screen. We investigated if this novel technology might aid performance of real-time ultrasound-guided spinal anesthesia. Twenty patients with body mass index < 35 kg/m(2) undergoing elective total joint arthroplasty under spinal anesthesia were recruited. Patients with previous back surgery and spinal abnormalities were excluded. Following a pre-procedural ultrasound scan, a 17G proprietary needle-sensor assembly was inserted in-plane to the transducer in four patients and out-of-plane in 16 patients. In both approaches, the trajectory of insertion was adjusted in real-time until the needle tip lay just superficial to the ligamentum flavum-dura mater complex. At this point, a 25G 120 mm Whitacre spinal needle was inserted through the 17G SonixGPS® needle. Successful dural puncture was confirmed by backflow of cerebrospinal fluid from the spinal needle. An overall success rate of 14/20 (70%) was seen with two failures (50%) and four failures (25%) in the in-plane and out-of-plane groups respectively. Dural puncture was successful on the first skin puncture in 71% of patients and in a single needle pass in 57% of patients. The median total procedure time was 16.4 and 11.1 min in the in-plane and out-of-plane groups respectively. The SonixGPS® system simplifies real-time ultrasound-guided spinal anesthesia to a large extent, especially the out-of-plane approach. Nevertheless, it remains a complex multi-step procedure that requires time, specialized equipment, and a working knowledge of spinal sonoanatomy. © 2014 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Ultrasound

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Ultrasound is a useful procedure for monitoring the baby's development in the uterus. Ultrasound uses inaudible sound waves to produce a two- ... sound waves and appear dark or black. An ultrasound can supply vital information about a mother's pregnancy ...

Accuracy of non-operative identification of the sentinel lymph node using combined gamma and ultrasound scanning.

PubMed

Whelehan, P; Vinnicombe, S J; Brown, D C; McLean, D; Evans, A

2014-08-01

To assess how accurately the sentinel lymph node (SLN) can be identified percutaneously, using gamma probe and ultrasound technology. Women with breast cancer, scheduled for wide local excision or mastectomy with SLN biopsy (SLNB), were included. Peri-areolar intradermal injection of technetium-99 nanocolloid was performed on the morning of surgery and 1-2 ml of blue dye was injected in the peri-areolar region once the patient was anaesthetized. Prior to surgery, a gamma probe was used over the skin to identify any hot spot that could represent a SLN. Ultrasound, guided by the hot spot, was then used to visualize potential SLNs and guide the insertion of a localizing wire. The accuracy in localizing the SLN by preoperative gamma-probe guided ultrasonography was assessed by comparison to SLNB. A SLN was correctly identified and marked using gamma-probe guided ultrasonography in 44 of 59 cases (75%; 95% CI: 63-86%). This study supports the case for investigating percutaneous gamma probe and ultrasound guided interventions in the axilla in women with breast cancer, as a potential alternative to surgical SLNB. Copyright © 2014 The Royal College of Radiologists. Published by Elsevier Ltd. 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.

Molecular mechanisms of the effect of ultrasound on the fibrinolysis of clots

PubMed Central

Chernysh, Irina N.; Everbach, E. Carr; Purohit, Prashant K.; Weisel, John W.

2016-01-01

Summary Background Ultrasound accelerates tissue-type plasminogen activator (t-PA)-induced fibrinolysis of clots in vitro and in vivo. Objective To identify mechanisms for the enhancement of t-PA-induced fibrinolysis of clots. Methods Turbidity is an accurate and convenient method, not previously used, to follow the effects of ultrasound. Deconvolution microscopy was used to determine changes in structure, while fluorescence recovery after photobleaching was used to characterize the kinetics of binding/unbinding and transport. Results The ultrasound pulse repetition frequency affected clot lysis times, but there were no thermal effects. Ultrasound in the absence of t-PA produced a slight but consistent decrease in turbidity, suggesting a decrease in fibrin diameter due solely to the action of the ultrasound, likely caused by an increase in protofibril tension because of vibration from ultrasound. Changes in fibrin network structure during lysis with ultrasound were visualized in real time by deconvolution microscopy, revealing that the network becomes unstable when 30–40% of the protein in the network was digested, whereas without ultrasound, the fibrin network was digested gradually and retained structural integrity. Fluorescence recovery after photobleaching during lysis revealed that the off-rate of oligomers from digesting fibers was not much affected but the number of binding/unbinding sites was increased. Conclusions Ultrasound causes a decrease in the diameter of the fibers due to tension as a result of vibration, leading to increased binding sites for plasmin(ogen)/t-PA. The positive feedback of this structural change together with increased mixing/transport of t-PA/plasmin(ogen) is likely to account for the observed enhancement of fibrinolysis by ultrasound. PMID:25619618

Three-dimensional diffuse optical mammography with ultrasound localization in a human subject

NASA Astrophysics Data System (ADS)

Holboke, Monica J.; Tromberg, Bruce J.; Li, Xingde; Shah, Natasha; Fishkin, Joshua B.; Kidney, D.; Butler, J.; Chance, Britton; Yodh, Arjun G.

2000-04-01

We describe an approach that combines clinical ultrasound and photon migration techniques to enhance the sensitivity and information content of diffuse optical tomography. Measurements were performed on a postmenopausal woman with a single 1.8 X 0.9 cm malignant ductal carcinoma in situ approximately 7.4 mm beneath the skin surface (UCI IRB protocol 95-563). The ultrasound-derived information about tumor geometry enabled us to segment the breast tissue into tumor and background regions. Optical data was obtained with a multifrequency, multiwavelength hand-held frequency-domain photon migration backscattering probe. The optical properties of the tumor and background were then computed using the ultrasound-derived geometrical constraints. An iterative perturbative approach, using parallel processing, provided quantitative information about scattering and absorption simultaneously with the ability to incorporate and resolve complex boundary conditions and geometries. A three to four fold increase in the tumor absorption coefficient and nearly 50% reduction in scattering coefficient relative to background was observed ((lambda) equals 674, 782, 803, and 849 nm). Calculations of the mean physiological parameters reveal fourfold greater tumor total hemoglobin concentration [Hbtot] than normal breast (67 (mu) M vs 16 (mu) M) and tumor hemoglobin oxygen saturation (SOx) values of 63% (vs 73% and 68% in the region surrounding the tumor and the opposite normal tissue, respectively). Comparison of semi-infinite to heterogeneous models shows superior tumor/background contrast for the latter in both absorption and scattering. Sensitivity studies assessing the impact of tumor size and refractive index assumptions, as well as scan direction, demonstrate modest effects on recovered properties.

Smartphone based automatic organ validation in ultrasound video.

PubMed

Vaish, Pallavi; Bharath, R; Rajalakshmi, P

2017-07-01

Telesonography involves transmission of ultrasound video from remote areas to the doctors for getting diagnosis. Due to the lack of trained sonographers in remote areas, the ultrasound videos scanned by these untrained persons do not contain the proper information that is required by a physician. As compared to standard methods for video transmission, mHealth driven systems need to be developed for transmitting valid medical videos. To overcome this problem, we are proposing an organ validation algorithm to evaluate the ultrasound video based on the content present. This will guide the semi skilled person to acquire the representative data from patient. Advancement in smartphone technology allows us to perform high medical image processing on smartphone. In this paper we have developed an Application (APP) for a smartphone which can automatically detect the valid frames (which consist of clear organ visibility) in an ultrasound video and ignores the invalid frames (which consist of no-organ visibility), and produces a compressed sized video. This is done by extracting the GIST features from the Region of Interest (ROI) of the frame and then classifying the frame using SVM classifier with quadratic kernel. The developed application resulted with the accuracy of 94.93% in classifying valid and invalid images.

A longitudinal study assessing lens thickness changes in the eye of the growing beagle using ultrasound scanning: relevance to age of dogs in regulatory toxicology studies.

PubMed

Maynard, Juliana; Sykes, Angela; Powell, Helen; Healing, Guy; Scott, Marietta; Holmes, Andrew; Ricketts, Sally-Ann; Stewart, Jane; Davis, Stewart

2014-12-01

The lens is formed in utero with new secondary lens fibres added as outer layers throughout life in a growth pattern characteristic of the species. This study examined the time course of beagle lens growth to better understand the optimal starting age of dogs for safety studies to support adult versus paediatric indications, and to assess the feasibility of non-invasively monitoring lens growth with high frequency ultrasound. Ultrasound scanning was performed in six female beagle dogs using the Vevo770. All dogs were imaged in B-mode using local anaesthetic but without sedation. Imaging was carried out every 2 weeks from 8 to 22 weeks of age and then monthly until 62 weeks of age. The dogs tolerated the procedure well. The lens was visible in all dogs and measuring the lens thickness with high frequency ultrasound demonstrated good analytical reproducibility [Root Mean Square (RMS) = 3.13%]. No differences between the left and right eye existed and lens thickness correlated with body weight. The highest weekly growth rate was before 12 weeks of age. A statistically significant difference between monthly thickness was detected until 42 weeks of age at which point growth reached a plateau. During the experiment, lenses grew by 29.7% reaching an average thickness of 6.4 mm ± 0.03. By 10 months of age (the typical age used for routine toxicological evaluation), beagles have reached a plateau in lens growth that is analogous to human adults. Where lens is a target organ of concern it is suggested that beagles under 6 months old may be a better model for determining paediatric safety. Copyright © 2014 John Wiley & Sons, Ltd.

Temperature measurement by thermal strain imaging with diagnostic power ultrasound, with potential for thermal index determination.

PubMed

Liang, Hai-Dong; Zhou, Li-Xia; Wells, Peter N T; Halliwell, Michael

2009-05-01

Over the years, there has been a substantial increase in acoustic exposure in diagnostic ultrasound as new imaging modalities with higher intensities and frame rates have been introduced; and more electronic components have been packed into the probe head, so that there is a tendency for it to become hotter. With respect to potential thermal effects, including those which may be hazardous occurring during ultrasound scanning, there is a correspondingly growing need for in vivo techniques to guide the operator as to the actual temperature rise occurring in the examined tissues. Therefore, an in vivo temperature estimator would be of considerable practical value. The commonly-used method of tissue thermal index (TI) measurement with a hydrophone in water could underestimate the actual value of TI (in one report by as much as 2.9 times). To obtain meaningful results, it is necessary to map the temperature elevation in 2-D (or 3-D) space. We present methodology, results and validation of a 2-D spatial and temporal thermal strain ultrasound temperature estimation technique in phantoms, and its apparently novel application in tracking the evolution of heat deposition at diagnostic exposure levels. The same ultrasound probe is used for both transmission and reception. The displacement and thermal strain estimation methods are similar to those used in high-intensity focused ultrasound thermal monitoring. The use of radiofrequency signals permits the application of cross correlation as a similarity measurement for tracking feature displacement. The displacement is used to calculate the thermal strain directly related to the temperature rise. Good agreement was observed between the temperature rise and the ultrasound power and scan duration. Thermal strain up to 1.4% was observed during 4000-s scan. Based on the results obtained for the temperature range studied in this work, the technique demonstrates potential for applicability in phantom (and possibly in vivo tissue

Lung Ultrasound Findings in Congenital Pulmonary Airway Malformation.

PubMed

Yousef, Nadya; Mokhtari, Mostafa; Durand, Philippe; Raimondi, Francesco; Migliaro, Fiorella; Letourneau, Alexandra; Tissières, Pierre; De Luca, Daniele

2018-05-01

 Congenital pulmonary airway malformation (CPAM) is a group of rare congenital malformations of the lung and airways. Lung ultrasound (LU) is increasingly used to diagnose neonatal respiratory diseases since it is quick, easy to learn, and radiation-free, but no formal data exist for congenital lung malformations. We aimed to describe LU findings in CPAM neonates needing neonatal intensive care unit (NICU) admission and to compare them with a control population.  A retrospective review of CPAM cases from three tertiary academic NICUs over 3 years (2014-2016) identified five patients with CPAM who had undergone LU examination. LU was compared with chest radiograms and computed tomography (CT) scans that were used as references.  CPAM lesions were easily identified and corresponded well with CT scans; they varied from a single large cystic lesion, multiple hypoechoic lesions, and/or consolidation. The first two LU findings have not been described in other respiratory conditions and were not found in controls.  We provide the first description of LU findings in neonates with CPAM. LU may be used to confirm antenatally diagnosed CPAM and to suspect CPAM in infants with respiratory distress if cystic lung lesions are revealed. Further studies are necessary to define the place of LU in the management of CPAM. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Robotic assisted laparoscopic partial nephrectomy using contrast-enhanced ultrasound scan to map renal blood flow.

PubMed

Alenezi, Ahmad; Motiwala, Aamir; Eves, Susannah; Gray, Rob; Thomas, Asha; Meiers, Isabelle; Sharif, Haytham; Motiwala, Hanif; Laniado, Marc; Karim, Omer

2017-03-01

The paper describes novel real-time 'in situ mapping' and 'sequential occlusion angiography' to facilitate selective ischaemia robotic partial nephrectomy (RPN) using intraoperative contrast enhanced ultrasound scan (CEUS). Data were collected and assessed for 60 patients (61 tumours) between 2009 and 2013. 31 (50.8%) tumours underwent 'Global Ischaemia', 27 (44.3%) underwent 'Selective Ischaemia' and 3 (4.9%) were removed 'Off Clamp Zero Ischaemia'. Demographics, operative variables, complications, renal pathology and outcomes were assessed. Median PADUA score was 9 (range 7-10). The mean warm ischaemia time in selective ischaemia was less and statistically significant than in global ischaemia (17.1 and 21.4, respectively). Mean operative time was 163 min. Postoperative complications (n = 10) included three (5%) Clavien grade 3 or above. Malignancy was demonstrated in 47 (77%) with negative margin in 43 (91.5%) and positive margin in four (8.5%). Long-term decrease in eGFR post selective ischaemia robotic partial nephrectomy was less compared with global ischaemia (four and eight, respectively) but not statistically significant. This technique is safe, feasible and cost-effective with comparable perioperative outcomes. The technical aspects elucidate the role of intraoperative CEUS to facilitate and ascertain selective ischaemia. Further work is required to demonstrate long-term oncological outcomes. © 2016 The Authors. The International Journal of Medical Robotics and Computer Assisted Surgery published by John Wiley & Sons, Ltd. © 2016 The Authors. The International Journal of Medical Robotics and Computer Assisted Surgery published by John Wiley & Sons, Ltd.

Articular cartilage degeneration classification by means of high-frequency ultrasound.

PubMed

Männicke, N; Schöne, M; Oelze, M; Raum, K

2014-10-01

To date only single ultrasound parameters were regarded in statistical analyses to characterize osteoarthritic changes in articular cartilage and the potential benefit of using parameter combinations for characterization remains unclear. Therefore, the aim of this work was to utilize feature selection and classification of a Mankin subset score (i.e., cartilage surface and cell sub-scores) using ultrasound-based parameter pairs and investigate both classification accuracy and the sensitivity towards different degeneration stages. 40 punch biopsies of human cartilage were previously scanned ex vivo with a 40-MHz transducer. Ultrasound-based surface parameters, as well as backscatter and envelope statistics parameters were available. Logistic regression was performed with each unique US parameter pair as predictor and different degeneration stages as response variables. The best ultrasound-based parameter pair for each Mankin subset score value was assessed by highest classification accuracy and utilized in receiver operating characteristics (ROC) analysis. The classifications discriminating between early degenerations yielded area under the ROC curve (AUC) values of 0.94-0.99 (mean ± SD: 0.97 ± 0.03). In contrast, classifications among higher Mankin subset scores resulted in lower AUC values: 0.75-0.91 (mean ± SD: 0.84 ± 0.08). Variable sensitivities of the different ultrasound features were observed with respect to different degeneration stages. Our results strongly suggest that combinations of high-frequency ultrasound-based parameters exhibit potential to characterize different, particularly very early, degeneration stages of hyaline cartilage. Variable sensitivities towards different degeneration stages suggest that a concurrent estimation of multiple ultrasound-based parameters is diagnostically valuable. In-vivo application of the present findings is conceivable in both minimally invasive arthroscopic ultrasound and high-frequency transcutaneous ultrasound

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

Supercritical carbon dioxide extraction of capsaicinoids from malagueta pepper (Capsicum frutescens L.) assisted by ultrasound.

PubMed

Santos, Philipe; Aguiar, Ana C; Barbero, Gerardo F; Rezende, Camila A; Martínez, Julian

2015-01-01

Extracts from malagueta pepper (Capsicum frutescens L.) were obtained using supercritical fluid extraction (SFE) assisted by ultrasound, with carbon dioxide as solvent at 15MPa and 40°C. The SFE global yield increased up to 77% when ultrasound waves were applied, and the best condition of ultrasound-assisted extraction was ultrasound power of 360W applied during 60min. Four capsaicinoids were identified in the extracts and quantified by high performance liquid chromatography. The use of ultrasonic waves did not influence significantly the capsaicinoid profiles and the phenolic content of the extracts. However, ultrasound has enhanced the SFE rate. A model based on the broken and intact cell concept was adequate to represent the extraction kinetics and estimate the mass transfer coefficients, which were increased with ultrasound. Images obtained by field emission scanning electron microscopy showed that the action of ultrasonic waves did not cause cracks on the cell wall surface. On the other hand, ultrasound promoted disturbances in the vegetable matrix, leading to the release of extractable material on the solid surface. The effects of ultrasound were more significant on SFE from larger solid particles. Copyright © 2014 Elsevier B.V. All rights reserved.

Interstitial ablation and imaging of soft tissue using miniaturized ultrasound arrays

NASA Astrophysics Data System (ADS)

Makin, Inder R. S.; Gallagher, Laura A.; Mast, T. Douglas; Runk, Megan M.; Faidi, Waseem; Barthe, Peter G.; Slayton, Michael H.

2004-05-01

A potential alternative to extracorporeal, noninvasive HIFU therapy is minimally invasive, interstitial ultrasound ablation that can be performed laparoscopically or percutaneously. Research in this area at Guided Therapy Systems and Ethicon Endo-Surgery has included development of miniaturized (~3 mm diameter) linear ultrasound arrays capable of high power for bulk tissue ablation as well as broad bandwidth for imaging. An integrated control system allows therapy planning and automated treatment guided by real-time interstitial B-scan imaging. Image quality, challenging because of limited probe dimensions and channel count, is aided by signal processing techniques that improve image definition and contrast. Simulations of ultrasonic heat deposition, bio-heat transfer, and tissue modification provide understanding and guidance for development of treatment strategies. Results from in vitro and in vivo ablation experiments, together with corresponding simulations, will be described. Using methods of rotational scanning, this approach is shown to be capable of clinically relevant ablation rates and volumes.

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

Efficacy of computer-based video and simulation in ultrasound-guided regional anesthesia training.

PubMed

Woodworth, Glenn E; Chen, Elliza M; Horn, Jean-Louis E; Aziz, Michael F

2014-05-01

To determine the effectiveness of a short educational video and simulation on improvement of ultrasound (US) image acquisition and interpretation skills. Prospective, randomized study. University medical center. 28 anesthesia residents and community anesthesiologists with varied ultrasound experience were randomized to teaching video with interactive simulation or sham video groups. Participants were assessed preintervention and postintervention on their ability to identify the sciatic nerve and other anatomic structures on static US images, as well as their ability to locate the sciatic nerve with US on live models. Pretest written test scores correlated with reported US block experience (Kendall tau rank r = 0.47) and with live US scanning scores (r = 0.64). The teaching video and simulation significantly improved scores on the written examination (P < 0.001); however, they did not significantly improve live US scanning skills. A short educational video with interactive simulation significantly improved knowledge of US anatomy, but failed to improve hands-on performance of US scanning to localize the nerve. Copyright © 2014 Elsevier Inc. All rights reserved.

Three-dimensional intraoperative ultrasound of vascular malformations and supratentorial tumors.

PubMed

Woydt, Michael; Horowski, Anja; Krauss, Juergen; Krone, Andreas; Soerensen, Niels; Roosen, Klaus

2002-01-01

The benefits and limits of a magnetic sensor-based 3-dimensional (3D) intraoperative ultrasound technique during surgery of vascular malformations and supratentorial tumors were evaluated. Twenty patients with 11 vascular malformations and 9 supratentorial tumors undergoing microsurgical resection or clipping were investigated with an interactive magnetic sensor data acquisition system allowing freehand scanning. An ultrasound probe with a mounted sensor was used after craniotomies to localize lesions, outline tumors or malformation margins, and identify supplying vessels. A 3D data set was obtained allowing reformation of multiple slices in all 3 planes and comparison to 2-dimensional (2D) intraoperative ultrasound images. Off-line gray-scale segmentation analysis allowed differentiation between tissue with different echogenicities. Color-coded information about blood flow was extracted from the images with a reconstruction algorithm. This allowed photorealistic surface displays of perfused tissue, tumor, and surrounding vessels. Three-dimensional intraoperative ultrasound data acquisition was obtained within 5 minutes. Off-line analysis and reconstruction time depends on the type of imaging display and can take up to 30 minutes. The spatial relation between aneurysm sac and surrounding vessels or the skull base could be enhanced in 3 out of 6 aneurysms with 3D intraoperative ultrasound. Perforating arteries were visible in 3 cases only by using 3D imaging. 3D ultrasound provides a promising imaging technique, offering the neurosurgeon an intraoperative spatial orientation of the lesion and its vascular relationships. Thereby, it may improve safety of surgery and understanding of 2D ultrasound images.

Sonoanatomy relevant for ultrasound-guided central neuraxial blocks via the paramedian approach in the lumbar region

PubMed Central

Karmakar, M K; Li, X; Kwok, W H; Ho, A M-H; Ngan Kee, W D

2012-01-01

Objectives The use of ultrasound to guide peripheral nerve blocks is now a well-established technique in regional anaesthesia. However, despite reports of ultrasound guided epidural access via the paramedian approach, there are limited data on the use of ultrasound for central neuraxial blocks, which may be due to a poor understanding of spinal sonoanatomy. The aim of this study was to define the sonoanatomy of the lumbar spine relevant for central neuraxial blocks via the paramedian approach. Methods The sonoanatomy of the lumbar spine relevant for central neuraxial blocks via the paramedian approach was defined using a “water-based spine phantom”, young volunteers and anatomical slices rendered from the Visible Human Project data set. Results The water-based spine phantom was a simple model to study the sonoanatomy of the osseous elements of the lumbar spine. Each osseous element of the lumbar spine, in the spine phantom, produced a “signature pattern” on the paramedian sagittal scans, which was comparable to its sonographic appearance in vivo. In the volunteers, despite the narrow acoustic window, the ultrasound visibility of the neuraxial structures at the L3/L4 and L4/L5 lumbar intervertebral spaces was good, and we were able to delineate the sonoanatomy relevant for ultrasound-guided central neuraxial blocks via the paramedian approach. Conclusion Using a simple water-based spine phantom, volunteer scans and anatomical slices from the Visible Human Project (cadaver) we have described the sonoanatomy relevant for ultrasound-guided central neuraxial blocks via the paramedian approach in the lumbar region. PMID:22010025

Synthesis of zirconium dioxide by ultrasound assisted precipitation: effect of calcination temperature.

PubMed

Prasad, Krishnamurthy; Pinjari, D V; Pandit, A B; Mhaske, S T

2011-09-01

Nanostructured zirconium dioxide was synthesized from zirconyl nitrate using both conventional and ultrasound assisted precipitation in alkaline medium. The synthesized samples were calcinated at temperatures ranging from 400°C to 900°C in steps of 100°C. The ZrO(2) specimens were characterized using X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The thermal characteristics of the samples were studied via Differential Scanning Calorimetry-Thermo-Gravimetry Analysis (DSC-TGA). The influence of the calcination temperature on the phase transformation process from monoclinic to tetragonal to cubic zirconia and its consequent effect on the crystallite size and % crystallinity of the synthesized ZrO(2) was studied and interpreted. It was observed that the ultrasound assisted technique helped to hasten to the phase transformation and also at some point resulted in phase stabilization of the synthesized zirconia. Copyright © 2011 Elsevier B.V. All rights reserved.

'Wakey wakey baby': narrating four-dimensional (4D) bonding scans.

PubMed

Roberts, Julie

2012-02-01

Commercial companies market 4D ultrasound scans to expectant parents for the stated purpose of reassurance, to promote bonding, and to get 'baby's first picture'. This article describes in detail the process of commercial 4D scanning in the UK, paying particular attention to the discursive exchanges in the scan room. It is argued that sonographers and clients engage in a process of 'collaborative coding' that, despite the realism of 4D, is essential to making the imagery on the screen personally and socially meaningful. While sonographers first help clients to get their bearings, expectant parents and others often engage in a complex process of narrating the images on the screen as they are created. The capacities of 4D ultrasound to image facial features and movements inform stories about fetal experience and family resemblances as well as enabling playfully imagined interactions with the fetus. While these stories are primarily based in experiences of the visual, there is also evidence that pregnant women seek to map the image onto their bodies and to reintroduce some elements of their embodied experiences into the narratives. © 2011 The Author. Sociology of Health & Illness © 2011 Foundation for the Sociology of Health & Illness/Blackwell Publishing Ltd.

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-mediation of self-illuminating reporters improves imaging resolution in optically scattering media

PubMed Central

Ahmad, Junaid; Jayet, Baptiste; Hill, Philip J.; Mather, Melissa L.; Dehghani, Hamid; Morgan, Stephen P.

2018-01-01

In vivo imaging of self-illuminating bio-and chemiluminescent reporters is used to observe the physiology of small animals. However, strong light scattering by biological tissues results in poor spatial resolution of the optical imaging, which also degrades the quantitative accuracy. To overcome this challenging problem, focused ultrasound is used to modulate the light from the reporter at the ultrasound frequency. This produces an ultrasound switchable light ‘beacon’ that reduces the influence of light scattering in order to improve spatial resolution. The experimental results demonstrate that apart from light modulation at the ultrasound frequency (AC signal at 3.5 MHz), ultrasound also increases the DC intensity of the reporters. This is shown to be due to a temperature rise caused by insonification that was minimized to be within acceptable mammalian tissue safety thresholds by adjusting the duty cycle of the ultrasound. Line scans of bio-and chemiluminescent objects embedded within a scattering medium were obtained using ultrasound modulated (AC) and ultrasound enhanced (DC) signals. Lateral resolution is improved by a factor of 12 and 7 respectively, as compared to conventional CCD imaging. Two chemiluminescent sources separated by ~10 mm at ~20 mm deep inside a 50 mm thick chicken breast have been successfully resolved with an average signal-to-noise ratio of approximately 8-10 dB. PMID:29675309

Is it time to include point-of-care ultrasound in general surgery training? A review to stimulate discussion.

PubMed

Mollenkopf, Maximilian; Tait, Noel

2013-12-01

Point-of-care ultrasound scanning or POCUS is a focused ultrasound (US) scan, performed by non-imaging clinicians during physical examination, an invasive procedure or surgery. As this technology becomes cheaper, smaller and easier to use, its scope for use by surgeons grows, a trend that may generate a gap between use and training. Opportunities for enhanced general surgery skill sets may be reduced unless consideration is given to inclusion of POCUS in general surgery training. To stimulate discussion regarding inclusion of POCUS in the general surgery curriculum; to resource this discussion with an overview of current trends and issues around POCUS; and to discuss concerns and controversies that may arise if POCUS was adopted into general surgery training. A literature search was performed using PUBMED, MEDLINE, Google and Google Scholar, using the terms 'ultrasound', 'point-of-care-ultrasound', 'bedside ultrasound', 'portable ultrasound' and 'hand-held ultrasound'. Literature, references and non-literature resources found were reviewed for relevance to US education in general surgery. Increasingly, medical students are graduating with basic POCUS skills. Specialty-specific uses of POCUS are proliferating. Training and assessment resources are not keeping up, in accessibility or standardization. A learned surgical college led training and accreditation process would require aligned education in anatomy and US technology and collaboration with the specialist imaging community to ensure appropriate standards are clarified and met. Research is also required into how general surgery trainees can best achieve and maintain POCUS competence. © 2013 Royal Australasian College of Surgeons.

Ultrasound-guided suprascapular nerve block: a correlation with fluoroscopic and cadaveric findings.

PubMed

Peng, Philip W H; Wiley, Michael J; Liang, James; Bellingham, Geoff A

2010-02-01

Previous work on the ultrasound-guided injection technique and the sonoanatomy of the suprascapular region relevant to the suprascapular nerve (SSN) block suggested that the ultrasound scan showed the presence of the suprascapular notch and transverse ligament. The intended target of the ultrasound-guided injection was the notch. The objective of this case report and the subsequent cadaver dissection findings is to reassess the interpretation of the ultrasound images when locating structures for SSN block. A 45-yr-old man with chronic shoulder pain received an ultrasound-guided SSN block using the suprascapular notch as the intended target. The position of the needle was verified by fluoroscopy, which showed the tip of the needle well outside the suprascapular notch. Similar ultrasound-guided SSN blocks were performed in two cadavers. Dissections were performed which showed that the needle tips were not at the suprascapular notch but, more accurately, were close to the SSN but at the floor of the suprascapular fossa between the suprascapular and spinoglenoid notch. Our fluoroscopic and cadaver dissection findings both suggest that the ultrasound image of the SSN block shown by the well-described technique is actually targeting the nerve on the floor of the suprascapular spine between the suprascapular and spinoglenoid notches rather than the suprascapular notch itself. The structure previously identified as the transverse ligament is actually the fascia layer of the supraspinatus muscle.

The ultrasound unit and infection control – Are we on the right track?

PubMed Central

Westerway, Susan C

2017-01-01

Best practice guidelines for the disinfection of ultrasound transducers and infection prevention in ultrasound departments are generally recommended by either government health groups or the ultrasound societies of individual countries. The literature shows a wide variance in not only transducer cleaning methods but basic hygiene practices in the ultrasound workplace. This paper describes results from a UK survey of disinfection of ultrasound transducers and hygiene practice in the workplace. The survey revealed that some ultrasound practitioners did not follow current guidelines with regard to the correct disinfection method of transducers, cords or ultrasound machine keyboards. Furthermore, the survey exposed the lack of training from the product manufacturers on how to use the disinfection product appropriately. These inconsistencies may be responsible for compliance issues and highlight the need for an awareness campaign and a unified approach to infection control by ultrasound practitioners. PMID:28228825

Detection of congenital heart defects throughout pregnancy; impact of first trimester ultrasound screening for cardiac abnormalities.

PubMed

Eleftheriades, Makarios; Tsapakis, Elsa; Sotiriadis, Alexandros; Manolakos, Emmanouil; Hassiakos, Demetrios; Botsis, Demetrios

2012-12-01

To evaluate prospectively the efficacy to screen for congenital heart defects (CHD) during the first trimester nuchal translucency (NT) ultrasound examination by assessing the four chambers' view of fetal heart. Pregnancies that were examined prospectively by ultrasound in the first trimester (11th-14th week), the second (19th-24th week) and third trimester were included in the study. 3774 fetuses were examined and fetal heart was assessed during the NT scan by examining the four chambers view. Detailed echocardiography was performed during the anomaly and growth scans. Diagnosis of congenital heart defects (CHD) was further confirmed by a fetal cardiologist. The four chambers view was obtained in 99.52% of the cases. CHD were diagnosed in 29 fetuses (0.77%). Thirteen cases (44.8%) were detected during the 11-13 weeks' scan, 14 cases (48.3%) during the anomaly scan, 1 CHD (3.5%) during the third trimester scan and 1 case (3.5%) postpartum. Assessment of the four chambers of fetal heart early in pregnancy was feasible and allowed the detection of 45% of CHD. Additional parameters of fetal cardiac anatomy during the NT scan may further improve the detection rate providing pregnancy management information early in the first trimester.

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

Freehand three-dimensional ultrasound imaging of carotid artery using motion tracking technology.

PubMed

Chung, Shao-Wen; Shih, Cho-Chiang; Huang, Chih-Chung

2017-02-01

Ultrasound imaging has been extensively used for determining the severity of carotid atherosclerotic stenosis. In particular, the morphological characterization of carotid plaques can be performed for risk stratification of patients. However, using 2D ultrasound imaging for detecting morphological changes in plaques has several limitations. Due to the scan was performed on a single longitudinal cross-section, the selected 2D image is difficult to represent the entire morphology and volume of plaque and vessel lumen. In addition, the precise positions of 2D ultrasound images highly depend on the radiologists' experience, it makes the serial long-term exams of anti-atherosclerotic therapies are difficult to relocate the same corresponding planes by using 2D B-mode images. This has led to the recent development of three-dimensional (3D) ultrasound imaging, which offers improved visualization and quantification of complex morphologies of carotid plaques. In the present study, a freehand 3D ultrasound imaging technique based on optical motion tracking technology is proposed. Unlike other optical tracking systems, the marker is a small rigid body that is attached to the ultrasound probe and is tracked by eight high-performance digital cameras. The probe positions in 3D space coordinates are then calibrated at spatial and temporal resolutions of 10μm and 0.01s, respectively. The image segmentation procedure involves Otsu's and the active contour model algorithms and accurately detects the contours of the carotid arteries. The proposed imaging technique was verified using normal artery and atherosclerotic stenosis phantoms. Human experiments involving freehand scanning of the carotid artery of a volunteer were also performed. The results indicated that compared with manual segmentation, the lowest percentage errors of the proposed segmentation procedure were 7.8% and 9.1% for the external and internal carotid arteries, respectively. Finally, the effect of handshaking was

Magnetic resonance-transcranial ultrasound fusion imaging: A novel tool for brain electrode location.

PubMed

Walter, Uwe; Müller, Jan-Uwe; Rösche, Johannes; Kirsch, Michael; Grossmann, Annette; Benecke, Reiner; Wittstock, Matthias; Wolters, Alexander

2016-03-01

A combination of preoperative magnetic resonance imaging (MRI) with real-time transcranial ultrasound, known as fusion imaging, may improve postoperative control of deep brain stimulation (DBS) electrode location. Fusion imaging, however, employs a weak magnetic field for tracking the position of the ultrasound transducer and the patient's head. Here we assessed its feasibility, safety, and clinical relevance in patients with DBS. Eighteen imaging sessions were conducted in 15 patients (7 women; aged 52.4 ± 14.4 y) with DBS of subthalamic nucleus (n = 6), globus pallidus interna (n = 5), ventro-intermediate (n = 3), or anterior (n = 1) thalamic nucleus and clinically suspected lead displacement. Minimum distance between DBS generator and magnetic field transmitter was kept at 65 cm. The pre-implantation MRI dataset was loaded into the ultrasound system for the fusion imaging examination. The DBS lead position was rated using validated criteria. Generator DBS parameters and neurological state of patients were monitored. Magnetic resonance-ultrasound fusion imaging and volume navigation were feasible in all cases and provided with real-time imaging capabilities of DBS lead and its location within the superimposed magnetic resonance images. Of 35 assessed lead locations, 30 were rated optimal, three suboptimal, and two displaced. In two cases, electrodes were re-implanted after confirming their inappropriate location on computed tomography (CT) scan. No influence of fusion imaging on clinical state of patients, or on DBS implantable pulse generator function, was found. Magnetic resonance-ultrasound real-time fusion imaging of DBS electrodes is safe with distinct precautions and improves assessment of electrode location. It may lower the need for repeated CT or MRI scans in DBS patients. © 2015 International Parkinson and Movement Disorder Society.

Non-invasive assessment of negative pressure wound therapy using high frequency diagnostic ultrasound: oedema reduction and new tissue accumulation.

PubMed

Young, Stephen R; Hampton, Sylvie; Martin, Robin

2013-08-01

Tissue oedema plays an important role in the pathology of chronic and traumatic wounds. Negative pressure wound therapy (NPWT) is thought to contribute to active oedema reduction, yet few studies have showed this effect. In this study, high frequency diagnostic ultrasound at 20 MHz with an axial resolution of 60 µm was used to assess the effect of NPWT at - 80 mmHg on pressure ulcers and the surrounding tissue. Wounds were monitored in four patients over a 3-month period during which changes in oedema and wound bed thickness (granulation tissue) were measured non-invasively. The results showed a rapid reduction of periwound tissue oedema in all patients with levels falling by a mean of 43% after 4 days of therapy. A 20% increase in the thickness of the wound bed was observed after 7 days due to new granulation tissue formation. Ultrasound scans through the in situ gauze NPWT filler also revealed the existence of macrodeformation in the tissue produced by the negative pressure. These preliminary studies suggest that non-invasive assessment using high frequency diagnostic ultrasound could be a valuable tool in clinical studies of NPWT. © 2012 The Authors. International Wound Journal © 2012 John Wiley & Sons Ltd and Medicalhelplines.com Inc.

Effect of ultrasound frequency on the Nakagami statistics of human liver tissues.

PubMed

Tsui, Po-Hsiang; Zhou, Zhuhuang; Lin, Ying-Hsiu; Hung, Chieh-Ming; Chung, Shih-Jou; Wan, Yung-Liang

2017-01-01

The analysis of the backscattered statistics using the Nakagami parameter is an emerging ultrasound technique for assessing hepatic steatosis and fibrosis. Previous studies indicated that the echo amplitude distribution of a normal liver follows the Rayleigh distribution (the Nakagami parameter m is close to 1). However, using different frequencies may change the backscattered statistics of normal livers. This study explored the frequency dependence of the backscattered statistics in human livers and then discussed the sources of ultrasound scattering in the liver. A total of 30 healthy participants were enrolled to undergo a standard care ultrasound examination on the liver, which is a natural model containing diffuse and coherent scatterers. The liver of each volunteer was scanned from the right intercostal view to obtain image raw data at different central frequencies ranging from 2 to 3.5 MHz. Phantoms with diffuse scatterers only were also made to perform ultrasound scanning using the same protocol for comparisons with clinical data. The Nakagami parameter-frequency correlation was evaluated using Pearson correlation analysis. The median and interquartile range of the Nakagami parameter obtained from livers was 1.00 (0.98-1.05) for 2 MHz, 0.93 (0.89-0.98) for 2.3 MHz, 0.87 (0.84-0.92) for 2.5 MHz, 0.82 (0.77-0.88) for 3.3 MHz, and 0.81 (0.76-0.88) for 3.5 MHz. The Nakagami parameter decreased with the increasing central frequency (r = -0.67, p < 0.0001). However, the effect of ultrasound frequency on the statistical distribution of the backscattered envelopes was not found in the phantom results (r = -0.147, p = 0.0727). The current results demonstrated that the backscattered statistics of normal livers is frequency-dependent. Moreover, the coherent scatterers may be the primary factor to dominate the frequency dependence of the backscattered statistics in a liver.

B-scan ultrasonography for the detection of space-occupying ocular masses.

PubMed

Miller, W W; Cartee, R E

1985-07-01

A noninvasive technique, B-scan ultrasonography, was used to obtain detailed cross-sectional images of ocular and orbital structure and form. When a low-frequency probe (5 MHz) was used, tissue penetration was excellent; however, axial resolution was limited. The technique was used in a study of 2 cats and 1 dog. The use of low-frequency B-scan ultrasound should aid in the diagnostic examinations of space-occupying masses in the posterior portion of the ocular bulb and the orbit.

Roller-transducer scanning of wooden pallet parts for defect detection

Treesearch

Mohammed F. Kabir; Daniel L. Schmoldt; Mark E. Schafer

2001-01-01

Ultrasonic scanning experiments were conducted on two species of pallet deckboards using rolling transducers in a pitch-catch arrangement. Sound and unsound knots, cross grain, bark pockets, holes, splits, decay, and wane were characterized using several ultrasound parameters. Almost all parameters displayed sensitivity to defects distinctly from clear wood regions—...

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.

Controlled morphology and size of curcumin using ultrasound in supercritical CO2 antisolvent.

PubMed

Jia, Jingfu; Wang, Wucong; Gao, Yahui; Zhao, Yaping

2015-11-01

Controllable morphology and size of crystal materials prepared by using a supercritical antisolvent (SAS) technique is still challenge. In this study, ultrasound was introduced into the SAS process to produce the particles of curcumin, a model compound. The effects of ultrasound power on the particle morphology and size were investigated in the range of 0 and 240 W at three different pressures. The observation of jet flow indicated ultrasound could accelerate the mixing speed between the liquid solution and the CO2, and thus reduced the gaseous region and the local saturation gradient. Mixed polymorphic and uniform particles of the curcumin were produced at a low and high mixing speed, respectively, confirmed by scanning electron microscopy. The needle- or rod-like particle, irregular lumpy particle and nano spherical particle were generated with the increase of the ultrasound power, attributed to the changes of the degree of supersaturation. Therefore, the ultrasound can be potentially applied to adjust the morphology and size of the crystal materials in supercritical CO2 antisolvent. Copyright © 2015 Elsevier B.V. All rights reserved.

Interleukin 16- (IL-16-) Targeted Ultrasound Imaging Agent Improves Detection of Ovarian Tumors in Laying Hens, a Preclinical Model of Spontaneous Ovarian Cancer.

PubMed

Barua, Animesh; Yellapa, Aparna; Bahr, Janice M; Adur, Malavika K; Utterback, Chet W; Bitterman, Pincas; Basu, Sanjib; Sharma, Sameer; Abramowicz, Jacques S

2015-01-01

Limited resolution of transvaginal ultrasound (TVUS) scanning is a significant barrier to early detection of ovarian cancer (OVCA). Contrast agents have been suggested to improve the resolution of TVUS scanning. Emerging evidence suggests that expression of interleukin 16 (IL-16) by the tumor epithelium and microvessels increases in association with OVCA development and offers a potential target for early OVCA detection. The goal of this study was to examine the feasibility of IL-16-targeted contrast agents in enhancing the intensity of ultrasound imaging from ovarian tumors in hens, a model of spontaneous OVCA. Contrast agents were developed by conjugating biotinylated anti-IL-16 antibodies with streptavidin coated microbubbles. Enhancement of ultrasound signal intensity was determined before and after injection of contrast agents. Following scanning, ovarian tissues were processed for the detection of IL-16 expressing cells and microvessels. Compared with precontrast, contrast imaging enhanced ultrasound signal intensity significantly in OVCA hens at early (P < 0.05) and late stages (P < 0.001). Higher intensities of ultrasound signals in OVCA hens were associated with increased frequencies of IL-16 expressing cells and microvessels. These results suggest that IL-16-targeted contrast agents improve the visualization of ovarian tumors. The laying hen may be a suitable model to test new imaging agents and develop targeted anti-OVCA therapeutics.

An image registration based ultrasound probe calibration

NASA Astrophysics Data System (ADS)

Li, Xin; Kumar, Dinesh; Sarkar, Saradwata; Narayanan, Ram

2012-02-01

Reconstructed 3D ultrasound of prostate gland finds application in several medical areas such as image guided biopsy, therapy planning and dose delivery. In our application, we use an end-fire probe rotated about its axis to acquire a sequence of rotational slices to reconstruct 3D TRUS (Transrectal Ultrasound) image. The image acquisition system consists of an ultrasound transducer situated on a cradle directly attached to a rotational sensor. However, due to system tolerances, axis of probe does not align exactly with the designed axis of rotation resulting in artifacts in the 3D reconstructed ultrasound volume. We present a rigid registration based automatic probe calibration approach. The method uses a sequence of phantom images, each pair acquired at angular separation of 180 degrees and registers corresponding image pairs to compute the deviation from designed axis. A modified shadow removal algorithm is applied for preprocessing. An attribute vector is constructed from image intensity and a speckle-insensitive information-theoretic feature. We compare registration between the presented method and expert-corrected images in 16 prostate phantom scans. Images were acquired at multiple resolutions, and different misalignment settings from two ultrasound machines. Screenshots from 3D reconstruction are shown before and after misalignment correction. Registration parameters from automatic and manual correction were found to be in good agreement. Average absolute differences of translation and rotation between automatic and manual methods were 0.27 mm and 0.65 degree, respectively. The registration parameters also showed lower variability for automatic registration (pooled standard deviation σtranslation = 0.50 mm, σrotation = 0.52 degree) compared to the manual approach (pooled standard deviation σtranslation = 0.62 mm, σrotation = 0.78 degree).

In situ formation deposited ZnO nanoparticles on silk fabrics under ultrasound irradiation.

PubMed

Khanjani, Somayeh; Morsali, Ali; Joo, Sang W

2013-03-01

Deposition of zinc(II) oxide (ZnO) nanoparticles on the surface of silk fabrics was prepared by sequential dipping steps in alternating bath of potassium hydroxide and zinc nitrate under ultrasound irradiation. This coating involves in situ generation and deposition of ZnO in a one step. The effects of ultrasound irradiation, concentration and sequential dipping steps on growth of the ZnO nanoparticles have been studied. Results show a decrease in the particles size as increasing power of ultrasound irradiation. Also, increasing of the concentration and sequential dipping steps increase particle size. The physicochemical properties of the nanoparticles were determined by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and wavelength dispersive X-ray (WDX). Copyright © 2012 Elsevier B.V. All rights reserved.

Influence of ultrasound pretreatment on wood physiochemical structure.

PubMed

He, Zhengbin; Wang, Zhenyu; Zhao, Zijian; Yi, Songlin; Mu, Jun; Wang, Xiaoxu

2017-01-01

As an initial step to increase the use of renewable biomass resources, this study was aimed at investigating the effects of ultrasound pretreatment on structural changes of wood. Samples were pretreated by ultrasound with the power of 300W and frequency of 28kHz in aqueous soda solution, aqueous acetic acid, or distilled water, then pretreated and control samples were characterized via X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). The results shown that ultrasound pretreatment is indeed effective in modifying the physiochemical structure of eucalyptus wood; the pretreatment decreased the quantity of alkali metals (e.g., potassium, calcium and magnesium) in the resulting material. Compared to the control group, the residual char content of samples pretreated in aqueous soda solution increased by 10.08%-20.12% and the reaction temperature decreased from 361°C to 341°C, however, in samples pretreated by ultrasound in acetic solution or distilled water, the residual char content decreased by 12.40%-21.45% and there were no significant differences in reactivity apart from a slightly higher maximum reaction rate. Ultrasound pretreatment increased the samples' crystallinity up to 35.5% and successfully removed cellulose, hemicellulose, and lignin from the samples; the pretreatment also increased the exposure of the sample to the treatment solutions, broke down sample pits, and generated collapses and microchannels on sample pits, and removed attachments in the samples. Copyright © 2016 Elsevier B.V. All rights reserved.

Remote ultrasound palpation for robotic interventions using absolute elastography.

PubMed

Schneider, Caitlin; Baghani, Ali; Rohling, Robert; Salcudean, Septimiu

2012-01-01

Although robotic surgery has addressed many of the challenges presented by minimally invasive surgery, haptic feedback and the lack of knowledge of tissue stiffness is an unsolved problem. This paper presents a system for finding the absolute elastic properties of tissue using a freehand ultrasound scanning technique, which utilizes the da Vinci Surgical robot and a custom 2D ultrasound transducer for intraoperative use. An external exciter creates shear waves in the tissue, and a local frequency estimation method computes the shear modulus. Results are reported for both phantom and in vivo models. This system can be extended to any 6 degree-of-freedom tracking method and any 2D transducer to provide real-time absolute elastic properties of tissue.

Toward dynamic lumbar punctures guidance based on single element synthetic tracked aperture ultrasound imaging

NASA Astrophysics Data System (ADS)

Zhang, Haichong K.; Lin, Melissa; Kim, Younsu; Paredes, Mateo; Kannan, Karun; Patel, Nisu; Moghekar, Abhay; Durr, Nicholas J.; Boctor, Emad M.

2017-03-01

Lumbar punctures (LPs) are interventional procedures used to collect cerebrospinal fluid (CSF), a bodily fluid needed to diagnose central nervous system disorders. Most lumbar punctures are performed blindly without imaging guidance. Because the target window is small, physicians can only accurately palpate the appropriate space about 30% of the time and perform a successful procedure after an average of three attempts. Although various forms of imaging based guidance systems have been developed to aid in this procedure, these systems complicate the procedure by including independent image modalities and requiring image-to-needle registration to guide the needle insertion. Here, we propose a simple and direct needle insertion platform utilizing a single ultrasound element within the needle through dynamic sensing and imaging. The needle-shaped ultrasound transducer can not only sense the distance between the tip and a potential obstacle such as bone, but also visually locate structures by combining transducer location tracking and back projection based tracked synthetic aperture beam-forming algorithm. The concept of the system was validated through simulation first, which revealed the tolerance to realistic error. Then, the initial prototype of the single element transducer was built into a 14G needle, and was mounted on a holster equipped with a rotation tracking encoder. We experimentally evaluated the system using a metal wire phantom mimicking high reflection bone structures and an actual spine bone phantom with both the controlled motion and freehand scanning. An ultrasound image corresponding to the model phantom structure was reconstructed using the beam-forming algorithm, and the resolution was improved compared to without beam-forming. These results demonstrated the proposed system has the potential to be used as an ultrasound imaging system for lumbar puncture procedures.

A Comparison of Ultrasound Tomography Methods in Circular Geometry

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

Leach, R R; Azevedo, S G; Berryman, J G

2002-01-24

Extremely high quality data was acquired using an experimental ultrasound scanner developed at Lawrence Livermore National Laboratory using a 2D ring geometry with up to 720 transmitter/receiver transducer positions. This unique geometry allows reflection and transmission modes and transmission imaging and quantification of a 3D volume using 2D slice data. Standard image reconstruction methods were applied to the data including straight-ray filtered back projection, reflection tomography, and diffraction tomography. Newer approaches were also tested such as full wave, full wave adjoint method, bent-ray filtered back projection, and full-aperture tomography. A variety of data sets were collected including a formalin-fixed humanmore » breast tissue sample, a commercial ultrasound complex breast phantom, and cylindrical objects with and without inclusions. The resulting reconstruction quality of the images ranges from poor to excellent. The method and results of this study are described including like-data reconstructions produced by different algorithms with side-by-side image comparisons. Comparisons to medical B-scan and x-ray CT scan images are also shown. Reconstruction methods with respect to image quality using resolution, noise, and quantitative accuracy, and computational efficiency metrics will also be discussed.« less

Evaluation of Ultrasound-Induced Damage to Escherichia coli and Staphylococcus aureus by Flow Cytometry and Transmission Electron Microscopy

PubMed Central

Li, Jiao; Ahn, Juhee; Liu, Donghong; Chen, Shiguo; Ye, Xingqian

2016-01-01

As a nonthermal sterilization technique, ultrasound has attracted great interest in the field of food preservation. In this study, flow cytometry and transmission electron microscopy were employed to investigate ultrasound-induced damage to Escherichia coli and Staphylococcus aureus. For flow cytometry studies, single staining with propidium iodide (PI) or carboxyfluorescein diacetate (cFDA) revealed that ultrasound treatment caused cell death by compromising membrane integrity, inactivating intracellular esterases, and inhibiting metabolic performance. The results showed that ultrasound damage was independent of initial bacterial concentrations, while the mechanism of cellular damage differed according to the bacterial species. For the Gram-negative bacterium E. coli, ultrasound worked first on the outer membrane rather than the cytoplasmic membrane. Based on the double-staining results, we inferred that ultrasound treatment might be an all-or-nothing process: cells ruptured and disintegrated by ultrasound cannot be revived, which can be considered an advantage of ultrasound over other nonthermal techniques. Transmission electron microscopy studies revealed that the mechanism of ultrasound-induced damage was multitarget inactivation, involving the cell wall, cytoplasmic membrane, and inner structure. Understanding of the irreversible antibacterial action of ultrasound has great significance for its further utilization in the food industry. PMID:26746712

Five-dimensional ultrasound system for soft tissue visualization.

PubMed

Deshmukh, Nishikant P; Caban, Jesus J; Taylor, Russell H; Hager, Gregory D; Boctor, Emad M

2015-12-01

A five-dimensional ultrasound (US) system is proposed as a real-time pipeline involving fusion of 3D B-mode data with the 3D ultrasound elastography (USE) data as well as visualization of these fused data and a real-time update capability over time for each consecutive scan. 3D B-mode data assist in visualizing the anatomy of the target organ, and 3D elastography data adds strain information. We investigate the feasibility of such a system and show that an end-to-end real-time system, from acquisition to visualization, can be developed. We present a system that consists of (a) a real-time 3D elastography algorithm based on a normalized cross-correlation (NCC) computation on a GPU; (b) real-time 3D B-mode acquisition and network transfer; (c) scan conversion of 3D elastography and B-mode volumes (if acquired by 4D wobbler probe); and (d) visualization software that fuses, visualizes, and updates 3D B-mode and 3D elastography data in real time. We achieved a speed improvement of 4.45-fold for the threaded version of the NCC-based 3D USE versus the non-threaded version. The maximum speed was 79 volumes/s for 3D scan conversion. In a phantom, we validated the dimensions of a 2.2-cm-diameter sphere scan-converted to B-mode volume. Also, we validated the 5D US system visualization transfer function and detected 1- and 2-cm spherical objects (phantom lesion). Finally, we applied the system to a phantom consisting of three lesions to delineate the lesions from the surrounding background regions of the phantom. A 5D US system is achievable with real-time performance. We can distinguish between hard and soft areas in a phantom using the transfer functions.

Variogram methods for texture classification of atherosclerotic plaque ultrasound images

NASA Astrophysics Data System (ADS)

Jeromin, Oliver M.; Pattichis, Marios S.; Pattichis, Constantinos; Kyriacou, Efthyvoulos; Nicolaides, Andrew

2006-03-01

Stroke is the third leading cause of death in the western world and the major cause of disability in adults. The type and stenosis of extracranial carotid artery disease is often responsible for ischemic strokes, transient ischemic attacks (TIAs) or amaurosis fugax (AF). The identification and grading of stenosis can be done using gray scale ultrasound scans. The appearance of B-scan pictures containing various granular structures makes the use of texture analysis techniques suitable for computer assisted tissue characterization purposes. The objective of this study is to investigate the usefulness of variogram analysis in the assessment of ultrasound plague morphology. The variogram estimates the variance of random fields, from arbitrary samples in space. We explore stationary random field models based on the variogram, which can be applied in ultrasound plaque imaging leading to a Computer Aided Diagnosis (CAD) system for the early detection of symptomatic atherosclerotic plaques. Non-parametric tests on the variogram coefficients show that the cofficients coming from symptomatic versus asymptomatic plaques come from distinct distributions. Furthermore, we show significant improvement in class separation, when a log point-transformation is applied to the images, prior to variogram estimation. Model fitting using least squares is explored for anisotropic variograms along specific directions. Comparative classification results, show that variogram coefficients can be used for the early detection of symptomatic cases, and also exhibit the largest class distances between symptomatic and asymptomatic plaque images, as compared to over 60 other texture features, used in the literature.

[Prenatal diagnosis of isolated otocefalia. Usefulness of three-dimensional ultrasound].

PubMed

Escribano Abad, David; Arbués Gabarre, Juan; Gómez Montes, Enery; Puente Agueda, José Manuel; Herraiz García, Ignacio; Galindo Izquierdo, Alberto

2011-08-01

Otocephaly is a rare and lethal congenital malformation characterized by the presence of agnathia, microstomia, aglossia and synotia. Despite its frequent association with severe malformations, diagnosis in the few published cases is usually made at III trimester. In this case, three-dimensional ultrasound scan was performed in a Chinese primigravida with no remarkable personal nor familiar history since mandible was difficulty visualized with two-dimensional sonography at 21 weeks of gestation. Multiplanar and rendering mode showed the typical cervicofacial features of otocephaly without associated malformations. After parental counselling, they opted for termination of pregnancy and necropsy confirmed our prenatal findings. Our case shows the usefulness of three-dimensional ultrasound in assessing fetal cervicofacial pathology. Volumetric capture allows a delayed study of fetal anatomy and multiplanar mode offers the reconstruction of views whose achivement is difficult with conventional 2D ultrasound. Surface rendering provides excellent spatial vision and enables parents to understand the severity of the malformation thus helping with their decisions.

Ultrasound contrast agents for bleeding detection and acoustic hemostasis

NASA Astrophysics Data System (ADS)

Zderic, Vesna; Luo, Wenbo; Brayman, Andrew; Crum, Lawrence; Vaezy, Shahram

2005-04-01

Objective: To investigate the application of ultrasound contrast agents (UCA) in improving both therapeutic and diagnostic aspects of ultrasound-guided High Intensity Focused Ultrasound (HIFU) therapy. Methods: Incisions (3 cm long, 0.5 cm deep) were made in rabbit livers (in anterior surface for HIFU treatment, or posterior surface for bleeding detection). UCA Optison (~0.1 ml/kg) was injected into mesenteric vein or ear vein. A HIFU applicator (5.5 MHz, 6400 W/cm2) was scanned manually over the incision until hemostasis was achieved. Occult bleeding was monitored with Doppler ultrasound. Results: The presence of Optison produced 37% reduction in hemostasis times normalized to initial bleeding rates. Gross and histological observations showed similar appearance of HIFU lesions produced in the presence of Optison and control HIFU lesions. The temperature reached 100°C in both HIFU only and HIFU+UCA treatments. Tension strength of hemostatic liver incisions was 0.9+/-0.5 N. Almost no bleeding could be detected before Optison injection. First appearance of contrast enhancement localized at the bleeding site was 15 s after Optison injection, and lasted for ~50 s. Conclusion: The presence of UCA during HIFU treatment of liver incisions resulted in shortening of HIFU application times and better visualization of bleeding sites.

Breast tumour visualization using 3D quantitative ultrasound methods

NASA Astrophysics Data System (ADS)

Gangeh, Mehrdad J.; Raheem, Abdul; Tadayyon, Hadi; Liu, Simon; Hadizad, Farnoosh; Czarnota, Gregory J.

2016-04-01

Breast cancer is one of the most common cancer types accounting for 29% of all cancer cases. Early detection and treatment has a crucial impact on improving the survival of affected patients. Ultrasound (US) is non-ionizing, portable, inexpensive, and real-time imaging modality for screening and quantifying breast cancer. Due to these attractive attributes, the last decade has witnessed many studies on using quantitative ultrasound (QUS) methods in tissue characterization. However, these studies have mainly been limited to 2-D QUS methods using hand-held US (HHUS) scanners. With the availability of automated breast ultrasound (ABUS) technology, this study is the first to develop 3-D QUS methods for the ABUS visualization of breast tumours. Using an ABUS system, unlike the manual 2-D HHUS device, the whole patient's breast was scanned in an automated manner. The acquired frames were subsequently examined and a region of interest (ROI) was selected in each frame where tumour was identified. Standard 2-D QUS methods were used to compute spectral and backscatter coefficient (BSC) parametric maps on the selected ROIs. Next, the computed 2-D parameters were mapped to a Cartesian 3-D space, interpolated, and rendered to provide a transparent color-coded visualization of the entire breast tumour. Such 3-D visualization can potentially be used for further analysis of the breast tumours in terms of their size and extension. Moreover, the 3-D volumetric scans can be used for tissue characterization and the categorization of breast tumours as benign or malignant by quantifying the computed parametric maps over the whole tumour volume.

Standardized ultrasound templates for diagnosing appendicitis reduce annual imaging costs.

PubMed

Nordin, Andrew B; Sales, Stephen; Nielsen, Jason W; Adler, Brent; Bates, David Gregory; Kenney, Brian

2018-01-01

Ultrasound is preferred over computed tomography (CT) for diagnosing appendicitis in children to avoid undue radiation exposure. We previously reported our experience in instituting a standardized appendicitis ultrasound template, which decreased CT rates by 67.3%. In this analysis, we demonstrate the ongoing cost savings associated with using this template. Retrospective chart review for the time period preceding template implementation (June 2012-September 2012) was combined with prospective review through December 2015 for all patients in the emergency department receiving diagnostic imaging for appendicitis. The type of imaging was recorded, and imaging rates and ultrasound test statistics were calculated. Estimated annual imaging costs based on pretemplate ultrasound and CT utilization rates were compared with post-template annual costs to calculate annual and cumulative savings. In the pretemplate period, ultrasound and CT rates were 80.2% and 44.3%, respectively, resulting in a combined annual cost of $300,527.70. Similar calculations were performed for each succeeding year, accounting for changes in patient volume. Using pretemplate rates, our projected 2015 imaging cost was $371,402.86; however, our ultrasound rate had increased to 98.3%, whereas the CT rate declined to 9.6%, yielding an annual estimated cost of $224,853.00 and a savings of $146,549.86. Since implementation, annual savings have steadily increased for a cumulative cost savings of $336,683.83. Standardizing ultrasound reports for appendicitis not only reduces the use of CT scans and the associated radiation exposure but also decreases annual imaging costs despite increased numbers of imaging studies. Continued cost reduction may be possible by using diagnostic algorithms. Copyright © 2017 Elsevier Inc. All rights reserved.

Distributed Network, Wireless and Cloud Computing Enabled 3-D Ultrasound; a New Medical Technology Paradigm

PubMed Central

Meir, Arie; Rubinsky, Boris

2009-01-01

Medical technologies are indispensable to modern medicine. However, they have become exceedingly expensive and complex and are not available to the economically disadvantaged majority of the world population in underdeveloped as well as developed parts of the world. For example, according to the World Health Organization about two thirds of the world population does not have access to medical imaging. In this paper we introduce a new medical technology paradigm centered on wireless technology and cloud computing that was designed to overcome the problems of increasing health technology costs. We demonstrate the value of the concept with an example; the design of a wireless, distributed network and central (cloud) computing enabled three-dimensional (3-D) ultrasound system. Specifically, we demonstrate the feasibility of producing a 3-D high end ultrasound scan at a central computing facility using the raw data acquired at the remote patient site with an inexpensive low end ultrasound transducer designed for 2-D, through a mobile device and wireless connection link between them. Producing high-end 3D ultrasound images with simple low-end transducers reduces the cost of imaging by orders of magnitude. It also removes the requirement of having a highly trained imaging expert at the patient site, since the need for hand-eye coordination and the ability to reconstruct a 3-D mental image from 2-D scans, which is a necessity for high quality ultrasound imaging, is eliminated. This could enable relatively untrained medical workers in developing nations to administer imaging and a more accurate diagnosis, effectively saving the lives of people. PMID:19936236

Distributed network, wireless and cloud computing enabled 3-D ultrasound; a new medical technology paradigm.

PubMed

Meir, Arie; Rubinsky, Boris

2009-11-19

Medical technologies are indispensable to modern medicine. However, they have become exceedingly expensive and complex and are not available to the economically disadvantaged majority of the world population in underdeveloped as well as developed parts of the world. For example, according to the World Health Organization about two thirds of the world population does not have access to medical imaging. In this paper we introduce a new medical technology paradigm centered on wireless technology and cloud computing that was designed to overcome the problems of increasing health technology costs. We demonstrate the value of the concept with an example; the design of a wireless, distributed network and central (cloud) computing enabled three-dimensional (3-D) ultrasound system. Specifically, we demonstrate the feasibility of producing a 3-D high end ultrasound scan at a central computing facility using the raw data acquired at the remote patient site with an inexpensive low end ultrasound transducer designed for 2-D, through a mobile device and wireless connection link between them. Producing high-end 3D ultrasound images with simple low-end transducers reduces the cost of imaging by orders of magnitude. It also removes the requirement of having a highly trained imaging expert at the patient site, since the need for hand-eye coordination and the ability to reconstruct a 3-D mental image from 2-D scans, which is a necessity for high quality ultrasound imaging, is eliminated. This could enable relatively untrained medical workers in developing nations to administer imaging and a more accurate diagnosis, effectively saving the lives of people.

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.

Ultrasound Backscatter Microscopy for Imaging of Oral Carcinoma

PubMed Central

Lam, Matthew; Chaudhari, Abhijit J.; Sun, Yang; Zhou, Feifei; Dobbie, Allison; Gandour-Edwards, Regina F.; Tinling, Steve P.; Farwell, D. Gregory; Monsky, Wayne L.; Shung, K. Kirk; Marcu, Laura

2013-01-01

Objectives Ultrasound backscatter microscopy (UBM), or ultrasound biomicroscopy, is a noninvasive, label-free, and ionizing radiation–free technique allowing high-resolution 3-dimensional structural imaging. The goal of this study was to evaluate UBM for resolving anatomic features associated with squamous cell carcinoma of the oral cavity. Methods The study was conducted in a hamster buccal pouch model. A carcinogen was topically applied to cheeks of 14 golden Syrian hamsters. Six additional hamsters served as healthy controls. A high-frequency (41 MHz, 6-mm focal depth, lateral and axial resolutions of 65 and 37 μm, respectively) UBM system was used for scanning the oral cavity after 14 weeks of carcinogen application. Histologic analyses were conducted on scanned regions. Results The histologic structure of buccal tissue and microvasculature networks could be visualized from the UBM images. Epithelial and mucosal hypertrophy and neoplastic changes were identified in animals subjected to the carcinogen. In animals with invasive squamous cell carcinoma, lesion development and destruction of the structural integrity of tissue layers were noted. Conclusions In this pilot study, UBM generated sufficient contrast for morphologic features associated with oral carcinoma compared to healthy tissue. This modality may present a practical technique for detection of oral neoplasms that is potentially translatable to humans. PMID:24065260

Catalytic reaction processes revealed by scanning probe microscopy. [corrected].

PubMed

Jiang, Peng; Bao, Xinhe; Salmeron, Miquel

2015-05-19

Heterogeneous catalysis is of great importance for modern society. About 80% of the chemicals are produced by catalytic reactions. Green energy production and utilization as well as environmental protection also need efficient catalysts. Understanding the reaction mechanisms is crucial to improve the existing catalysts and develop new ones with better activity, selectivity, and stability. Three components are involved in one catalytic reaction: reactant, product, and catalyst. The catalytic reaction process consists of a series of elementary steps: adsorption, diffusion, reaction, and desorption. During reaction, the catalyst surface can change at the atomic level, with roughening, sintering, and segregation processes occurring dynamically in response to the reaction conditions. Therefore, it is imperative to obtain atomic-scale information for understanding catalytic reactions. Scanning probe microscopy (SPM) is a very appropriate tool for catalytic research at the atomic scale because of its unique atomic-resolution capability. A distinguishing feature of SPM, compared to other surface characterization techniques, such as X-ray photoelectron spectroscopy, is that there is no intrinsic limitation for SPM to work under realistic reaction conditions (usually high temperature and high pressure). Therefore, since it was introduced in 1981, scanning tunneling microscopy (STM) has been widely used to investigate the adsorption, diffusion, reaction, and desorption processes on solid catalyst surfaces at the atomic level. STM can also monitor dynamic changes of catalyst surfaces during reactions. These invaluable microscopic insights have not only deepened the understanding of catalytic processes, but also provided important guidance for the development of new catalysts. This Account will focus on elementary reaction processes revealed by SPM. First, we will demonstrate the power of SPM to investigate the adsorption and diffusion process of reactants on catalyst surfaces

Feasibility of a focused ultrasound training programme for medical undergraduate students.

PubMed

Wong, Ivan; Jayatilleke, Thilina; Kendall, Richard; Atkinson, Paul

2011-03-01

Although ultrasound is a core skill for many clinical specialties, UK medical schools are not currently required to teach this skill. The College of Emergency Medicine (CEM) has championed the use of ultrasound to answer focused clinical questions in emergency settings. We have designed and piloted an ultrasound training course for undergraduate medical students addressing one important indication: ultrasound assessment of the abdominal aorta. Fourteen clinical students, who had no prior experience of using ultrasound, received focused ultrasound training in the form of didactic instruction, a short bedside practical workshop and self-directed learning over a 20-day period. At the end of this period, the students were assessed by a structured viva and an observed structured clinical examination (OSCE) used for accreditation by the CEM. The primary endpoint was the number of students who passed the assessment. The secondary endpoint was the accuracy of the students' anatomical measurements. Thirteen of the 14 (93%) students completed the training and assessment. Eight of the 13 (62%) students passed both the viva and OSCE, and were deemed to have achieved the CEM standard. The measurements by the competent students were not statistically different from those of experienced practitioners. We have shown for the first time that it is feasible to train inexperienced undergraduate students to scan the abdominal aorta to a professional standard using a focused training course. It is time for the medical education community to address whether focused ultrasound training should accompany traditional clinical skills, such as using a stethoscope, in UK medical school curricula. © Blackwell Publishing Ltd 2011.

Dependence of thresholds for pulmonary capillary hemorrhage on diagnostic ultrasound frequency.

PubMed

Miller, Douglas L; Dou, Chunyan; Raghavendran, Krishnan

2015-06-01

Pulmonary ultrasound examination has become routine for diagnosis in many clinical and point-of-care medical settings. However, the phenomenon of pulmonary capillary hemorrhage (PCH) induction during diagnostic ultrasound imaging presents a poorly understood risk factor. PCH was observed in anesthetized rats exposed to 1.5-, 4.5- and 12.0-MHz diagnostic ultrasound to investigate the frequency dependence of PCH thresholds. PCH was detected in the ultrasound images as growing comet tail artifacts and was assessed using photographs of the surface of excised lungs. Previous photographs acquired after exposure to 7.6-MHz diagnostic ultrasound were included for analysis. In addition, at each frequency we measured dosimetric parameters, including peak rarefactional pressure amplitude and spatial peak, pulse average intensity attenuated by rat chest wall samples. Peak rarefactional pressure amplitude thresholds determined at each frequency, based on the proportion of PCH in groups of five rats, were 1.03 ± 0.02, 1.28 ± 0.14, 1.18 ± 0.12 and 1.36 ± 0.15 MPa at 1.5, 4.5, 7.6 and 12.0 MHz, respectively. Although the PCH lesions decreased in size with increasing ultrasonic frequency, owing to the smaller beam widths and scan lengths, the peak rarefactional pressure amplitude thresholds remained approximately constant. This dependence was different from that of the mechanical index, which indicates a need for a specific dosimetric parameter for safety guidance in pulmonary ultrasound. Copyright © 2015 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

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.

Contrast-enhanced and targeted ultrasound.

PubMed

Postema, Michiel; Gilja, Odd Helge

2011-01-07

Ultrasonic imaging is becoming the most popular medical imaging modality, owing to the low price per examination and its safety. However, blood is a poor scatterer of ultrasound waves at clinical diagnostic transmit frequencies. For perfusion imaging, markers have been designed to enhance the contrast in B-mode imaging. These so-called ultrasound contrast agents consist of microscopically small gas bubbles encapsulated in biodegradable shells. In this review, the physical principles of ultrasound contrast agent microbubble behavior and their adjustment for drug delivery including sonoporation are described. Furthermore, an outline of clinical imaging applications of contrast-enhanced ultrasound is given. It is a challenging task to quantify and predict which bubble phenomenon occurs under which acoustic condition, and how these phenomena may be utilized in ultrasonic imaging. Aided by high-speed photography, our improved understanding of encapsulated microbubble behavior will lead to more sophisticated detection and delivery techniques. More sophisticated methods use quantitative approaches to measure the amount and the time course of bolus or reperfusion curves, and have shown great promise in revealing effective tumor responses to anti-angiogenic drugs in humans before tumor shrinkage occurs. These are beginning to be accepted into clinical practice. In the long term, targeted microbubbles for molecular imaging and eventually for directed anti-tumor therapy are expected to be tested.

Contrast-enhanced and targeted ultrasound

PubMed Central

Postema, Michiel; Gilja, Odd Helge

2011-01-01

Ultrasonic imaging is becoming the most popular medical imaging modality, owing to the low price per examination and its safety. However, blood is a poor scatterer of ultrasound waves at clinical diagnostic transmit frequencies. For perfusion imaging, markers have been designed to enhance the contrast in B-mode imaging. These so-called ultrasound contrast agents consist of microscopically small gas bubbles encapsulated in biodegradable shells. In this review, the physical principles of ultrasound contrast agent microbubble behavior and their adjustment for drug delivery including sonoporation are described. Furthermore, an outline of clinical imaging applications of contrast-enhanced ultrasound is given. It is a challenging task to quantify and predict which bubble phenomenon occurs under which acoustic condition, and how these phenomena may be utilized in ultrasonic imaging. Aided by high-speed photography, our improved understanding of encapsulated microbubble behavior will lead to more sophisticated detection and delivery techniques. More sophisticated methods use quantitative approaches to measure the amount and the time course of bolus or reperfusion curves, and have shown great promise in revealing effective tumor responses to anti-angiogenic drugs in humans before tumor shrinkage occurs. These are beginning to be accepted into clinical practice. In the long term, targeted microbubbles for molecular imaging and eventually for directed anti-tumor therapy are expected to be tested. PMID:21218081

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

Mutational scanning reveals the determinants of protein insertion and association energetics in the plasma membrane.

PubMed

Elazar, Assaf; Weinstein, Jonathan; Biran, Ido; Fridman, Yearit; Bibi, Eitan; Fleishman, Sarel Jacob

2016-01-29

Insertion of helix-forming segments into the membrane and their association determines the structure, function, and expression levels of all plasma membrane proteins. However, systematic and reliable quantification of membrane-protein energetics has been challenging. We developed a deep mutational scanning method to monitor the effects of hundreds of point mutations on helix insertion and self-association within the bacterial inner membrane. The assay quantifies insertion energetics for all natural amino acids at 27 positions across the membrane, revealing that the hydrophobicity of biological membranes is significantly higher than appreciated. We further quantitate the contributions to membrane-protein insertion from positively charged residues at the cytoplasm-membrane interface and reveal large and unanticipated differences among these residues. Finally, we derive comprehensive mutational landscapes in the membrane domains of Glycophorin A and the ErbB2 oncogene, and find that insertion and self-association are strongly coupled in receptor homodimers.

Ultrasound - Breast

MedlinePlus

... the patient. Because ultrasound images are captured in real-time, they can show the structure and movement of ... perform an ultrasound-guided biopsy . Because ultrasound provides real-time images, it is often used to guide biopsy ...

Cumulative phase delay imaging - A new contrast enhanced ultrasound modality

NASA Astrophysics Data System (ADS)

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

2015-10-01

Recently, a new acoustic marker for ultrasound contrast agents (UCAs) has been introduced. A cumulative phase delay (CPD) between the second harmonic and fundamental pressure wave field components is in fact observable for ultrasound propagating through UCAs. This phenomenon is absent in the case of tissue nonlinearity and is dependent on insonating pressure and frequency, UCA concentration, and propagation path length through UCAs. In this paper, ultrasound images based on this marker are presented. The ULA-OP research platform, in combination with a LA332 linear array probe (Esaote, Firenze Italy), were used to image a gelatin phantom containing a PVC plate (used as a reflector) and a cylindrical cavity measuring 7 mm in diameter (placed in between the observation point and the PVC plate). The cavity contained a 240 µL/L SonoVueO® UCA concentration. Two insonating frequencies (3 MHz and 2.5 MHz) were used to scan the gelatine phantom. A mechanical index MI = 0.07, measured in water at the cavity location with a HGL-0400 hydrophone (Onda, Sunnyvale, CA), was utilized. Processing the ultrasound signals backscattered from the plate, ultrasound images were generated in a tomographic fashion using the filtered back-projection method. As already observed in previous studies, significantly higher CPD values are measured when imaging at a frequency of 2.5 MHz, as compared to imaging at 3 MHz. In conclusion, these results confirm the applicability of the discussed CPD as a marker for contrast imaging. Comparison with standard contrast-enhanced ultrasound imaging modalities will be the focus of future work.

Extraction of curcumin from Curcuma longa L. using ultrasound assisted supercritical carbon dioxide

NASA Astrophysics Data System (ADS)

Kimthet, Chhouk; Wahyudiono, Kanda, Hideki; Goto, Motonobu

2017-05-01

Curcumin is one of phenolic compounds, which has been recently shown to have useful pharmacological properties such as anti-inflammatory, anti-bacterial, anti-carcinogenic, antifungal, and antimicrobial activities. The objective of this research is to extract the curcumin from Curcuma longa L. using ultrasound assisted supercritical carbon dioxide extraction (USC-CO2). The extraction was performed at 50°C, 25 MPa, CO2 flow rate of 3 mL/min with 10% cosolvent. The result of extraction, thermogravimetry (TG), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM) showed that ultrasound power could disrupt cell wall and release the target compounds from Curcuma longa L. USC-CO2 could provide higher curcumin content in the extracts and faster extraction compared to SC-CO2 extraction without ultrasound.

Application of airborne ultrasound in the convective drying of fruits and vegetables: A review.

PubMed

Fan, Kai; Zhang, Min; Mujumdar, Arun S

2017-11-01

The application of airborne ultrasound is a promising technology in the drying of foods, particularly to fruits and vegetables. In this paper, designs of dryers using ultrasound to combine the convective drying process are described. The main factors affecting the drying kinetics with the ultrasound application are discussed. The results show that the ultrasound application accelerated the drying kinetics. Ultrasound application during the convective drying of fruits and vegetables shorten the drying time. Ultrasound application can produce an increase of the effective moisture diffusivity and the mass transfer coefficient. The influence of ultrasound on physical and chemical parameters evaluating the product quality is reviewed. Ultrasound application can decrease the total color change, reveal a low water activity and reduce the loss of some nutrient elements. Meanwhile, ultrasound application can also better preserve the microstructure of fruits and vegetables in comparison to convective drying. Copyright © 2017 Elsevier B.V. All rights reserved.

Lung ultrasound in the critically ill.

PubMed

Lichtenstein, Daniel A

2014-01-09

), many disciplines (pulmonology, cardiology…), austere countries, and a help in any procedure (thoracentesis). A 1992, cost-effective gray-scale unit, without Doppler, and a microconvex probe are efficient. Lung ultrasound is a holistic discipline for many reasons (e.g., one probe, perfect for the lung, is able to scan the whole-body). Its integration can provide a new definition of priorities. The BLUE-protocol and FALLS-protocol allow simplification of expert echocardiography, a clear advantage when correct cardiac windows are missing.

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.

Dissociable Modulation of Overt Visual Attention in Valence and Arousal Revealed by Topology of Scan Path

PubMed Central

Ni, Jianguang; Jiang, Huihui; Jin, Yixiang; Chen, Nanhui; Wang, Jianhong; Wang, Zhengbo; Luo, Yuejia; Ma, Yuanye; Hu, Xintian

2011-01-01

Emotional stimuli have evolutionary significance for the survival of organisms; therefore, they are attention-grabbing and are processed preferentially. The neural underpinnings of two principle emotional dimensions in affective space, valence (degree of pleasantness) and arousal (intensity of evoked emotion), have been shown to be dissociable in the olfactory, gustatory and memory systems. However, the separable roles of valence and arousal in scene perception are poorly understood. In this study, we asked how these two emotional dimensions modulate overt visual attention. Twenty-two healthy volunteers freely viewed images from the International Affective Picture System (IAPS) that were graded for affective levels of valence and arousal (high, medium, and low). Subjects' heads were immobilized and eye movements were recorded by camera to track overt shifts of visual attention. Algebraic graph-based approaches were introduced to model scan paths as weighted undirected path graphs, generating global topology metrics that characterize the algebraic connectivity of scan paths. Our data suggest that human subjects show different scanning patterns to stimuli with different affective ratings. Valence salient stimuli (with neutral arousal) elicited faster and larger shifts of attention, while arousal salient stimuli (with neutral valence) elicited local scanning, dense attention allocation and deep processing. Furthermore, our model revealed that the modulatory effect of valence was linearly related to the valence level, whereas the relation between the modulatory effect and the level of arousal was nonlinear. Hence, visual attention seems to be modulated by mechanisms that are separate for valence and arousal. PMID:21494331

Ultrasound diagnosis and management of acquired uterine enhanced myometrial vascularity/arteriovenous malformations.

PubMed

Timor-Tritsch, Ilan E; Haynes, Meagan Campol; Monteagudo, Ana; Khatib, Nizar; Kovács, Sándor

2016-06-01

Arteriovenous malformation is a short circuit between an organ's arterial and venous circulation. Arteriovenous malformations are classified as congenital and acquired. In the uterus, they may appear after curettage, cesarean delivery, and myomectomy among others. Their clinical feature is usually vaginal bleeding, which may be severe, if curettage is performed in unrecognized cases. Sonographically on 2-dimensional grayscale ultrasound scanning, the pathologic evidence appears as irregular, anechoic, tortuous, tubular structures that show evidence of increased vascularity when color Doppler is applied. Most of the time they resolve spontaneously; however, if left untreated, they may require involved treatments such as uterine artery embolization or hysterectomy. In the past, uterine artery angiography was the gold standard for the diagnosis; however, ultrasound scanning has diagnosed successfully and helped in the clinical management. Recently, arteriovenous malformations have been referred to as enhanced myometrial vascularities. The purpose of this study was to evaluate the role of transvaginal ultrasound scanning in the diagnosis and treatment of acquired enhanced myometrial vascularity/arteriovenous malformations to outline the natural history of conservatively followed vs treated lesions. This was a retrospective study to assess the presentation, treatment, and clinical pictures of patients with uterine Enhanced myometrial vascularity/arteriovenous malformations that were diagnosed with transvaginal ultrasound scanning. We reviewed both (1) ultrasound data (images, measured dimensions, and Doppler blood flow that were defined by its peak systolic velocity and (2) clinical data (age, reproductive status, clinical presentation, inciting event or procedure, surgical history, clinical course, time intervals that included detection to resolution or detection to treatment, and treatment rendered). The diagnostic criteria were "subjective" with a rich vascular

WE-B-210-02: The Advent of Ultrafast Imaging in Biomedical Ultrasound

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

Tanter, M.

In the last fifteen years, the introduction of plane or diverging wave transmissions rather than line by line scanning focused beams has broken the conventional barriers of ultrasound imaging. By using such large field of view transmissions, the frame rate reaches the theoretical limit of physics dictated by the ultrasound speed and an ultrasonic map can be provided typically in tens of micro-seconds (several thousands of frames per second). Interestingly, this leap in frame rate is not only a technological breakthrough but it permits the advent of completely new ultrasound imaging modes, including shear wave elastography, electromechanical wave imaging, ultrafastmore » doppler, ultrafast contrast imaging, and even functional ultrasound imaging of brain activity (fUltrasound) introducing Ultrasound as an emerging full-fledged neuroimaging modality. At ultrafast frame rates, it becomes possible to track in real time the transient vibrations – known as shear waves – propagating through organs. Such “human body seismology” provides quantitative maps of local tissue stiffness whose added value for diagnosis has been recently demonstrated in many fields of radiology (breast, prostate and liver cancer, cardiovascular imaging, …). Today, Supersonic Imagine company is commercializing the first clinical ultrafast ultrasound scanner, Aixplorer with real time Shear Wave Elastography. This is the first example of an ultrafast Ultrasound approach surpassing the research phase and now widely spread in the clinical medical ultrasound community with an installed base of more than 1000 Aixplorer systems in 54 countries worldwide. For blood flow imaging, ultrafast Doppler permits high-precision characterization of complex vascular and cardiac flows. It also gives ultrasound the ability to detect very subtle blood flow in very small vessels. In the brain, such ultrasensitive Doppler paves the way for fUltrasound (functional ultrasound imaging) of brain activity with

Nano-TiO2, ultrasound and sequential nano-TiO2/ultrasonic degradation of N-acetyl-para-aminophenol from aqueous solution.

PubMed

Ayanda, Olushola S; Nelana, Simphiwe M; Petrik, Leslie F; Naidoo, Eliazer B

2017-10-01

The application of nano-TiO 2 as adsorbent combined with ultrasound for the degradation of N-acetyl-para-aminophenol (AAP) from aqueous solution was investigated. The nano-TiO 2 was characterized by means of powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), and attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR). Experimental results revealed that the adsorption of AAP by nano-TiO 2 fitted the pseudo-second-order kinetic model, the equilibrium could be explained by the Freundlich isotherm and the treatment process is exothermic. The optimum removal efficiency of AAP (128.89 mg/g (77.33%)) was achieved at pH 4 when 0.03 g of nano-TiO 2 was mixed with 50 mL of 100 mg/L AAP aqueous solution at ambient temperature, 60 min contact time, and a stirring speed of 120 rpm. Ultrasound at 20 kHz and pH 3 was favorable and it resulted in 52.61% and 57.43% removal efficiency with and without the addition of nano-TiO 2 , respectively. The degradation of AAP by ultrasound followed by nano-TiO 2 treatment resulted in approximately 99.50% removal efficiency. This study showed that a sequential ultrasound and nano-TiO 2 treatment process could be employed for the removal of AAP or other emerging water and wastewater contaminants.

The Effect of Diacutaneous Fibrolysis on Patellar Position Measured Using Ultrasound Scanning in Patellofemoral Pain Syndrome Patients.

PubMed

Fanlo-Mazas, Pablo; Bueno-Gracia, Elena; de Escudero-Zapico, Alazne Ruiz; Tricás-Moreno, José Miguel; Lucha-López, María Orosia

2018-04-13

Tightness or lack of flexibility of flexibility of several muscles of the thigh has been associated with patellofemoral-join pain. A tight iliotibial band can lead to laterally located patella and an abnormal patellar tracking pattern. Diacutaneous fibrolysis is commonly used to reduce muscle tightness, but no studies have evaluated the effects of this technique in the treatment of patellofemoral pain syndrome patients. To assess the effect of diacutaneous fibrolysis on patellar position in patients with patellofemoral pain syndrome. A single-group, pretest-posttest clinical trial. University of Zaragoza. 46 subjects with patellofemoral pain (20 males, 26 females (age 27.8 ± 6.9 years)). 3 sessions of diacutaneous fibrolysis. Patellar position measurement using real time ultrasound scanning, pain intensity measured with visual analogue scale and function measured with the Anterior Knee Pain Scale. The application of three sessions of diacutaneous fibrolysis significantly increased the patellar position at post-treatment evaluation (p<0.001) and at one-week follow-up (p<0.001). There was not a significance difference on patellar position between post-treatment and follow-up measurements (p=0.283). There were also a statistically significant decrease in pain and increase in function at post-treatment and at one-week follow-up measurements (p<0.001). This study found that patellar position, pain intensity and function were significantly improved after three sessions of diacutaneous fibrolysis and at one week follow up.

Integration of Medical Imaging Including Ultrasound into a New Clinical Anatomy Curriculum

ERIC Educational Resources Information Center

Moscova, Michelle; Bryce, Deborah A.; Sindhusake, Doungkamol; Young, Noel

2015-01-01

In 2008 a new clinical anatomy curriculum with integrated medical imaging component was introduced into the University of Sydney Medical Program. Medical imaging used for teaching the new curriculum included normal radiography, MRI, CT scans, and ultrasound imaging. These techniques were incorporated into teaching over the first two years of the…

Ultrasound transducer selection in clinical imaging practice.

PubMed

Szabo, Thomas L; Lewin, Peter A

2013-04-01

Many types of medical ultrasound transducers are used in clinical practice. They operate at different center frequencies, have different physical dimensions, footprints, and shapes, and provide different image formats. However, little information is available about which transducers are most appropriate for a given application, and the purpose of this article is to address this deficiency. Specifically, the relationship between the transducer, imaging format, and clinical applications is discussed, and systematic selection criteria that allow matching of transducers to specific clinical needs are presented. These criteria include access to and coverage of the region of interest, maximum scan depth, and coverage of essential diagnostic modes required to optimize a patient's diagnosis. Three comprehensive figures organize and summarize the imaging planes, scanning modes, and types of diagnostic transducers to facilitate their selection in clinical diagnosis.

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.

Ultrasound-guided thrombin injection of genicular artery pseudoaneurysm.

PubMed

Rachakonda, Aditya; Qato, Khalil; Khaddash, Tamim; Carroccio, Alfio; Pamoukian, Vicken; Giangola, Gary

2015-07-01

Pseudoaneurysm is a rare complication after arthroscopic procedures involving the knee. A 38-year-old man presented 1 month after right-knee arthroscopy with a 2-cm pulsating mass on the medial side of the right knee. Duplex ultrasound evaluation revealed 2.5 × 2.1-cm pseudoaneurysm just distal to the patella with arterialized flow communicating with the inferior medial genicular artery. Ultrasound-guided thrombin injection was performed in an office setting, and the resolution of active flow within the pseudoaneurysm was confirmed with duplex ultrasonography. Copyright © 2015 Elsevier Inc. All rights reserved.

Fluid mechanics of blood flow in human fetal left ventricles based on patient-specific 4D ultrasound scans.

PubMed

Lai, Chang Quan; Lim, Guat Ling; Jamil, Muhammad; Mattar, Citra Nurfarah Zaini; Biswas, Arijit; Yap, Choon Hwai

2016-10-01

The mechanics of intracardiac blood flow and the epigenetic influence it exerts over the heart function have been the subjects of intense research lately. Fetal intracardiac flows are especially useful for gaining insights into the development of congenital heart diseases, but have not received due attention thus far, most likely because of technical difficulties in collecting sufficient intracardiac flow data in a safe manner. Here, we circumvent such obstacles by employing 4D STIC ultrasound scans to quantify the fetal heart motion in three normal 20-week fetuses, subsequently performing 3D computational fluid dynamics simulations on the left ventricles based on these patient-specific heart movements. Analysis of the simulation results shows that there are significant differences between fetal and adult ventricular blood flows which arise because of dissimilar heart morphology, E/A ratio, diastolic-systolic duration ratio, and heart rate. The formations of ventricular vortex rings were observed for both E- and A-wave in the flow simulations. These vortices had sufficient momentum to last until the end of diastole and were responsible for generating significant wall shear stresses on the myocardial endothelium, as well as helicity in systolic outflow. Based on findings from previous studies, we hypothesized that these vortex-induced flow properties play an important role in sustaining the efficiency of diastolic filling, systolic pumping, and cardiovascular flow in normal fetal hearts.

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.

Validation of Bedside Ultrasound of Muscle Layer Thickness of the Quadriceps in the Critically Ill Patient (VALIDUM Study).

PubMed

Paris, Michael T; Mourtzakis, Marina; Day, Andrew; Leung, Roger; Watharkar, Snehal; Kozar, Rosemary; Earthman, Carrie; Kuchnia, Adam; Dhaliwal, Rupinder; Moisey, Lesley; Compher, Charlene; Martin, Niels; Nicolo, Michelle; White, Tom; Roosevelt, Hannah; Peterson, Sarah; Heyland, Daren K

2017-02-01

In critically ill patients, muscle atrophy is associated with long-term disability and mortality. Bedside ultrasound may quantify muscle mass, but it has not been validated in the intensive care unit (ICU). Here, we compared ultrasound-based quadriceps muscle layer thickness (QMLT) with precise quantifications of computed tomography (CT)-based muscle cross-sectional area (CSA). Patients ≥18 years old with abdominal CT scans performed for clinical reasons were recruited from 9 ICUs for an ultrasound assessment of the quadriceps. CT scans of the third lumbar vertebra, performed <24 hours before or <72 hours after ICU admission, were analyzed for CSA. Low muscularity was defined as 170 cm 2 for men and 110 cm 2 for women. The ultrasound probe was maximally compressed against the skin and QMLT was measured on 2 sites of each quadriceps <72 hours of the CT scan. Mean CT-derived muscle CSA was 109 ± 25 cm 2 for women and 168 ± 37 cm 2 for men, where 58% of patients exhibited low muscularity; only 2.7% patients were underweight according to body mass index. QMLT was positively correlated with CT CSA ( r = 0.45, P < .001). Based on logistic regression to predict low muscularity, QMLT independently generated a concordance index ( c) of 0.67 ( P < .002), which increased to 0.77 ( P < .001) when age, sex, body mass index, Charlson Comorbidity Index, and admission type (surgical vs medical) were added. Our results suggest that QMLT alone with our current protocol may not accurately identify patients with low muscle mass.

Investigation of dental samples using a 35MHz focussed ultrasound piezocomposite transducer.

PubMed

Hughes, D A; Girkin, J M; Poland, S; Longbottom, C; Button, T W; Elgoyhen, J; Hughes, H; Meggs, C; Cochran, S

2009-02-01

Dental erosion and decay are increasingly prevalent but as yet there is no quantitative monitoring tool. Such a tool would allow earlier diagnosis and treatment and ultimately the prevention of more serious disease and pain. Despite ultrasound having been demonstrated as a method of probing the internal structures of teeth more than 40 years ago, development of a clinical tool has been slow. The aim of the study reported here was to investigate the use of a novel high frequency ultrasound transducer and validate it using a known dental technique. A tooth extracted for clinical reasons was sectioned to provide a sample that contained an enamel and dentine layer such that the enamel-dentine junction (EDJ) was of a varying depth. The sample was then submerged in water and a B-scan recorded using a custom-designed piezocomposite ultrasound transducer with a centre frequency of 35 MHz and a -6 dB bandwidth of 24 MHz. The transducer has an axial resolution of 180 microm and a spatial resolution of 110 microm, a significant advance on previous work using lower frequencies. The depth of the EDJ was measured from the resulting data set and compared to measurements from the sequential grinding and imaging (SGI) method. The B-scan showed that the EDJ was of varying depth. Subsequently, the EDJ measurements were found to have a correlation of 0.89 (p<0.01) against the SGI measurements. The results indicate that high frequency ultrasound is capable of measuring enamel thickness to an accuracy of within 10% of the total enamel thickness, whereas currently there is no clinical tool available to measure enamel thickness.

Standardized 2D ultrasound versus 3D/4D ultrasound and image fusion for measurement of aortic aneurysm diameter in follow-up after EVAR.

PubMed

Pfister, Karin; Schierling, Wilma; Jung, Ernst Michael; Apfelbeck, Hanna; Hennersperger, Christoph; Kasprzak, Piotr M

2016-01-01

To compare standardised 2D ultrasound (US) to the novel ultrasonographic imaging techniques 3D/4D US and image fusion (combined real-time display of B mode and CT scan) for routine measurement of aortic diameter in follow-up after endovascular aortic aneurysm repair (EVAR). 300 measurements were performed on 20 patients after EVAR by one experienced sonographer (3rd degree of the German society of ultrasound (DEGUM)) with a high-end ultrasound machine and a convex probe (1-5 MHz). An internally standardized scanning protocol of the aortic aneurysm diameter in B mode used a so called leading-edge method. In summary, five different US methods (2D, 3D free-hand, magnetic field tracked 3D - Curefab™, 4D volume sweep, image fusion), each including contrast-enhanced ultrasound (CEUS), were used for measurement of the maximum aortic aneurysm diameter. Standardized 2D sonography was the defined reference standard for statistical analysis. CEUS was used for endoleak detection. Technical success was 100%. In augmented transverse imaging the mean aortic anteroposterior (AP) diameter was 4.0±1.3 cm for 2D US, 4.0±1.2 cm for 3D Curefab™, and 3.9±1.3 cm for 4D US and 4.0±1.2 for image fusion. The mean differences were below 1 mm (0.2-0.9 mm). Concerning estimation of aneurysm growth, agreement was found between 2D, 3D and 4D US in 19 of the 20 patients (95%). Definitive decision could always be made by image fusion. CEUS was combined with all methods and detected two out of the 20 patients (10%) with an endoleak type II. In one case, endoleak feeding arteries remained unclear with 2D CEUS but could be clearly localized by 3D CEUS and image fusion. Standardized 2D US allows adequate routine follow-up of maximum aortic aneurysm diameter after EVAR. Image Fusion enables a definitive statement about aneurysm growth without the need for new CT imaging by combining the postoperative CT scan with real-time B mode in a dual image display. 3D/4D CEUS and image fusion

Power ultrasound irradiation during the alkaline etching process of the 2024 aluminum alloy

NASA Astrophysics Data System (ADS)

Moutarlier, V.; Viennet, R.; Rolet, J.; Gigandet, M. P.; Hihn, J. Y.

2015-11-01

Prior to any surface treatment on an aluminum alloy, a surface preparation is necessary. This commonly consists in performing an alkaline etching followed by acid deoxidizing. In this work, the use of power ultrasound irradiation during the etching step on the 2024 aluminum alloy was studied. The etching rate was estimated by weight loss, and the alkaline film formed during the etching step was characterized by glow discharge optical emission spectrometry (GDOES) and scanning electron microscope (SEM). The benefit of power ultrasound during the etching step was confirmed by pitting potential measurement in NaCl solution after a post-treatment (anodizing).

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.

FD115 (Flight Day 115) SPRINT leg muscle self scan

NASA Image and Video Library

2011-10-03

ISS029-E-025280 (3 Oct. 2011) --- NASA astronaut Mike Fossum, Expedition 29 commander, performs a SPRINT leg muscle self scan in the Columbus laboratory of the International Space Station. Fossum powered on the Ultrasound 2 (USND-2) unit and Video Power Converter (VPC) hardware, and connected the VPC to Human Research Facility 1 (HRF-1) in order to perform this activity.

FD115 (Flight Day 115) SPRINT leg muscle self scan

NASA Image and Video Library

2011-10-03

ISS029-E-025270 (3 Oct. 2011) --- NASA astronaut Mike Fossum, Expedition 29 commander, performs a SPRINT leg muscle self scan in the Columbus laboratory of the International Space Station. Fossum powered on the Ultrasound 2 (USND-2) unit and Video Power Converter (VPC) hardware, and connected the VPC to Human Research Facility 1 (HRF-1) in order to perform this activity.

Genome scan for nonadditive heterotic trait loci reveals mainly underdominant effects in Saccharomyces cerevisiae.

PubMed

Laiba, Efrat; Glikaite, Ilana; Levy, Yael; Pasternak, Zohar; Fridman, Eyal

2016-04-01

The overdominant model of heterosis explains the superior phenotype of hybrids by synergistic allelic interaction within heterozygous loci. To map such genetic variation in yeast, we used a population doubling time dataset of Saccharomyces cerevisiae 16 × 16 diallel and searched for major contributing heterotic trait loci (HTL). Heterosis was observed for the majority of hybrids, as they surpassed their best parent growth rate. However, most of the local heterozygous loci identified by genome scan were surprisingly underdominant, i.e., reduced growth. We speculated that in these loci adverse effects on growth resulted from incompatible allelic interactions. To test this assumption, we eliminated these allelic interactions by creating hybrids with local hemizygosity for the underdominant HTLs, as well as for control random loci. Growth of hybrids was indeed elevated for most hemizygous to HTL genes but not for control genes, hence validating the results of our genome scan. Assessing the consequences of local heterozygosity by reciprocal hemizygosity and allele replacement assays revealed the influence of genetic background on the underdominant effects of HTLs. Overall, this genome-wide study on a multi-parental hybrid population provides a strong argument against single gene overdominance as a major contributor to heterosis, and favors the dominance complementation model.

Ultrasound-aided Multi-parametric Photoacoustic Microscopy of the Mouse Brain.

PubMed

Ning, Bo; Sun, Naidi; Cao, Rui; Chen, Ruimin; Kirk Shung, K; Hossack, John A; Lee, Jin-Moo; Zhou, Qifa; Hu, Song

2015-12-21

High-resolution quantitative imaging of cerebral oxygen metabolism in mice is crucial for understanding brain functions and formulating new strategies to treat neurological disorders, but remains a challenge. Here, we report on our newly developed ultrasound-aided multi-parametric photoacoustic microscopy (PAM), which enables simultaneous quantification of the total concentration of hemoglobin (CHb), the oxygen saturation of hemoglobin (sO2), and cerebral blood flow (CBF) at the microscopic level and through the intact mouse skull. The three-dimensional skull and vascular anatomies delineated by the dual-contrast (i.e., ultrasonic and photoacoustic) system provide important guidance for dynamically focused contour scan and vessel orientation-dependent correction of CBF, respectively. Moreover, bi-directional raster scan allows determining the direction of blood flow in individual vessels. Capable of imaging all three hemodynamic parameters at the same spatiotemporal scale, our ultrasound-aided PAM fills a critical gap in preclinical neuroimaging and lays the foundation for high-resolution mapping of the cerebral metabolic rate of oxygen (CMRO2)-a quantitative index of cerebral oxygen metabolism. This technical innovation is expected to shed new light on the mechanism and treatment of a broad spectrum of neurological disorders, including Alzheimer's disease and ischemic stroke.

Automated hierarchical time gain compensation for in-vivo ultrasound imaging

NASA Astrophysics Data System (ADS)

Moshavegh, Ramin; Hemmsen, Martin C.; Martins, Bo; Brandt, Andreas H.; Hansen, Kristoffer L.; Nielsen, Michael B.; Jensen, Jørgen A.

2015-03-01

Time gain compensation (TGC) is essential to ensure the optimal image quality of the clinical ultrasound scans. When large fluid collections are present within the scan plane, the attenuation distribution is changed drastically and TGC compensation becomes challenging. This paper presents an automated hierarchical TGC (AHTGC) algorithm that accurately adapts to the large attenuation variation between different types of tissues and structures. The algorithm relies on estimates of tissue attenuation, scattering strength, and noise level to gain a more quantitative understanding of the underlying tissue and the ultrasound signal strength. The proposed algorithm was applied to a set of 44 in vivo abdominal movie sequences each containing 15 frames. Matching pairs of in vivo sequences, unprocessed and processed with the proposed AHTGC were visualized side by side and evaluated by two radiologists in terms of image quality. Wilcoxon signed-rank test was used to evaluate whether radiologists preferred the processed sequences or the unprocessed data. The results indicate that the average visual analogue scale (VAS) is positive ( p-value: 2.34 × 10-13) and estimated to be 1.01 (95% CI: 0.85; 1.16) favoring the processed data with the proposed AHTGC algorithm.

Integrated medical school ultrasound: development of an ultrasound vertical curriculum.

PubMed

Bahner, David P; Adkins, Eric J; Hughes, Daralee; Barrie, Michael; Boulger, Creagh T; Royall, Nelson A

2013-07-02

Physician-performed focused ultrasonography is a rapidly growing field with numerous clinical applications. Focused ultrasound is a clinically useful tool with relevant applications across most specialties. Ultrasound technology has outpaced the education, necessitating an early introduction to the technology within the medical education system. There are many challenges to integrating ultrasound into medical education including identifying appropriately trained faculty, access to adequate resources, and appropriate integration into existing medical education curricula. As focused ultrasonography increasingly penetrates academic and community practices, access to ultrasound equipment and trained faculty is improving. However, there has remained the major challenge of determining at which level is integrating ultrasound training within the medical training paradigm most appropriate. The Ohio State University College of Medicine has developed a novel vertical curriculum for focused ultrasonography which is concordant with the 4-year medical school curriculum. Given current evidenced-based practices, a curriculum was developed which provides medical students an exposure in focused ultrasonography. The curriculum utilizes focused ultrasonography as a teaching aid for students to gain a more thorough understanding of basic and clinical science within the medical school curriculum. The objectives of the course are to develop student understanding in indications for use, acquisition of images, interpretation of an ultrasound examination, and appropriate decision-making of ultrasound findings. Preliminary data indicate that a vertical ultrasound curriculum is a feasible and effective means of teaching focused ultrasonography. The foreseeable limitations include faculty skill level and training, initial cost of equipment, and incorporating additional information into an already saturated medical school curriculum. Focused ultrasonography is an evolving concept in medicine

[Feasibility and accuracy of ultrasound-guided methodology in the examination of lumbar spine facet joints].

PubMed

Wen, Chuan-Bing; Li, Yong-Zhong; Tang, Qin-Qin; Sun, Lin; Xiao, Hong; Yang, Bang-Xiang; Song, Li; Liu, Hui

2013-03-01

To investigate the feasibility, accuracy of B ultrasound in the examination of joint space of lumbar spine facet joints compared with CT scan. Ten healthy adult volunteers were enrolled. The joint space of lumbar facet joints was measured by ultrasound. To identify the spinal levels, the posterior parasagittal sonograms were obtained at levels L1 to S1. The lumbar facet joints were delineated with the help of transverse sonograms at each level. Meanwhile, the lumbar facet joints were evaluated by spiral CT on the same plane, reformatted to 1-mm axial slices. A total of 88 lumbar facet joints from L1 to S1 were clearly visualized in the 10 volunteers. Both ultrasound and CT measurements showed the same average depth and lateral distance of lumbar facet joint space (P > 0.05). The lumbar facet joint space can be accurately demonstrated by ultrasound.

Surveillance of hemodialysis vascular access with ultrasound vector flow imaging

NASA Astrophysics Data System (ADS)

Brandt, Andreas H.; Olesen, Jacob B.; Hansen, Kristoffer L.; Rix, Marianne; Jensen, Jørgen A.; Nielsen, Michael B.

2015-03-01

The aim of this study was prospectively to monitor the volume flow in patients with arteriovenous fistula (AVF) with the angle independent ultrasound technique Vector Flow Imaging (VFI). Volume flow values were compared with Ultrasound dilution technique (UDT). Hemodialysis patients need a well-functioning vascular access with as few complications as possible and preferred vascular access is an AVF. Dysfunction due to stenosis is a common complication, and regular monitoring of volume flow is recommended to preserve AVF patency. UDT is considered the gold standard for volume flow surveillance, but VFI has proven to be more precise, when performing single repeated instantaneous measurements. Three patients with AVF were monitored with UDT and VFI monthly for five months. A commercial ultrasound scanner with a 9 MHz linear array transducer with integrated VFI was used to obtain data. UDT values were obtained with Transonic HD03 Flow-QC Hemodialysis Monitor. Three independent measurements at each scan session were obtained with UDT and VFI each month. Average deviation of volume flow between UDT and VFI was 25.7 % (Cl: 16.7% to 34.7%) (p= 0.73). The standard deviation for all patients, calculated from the mean variance of each individual scan sessions, was 199.8 ml/min for UDT and 47.6 ml/min for VFI (p = 0.002). VFI volume flow values were not significantly different from the corresponding estimates obtained using UDT, and VFI measurements were more precise than UDT. The study indicates that VFI can be used for surveillance of volume flow.

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

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.

Feasibility study: real-time 3-D ultrasound imaging of the brain.

PubMed

Smith, Stephen W; Chu, Kengyeh; Idriss, Salim F; Ivancevich, Nikolas M; Light, Edward D; Wolf, Patrick D

2004-10-01

We tested the feasibility of real-time, 3-D ultrasound (US) imaging in the brain. The 3-D scanner uses a matrix phased-array transducer of 512 transmit channels and 256 receive channels operating at 2.5 MHz with a 15-mm diameter footprint. The real-time system scans a 65 degrees pyramid, producing up to 30 volumetric scans per second, and features up to five image planes as well as 3-D rendering, 3-D pulsed-wave and color Doppler. In a human subject, the real-time 3-D scans produced simultaneous transcranial horizontal (axial), coronal and sagittal image planes and real-time volume-rendered images of the gross anatomy of the brain. In a transcranial sheep model, we obtained real-time 3-D color flow Doppler scans and perfusion images using bolus injection of contrast agents into the internal carotid artery.

Investigation of Acrylic Resin Disinfection Using Chemicals and Ultrasound.

PubMed

Muscat, Ylainia; Farrugia, Cher; Camilleri, Liberato; Arias-Moliz, Maria Teresa; Valdramidis, Vasilis; Camilleri, Josette

2018-06-01

Dental prosthetic and orthodontic appliances are transported from the clinic to the laboratory for additions and repairs. These appliances, containing microbes from the oral flora, are a high risk for cross-contamination. The aim of this study was to evaluate the effect of chemical and ultrasound disinfection against two in vitro biofilms and an in vivo formed biofilm grown on unprepared and polished polymethyl methacrylate (PMMA) surfaces. Rough and polished self-curing PMMA surfaces were infected with strains of both Candida albicans and Streptococcus oralis. After incubation, the samples were treated with different disinfection methods, including ultrasound treatment for both 15 and 30 seconds, and immersion in glutaraldehyde and alcohol-based chemical disinfectants (MD520 and Minuten, respectively). The disinfecting efficacy was assessed by colony forming units (CFU) analysis and by scanning electron microscopy (SEM). Furthermore the adequacy of bacterial elimination of application of 30-second ultrasound and MD520 was assessed on PMMA retrieved from ten volunteers by CFU analyses. ANOVA with p = 0.05 followed by the Tukey post hoc test and the Student t-test was used to analyze the data. The ultrasound treatment for 30 seconds, MD520, and Minuten were the most effective disinfectant methods as they reduced the microbial counts compared to the control (p < 0.05) as shown in the in vitro analyses. S. oralis adhered more to rough acrylic resin surfaces (p < 0.05). Ultrasound treatment was the most effective way to reduce microbial counts on PMMA exposed to oral flora (p = 0.043). Ultrasound treatment for 30 seconds was effective against C. albicans, S. oralis, and the oral flora as shown by testing microbial growth on agar plates and SEM. © 2016 by the American College of Prosthodontists.

Introduction of basic obstetrical ultrasound screening in undergraduate medical education.

PubMed

Hamza, A; Solomayer, E-F; Takacs, Z; Juhasz-Boes, I; Joukhadar, R; Radosa, J C; Mavrova, R; Marc, W; Volk, T; Meyberg-Solomayer, G

2016-09-01

Teaching ultrasound procedures to undergraduates has recently been proposed to improve the quality of medical education. We address the impact of applying standardized ultrasound teaching to our undergraduates. Medical students received an additional theoretical and practical course involving hands-on ultrasound screening during their mandatory practical training week in obstetrics and gynecology. The students' theoretical knowledge and fetal image recognition skills were tested before and after the course. After the course, the students were asked to answer a course evaluation questionnaire. To standardize the teaching procedure, we used Peyton's 4-Step Approach to teach the skills needed for a German Society of Ultrasound in Medicine Level 1 ultrasound examiner. The multiple-choice question scores after the course showed statistically significant improvement (50 vs. 80 %; P < 0.001). The questionnaire revealed that students were satisfied with the course, felt that it increased their ultrasound knowledge, and indicated that they wanted more sonographic hands-on training in both obstetrics and gynecology and other medical fields. Using practical, hands-on medical teaching is an emerging method for undergraduate education that should be further evaluated, standardized, and developed.

Nerve ultrasound normal values - Readjustment of the ultrasound pattern sum score UPSS.

PubMed

Grimm, Alexander; Axer, Hubertus; Heiling, Bianka; Winter, Natalie

2018-07-01

Reference values are crucial for nerve ultrasound. Here, we reevaluated normal nerve and fascicle cross-sectional area (CSA) values in humans and compared them to published values. Based on these data, ultrasound pattern sum score (UPSS) boundary values were revisited and readjusted. Ultrasound of different peripheral nerves was performed in 100 healthy subjects at anatomically defined landmarks. Correlations with age, gender, height and weight were calculated. Overall, correspondence to other published reference values was high. Gender-dependency was found for the proximal median nerve. Dependency from height occurred in the tibial nerve (TN). Weight-dependency was not found. However, the most obvious differences were found in the TN between men >60 years and women <60 years. Thus, general boundary values were defined using the mean plus the twofold standard deviation for all subjects and nerve segments except for the TN, in which different cut-offs were proposed for elder men. Accordingly, the cut-offs for the UPSS were re-adjusted, none of the individuals revealed more than 2 points at maximum. The influence of distinct epidemiological factors on nerve size is most prominent in the TN, for which thus several normal values are useful. Adjusted reference values improve the accuracy of the UPSS. Copyright © 2018 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

Transvaginal ultrasound appearances of the ovary in normal women and hirsute women with oligomenorrhoea.

PubMed

Fox, R

1999-02-01

The transvaginal ultrasound appearances of the ovary were determined in women with clinical and endocrine features of polycystic ovarian disease (PCOD) and apparently normal women. At scan the number of small follicles were counted and ovarian volume was calculated. The maximum width of the ovarian cortex was also measured. Blood was sent for measurement of LH, FSH and testosterone. The women with oligomenorrhoea were scanned at random and the normal women were seen within the first 5 days of the start of menstruation. There were significant differences between median values for the 2 groups in terms of number of small follicles, ovarian volume and stromal width; the ovaries of the hirsute women had more follicles, were of larger volume, and had greater stromal width. The 2 ranges for number of follicles did overlap, however. Four hirsute oligomenorrhoeic women had a normal number of follicles; all 4 had the several clinical and endocrine features indicative of PCOD. These data suggest that the classical ultrasound features of PCOD are not consistently present and that the absence of increased follicularity at scan should not necessarily deter clinicians from making the functional diagnosis of PCOD.

Relationships Between Quantitative Pulse-Echo Ultrasound Parameters from the Superficial Zone of the Human Articular Cartilage and Changes in Surface Roughness, Collagen Content or Collagen Orientation Caused by Early Degeneration.

PubMed

Kiyan, Wataru; Ito, Akira; Nakagawa, Yasuaki; Mukai, Shogo; Mori, Koji; Arai, Tatsuo; Uchino, Eiichiro; Okuno, Yasushi; Kuroki, Hiroshi

2017-08-01

We aimed to quantitatively investigate the relationship between amplitude-based pulse-echo ultrasound parameters and early degeneration of the knee articular cartilage. Twenty samples from six human femoral condyles judged as grade 0 or 1 according to International Cartilage Repair Society grading were assessed using a 15-MHz pulsed-ultrasound 3-D scanning system ex vivo. Surface roughness (R q ), average collagen content (A 1 ) and collagen orientation (A 12 ) in the superficial zone of the cartilage were measured via laser microscopy and Fourier transform infrared imaging spectroscopy. Multiple regression analysis with a linear mixed-effects model (LMM) revealed that a time-domain reflection coefficient at the cartilage surface (R c ) had a significant coefficient of determination with R q and A 12 (R LMMm 2 =0.79); however, R c did not correlate with A 1 . Concerning the collagen characteristic in the superficial zone, R c was found to be a sensitive indicator reflecting collagen disorganization, not collagen content, for the early degeneration samples. Copyright © 2017 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

The Behavior of Lipid Debris Left on Cell Surfaces from Microbubble Based Ultrasound Molecular Imaging

PubMed Central

Ibsen, Stuart; Shi, Guixin; Schutt, Carolyn; Shi, Linda; Suico, Kyle-David; Benchimol, Michael; Serra, Viviana; Simberg, Dmitri; Berns, Michael; Esener, Sadik

2014-01-01

Lipid monolayer coated microbubbles are currently being developed to identify vascular regions that express certain surface proteins as part of the new technique of ultrasound molecular imaging. The microbubbles are functionalized with targeting ligands which bind to the desired cells holding the microbubbles in place as the remaining unbound microbubbles are eliminated from circulation. Subsequent scanning with ultrasound can detect the highly reflectant microbubbles that are left behind. The ultrasound scanning and detection process results in the destruction of the microbubble, creating lipid fragments from the monolayer. Here we demonstrate that microbubbles targeted to 4T1 murine breast cancer cells and human umbilical cord endothelial cells leave behind adhered fragments of the lipid monolayer after exposure to ultrasound with peak negative pressures of 0.18 and 0.8 MPa. Most of the observed fragments were large enough to be resistant to receptor mediated endocytosis. The fragments were not observed to incorporate into the lipid membrane of the cell over a period of 96 min. They were not observed to break into smaller pieces or significantly change shape but they were observed to undergo translation and rotation across the cell surface as the cells migrated over the substrate. These large fragments will apparently remain on the surface of the targeted cells for significant periods of time and need to be considered for their potential effects on blood flow through the microcapillaries and potential for immune system recognition. PMID:25059435

Corneal thickness and elevation measurements using swept-source optical coherence tomography and slit scanning topography in normal and keratoconic eyes.

PubMed

Jhanji, Vishal; Yang, Bingzhi; Yu, Marco; Ye, Cong; Leung, Christopher K S

2013-11-01

To compare corneal thickness and corneal elevation using swept source optical coherence tomography and slit scanning topography. Prospective study. 41 normal and 46 keratoconus subjects. All eyes were imaged using swept source optical coherence tomography and slit scanning tomography during the same visit. Mean corneal thickness and best-fit sphere measurements were compared between the instruments. Agreement of measurements between swept source optical coherence tomography and scanning slit topography was analyzed. Intra-rater reproducibility coefficient and intraclass correlation coefficient were evaluated. In normal eyes, central corneal thickness measured by swept source optical coherence tomography was thinner compared with slit scanning topography (p < 0.0001) and ultrasound pachymetry (p = < .0001). Ultrasound pachymetry readings had better 95% limits of agreement with swept source optical coherence tomography than slit scanning topography. In keratoconus eyes, central corneal thickness was thinner on swept source optical coherence tomography than slit scanning topography (p = 0.081) and ultrasound pachymetry (p = 0.001). There were significant differences between thinnest corneal thickness, and, anterior and posterior best-fit sphere measurements between both instruments (p < 0.05 for all). Overall, reproducibility coefficients and intraclass correlation coefficients were significantly better with swept source optical coherence tomography for measurement of central corneal thickness, anterior best-fit sphere and, posterior best-fit sphere (all p < 0.001). Corneal thickness and elevation measurements were significantly different between swept source optical coherence tomography and slit scanning topography. With better reproducibility coefficients and intraclass correlation coefficients, swept source optical coherence tomography may provide a reliable alternative for measurement of corneal parameters. © 2013 The Authors. Clinical

Improving the quality of transvaginal ultrasound scan by simulation training for general practice residents.

PubMed

Le Lous, M; De Chanaud, N; Bourret, A; Senat, M V; Colmant, C; Jaury, P; Tesnière, A; Tsatsaris, V

2017-01-01

Ultrasonography (US) is an essential tool for the diagnosis of acute gynecological conditions. General practice (GP) residents are involved in the first-line management of gynecologic emergencies. They are not familiar with US equipment. Initial training on simulators was conducted.The aim of this study was to evaluate the impact of simulation-based training on the quality of the sonographic images achieved by GP residents 2 months after the simulation training versus clinical training alone. Young GP residents assigned to emergency gynecology departments were invited to a one-day simulation-based US training session. A prospective controlled trial aiming to assess the impact of such training on TVS (transvaginal ultrasound scan) image quality was conducted. The first group included GP residents who attended the simulation training course. The second group included GP residents who did not attend the course. Written consent to participate was obtained from all participants. Images achieved 2 months after the training were scored using standardized quality criteria and compared in both groups. The stress generated by this examination was also assessed with a simple numeric scale. A total of 137 residents attended the simulation training, 26 consented to participate in the controlled trial. Sonographic image quality was significantly better in the simulation group for the sagittal view of the uterus (3.6 vs 2.7, p  = 0.01), for the longitudinal view of the right ovary (2.8 vs 1.4, p  = 0.027), and for the Morrison space (1.7 vs 0.4, p  = 0.034), but the difference was not significant for the left ovary (2.9 vs 1.7, p  = 0.189). The stress generated by TVS after 2 months was not different between the groups (6.0 vs 4.8, p  = 0.4). Simulation-based training improved the quality of pelvic US images in GP residents assessed after 2 months of experience in gynecology compared to clinical training alone.

Cumulative phase delay imaging - A new contrast enhanced ultrasound modality

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

Demi, Libertario, E-mail: l.demi@tue.nl; Sloun, Ruud J. G. van; Mischi, Massimo

Recently, a new acoustic marker for ultrasound contrast agents (UCAs) has been introduced. A cumulative phase delay (CPD) between the second harmonic and fundamental pressure wave field components is in fact observable for ultrasound propagating through UCAs. This phenomenon is absent in the case of tissue nonlinearity and is dependent on insonating pressure and frequency, UCA concentration, and propagation path length through UCAs. In this paper, ultrasound images based on this marker are presented. The ULA-OP research platform, in combination with a LA332 linear array probe (Esaote, Firenze Italy), were used to image a gelatin phantom containing a PVC platemore » (used as a reflector) and a cylindrical cavity measuring 7 mm in diameter (placed in between the observation point and the PVC plate). The cavity contained a 240 µL/L SonoVueO{sup ®} UCA concentration. Two insonating frequencies (3 MHz and 2.5 MHz) were used to scan the gelatine phantom. A mechanical index MI = 0.07, measured in water at the cavity location with a HGL-0400 hydrophone (Onda, Sunnyvale, CA), was utilized. Processing the ultrasound signals backscattered from the plate, ultrasound images were generated in a tomographic fashion using the filtered back-projection method. As already observed in previous studies, significantly higher CPD values are measured when imaging at a frequency of 2.5 MHz, as compared to imaging at 3 MHz. In conclusion, these results confirm the applicability of the discussed CPD as a marker for contrast imaging. Comparison with standard contrast-enhanced ultrasound imaging modalities will be the focus of future work.« less

Endoscopic ultrasound description of liver segmentation and anatomy.

PubMed

Bhatia, Vikram; Hijioka, Susumu; Hara, Kazuo; Mizuno, Nobumasa; Imaoka, Hiroshi; Yamao, Kenji

2014-05-01

Endoscopic ultrasound (EUS) can demonstrate the detailed anatomy of the liver from the transgastric and transduodenal routes. Most of the liver segments can be imaged with EUS, except the right posterior segments. The intrahepatic vascular landmarks include the major hepatic veins, portal vein radicals, hepatic arterial branches, and the inferior vena cava, and the venosum and teres ligaments are other important intrahepatic landmarks. The liver hilum and gallbladder serve as useful surface landmarks. Deciphering liver segmentation and anatomy by EUS requires orienting the scan planes with these landmarkstructures, and is different from the static cross-sectional radiological images. Orientation during EUS requires appreciation of the numerous scan planes possible in real-time, and the direction of scanning from the stomach and duodenal bulb. We describe EUS imaging of the liver with a curved linear probe in a step-by-step approach, with the relevant anatomical details, potential applications, and pitfalls of this novel EUS application. © 2013 The Authors. Digestive Endoscopy © 2013 Japan Gastroenterological Endoscopy Society.

Ultrasound in Arthritis.

PubMed

Sudoł-Szopińska, Iwona; Schueller-Weidekamm, Claudia; Plagou, Athena; Teh, James

2017-09-01

Ultrasound is currently performed in everyday rheumatologic practice. It is used for early diagnosis, to monitor treatment results, and to diagnose remission. The spectrum of pathologies seen in arthritis with ultrasound includes early inflammatory features and associated complications. This article discusses the spectrum of ultrasound features of arthritides seen in rheumatoid arthritis and other connective tissue diseases in adults, such as Sjögren syndrome, lupus erythematosus, dermatomyositis, polymyositis, and juvenile idiopathic arthritis. Ultrasound findings in spondyloarthritis, osteoarthritis, and crystal-induced diseases are presented. Ultrasound-guided interventions in patients with arthritis are listed, and the advantages and disadvantages of ultrasound are discussed. Copyright © 2017 Elsevier Inc. All rights reserved.

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

PubMed

Sivakumar, Venkatasubramanian; Rao, Paruchuri Gangadhar

2004-03-01

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.

Assessment of the accuracy of an ultrasound elastography liver scanning system using a PVA-cryogel phantom with optimal acoustic and mechanical properties

NASA Astrophysics Data System (ADS)

Cournane, S.; Cannon, L.; Browne, J. E.; Fagan, A. J.

2010-10-01

The accuracy of a transient elastography liver-scanning ultrasound system was assessed using a novel application of PVA-cryogel as a tissue-mimicking material with acoustic and shear elasticity properties optimized to best represent those of liver tissue. Although the liver-scanning system has been shown to offer a safer alternative for diagnosing liver cirrhosis through stiffness measurement, as compared to the liver needle biopsy exam, the scanner's accuracy has not been fully established. Young's elastic modulus values of 5-6 wt% PVA-cryogel phantoms, also containing glycerol and 0.3 µm Al2O3 and 3 µm Al2O3, were measured using a 'gold standard' mechanical testing technique and transient elastography. The mechanically measured values and acoustic velocities of the phantoms ranged between 1.6 and 16.1 kPa and 1540 and 1570 m s-1, respectively, mimicking those observed in liver tissue. The values reported by the transient elastography system overestimated Young's elastic modulus values representative of the progressive stages of liver fibrosis by up to 32%. These results were attributed to the relative rather than absolute nature of the measurement arising from the single-point acoustic velocity calibration of the system, rendering the measurements critically dependent on the speed of sound of the sample under investigation. Given the wide range of acoustic velocities which exist in the liver, spanning healthy tissue to cirrhotic pathology, coupled with the system's assumption that the liver is approximately elastic when it is rather highly viscoelastic, care should be exercised when interpreting the results from this system in patient groups.

Improving ultrasound gene transfection efficiency by controlling ultrasound excitation of microbubbles

PubMed Central

Fan, Z.; Chen, D.; Deng, C.X.

2013-01-01

Ultrasound application in the presence of microbubbles has shown great potential for non-viral gene transfection via transient disruption of cell membrane (sonoporation). However, improvement of its efficiency has largely relied on empirical approaches without consistent and translatable results. The goal of this study is to develop a rational strategy based on new results obtained using novel experimental techniques and analysis to improve sonoporation gene transfection. We conducted experiments using targeted microbubbles that were attached to cell membrane to facilitate sonoporation. We quantified the dynamic activities of microbubbles exposed to pulsed ultrasound and the resulting sonoporation outcome and identified distinct regimes of characteristic microbubble behaviors: stable cavitation, coalescence and translation, and inertial cavitation. We found that inertial cavitation generated the highest rate of membrane poration. By establishing direct correlation of ultrasound-induced bubble activities with intracellular uptake and pore size, we designed a ramped pulse exposure scheme for optimizing microbubble excitation to improve sonoporation gene transfection. We implemented a novel sonoporation gene transfection system using an aqueous two phase system (ATPS) for efficient use of reagents and high throughput operation. Using plasmid coding for the green fluorescence protein (GFP), we achieved a sonoporation transfection efficiency in rate aortic smooth muscle cells (RASMCs) of 6.9% ± 2.2% (n = 9), comparable with lipofection (7.5% ± 0.8%, n = 9). Our results reveal characteristic microbubble behaviors responsible for sonoporation and demonstrated a rational strategy to improve sonoporation gene transfection. PMID:23770009

Optical tomography of fluorophores in dense scattering media based on ultrasound-enhanced chemiluminescence

NASA Astrophysics Data System (ADS)

Kobayashi, Masaki; Kikuchi, Naoto; Sato, Akihiro

2015-01-01

This letter proposes and demonstrates ultrasound-combined optical imaging in dense scattering media. A peroxyoxalate chemiluminescence system that includes fluorophores to chemically excite the pigment is stimulated by ultrasound irradiation with power of less than 0.14 W/cm2. Using focused ultrasound, the chemiluminescence is selectively spatially enhanced, which leads to imaging of the pigment when embedded in a light-scattering medium via scanning of the focal point. The ultrasonically enhanced intensity of the chemiluminescence depends on the base intensity of the chemiluminescence without the applied ultrasound irradiation, which thereby enables quantitative determination of the fluorophore concentration. The authors demonstrate the potential of this method to resolve chemiluminescent targets in a dense scattering medium that is comparable to biological tissue. An image was acquired of a chemiluminescent target that included indocyanine green as the fluorophore embedded at a depth of 20 mm in an Intralipid-10% 200 ml/l solution scattering medium (the reduced scattering coefficient was estimated to be approximately 1.3 mm-1), indicating the potential for expansion of this technique for use in biological applications.

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.

Breast ultrasound in the management of gynecomastia in Peutz-Jeghers syndrome in monozygotic twins: two case reports.

PubMed

Di Grezia, Graziella; Romano, Tiziana; De Francesco, Francesco; Somma, Francesco; Rea, Gaetano; Grassi, Roberto; Gatta, Gianluca

2014-12-18

Peutz-Jeghers syndrome is an autosomal dominant disease with incomplete penetrance and variable expression caused by germline mutation of serine threonine kinase 11/liver kinase B1; it is characterized by hamartomatous polyps in the gastrointestinal tract, mucocutaneous melanin pigmentation, and increased predisposition to neoplasms. In Peutz-Jeghers syndrome, bilateral Sertoli cell testicular tumors cause endocrine manifestations including gynecomastia and feminization. This study aimed to assess the role of breast ultrasound in the evaluation of the effectiveness of an innovative surgical approach. This report presents a pair of European 9-year-old identical male twins with Peutz-Jeghers syndrome, bilateral prepubertal gynecomastia, and testicular multifocal calcifications. Both twins were treated with anastrozole for 2 years. After finishing treatment, both underwent subcutaneous mastectomy performed by the "modified" Webster technique. Breast examination and ultrasound were performed before and after the pharmacological and surgical treatment. A breast ultrasound scan before surgery showed bilateral gynecomastia in both patients. No solid nodular or cystic formations were present on either side. After pharmacological therapy and surgical glandular removal, a breast examination showed a significant reduction in breast volume; 1 year after surgery, a breast ultrasound scan of both patients showed a total absence of glandular parenchyma, with muscle planes well represented. Breast examination and ultrasound have proved to be a valid approach in the assessment of the treatment of prepubertal gynecomastia because they allow the efficacy of the pharmacological and surgical treatment to be evaluated in a multidisciplinary approach to one of the most frequent endocrine manifestations of Peutz-Jeghers syndrome.

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

Real-time 3D ultrasound imaging of infant tongue movements during breast-feeding.

PubMed

Burton, Pat; Deng, Jing; McDonald, Daren; Fewtrell, Mary S

2013-09-01

Whether infants use suction or peristaltic tongue movements or a combination to extract milk during breast-feeding is controversial. The aims of this pilot study were 1] to evaluate the feasibility of using 3D ultrasound scanning to visualise infant tongue movements; and 2] to ascertain whether peristaltic tongue movements could be demonstrated during breast-feeding. 15 healthy term infants, aged 2 weeks to 4 months were scanned during breast-feeding, using a real-time 3D ultrasound system, with a 7 MHz transducer placed sub-mentally. 1] The method proved feasible, with 72% of bi-plane datasets and 56% of real-time 3D datasets providing adequate coverage [>75%] of the infant tongue. 2] Peristaltic tongue movement was observed in 13 of 15 infants [83%] from real-time or reformatted truly mid-sagittal views under 3D guidance. This is the first study to demonstrate the feasibility of using 3D ultrasound to visualise infant tongue movements during breast-feeding. Peristaltic infant tongue movement was present in the majority of infants when the image plane was truly mid-sagittal but was not apparent if the image was slightly off the mid-sagittal plane. This should be considered in studies investigating the relative importance of vacuum and peristalsis for milk transfer. Copyright © 2013 Elsevier Ltd. All rights reserved.

[A new technique for ensuring negative surgical margins during partial nephrectomy: the ex vivo ultrasound control].

PubMed

Desmonts, A; Tillou, X; Le Gal, S; Secco, M; Orczyk, C; Bensadoun, H; Doerfler, A

2013-10-01

To evaluate the feasibility and the efficiency of intraoperative ex vivo ultrasound of resection margins in patients undergoing partial nephrectomy by urologist. Patients undergoing partial nephrectomy from July 2010 to November 2012 for T1-T2 renal tumors were included in analysis. Tumor margin status was immediately determined by ex vivo ultrasound done by the surgeon himself. Results were compared with margin status on definitive pathological evaluation. A total of 26 men and 15 women with a median age of 61 (30-82) years old were included in analysis. Intraoperative ex vivo ultrasound revealed negative surgical margins in 38 cases and positive margins in two. Final pathological results revealed negative margins in all except one case. Ultrasound sensitivity and specificity were 100% and 97%, respectively. Mean ultrasound duration was 1minute±1. Mean tumor and margin sizes were 3.4±1.8cm and 2.38±1.76mm, respectively. Intraoperative ex vivo ultrasound of resection margins in patients undergoing partial nephrectomy by a urologist seemed to be feasible, efficient and easy. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Portable bladder ultrasound: an evidence-based analysis.

PubMed

2006-01-01

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

In vivo ultrasound imaging of the bone cortex

NASA Astrophysics Data System (ADS)

Renaud, Guillaume; Kruizinga, Pieter; Cassereau, Didier; Laugier, Pascal

2018-06-01

Current clinical ultrasound scanners cannot be used to image the interior morphology of bones because these scanners fail to address the complicated physics involved for exact image reconstruction. Here, we show that if the physics is properly addressed, bone cortex can be imaged using a conventional transducer array and a programmable ultrasound scanner. We provide in vivo proof for this technique by scanning the radius and tibia of two healthy volunteers and comparing the thickness of the radius bone with high-resolution peripheral x-ray computed tomography. Our method assumes a medium that is composed of different homogeneous layers with unique elastic anisotropy and ultrasonic wave-speed values. The applicable values of these layers are found by optimizing image sharpness and intensity over a range of relevant values. In the algorithm of image reconstruction we take wave refraction between the layers into account using a ray-tracing technique. The estimated values of the ultrasonic wave-speed and anisotropy in cortical bone are in agreement with ex vivo studies reported in the literature. These parameters are of interest since they were proposed as biomarkers for cortical bone quality. In this paper we discuss the physics involved with ultrasound imaging of bone and provide an algorithm to successfully image the first segment of cortical bone.

Combined use of late phase dimercapto-succinic acid renal scintigraphy and ultrasound as first line screening after urinary tract infection in children.

PubMed

Quirino, Isabel G; Silva, Jose Maria P; Diniz, Jose S; Lima, Eleonora M; Rocha, Ana Cristina S; Simões e Silva, Ana Cristina; Oliveira, Eduardo A

2011-01-01

The aim of this study was to evaluate the diagnostic accuracy of dimercapto-succinic acid renal scintigraphy and renal ultrasound in identifying high grade vesicoureteral reflux in children after a first episode of urinary tract infection. A total of 533 children following a first urinary tract infection were included in the analysis. Patients were assessed by 3 diagnostic imaging studies, renal ultrasound, dimercapto-succinic acid scan and voiding cystourethrography. The main event of interest was the presence of high grade (III to V) vesicoureteral reflux. The combined and separate diagnostic accuracy of screening methods was assessed by calculation of diagnostic OR, sensitivity, specificity, positive predictive value, negative predictive value and likelihood ratio. A total of 246 patients had reflux, of whom 144 (27%) had high grade (III to V) disease. Sensitivity, negative predictive value and diagnostic OR of ultrasound for high grade reflux were 83.3%, 90.8% and 7.9, respectively. Dimercapto-succinic acid scan had the same sensitivity as ultrasound but a higher negative predictive value (91.7%) and diagnostic OR (10.9). If both tests were analyzed in parallel by using the OR rule, ie a negative diagnosis was established only when both test results were normal, sensitivity increased to 97%, negative predictive value to 97% and diagnostic OR to 25.3. Only 9 children (6.3%) with dilating reflux had an absence of alterations in both tests. Our findings support the idea that ultrasound and dimercapto-succinic acid scan used in combination are reliable predictors of dilating vesicoureteral reflux. Copyright © 2011 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Lung ultrasound in the critically ill

PubMed Central

2014-01-01

in adults), many disciplines (pulmonology, cardiology…), austere countries, and a help in any procedure (thoracentesis). A 1992, cost-effective gray-scale unit, without Doppler, and a microconvex probe are efficient. Lung ultrasound is a holistic discipline for many reasons (e.g., one probe, perfect for the lung, is able to scan the whole-body). Its integration can provide a new definition of priorities. The BLUE-protocol and FALLS-protocol allow simplification of expert echocardiography, a clear advantage when correct cardiac windows are missing. PMID:24401163

Surface waves on floating liquids induced by ultrasound field

NASA Astrophysics Data System (ADS)

Geng, D. L.; Xie, W. J.; Yan, N.; Wei, B.

2013-01-01

We demonstrate a kind of wave pattern on the surface of floating liquids in a modulated ultrasound field. The waves are related to the liquid/solid phase transformation process. The nucleation sites of the eutectics locate at the center of these waves, and the eutectic growth direction is parallel to the propagation direction of the waves. It is revealed that such wave phenomenon can be ascribed to the interaction between ultrasound and eutectic growth at the liquid/solid interface. This result may provide a potential method for fabricating wave patterned surfaces on eutectic alloys.

3-D ultrasound volume reconstruction using the direct frame interpolation method.

PubMed

Scheipers, Ulrich; Koptenko, Sergei; Remlinger, Rachel; Falco, Tony; Lachaine, Martin

2010-11-01

A new method for 3-D ultrasound volume reconstruction using tracked freehand 3-D ultrasound is proposed. The method is based on solving the forward volume reconstruction problem using direct interpolation of high-resolution ultrasound B-mode image frames. A series of ultrasound B-mode image frames (an image series) is acquired using the freehand scanning technique and position sensing via optical tracking equipment. The proposed algorithm creates additional intermediate image frames by directly interpolating between two or more adjacent image frames of the original image series. The target volume is filled using the original frames in combination with the additionally constructed frames. Compared with conventional volume reconstruction methods, no additional filling of empty voxels or holes within the volume is required, because the whole extent of the volume is defined by the arrangement of the original and the additionally constructed B-mode image frames. The proposed direct frame interpolation (DFI) method was tested on two different data sets acquired while scanning the head and neck region of different patients. The first data set consisted of eight B-mode 2-D frame sets acquired under optimal laboratory conditions. The second data set consisted of 73 image series acquired during a clinical study. Sample volumes were reconstructed for all 81 image series using the proposed DFI method with four different interpolation orders, as well as with the pixel nearest-neighbor method using three different interpolation neighborhoods. In addition, volumes based on a reduced number of image frames were reconstructed for comparison of the different methods' accuracy and robustness in reconstructing image data that lies between the original image frames. The DFI method is based on a forward approach making use of a priori information about the position and shape of the B-mode image frames (e.g., masking information) to optimize the reconstruction procedure and to reduce

Development and validation of an efficient ultrasound assisted extraction of phenolic compounds from flax (Linum usitatissimum L.) seeds.

PubMed

Corbin, Cyrielle; Fidel, Thibaud; Leclerc, Emilie A; Barakzoy, Esmatullah; Sagot, Nadine; Falguiéres, Annie; Renouard, Sullivan; Blondeau, Jean-Philippe; Ferroud, Clotilde; Doussot, Joël; Lainé, Eric; Hano, Christophe

2015-09-01

Flaxseed accumulates in its seedcoat a macromolecular complex composed of lignan (secoisolariciresinol diglucoside, SDG), flavonol (herbacetin diglucoside, HDG) and hydroxycinnamic acids (p-couramic, caffeic and ferulic acid glucosides). Their antioxidant and/or cancer chemopreventive properties support their interest in human health and therefore, the demand for their extraction. In the present study, ultrasound-assisted extraction (UAE) of flaxseed phenolic compounds was investigated. Scanning Electron Microscopy imaging and histochemical analysis revealed the deep alteration of the seedcoat ultrastructure and the release of the mucilage following ultrasound treatment. Therefore, this method was found to be very efficient for the reduction of mucilage entrapment of flaxseed phenolics. The optimal conditions for UAE phenolic compounds extraction from flaxseeds were found to be: water as solvent supplemented with 0.2N of sodium hydroxide for alkaline hydrolysis of the SDG-HMG complex, an extraction time of 60 min at a temperature of 25°C and an ultrasound frequency of 30 kHz. Under these optimized and validated conditions, highest yields of SDG, HDG and hydroxycinnamic acid glucosides were detected in comparison to other published methods. Therefore, the procedure presented herein is a valuable method for efficient extraction and quantification of the main flaxseed phenolics. Moreover, this UAE is of particular interest within the context of green chemistry in terms of reducing energy consumption and valuation of flaxseed cakes as by-products resulting from the production of flax oil. Copyright © 2015 Elsevier B.V. All rights reserved.