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Sample records for comparative ultrasound biomicroscopic

  1. A New Ultrasound Biomicroscopic Sign seen after Deep Sclerectomy (Dolphin Head Sign)

    PubMed Central

    Abdelrahman, Ahmed M; Cheweikh, Hala M El; Allam, Riham SHM

    2016-01-01

    ABSTRACT Purpose: To describe a new ultrasound biomicroscopic (UBM) sign seen in patients who underwent deep sclerectomy (DS) as a surgical procedure for the management of uncontrolled primary open-angle glaucoma (POAG). The presence of this sign in ultrasound biomicroscopy is suggested to be an indicator of successful surgery. We would like to name this sign as the “dolphin head sign.” Design: Prospective interventional study. Materials and methods: Twenty-eight eyes of 17 patients with POAG underwent DS with intraoperative mitomycin C (MMC) 0.3% applied for 2 minutes under the superficial scleral flap. Patients were followed up for a minimum of 6 months. Ultrasound biomicroscopy was done at the third postoperative month to evaluate the surgical area in both successful and failed cases. Results: The study included 28 eyes of 17 patients. The mean age of the study group was 42.90 ± 14.37 years (20–64 years). The study included 10 females and 7 males. The mean preoperative intraocular pressure (IOP) was 24.57 ± 6.37 mm Hg (20-38 mm Hg). The mean best corrected visual acuity (BCVA) was 0.57 ± 0.3 (0.05–1.00). Complete success has been achieved in 21 eyes (75%) during the follow-up period, with a mean IOP of 12.00 ± 3.86 mm Hg (6–20 mm Hg). The dolphin head sign was demonstrated only in successful cases, whereas the unsuccessful cases failed to show the typical sign. Conclusion: The presence of a “dolphin head” configuration in UBM images could be taken as an indicator of successful DS. How to cite this article: Abdelrahman AM, El Cheweikh HM, El-Fayoumi DMS, Allam RSHM. A New Ultrasound Biomicroscopic Sign seen after Deep Sclerectomy (Dolphin Head Sign). J Curr Glaucoma Pract 2016;10(2):56-59. PMID:27536048

  2. The suitability of the ultrasound biomicroscope for establishing texture in giant cell arteritis

    PubMed Central

    Roters, S.; Szurman, P.; Engels, B.; Brunner, R.

    2001-01-01

    AIM—To establish whether ultrasound biomicroscope (UBM) is a helpful tool in locating the arterial segment responsible in patients with segmental attacks in giant cell arteritis
METHODS—The superficial temporal arteries of 19 patients with suspected giant cell arteritis were examined with the UBM before biopsy.
RESULTS—20 specimens provided the histological proof of giant cell arteritis in five patients. Side differences, a dark perivascular halo, and high reflexivity of the intra-arterial space were found.
CONCLUSION—it is assumed that there are two types of arteritic inflammation: (1) the occlusion of intra-arterial space due to intimal fibrosis (UBM: high reflexive "filling"), and (2) inflammation of the perivascular zone with oedematous thickening and infiltration of the media (UBM: dark halo) and its combination. UBM is helpful in obtaining an indication of the side and segment for biopsy.

 PMID:11466252

  3. Ultrasound biomicroscopic evaluation of anterior segment cysts as a risk factor for ocular hypertension and closure angle glaucoma

    PubMed Central

    Dusak, Abdurrahim; Baykara, Mehmet; Ozkaya, Guven; Erdogan, Cuneyt; Ozcetin, Hikmet; Tuncel, Ercan

    2013-01-01

    AIM To investigate the relationship between the ultrasound biomicroscopic (UBM) features of anterior-segment cysts (ASCs) and increased intraocular pressure (IOP) as a risk factor for closed-angle glaucoma (CAG). METHODS Totally 24 eyes with recently diagnosed ASCs were divided into two groups. First group with ASC and ocular normotension (n=13), second group with ASC and ocular hypertension (n=11). An ophthalmologic examination, including tonometry, slit-lamp biomicroscopy (SLBM), gonioscopy, fundoscopy, pentacam, and UBM, was performed. The features of the ASCs were compared with the IOP. RESULTS ASCs were accurately diagnosed and delineated in 24 eyes using UBM. IOP was elevated in those ASCs with a secondary aetiology (P=0.027), iridociliary location (P=0.006), deformed shape (P=0.013), increased size (P=0.001) and elongated pupillary aperture (P=0.009). However, the count (P=0.343) of ASCs, anterior chamber depth (ACD; P=0.22) and axial lenght (AL; P=0.31) were not associated with ocular hypertension. Correlations were found between the IOP and ASC size (r=-0.712; P=0.003), anterior chamber angle (ACA; r=-0.985; P<0.001), angle opening area (AOA; r=0.885; P<0.001), angulation of iris (r=-0.776, P<0.001), and affected iris quadrant (r =-0.655, P=0.002). CONCLUSION Ocular hypertension in some eyes with ASC might be associated with various mechanisms, including secondary aetiology, iridociliary location, deformed shape, increased size and elongated pupill, which can be determined by UBM. PMID:23991389

  4. Ultrasound biomicroscopic findings of the iridocorneal angle in live healthy and glaucomatous dogs

    PubMed Central

    HASEGAWA, Takashi; KAWATA, Manabu; OTA, Mitsuharu

    2015-01-01

    By using ultrasound biomicroscopy (UBM), the cross-sectional structures of the entire iridocorneal angle (ICA) which are unable to assess with gonioscopic examination were evaluated objectively and quantitatively in live healthy and glaucomatous dogs. The ICAs of normotensive eyes in healthy dogs with normal open angle (NOR), a predisposition to primary closed angle glaucoma (PCAG) (PREDIS) and suffering from unilateral PCAG (UNI), as well as the ICAs of hypertensive eyes with acute and chronic PCAG (ACG and CRG), were assessed. The opening of the ciliary cleft in PREDIS was smaller than that in NOR. In UNI, the opening and area of the ciliary cleft were significantly decreased compared with those of NOR and PREDIS. ACG had widespread structural abnormalities including marked decrease in the ciliary cleft and scleral venous plexus, and a thinner sclera than those in normotensive eyes, whereas the ICA collapsed in CRG with the thinnest sclera. Medical therapy-responsive glaucomatous cases had wider ciliary cleft and scleral venous plexus than unresponsive ones. These findings suggest that the ciliary cleft and scleral venous plexus of the ICA are key structures contributing to not only the pathophysiology of canine glaucoma but also the responsiveness to medical therapy in glaucomatous eyes, and cross-sectional entire structures of the ICA should be evaluated quantitatively with UBM when diagnosing and managing canine glaucoma. PMID:26212256

  5. Development of a fast-scanning combined ultrasound-photoacoustic biomicroscope

    NASA Astrophysics Data System (ADS)

    Zemp, Roger J.; Lu, Huihong; Mathewson, Kory; Ranasinghesagara, Janaka; Jiang, Yan; Walsh, Andrew; Chen, Xuhui

    2009-02-01

    Recently a realtime photoacoustic microscopy system has been demonstrated. Unfortunately, however, displayed B-scan images were sometimes difficult to interpret as there was little structural context. In this work, we provide structural context for photoacoustic microscopy images by adding ultrasound biomicroscopy as a complementary and synergistic modality. Our system uses a voice-coil translation stage capable of 1" lateral translation, and can operate in excess of 15 Hz for 1-cm translations, providing up to 30 ultrasound frames per second. The frame-rate of the photoacoustic acquisitions is limited by the 20-Hz pulse-repetition rate of the laser, but can be increased with a faster-repetition-rate laser. Data from the system is streamed in real time from a 2GS/s PCI data acquisition card to the host PC at rates as high as 200 MB/s. The system should prove useful for various in vivo studies, including combined ultrasound Doppler and photoacoustic imaging.

  6. Reliability of measurements of rat lateral gastrocnemius architectural parameters obtained from ultrasound biomicroscopic images.

    PubMed

    Peixinho, Carolina Carneiro; Martins, Natália Santos da Fonseca; de Oliveira, Liliam Fernandes; Machado, João Carlos

    2014-01-01

    This study used ultrasound biomicroscopy (UBM) to quantify the pennation angle (PA) and muscle thickness (MT) of rat skeletal muscle and evaluated the reliability and reproducibility of the method by statistical analysis, determining the coefficient of variation (CV), intraclass correlation coefficient (ICC) and typical error of measurement. A UBM system with a center frequency of 40 MHz was used to acquire images of the right lateral gastrocnemius of ten male Wistar rats on two different days and with two ankle positions (90° or 150°). Two independent measurements of the PA and MT were randomly performed in each of three picture frames. The analysis resulted in CVs of 10.47% and 4.81% for the PA and the MT, respectively, for the ankle at 90° and 9.24% and 5.98% for the ankle at 150°. Additionally, the ICC values ranged from 0.75 to 0.92 for the PA and 0.57 to 0.99 for the MT. Statistically significant differences between the ankle positions were observed for the PA (p = 0.00013). The reliability of the PA and MT measurements for the rat right lateral gastrocnemius, determined from the ultrasound biomicroscopy images, was high (>0.90) for the methodology proposed. This finding indicates the potential of ultrasound biomicroscopy for quantitative muscle characterization and the longitudinal examination of tissue adaptation to different conditions of use, disease and rehabilitation. PMID:24505306

  7. An ultrasound biomicroscopic and water jet ultrasound indentation method for detecting the degenerative changes of articular cartilage in a rabbit model of progressive osteoarthritis.

    PubMed

    Wang, Yuexiang; Huang, Yan-Ping; Liu, Aijun; Wan, Wenbo; Zheng, Yong-Ping

    2014-06-01

    It is important to assess the early degeneration of articular cartilage associated with osteoarthritis (OA) for early intervention and treatment planning. Previously, we have developed a high frequency ultrasound and water jet indentation method for the morphologic, acoustic and mechanical assessment of articular cartilage, using the enzymatic digestion as a model of osteoarthritic degeneration. No naturally degenerated articular cartilage has been tested with the developed method. In this study, we aimed to determine the usefulness of the developed method for detecting the natural degeneration of articular cartilage in a standard surgical model of OA in rabbits. Forty adult New Zealand white female rabbits were used in this study, which included 30 experimental rabbits undergoing the right anterior cruciate ligament transection surgery and 10 control rabbits. At the 3rd, 6th, and 9th week post-surgery, 10 experimental rabbits were sacrificed, respectively, for assessment of the knee cartilage quality. The cartilage at the medial and lateral femoral condyles and tibial plateaus (four points) was measured by the high frequency ultrasound biomicroscopy, the water jet ultrasound indentation and a contact mechanical indentation test before a histopathologic analysis for grading of degeneration severity. Measured parameters were compared among different groups classified either by post-surgery time or by histopathologic grade. The results showed a general trend of increase for ultrasound roughness index and a general trend of decrease for integrated reflection coefficient, stiffness coefficient from water-jet indentation and Young's modulus (E) from the mechanical indentation with the increase of post-surgery time. Comparisons among groups with different histopathologic grades showed similar trend with the increase of degeneration severity. The water jet ultrasound indentation method was demonstrated to be an effective method to measure the mechanical properties of the

  8. Excimer laser phototherapeutic keratectomy in eyes with anterior corneal dystrophies: preoperative and postoperative ultrasound biomicroscopic examination and short-term clinical outcomes with and without an antihyperopia treatment.

    PubMed Central

    Rapuano, Christopher J

    2003-01-01

    PURPOSE: To evaluate the use of high-frequency ultrasound biomicroscopy (UBM) in determining the depth of corneal pathology in eyes undergoing excimer laser phototherapeutic keratectomy (PTK) for primary or recurrent anterior stromal corneal dystrophies. Corneal clarity, visual acuity and refractive changes in eyes with and without an antihyperopia treatment were also analyzed. METHODS: Twenty eyes of 14 patients with anterior stromal corneal dystrophies were treated with PTK. Eyes were evaluated preoperatively and 6 to 8 weeks postoperatively with slit-lamp biomicroscopy, manifest refraction, keratometry, computerized corneal topography, ultrasound pachymetry, and UBM. RESULTS: Nineteen of 20 corneas (95%) had greatly improved corneal clarity after PTK. Mean uncorrected Snellen vision improved from 20/102 to 20/69 and best corrected vision improved from 20/62 to 20/38. Nine eyes (45%) improved 2 or more lines of uncorrected vision, and 13 eyes (65%) improved 2 or more lines of best corrected vision. Mean change in spherical equivalent was just -0.92 diopters (D); however, the range was large (-13 to +3.88 D). UBM measurement of central corneal pathology did not correlate with the actual PTK ablation depth (P = .07). The amount of antihyperopia treatment did not correlate with changes in manifest refraction spherical equivalent, keratometry, or computerized corneal topography readings, but did correlate with length of time until corneal reepithelialization after PTK (P = .003). CONCLUSIONS: PTK resulted in improvements in corneal clarity and visual acuity in most patients with superficial corneal stromal dystrophies. UBM was not an effective tool to accurately measure the depth of corneal pathology preoperatively. The combined approach of minimizing ablation depth and selective use of an antihyperopia treatment resulted in minimal mean change in spherical equivalent; however, the range was large. PTK is a very good minimally invasive technique to improve vision in

  9. 21 CFR 886.1850 - AC-powered slitlamp biomicroscope.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false AC-powered slitlamp biomicroscope. 886.1850 Section 886.1850 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... a thin, intense beam of light. (b) Classification. Class II....

  10. 21 CFR 886.1850 - AC-powered slitlamp biomicroscope.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false AC-powered slitlamp biomicroscope. 886.1850 Section 886.1850 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... microscope intended for use in eye examination that projects into a patient's eye through a control...

  11. Comparative evaluation of ultrasound scanner accuracy in distance measurement

    NASA Astrophysics Data System (ADS)

    Branca, F. P.; Sciuto, S. A.; Scorza, A.

    2012-10-01

    The aim of the present study is to develop and compare two different automatic methods for accuracy evaluation in ultrasound phantom measurements on B-mode images: both of them give as a result the relative error e between measured distances, performed by 14 brand new ultrasound medical scanners, and nominal distances, among nylon wires embedded in a reference test object. The first method is based on a least squares estimation, while the second one applies the mean value of the same distance evaluated at different locations in ultrasound image (same distance method). Results for both of them are proposed and explained.

  12. Comparing Ultrasound and Mechanical Steering in a Biodiesel Production Process

    NASA Astrophysics Data System (ADS)

    Costa-Felix, Rodrigo P. B.; Ferreira, Jerusa R. L.

    The analysis of the kinetics of the transesterification reaction is crucial to compare different routes or routes with different catalysts or reaction accelerators. The use of ultrasound is considereda method for accelerating the biodiesel production. However, little effort has been done and is reported in the literature about how and under what conditions the use of ultrasound really speeds up the process, or the conditions under which its use is unnecessary or even harmful, burdening the process. Two dissimilar energy injections into a typical route were tested: ultrasound (@ 1 MHz and no heating) and mechanical steering (with heating), both applied in an 8:1 ratio of soybean oil and methanol, adding 1% of KOH as catalyzer. As results, during the first 10 minutes of reaction ultrasound showed unbearable effect on the transesterification, whilst mechanical steering and heating achieved almost 70% of conversion ratio. However, during the following 10 minutes, the mechanical steering and heating got nothing more than 80% of conversion, a considerable less efficient process than ultrasound assisted one, which achieved more than 90%. The straightforward explanation is that ultrasound continually inserts energy in a slower rate, what can result in a more stable conversion scenario. On the other hand, mechanical steering and heating provides more energy at a glance, but cannot push the final conversion rate beyond a limit, as the transesterification is a double-way chemical process. The instability mechanical steering and heating settles in the reaction medium pulls the components back to their original states more than pushes than to the converted equilibrium state of the matter.

  13. 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 ...

  14. Ultrasound

    MedlinePlus Videos and Cool Tools

    Ultrasound is a useful procedure for monitoring the baby's development in the uterus. Ultrasound uses inaudible sound waves to ... no known risks for ultrasound at present, it is highly recommended that pregnant women consult their physician ...

  15. Diagnostic Usefulness of Transrectal Ultrasound Compared with Transvaginal Ultrasound Assessment in Young Korean Women with Polycystic Ovary Syndrome

    PubMed Central

    Lee, Da Eun; Park, So Yun; Lee, Sa Ra; Chung, Hye Won

    2015-01-01

    Objectives To determine the diagnostic performance of transrectal ultrasound in virgin patients with polycystic ovary syndrome (PCOS) by receiver operating characteristic (ROC) curve analysis, compared with conventional transvaginal ultrasound assessment. Methods Ultrasound examinations were performed in 963 Korean women, with transvaginal transducers in 677 women and transrectal transducers in 286 women at Ewha Womans University Mokdong Hospital. Transvaginal ultrasound examinations were performed in 494 normal control women and 183 PCOS patients according to National Institutes of Health (NIH) PCOS diagnostic criteria. In virgin patients, transrectal ultrasound examinations were performed in 141 normal control women and 145 PCOS patients. ROC curves were calculated for ovarian volume and follicle number. Results By transvaginal ultrasound examination, the ovarian volume showed an area under the ROC curve (AURC) of 0.838. An ovarian volume decision threshold > 7 cm3 had a sensitivity of 73.0% and a specificity of 84.2% for the diagnosis of PCOS. The follicle number showed an AURC of 0.886. A follicle number decision threshold ≥ 9 had a sensitivity of 78.6% and a specificity of 87.2% for the diagnosis of PCOS. By transrectal ultrasound examination, the ovarian volume and the follicle number showed AURCs of 0.815 as same thresholds with a sensitivity of 67.2% and 66.4%, respectively and a specificity of 86.8% each. Ovarian volume and follicle number by transvaginal and transrectal ultrasound assessment had a high diagnostic power for PCOS screening. Conclusion Transrectal ultrasound assessment is as effective as conventional transvaginal ultrasound for the detection of PCOS in virgin patients. PMID:26793680

  16. Ultrasound

    MedlinePlus

    Ultrasound uses high-frequency sound waves to make images of organs and structures inside the body. ... An ultrasound machine makes images so that organs inside the body can be examined. The machine sends out high- ...

  17. Breast imaging with ultrasound tomography: a comparative study with MRI

    NASA Astrophysics Data System (ADS)

    Ranger, Bryan; Littrup, Peter; Duric, Neb; Li, Cuiping; Schmidt, Steven; Lupinacci, Jessica; Myc, Lukasz; Szczepanski, Amy; Rama, Olsi; Bey-Knight, Lisa

    2010-03-01

    The purpose of this study was to investigate the performance of an ultrasound tomography (UST) prototype relative to magnetic resonance (MR) for imaging overall breast anatomy and accentuating tumors relative to background tissue. The study was HIPAA compliant, approved by the Institutional Review Board, and performed after obtaining the requisite informed consent. Twenty-three patients were imaged with MR and the UST prototype. T1 weighted images with fat saturation, with and without gadolinium enhancement, were used to examine anatomical structures and tumors, while T2 weighted images were used to identify cysts. The UST scans generated sound speed, attenuation, and reflection images. A qualitative visual comparison of the MRI and UST images was then used to identify anatomical similarities. A more focused approach that involved a comparison of reported masses, lesion volumes, and breast density was used to quantify the findings from the visual assessment. Our acoustic tomography prototype imaged distributions of fibrous stroma, parenchyma, fatty tissues, and lesions in patterns similar to those seen in the MR images. The range of thresholds required to establish tumor volume equivalency between MRI and UST suggested that a universal threshold for isolating masses relative to background tissue is feasible with UST. UST has demonstrated the ability to visualize and characterize breast tissues in a manner comparable to MRI. Thresholding techniques accentuate masses relative to background anatomy, which may prove clinically useful for early cancer detection.

  18. Ultrasound

    MedlinePlus

    ... please enable JavaScript. Ultrasound uses high-frequency sound waves to make images of organs and structures inside ... examined. The machine sends out high-frequency sound waves, which reflect off body structures. A computer receives ...

  19. A comparative study in ultrasound breast imaging classification

    NASA Astrophysics Data System (ADS)

    Yap, Moi Hoon; Edirisinghe, Eran A.; Bez, Helmut E.

    2009-02-01

    American College of Radiology introduces a standard in classification, the breast imaging reporting and data system (BIRADS), standardize the reporting of ultrasound findings, clarify its interpretation, and facilitate communication between clinicians. The effective use of new technologies to support healthcare initiatives is important and current research is moving towards implementing computer tools in the diagnostics process. Initially a detailed study was carried out to evaluate the performance of two commonly used appearance based classification algorithms, based on the use of Principal Component Analysis (PCA), and two dimensional linear discriminant analysis (2D-LDA). The study showed that these two appearance based classification approaches are not capable of handling the classification of ultrasound breast image lesions. Therefore further investigations in the use of a popular feature based classifier - Support Vector Machine (SVM) was conducted. A pre-processing step before feature based classification is feature extraction, which involve shape, texture and edge descriptors for the Region of Interest (ROI). The input dataset to SVM classification is from a fully automated ROI detection. We achieve the success rate of 0.550 in PCA, 0.500 in LDA, and 0.931 in SVM. The best combination of features in SVM classification is to combine the shape, texture and edge descriptors, with sensitivity 0.840 and specificity 0.968. This paper briefly reviews the background to the project and then details the ongoing research. In conclusion, we discuss the contributions, limitations, and future plans of our work.

  20. Atherosclerotic Calcification Detection: A Comparative Study of Carotid Ultrasound and Cone Beam CT

    PubMed Central

    Jashari, Fisnik; Ibrahimi, Pranvera; Johansson, Elias; Ahlqvist, Jan; Arnerlöv, Conny; Garoff, Maria; Levring Jäghagen, Eva; Wester, Per; Henein, Michael Y.

    2015-01-01

    Background and Aim: Arterial calcification is often detected on ultrasound examination but its diagnostic accuracy is not well validated. The aim of this study was to determine the accuracy of carotid ultrasound B mode findings in detecting atherosclerotic calcification quantified by cone beam computed tomography (CBCT). Methods: We analyzed 94 carotid arteries, from 88 patients (mean age 70 ± 7 years, 33% females), who underwent pre-endarterectomy ultrasound examination. Plaques with high echogenic nodules and posterior shadowing were considered calcified. After surgery, the excised plaques were examined using CBCT, from which the calcification volume (mm3) was calculated. In cases with multiple calcifications the largest calcification nodule volume was used to represent the plaque. Carotid artery calcification by the two imaging techniques was compared using conventional correlations. Results: Carotid ultrasound was highly accurate in detecting the presence of calcification; with a sensitivity of 88.2%. Based on the quartile ranges of calcification volumes measured by CBCT we have divided plaque calcification into four groups: <8; 8–35; 36–70 and >70 mm3. Calcification volumes ≥8 were accurately detectable by ultrasound with a sensitivity of 96%. Of the 21 plaques with <8 mm3 calcification volume; only 13 were detected by ultrasound; resulting in a sensitivity of 62%. There was no difference in the volume of calcification between symptomatic and asymptomatic patients. Conclusion: Carotid ultrasound is highly accurate in detecting the presence of calcified atherosclerotic lesions of volume ≥8 mm3; but less accurate in detecting smaller volume calcified plaques. Further development of ultrasound techniques should allow better detection of early arterial calcification. PMID:26307978

  1. Ultrasound and Cadaveric Prosections as Methods for Teaching Cardiac Anatomy: A Comparative Study

    ERIC Educational Resources Information Center

    Griksaitis, Michael J.; Sawdon, Marina A.; Finn, Gabrielle M.

    2012-01-01

    This study compared the efficacy of two cardiac anatomy teaching modalities, ultrasound imaging and cadaveric prosections, for learning cardiac gross anatomy. One hundred and eight first-year medical students participated. Two weeks prior to the teaching intervention, students completed a pretest to assess their prior knowledge and to ensure that…

  2. Comparative evaluation of despeckle filtering in ultrasound imaging of the carotid artery.

    PubMed

    Loizou, Christos P; Pattichis, Constantinos S; Christodoulou, Christodoulos I; Istepanian, Robert S H; Pantziaris, Marios; Nicolaides, Andrew

    2005-10-01

    It is well-known that speckle is a multiplicative noise that degrades the visual evaluation in ultrasound imaging. The recent advancements in ultrasound instrumentation and portable ultrasound devices necessitate the need of more robust despeckling techniques for enhanced ultrasound medical imaging for both routine clinical practice and teleconsultation. The objective of this work was to carry out a comparative evaluation of despeckle filtering based on texture analysis, image quality evaluation metrics, and visual evaluation by medical experts in the assessment of 440 (220 asymptomatic and 220 symptomatic) ultrasound images of the carotid artery bifurcation. In this paper a total of 10 despeckle filters were evaluated based on local statistics, median filtering, pixel homogeneity, geometric filtering, homomorphic filtering, anisotropic diffusion, nonlinear coherence diffusion, and wavelet filtering. The results of this study suggest that the first order statistics filter lsmv, gave the best performance, followed by the geometric filter gf4d, and the homogeneous mask area filter lsminsc. These filters improved the class separation between the asymptomatic and the symptomatic classes based on the statistics of the extracted texture features, gave only a marginal improvement in the classification success rate, and improved the visual assessment carried out by the two experts. More specifically, filters lsmv or gf4d can be used for despeckling asymptomatic images in which the expert is interested mainly in the plaque composition and texture analysis; and filters lsmv, gf4d, or lsminsc can be used for the despeckling of symptomatic images in which the expert is interested in identifying the degree of stenosis and the plaque borders. The proper selection of a despeckle filter is very important in the enhancement of ultrasonic imaging of the carotid artery. Further work is needed to evaluate at a larger scale and in clinical practice the performance of the proposed

  3. Ultrasound-based transient elastography compared to magnetic resonance elastography in soft tissue-mimicking gels.

    PubMed

    Oudry, Jennifer; Vappou, Jonathan; Choquet, Philippe; Willinger, Rémy; Sandrin, Laurent; Constantinesco, André

    2009-11-21

    Ultrasound-based transient elastography (TE) and magnetic resonance elastography (MRE) are increasingly used methods for the clinical evaluation of soft tissue mechanical properties and their alteration under diseased conditions. This study proposes a comparison between magnetic resonance elastography (MRE) and ultrasound-based transient elastography (TE). Both methods were tested on the same soft tissue-mimicking gels in a common frequency range in order to allow for direct quantitative comparison. For the four gels tested, relatively good agreement was found between the shear moduli measured by both methods, with an averaged relative difference of 23%. This study demonstrates that under the assumption of homogeneous media that are significantly more elastic than viscous, quantitative results obtained by both methods are comparable. PMID:19887718

  4. Automated Breast Ultrasound: Dual-Sided Compared with Single-Sided Imaging.

    PubMed

    Larson, Eric D; Lee, Won-Mean; Roubidoux, Marilyn A; Goodsitt, Mitchel M; Lashbrook, Chris; Zafar, Fouzaan; Kripfgans, Oliver D; Thomenius, Kai; Carson, Paul L

    2016-09-01

    The design and performance of a mammographically configured, dual-sided, automated breast ultrasound (ABUS) 3-D imaging system are described. Dual-sided imaging (superior and inferior) is compared with single-sided imaging to aid decisions on clinical implementation of the more complex, but potentially higher-quality dual-sided imaging. Marked improvement in image quality and coverage of the breast is obtained in dual-sided ultrasound over single-sided ultrasound. Among hypo-echoic masses imaged, there are increases in the mean contrast-to-noise ratio of 57% and 79%, respectively, for spliced dual-sided versus superior or inferior single-sided imaging. The fractional breast volume coverage, defined as the percentage volume in the transducer field of view that is imaged with clinically acceptable quality, is improved from 59% in both superior and inferior single-sided imaging to 89% in dual-sided imaging. Applying acoustic coupling to the breast requires more effort or sophisticated methods in dual-sided imaging than in single-sided imaging. PMID:27264914

  5. /sup 201/Tl perfusion study of ''ischemic'' ulcers of the leg: prognostic ability compared with Doppler ultrasound

    SciTech Connect

    Siegel, M.E.; Stewart, C.A.; Kwong, P.; Sakimura, I.

    1982-04-01

    Thallium 201 perfusion analysis was compared with Doppler ultrasound as a means of determining the healing potential of an ischemic ulcer of the leg in 27 patients. The degree of hyperemia was determined by comparative point counting of the 201Tl distribution in and about the ulcer. Using established Doppler criteria and a hyperemia ratio greater than 1.5:1, ultrasound alone correctly predicted healing in 15 out of 23 cases and 201Tl in 20 out of 23. Ultrasound correctly predicted non-healing in 3 out of 6 cases, compared with 5 out of 6 for 201Tl. The positive predictive value of the 201Tl study was 63%, versus 27% for ultrasound, and the negative predictive value was 95% for 201Tl and 83% for ultrasound. The accuracy of 201Tl and ultrasound was 86% and 62%, respectively. This limited study suggests that 201Tl perfusion scanning is a useful noninvasive test of ulcer healing potential and may be more sensitive than Doppler ultrasound.

  6. Ultrasound aspects in therapy-naive CIDP compared to long-term treated CIDP.

    PubMed

    Grimm, Alexander; Vittore, Debora; Schubert, Victoria; Rasenack, Maria; Décard, Bernhard F; Heiling, Bianka; Hammer, Nadin; Axer, Hubertus

    2016-06-01

    To investigate the use of nerve ultrasound (NUS) along with the European Federation of Neurological Societies (EFNS) guidelines and clinical scores in untreated, recently diagnosed chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) vs. long-lasting treated CIDP. NUS and nerve conduction studies (NCS) of predefined nerves/cervical roots were performed in CIDP on diagnostic onset and "chronic-CIDP" (diagnosis and therapy >6 months), compared to controls. Nerve morphology was quantified using the modified ultrasound pattern sum score mUPSS, which is the sum of 3 ultrasound scores derived at 12 predefined measurement points and the homogeneity score (HS) in ulnar, median, and tibial nerve. 21 onset-CIDP, 21 "chronic-CIDP", and 21 age-matched controls were included. No differences in clinical scores or in the number of electrophysiologically affected nerves existed between the groups. Significantly enlarged cross-sectional areas of the nerves and diameters of the roots ensued already in onset-CIDP; however, with proximal predominance, whilst in chronic-CIDP, nerve enlargement was more prominent and ubiquitous. Increased UPS scores were shown in both patient groups compared to the controls. Significant differences between the patient groups were found particularly in the peripheral nerve score UPSA. Evaluation by means of HS revealed that the nerves in onset-CIDP were mostly regionally enlarged (often sparing distal segments) whereas in chronic-CIDP, nerves were more generalized enlarged. Onset- and chronic-CIDP show enlarged nerves and therefore increased mUPSS, however, nerve enlargement shows a more generalized pattern in chronic-CIDP compared to disease onset and correlates with disease duration and delayed therapy start, but not with disability. PMID:27017343

  7. Liver metastases: Contrast-enhanced ultrasound compared with computed tomography and magnetic resonance.

    PubMed

    Cantisani, Vito; Grazhdani, Hektor; Fioravanti, Cristina; Rosignuolo, Maria; Calliada, Fabrizio; Messineo, Daniela; Bernieri, Maria Giulia; Redler, Adriano; Catalano, Carlo; D'Ambrosio, Ferdinando

    2014-08-01

    The development of ultrasound contrast agents with excellent tolerance and safety profiles has notably improved liver evaluation with ultrasound (US) for several applications, especially for the detection of metastases. In particular, contrast enhanced ultrasonography (CEUS) allows the display of the parenchymal microvasculature, enabling the study and visualization of the enhancement patterns of liver lesions in real time and in a continuous manner in all vascular phases, which is similar to contrast-enhanced computed tomography (CT) and contrast-enhanced magnetic resonance imaging. Clinical studies have reported that the use of a contrast agent enables the visualization of more metastases with significantly improved sensitivity and specificity compared to baseline-US. Furthermore, studies have shown that CEUS yields sensitivities comparable to CT. In this review, we describe the state of the art of CEUS for detecting colorectal liver metastases, the imaging features, the literature reports of metastases in CEUS as well as its technique, its clinical role and its potential applications. Additionally, the updated international consensus panel guidelines are reported in this review with the inherent limitations of this technique and best practice experiences. PMID:25110428

  8. Advanced noise reduction in placental ultrasound imaging using CPU and GPU: a comparative study

    NASA Astrophysics Data System (ADS)

    Zombori, G.; Ryan, J.; McAuliffe, F.; Rainford, L.; Moran, M.; Brennan, P.

    2010-03-01

    This paper presents a comparison of different implementations of 3D anisotropic diffusion speckle noise reduction technique on ultrasound images. In this project we are developing a novel volumetric calcification assessment metric for the placenta, and providing a software tool for this purpose. The tool can also automatically segment and visualize (in 3D) ultrasound data. One of the first steps when developing such a tool is to find a fast and efficient way to eliminate speckle noise. Previous works on this topic by Duan, Q. [1] and Sun, Q. [2] have proven that the 3D noise reducing anisotropic diffusion (3D SRAD) method shows exceptional performance in enhancing ultrasound images for object segmentation. Therefore we have implemented this method in our software application and performed a comparative study on the different variants in terms of performance and computation time. To increase processing speed it was necessary to utilize the full potential of current state of the art Graphics Processing Units (GPUs). Our 3D datasets are represented in a spherical volume format. With the aim of 2D slice visualization and segmentation, a "scan conversion" or "slice-reconstruction" step is needed, which includes coordinate transformation from spherical to Cartesian, re-sampling of the volume and interpolation. Combining the noise filtering and slice reconstruction in one process on the GPU, we can achieve close to real-time operation on high quality data sets without the need for down-sampling or reducing image quality. For the GPU programming OpenCL language was used. Therefore the presented solution is fully portable.

  9. Transverse vs torsional ultrasound: prospective randomized contralaterally controlled study comparing two phacoemulsification-system handpieces

    PubMed Central

    Assil, Kerry K; Harris, Lindsay; Cecka, Jeannie

    2015-01-01

    Purpose To compare surgical efficiency and multiple early clinical outcome variables in eyes undergoing phacoemulsification using either transversal or torsional ultrasound systems. Setting Assil Eye Institute, Beverly Hills, CA, USA. Design Prospective, randomized, clinician-masked, contralaterally controlled single-center evaluation. Patients and methods Patients seeking cataract removal in both eyes with implantation of multifocal intraocular lenses were randomly assigned to one of two treatment rooms for phacoemulsification with either a transverse ultrasound system or torsional handpiece system. The contralateral eye was treated at a later date with the alternate device. A total of 54 eyes of 27 patients having similar degrees of cataract, astigmatism, and visual potential were included. All operative data were collected for analysis, and patients were followed for 3 months after surgery. Results Similar visual acuity was reported at all postoperative visits between the two groups. Mean phacoemulsification time and total power required were both significantly lower with the transverse system than with the torsional technique (P<0.05 for both). Similarly, mean total balanced salt solution used was significantly less with the transverse system vs torsional (P<0.05). Postoperative safety demonstrated significantly lower endothelial cell loss at 1 day and 1 month (P<0.05) with transverse vs torsional. Macular swelling was less at 1 week, 1 month, and 3 months with transverse vs torsional, although the difference did not achieve significance (P=0.1) at any single time point. Clinically detectable corneal edema was reported less frequently at all postoperative time points with the transverse system. Conclusion The transverse ultrasound system was found to be possibly associated with less balanced salt-solution use, less phacoemulsification time, and less power required than the torsional phaco system. Postoperative data suggested that improved phaco efficiency may

  10. A multi-centre randomised trial comparing ultrasound vs mammography for screening breast cancer in high-risk Chinese women

    PubMed Central

    Shen, S; Zhou, Y; Xu, Y; Zhang, B; Duan, X; Huang, R; Li, B; Shi, Y; Shao, Z; Liao, H; Jiang, J; Shen, N; Zhang, J; Yu, C; Jiang, H; Li, S; Han, S; Ma, J; Sun, Q

    2015-01-01

    Background: Chinese women tend to have small and dense breasts and ultrasound is a common method for breast cancer screening in China. However, its efficacy and cost comparing with mammography has not been evaluated in randomised trials. Methods: At 14 breast centres across China during 2008–2010, 13 339 high-risk women aged 30–65 years were randomised to be screened by mammography alone, ultrasound alone, or by both methods at enrolment and 1-year follow-up. Results: A total of 12 519 and 8692 women underwent the initial and second screenings, respectively. Among the 30 cancers (of which 15 were stage 0/I) detected, 5 (0.72/1000) were in the mammography group, 11 (1.51/1000) in the ultrasound group, and 14 (2.02/1000) in the combined group (P=0.12). In the combined group, ultrasound detected all the 14 cancers, whereas mammography detected 8, making ultrasound more sensitive (100 vs 57.1%, P=0.04) with a better diagnostic accuracy (0.999 vs 0.766, P=0.01). There was no difference between mammography and ultrasound in specificity (100 vs 99.9%, P=0.51) and positive predictive value (72.7 vs 70.0% P=0.87). To detect one cancer, the costs of ultrasound, mammography, and combined modality were $7876, $45 253, and $21 599, respectively. Conclusions: Ultrasound is superior to mammography for breast cancer screening in high-risk Chinese women. PMID:25668012

  11. Comparative accuracy of mammography and ultrasound in women with breast symptoms according to age and breast density.

    PubMed

    Devolli-Disha, Emine; Manxhuka-Kërliu, Suzana; Ymeri, Halit; Kutllovci, Arben

    2009-05-01

    Breast cancer is the most common cancer and the second most common cause of death from cancer in women.The aim of this studywas to determine which is more accurate imaging test mammography or ultrasound for diagnosis of breast cancer based on the women's age and breast density. We examined 546 patients with breast symptoms, by clinical breast examination, mammography and ultrasound. A total of 546 breast lesions were examined by histopathology analyses. Histopathology results revealed the presence of 259 invasive cancers, and 287 benign lesions. Sensitivity varied significantly with age and breast density. In the 259 women who had both tests, ultrasound had a higher sensitivity than mammography in women younger than 45 years, whereas mammography had a higher sensitivity than ultrasound in women older than 60 years. The sensitivity according to age was 52,1% for mammography and 72,6% for ultrasound. The specificity according to age was 88, 5% for ultrasound and 73, 9% for mammography. Comparing the sensitivity of mammography and ultrasound according to the breast density indicates that mammographic sensitivity was 82,2% among women with predominantly fatty breast, but 23.7% in women with heterogeneous dense breasts, with the increase of fibro glandular density the level of sensitivity with mammography decreases, while ultrasonographic sensitivity was 71,1% among women with predominantly fatty breast and 57,0% for heterogeneous dense breasts. Our data indicate that sensitivity and specificity of ultrasound was statistically significantly greater than mammography in patients with breast symptoms for the detection of breast cancer and benign lesions particularly in dense breast and in young women. PMID:19485945

  12. Duplex ultrasound

    MedlinePlus

    Vascular ultrasound; Peripheral vascular ultrasound ... A duplex ultrasound combines traditional ultrasound with Doppler ultrasound . Traditional ultrasound uses sound waves that bounce off blood vessels to create ...

  13. Sensory and Quality Evaluation of Traditional Compared with Power Ultrasound Processed Corn (Zea Mays) Tortilla Chips.

    PubMed

    Janve, Bhaskar; Yang, Wade; Sims, Charles

    2015-06-01

    Power ultrasound reduces the traditional corn steeping time from 18 to 1.5 h during tortilla chips dough (masa) processing. This study sought to examine consumer (n = 99) acceptability and quality of tortilla chips made from the masa by traditional compared with ultrasonic methods. Overall appearance, flavor, and texture acceptability scores were evaluated using a 9-point hedonic scale. The baked chips (process intermediate) before and after frying (finished product) were analyzed using a texture analyzer and machine vision. The texture values were determined using the 3-point bend test using breaking force gradient (BFG), peak breaking force (PBF), and breaking distance (BD). The fracturing properties determined by the crisp fracture support rig using fracture force gradient (FFG), peak fracture force (PFF), and fracture distance (FD). The machine vision evaluated the total surface area, lightness (L), color difference (ΔE), Hue (°h), and Chroma (C*). The results were evaluated by analysis of variance and means were separated using Tukey's test. Machine vision values of L, °h, were higher (P < 0.05) and ΔE was lower (P < 0.05) for fried and L, °h were significantly (P < 0.05) higher for baked chips produced from ultra-sonication as compare to traditional. Baked chips texture for ultra-sonication was significantly higher (P < 0.05) on BFG, BPD, PFF, and FD. Fried tortilla chips texture were higher significantly (P < 0.05) in BFG and PFF for ultra-sonication than traditional processing. However, the instrumental differences were not detected in sensory analysis, concluding possibility of power ultrasound as potential tortilla chips processing aid. PMID:25939826

  14. A Comparative Study of Fibroid Ablation Rates Using Radio Frequency or High-Intensity Focused Ultrasound

    SciTech Connect

    Meng Xin; He Guangbin; Zhang Jun; Han Zenghui; Yu Ming; Zhang Miaomiao; Tang Yu; Fang Ling; Zhou Xiaodong

    2010-08-15

    This study compared the technical success of fibroid devascularization using high-intensity focused ultrasound (HIFU) and radio frequency (RF) to provide an experimental basis for the clinical selection of a suitable, minimally invasive method for treating uterine fibroids. Patients were randomly divided into two groups and treated with HIFU or RF accordingly. The two groups of patients were divided again into subgroups A, B, and C based on fibroid diameter and subgroups A', B', and C' based on fibroid blood supply grades. The fibroid diameters in subgroups A, B, and C were 2.0 cm {<=} D < 4.0 cm, 4.0 cm {<=} D<6.0 cm and 6.0 cm {<=} D<8.0 cm, respectively, and fibroid blood supplies were classified into three grades corresponding to subgroups A', B', and C', respectively. The complete ablation rates of the two treatments were compared by contrast-enhanced ultrasound. Both treatments were effective, but the general complete ablation rate of RF was higher than that of HIFU (p < 0.05). The comparison between the two treatments in subgroup A and subgroup A' showed that the complete ablation rate of HIFU was as good as that of RF (p > 0.05). In other subgroups, the complete ablation rates of RF were better than those of HIFU (p < 0.05). No severe complications were observed after these two treatments. RF can be applied for the majority of fibroids. As a noninvasive therapy, HIFU could be the preferred method for the treatment of small, hypovascular fibroids.

  15. Ozil® versus conventional ultrasound phacoemulsification: a randomized comparative study.

    PubMed

    Maalej, Afef; Khallouli, Asma; Wathek, Cheima; Rannen, Riadh

    2015-08-01

    The purpose of this study is to compare and assess the performance and the postoperative outcomes of torsional mode and ultrasound (US) mode performed in the phacoemulsification of cataract with different nuclear densities. This is a randomized comparative clinical study. Two groups of 75 eyes (the first operated by Ozil(®) and the second by US) were comparable in age, gender, cataract density, corneal incision size, and intraocular lens type. We assessed peroperative parameters: US time (UST) and cumulative dissipated energy (CDE). Postoperative outcome measures were corneal edema and final best-corrected visual acuity. The UST was significantly lower in the ozil(®) group for all nucleus grades (73.43 s ± 8.3 with US vs. 46.02 s ± 23 with Ozil(®)) (p = 0.0003). The CDE was lower in the Ozil(®) group for grade III and IV cataract (p = 0.005). However, no significant difference was noted for grade II cataract (p = 0.07). Immediate postoperative corneal edema was significantly harder in the US group (p = 0.00002). The mean one month postoperative visual acuity was 0.2 ± 0.03 logMAR and 0.15 ± 0.07 logMAR, respectively, in the US group and the Ozil(®) group (p = 0.06). Ozil(®) mode seems to dissipate less energy in the eye than US mode. The visual outcome at one month is comparable in the two groups. PMID:25155201

  16. Critical assessment of intramodality 3D ultrasound imaging for prostate IGRT compared to fiducial markers

    SciTech Connect

    Meer, Skadi van der; Bloemen-van Gurp, Esther; Hermans, Jolanda; Voncken, Robert; Heuvelmans, Denys; Gubbels, Carol; Fontanarosa, Davide; Visser, Peter; Lutgens, Ludy; Gils, Francis van; Verhaegen, Frank

    2013-07-15

    Purpose: A quantitative 3D intramodality ultrasound (US) imaging system was verified for daily in-room prostate localization, and compared to prostate localization based on implanted fiducial markers (FMs).Methods: Thirteen prostate patients underwent multiple US scans during treatment. A total of 376 US-scans and 817 matches were used to determine the intra- and interoperator variability. Additionally, eight other patients underwent daily prostate localization using both US and electronic portal imaging (EPI) with FMs resulting in 244 combined US-EPI scans. Scanning was performed with minimal probe pressure and a correction for the speed of sound aberration was performed. Uncertainties of both US and FM methods were assessed. User variability of the US method was assessed.Results: The overall US user variability is 2.6 mm. The mean differences between US and FM are: 2.5 {+-} 4.0 mm (LR), 0.6 {+-} 4.9 mm (SI), and -2.3 {+-} 3.6 mm (AP). The intramodality character of this US system mitigates potential errors due to transducer pressure and speed of sound aberrations.Conclusions: The overall accuracy of US (3.0 mm) is comparable to our FM workflow (2.2 mm). Since neither US nor FM can be considered a gold standard no conclusions can be drawn on the superiority of either method. Because US imaging captures the prostate itself instead of surrogates no invasive procedure is required. It requires more effort to standardize US imaging than FM detection. Since US imaging does not involve a radiation burden, US prostate imaging offers an alternative for FM EPI positioning.

  17. Automatic Cataract Classification based on Ultrasound Technique Using Machine Learning: A comparative Study

    NASA Astrophysics Data System (ADS)

    Caxinha, Miguel; Velte, Elena; Santos, Mário; Perdigão, Fernando; Amaro, João; Gomes, Marco; Santos, Jaime

    This paper addresses the use of computer-aided diagnosis (CAD) system for the cataract classification based on ultrasound technique. Ultrasound A-scan signals were acquired in 220 porcine lenses. B-mode and Nakagami images were constructed. Ninety-seven parameters were extracted from acoustical, spectral and image textural analyses and were subjected to feature selection by Principal Component Analysis (PCA). Bayes, K Nearest-Neighbors (KNN), Fisher Linear Discriminant (FLD) and Support Vector Machine (SVM) classifiers were tested. The classification of healthy and cataractous lenses shows a good performance for the four classifiers (F-measure ≥92.68%) with SVM showing the highest performance (90.62%) for initial versus severe cataract classification.

  18. A Comparative Analysis of Ultrasound Velocity in Binary Liquid Systems of PPG by Mathematical and Experimental Methods

    NASA Astrophysics Data System (ADS)

    Gayathri, A.; Venugopal, T.; Venkatramanan, K.

    The estimation of the speed of ultrasound is the fundamental requirement for investigating the transport properties of liquid and solid systems. Ultrasonic velocities of liquid mixtures containing polar and non-polar groups are of considerable importance in understanding inter-molecular interaction between component molecules and they find applications in several industrial and technological processes. There are many standard mathematical methods available to measure the ultrasonic velocity. In the present study, interferometric technique is planned for experimental measurement of ultrasound velocity. In this paper, the speed of ultrasound waves in Polypropylene Glycol (PPG 400, PPG 4000) in toluene has been estimated for different concentrations (2%, 4%, 6%, 8% & 10%) at 303K and these experimental values compared with theoretical values obtained by using various mathematical methods like Nomotto's Relation, Vandeal Vangeal Relation, Impedance Relation, and Rao's specific sound velocity. The most reliable method that matches with experimental method is identified using Average Percentage Error (APE) and analysed in the light of molecular interactions occurring in the binary liquid systems. Comparison of evaluated theoretical velocities with experimental values will reveal the nature of interaction between component molecules in the mixtures. Such theoretical study is useful in defining a comprehensive theoretical model for a specific liquid mixture. Also, various molecular interaction parameters like free volume, internal pressure, viscous relaxation time, inter atomic free length, etc are calculated and discussed in terms of polymer-solvent interactions.

  19. A randomised controlled trial comparing meat-based with human cadaveric models for teaching ultrasound-guided regional anaesthesia.

    PubMed

    Chuan, A; Lim, Y C; Aneja, H; Duce, N A; Appleyard, R; Forrest, K; Royse, C F

    2016-08-01

    The aim of this prospective, blinded, randomised controlled study was to compare novices' acquisition of the technical skills of ultrasound-guided regional anaesthesia using either a meat phantom model or fresh-frozen human cadavers. The primary outcome was the time taken to successfully perform an ultrasound-guided sciatic nerve block on a cadaver; secondary outcomes were the cumulative score of errors, and best image quality of the sciatic nerve achieved. After training, the median (IQR [range]) time taken to perform the block was 311(164-390 [68-600]) s in the meat model trained group and 210 (174-354 [85-600]) s in the fresh-frozen cadaver trained group (p = 0.24). Participants made a median (IQR [range]) of 18 (14-33 [8-55]) and 15 (12-22 [8-44]) errors in the two groups respectively (p = 0.39). The image quality score was also not different, with a median (IQR [range]) of 62.5 (59.4-65.6 [25.0-100.0])% vs 62.5 (62.5-75.0 [25.0-87.5])% respectively (p = 0.58). The training and deliberate feedback improved all participants' block performance, the median (IQR [range]) times being 310 (206-532 [110-600]) s before and 240 (174-354 [85-600]) s after training (p = 0.02). We conclude that novices taught ultrasound scanning and needle guidance skills using an inexpensive and easily constructed meat model perform similarly to those trained on a cadaveric model. PMID:26993374

  20. Note: Comparative experimental studies on the performance of 2-2 piezocomposite for medical ultrasound transducers.

    PubMed

    Marinozzi, F; Bini, F; Biagioni, A; Grandoni, A; Spicci, L

    2013-09-01

    The paper reports the experimental investigation of the behavior of 2-2 Lead Zirconate Titanate (PZT)-polymer composite transducers array for clinical ultrasound equipments. Several 2-2 plate composites having the same dicing pitch of 0.11 mm and different volume fractions were manufactured and investigated. Measurements were performed through different techniques such as electrical impedance, pulse-echo, and Laser Doppler Vibrometer. With the last one, maps of the surface displacement were presented relative to thickness mode and first lateral mode resonance frequencies. The transducers with volume fractions of the 40% resulted markedly inefficient, whereas the largest bandwidth and best band shape were achieved by the 50%. PMID:24089885

  1. A randomized controlled cross-over trial and cost analysis comparing endoscopic ultrasound fine needle aspiration and fine needle biopsy*

    PubMed Central

    Aadam, A. Aziz; Wani, Sachin; Amick, Ashley; Shah, Janak N.; Bhat, Yasser M.; Hamerski, Christopher M.; Klapman, Jason B.; Muthusamy, V. Raman; Watson, Rabindra R.; Rademaker, Alfred W.; Keswani, Rajesh N.; Keefer, Laurie; Das, Ananya; Komanduri, Srinadh

    2016-01-01

    Background and study aims: Techniques to optimize endoscopic ultrasound-guided tissue acquisition (EUS-TA) in a variety of lesion types have not yet been established. The primary aim of this study was to compare the diagnostic yield (DY) of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) to endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) for pancreatic and non-pancreatic masses. Patients and methods: Consecutive patients referred for EUS-TA underwent randomization to EUS-FNA or EUS-FNB at four tertiary-care medical centers. A maximum of three passes were allowed for the initial method of EUS-TA and patients were crossed over to the other arm based on on-site specimen adequacy. Results: A total of 140 patients were enrolled. The overall DY was significantly higher with specimens obtained by EUS-FNB compared to EUS-FNA (90.0 % vs. 67.1 %, P = 0.002). While there was no difference in the DY between the two groups for pancreatic masses (FNB: 91.7 % vs. FNA: 78.4 %, P = 0.19), the DY of EUS-FNB was higher than the EUS-FNA for non-pancreatic lesions (88.2 % vs. 54.5 %, P = 0.006). Specimen adequacy was higher for EUS-FNB compared to EUS-FNA for all lesions (P = 0.006). There was a significant rescue effect of crossover from failed FNA to FNB in 27 out of 28 cases (96.5 %, P = 0.0003). Decision analysis showed that the strategy of EUS-FNB was cost saving compared to EUS-FNA over a wide range of cost and outcome probabilities. Conclusions: Results of this RCT and decision analysis demonstrate superior DY and specimen adequacy for solid mass lesions sampled by EUS-FNB. PMID:27227104

  2. A Comparative Study of Three Speckle Reducing Methods for Intima-Media Thickness Ultrasound Images

    PubMed Central

    Rafati, Mehravar; Arabfard, Masoud; Rafati Rahimzadeh, Mehrdad; Voshtani, Hasan; Moladoust, Hassan

    2015-01-01

    Background: Ultrasonic evaluation of intima-media thickness (IMT) is an early marker of assessing the development of atherosclerosis and determining cardiovascular risk. To attain the best possible diagnosis, it is essential that medical images be clear, sharp and without noise and artifacts. Objectives: Comparison of speckle reducing anisotropic diffusion (SRAD), discrete (DTD) and continuum topological derivative (CTD) on B-mode ultrasound images of common carotid and brachial arteries throughout the cardiac cycle. Patients and Methods: In a cross-sectional design, an examination was performed on forty-two human subjects with a mean age of 44 ± 6 years from April 2013 to June 2013. This study was approved by the ethics committees of Kashan University of Medical Sciences and Beheshti Hospital. An ultrasonic examination of common carotid and brachial arteries of forty-two human subjects was performed. The program was designed in MATLAB software to extract consecutive B-mode images and apply region of interest (ROI) on the IMT of the common carotid and brachial arteries. Then, three different noise reduction filters with the Canny edge detection were used in ROI separately. Finally, the program measured the image quality metrics. Results: According to values of eleven different image quality metrics (mentioned in the main text), there was a significant difference between CTD, DTD and SRAD filters with the Canny edge detection status in the common carotid and brachial arteries throughout the cardiac cycle (all P values < 0.001). For example, peak signal to noise ratios (PSNR) using CTD, DTD and SRAD filters were 95.43 ± 0.64, 88.86 ± 0.82 and 73.02 ± 0.20 in common carotid and 96.39 ± 1.25, 92.58 ± 0.11 and 88.27 ± 0.63 in brachial arteries, respectively (both P values < 0.001). Conclusions: By measuring image quality metrics, this study showed that DTD and CTD filters with the Canny edge detection respectively, are better than SRAD filter with the Canny

  3. Comparative sensitivity of human and bovine erythrocytes to sonolysis by 1-MHz ultrasound.

    PubMed

    Miller, M W; Sherman, T A; Brayman, A A

    2000-10-01

    This project tested the hypothesis that human erythrocytes, being larger than bovine erythrocytes, would be the more sensitive to sonolysis induced by inertial cavitation. The rationale behind this hypothesis was an earlier demonstration that, among sized populations of erythrocytes, an inverse relation existed between erythrocyte volume and mechanically-induced shear forces in the surrounding medium; viz, the larger the cell, the less shear force required to rupture the cell's membrane. At low erythrocyte densities (i.e., approximately 5% hematocrit) the hypothesis was supported; at high cell densities (i.e., approximately 35% hematocrit) it was not supported. The data are consistent with an ultrasound (US)-induced symmetric implosion of affected gas nuclei as causing the effect at low cell densities; under such conditions there is ample spacing among cells for US-induced symmetric growth and collapse of gas nuclei and the concomitant production of radially-expanding shock waves (which lyse the cells); at high cell densities there is not sufficient spacing among cells for US-induced symmetric growth and collapse of bubbles and an alternative mechanism, possibly asymmetric bubble collapse, becomes operational. PMID:11120370

  4. Volumetric breast density evaluation by ultrasound tomography and magnetic resonance imaging: a preliminary comparative study

    NASA Astrophysics Data System (ADS)

    Myc, Lukasz; Duric, Neb; Littrup, Peter; Li, Cuiping; Ranger, Bryan; Lupinacci, Jessica; Schmidt, Steven; Rama, Olsi; Bey-Knight, Lisa

    2010-03-01

    Since a 1976 study by Wolfe, high breast density has gained recognition as a factor strongly correlating with an increased incidence of breast cancer. These observations have led to mammographic density being designated a "risk factor" for breast cancer. Clinically, the exclusive reliance on mammography for breast density measurement has forestalled the inclusion of breast density into statistical risk models. This exclusion has in large part been due to the ionizing radiation associated with the method. Additionally, the use of mammography as valid tool for measuring a three dimensional characteristic (breast density) has been criticized for its prima facie incongruity. These shortfalls have prompted MRI studies of breast density as an alternative three-dimensional method of assessing breast density. Although, MRI is safe and can be used to measure volumetric density, its cost has prohibited its use in screening. Here, we report that sound speed measurements using a prototype ultrasound tomography device have potential for use as surrogates for breast density measurement. Accordingly, we report a strong positive linear correlation between volume-averaged sound speed of the breast and percent glandular tissue volume as assessed by MR.

  5. [Comparative evaluation of bone mineral density in Mexican women using x-ray bone densitometry and ultrasound].

    PubMed

    Llaca Rodríguez, V; Aguilera Pérez, R; Ahued Ahued, R; Rio de la Loza, F; Mendoza Torres, L J; Coria Soto, I; Zambrana Castañeda, M M

    2000-03-01

    With lifestyle changes in women, smoking and use of beverages with caffeine, and sedentarism increasing, so the risk factors for decalcification, increase; which is a public health problem by the higher incidence of osteoporotic fractures, as the age advances, specially in the postmenopause woman, which means a greater secondary morbidity-mortality; an important cause of physical disability, which directly affects psychoemotional wellbeing in women. In this study two methods of bone densitometry, were used; one of x ray, and other with ultrasound in 138 women during postmenopause with an average index of corporal mass of 29. Both results were compared of bone density, T measurement with osteopenia and osteoporosis. Double densitometry, was done in the 138 patients of lumbar spine with DEXA equipment, and of calcaneum with DTU-one equipment, by the same technician, finding the difference of T punctuation in this double study. PMID:10808616

  6. Comparative imaging study in ultrasound, MRI, CT, and DSA using a multimodality renal artery phantom

    SciTech Connect

    King, Deirdre M.; Fagan, Andrew J.; Moran, Carmel M.; Browne, Jacinta E.

    2011-02-15

    Purpose: A range of anatomically realistic multimodality renal artery phantoms consisting of vessels with varying degrees of stenosis was developed and evaluated using four imaging techniques currently used to detect renal artery stenosis (RAS). The spatial resolution required to visualize vascular geometry and the velocity detection performance required to adequately characterize blood flow in patients suffering from RAS are currently ill-defined, with the result that no one imaging modality has emerged as a gold standard technique for screening for this disease. Methods: The phantoms, which contained a range of stenosis values (0%, 30%, 50%, 70%, and 85%), were designed for use with ultrasound, magnetic resonance imaging, x-ray computed tomography, and x-ray digital subtraction angiography. The construction materials used were optimized with respect to their ultrasonic speed of sound and attenuation coefficient, MR relaxometry (T{sub 1},T{sub 2}) properties, and Hounsfield number/x-ray attenuation coefficient, with a design capable of tolerating high-pressure pulsatile flow. Fiducial targets, incorporated into the phantoms to allow for registration of images among modalities, were chosen to minimize geometric distortions. Results: High quality distortion-free images of the phantoms with good contrast between vessel lumen, fiducial markers, and background tissue to visualize all stenoses were obtained with each modality. Quantitative assessments of the grade of stenosis revealed significant discrepancies between modalities, with each underestimating the stenosis severity for the higher-stenosed phantoms (70% and 85%) by up to 14%, with the greatest discrepancy attributable to DSA. Conclusions: The design and construction of a range of anatomically realistic renal artery phantoms containing varying degrees of stenosis is described. Images obtained using the main four diagnostic techniques used to detect RAS were free from artifacts and exhibited adequate contrast

  7. Intravascular ultrasound

    MedlinePlus

    IVUS; Ultrasound - coronary artery; Endovascular ultrasound; Intravascular echocardiography ... A tiny ultrasound wand is attached to the top of a thin tube called a catheter. This ultrasound catheter is inserted ...

  8. Duplex ultrasound

    MedlinePlus

    ... ultrasound with Doppler ultrasound . Traditional ultrasound uses sound waves that bounce off blood vessels to create pictures. Doppler ultrasound records sound waves reflecting off moving objects, such as blood, to ...

  9. Computer-aided diagnosis of Myocardial Infarction using ultrasound images with DWT, GLCM and HOS methods: A comparative study.

    PubMed

    Vidya, K Sudarshan; Ng, E Y K; Acharya, U Rajendra; Chou, Siaw Meng; Tan, Ru San; Ghista, Dhanjoo N

    2015-07-01

    Myocardial Infarction (MI) or acute MI (AMI) is one of the leading causes of death worldwide. Precise and timely identification of MI and extent of muscle damage helps in early treatment and reduction in the time taken for further tests. MI diagnosis using 2D echocardiography is prone to inter-/intra-observer variability in the assessment. Therefore, a computerised scheme based on image processing and artificial intelligent techniques can reduce the workload of clinicians and improve the diagnosis accuracy. A Computer-Aided Diagnosis (CAD) of infarcted and normal ultrasound images will be useful for clinicians. In this study, the performance of CAD approach using Discrete Wavelet Transform (DWT), second order statistics calculated from Gray-Level Co-Occurrence Matrix (GLCM) and Higher-Order Spectra (HOS) texture descriptors are compared. The proposed system is validated using 400 MI and 400 normal ultrasound images, obtained from 80 patients with MI and 80 normal subjects. The extracted features are ranked based on t-value and fed to the Support Vector Machine (SVM) classifier to obtain the best performance using minimum number of features. The features extracted from DWT coefficients obtained an accuracy of 99.5%, sensitivity of 99.75% and specificity of 99.25%; GLCM have achieved an accuracy of 85.75%, sensitivity of 90.25% and specificity of 81.25%; and HOS obtained an accuracy of 93.0%, sensitivity of 94.75% and specificity of 91.25%. Among the three techniques presented DWT yielded the highest classification accuracy. Thus, the proposed CAD approach may be used as a complementary tool to assist cardiologists in making a more accurate diagnosis for the presence of MI. PMID:25912990

  10. Evaluation of cost-effectiveness from the funding body's point of view of ultrasound-guided central venous catheter insertion compared with the conventional technique

    PubMed Central

    Noritomi, Danilo Teixeira; Zigaib, Rogério; Ranzani, Otavio T.; Teich, Vanessa

    2016-01-01

    Objective To evaluate the cost-effectiveness, from the funding body's point of view, of real-time ultrasound-guided central venous catheter insertion compared to the traditional method, which is based on the external anatomical landmark technique. Methods A theoretical simulation based on international literature data was applied to the Brazilian context, i.e., the Unified Health System (Sistema Único de Saúde - SUS). A decision tree was constructed that showed the two central venous catheter insertion techniques: real-time ultrasonography versus external anatomical landmarks. The probabilities of failure and complications were extracted from a search on the PubMed and Embase databases, and values associated with the procedure and with complications were taken from market research and the Department of Information Technology of the Unified Health System (DATASUS). Each central venous catheter insertion alternative had a cost that could be calculated by following each of the possible paths on the decision tree. The incremental cost-effectiveness ratio was calculated by dividing the mean incremental cost of real-time ultrasound compared to the external anatomical landmark technique by the mean incremental benefit, in terms of avoided complications. Results When considering the incorporation of real-time ultrasound and the concomitant lower cost due to the reduced number of complications, the decision tree revealed a final mean cost for the external anatomical landmark technique of 262.27 Brazilian reals (R$) and for real-time ultrasound of R$187.94. The final incremental cost of the real-time ultrasound-guided technique was -R$74.33 per central venous catheter. The incremental cost-effectiveness ratio was -R$2,494.34 due to the pneumothorax avoided. Conclusion Real-time ultrasound-guided central venous catheter insertion was associated with decreased failure and complication rates and hypothetically reduced costs from the view of the funding body, which in this

  11. Comparative assessments of the effects of alcohol exposure on fetal brain development using optical coherence tomography and ultrasound imaging

    NASA Astrophysics Data System (ADS)

    Sudheendran, Narendran; Bake, Shameena; Miranda, Rajesh C.; Larin, Kirill V.

    2013-02-01

    The developing fetal brain is vulnerable to a variety of environmental agents including maternal ethanol consumption. Preclinical studies on the development and amelioration of fetal teratology would be significantly facilitated by the application of high resolution imaging technologies like optical coherence tomography (OCT) and high-frequency ultrasound (US). This study investigates the ability of these imaging technologies to measure the effects of maternal ethanol exposure on brain development, ex vivo, in fetal mice. Pregnant mice at gestational day 12.5 were administered ethanol (3 g/Kg b.wt.) or water by intragastric gavage, twice daily for three consecutive days. On gestational day 14.5, fetuses were collected and imaged. Three-dimensional images of the mice fetus brains were obtained by OCT and high-resolution US, and the volumes of the left and right ventricles of the brain were measured. Ethanol-exposed fetuses exhibited a statistically significant, 2-fold increase in average left and right ventricular volumes compared with the ventricular volume of control fetuses, with OCT-derived measures of 0.38 and 0.18 mm3, respectively, whereas the boundaries of the fetal mouse lateral ventricles were not clearly definable with US imaging. Our results indicate that OCT is a useful technology for assessing ventriculomegaly accompanying alcohol-induced developmental delay. This study clearly demonstrated advantages of using OCT for quantitative assessment of embryonic development compared with US imaging.

  12. Comparative assessments of the effects of alcohol exposure on fetal brain development using optical coherence tomography and ultrasound imaging.

    PubMed

    Sudheendran, Narendran; Bake, Shameena; Miranda, Rajesh C; Larin, Kirill V

    2013-02-01

    The developing fetal brain is vulnerable to a variety of environmental agents including maternal ethanol consumption. Preclinical studies on the development and amelioration of fetal teratology would be significantly facilitated by the application of high resolution imaging technologies like optical coherence tomography (OCT) and high-frequency ultrasound (US). This study investigates the ability of these imaging technologies to measure the effects of maternal ethanol exposure on brain development, ex vivo, in fetal mice. Pregnant mice at gestational day 12.5 were administered ethanol (3 g/Kg b.wt.) or water by intragastric gavage, twice daily for three consecutive days. On gestational day 14.5, fetuses were collected and imaged. Three-dimensional images of the mice fetus brains were obtained by OCT and high-resolution US, and the volumes of the left and right ventricles of the brain were measured. Ethanol-exposed fetuses exhibited a statistically significant, 2-fold increase in average left and right ventricular volumes compared with the ventricular volume of control fetuses, with OCT-derived measures of 0.38 and 0.18 mm3, respectively, whereas the boundaries of the fetal mouse lateral ventricles were not clearly definable with US imaging. Our results indicate that OCT is a useful technology for assessing ventriculomegaly accompanying alcohol-induced developmental delay. This study clearly demonstrated advantages of using OCT for quantitative assessment of embryonic development compared with US imaging. PMID:23386196

  13. Comparing a volume based template approach and ultrasound guided freehand approach in multicatheter interstitial accelerated partial breast irradiation

    PubMed Central

    Koh, Vicky Y.; Buhari, Shaik A.; Tan, Poh Wee; Tan, Yun Inn; Leong, Yuh Fun; Earnest, Arul

    2014-01-01

    Purpose Currently, there are two described methods of catheter insertion for women undergoing multicatheter interstitial accelerated partial breast irradiation (APBI). These are a volume based template approach (template) and a non-template ultrasound guidance freehand approach (non-template). We aim to compare dosimetric endpoints between the template and non-template approach. Material and methods Twenty patients, who received adjuvant multicatheter interstitial APBI between August 2008 to March 2010 formed the study cohort. Dosimetric planning was based on the RTOG 04-13 protocol. For standardization, the planning target volume evaluation (PTV-Eval) and organs at risk were contoured with the assistance of the attending surgeon. Dosimetric endpoints include D90 of the PTV-Eval, Dose Homogeneity Index (DHI), V200, maximum skin dose (MSD), and maximum chest wall dose (MCD). A median of 18 catheters was used per patient. The dose prescribed was 34 Gy in 10 fractions BID over 5 days. Results The average breast volume was 846 cm3 (526-1384) for the entire cohort and there was no difference between the two groups (p = 0.6). Insertion time was significantly longer for the non-template approach (mean 150 minutes) compared to the template approach (mean: 90 minutes) (p = 0.02). The planning time was also significantly longer for the non-template approach (mean: 240 minutes) compared to the template approach (mean: 150 minutes) (p < 0.01). The template approach yielded a higher D90 (mean: 95%) compared to the non-template approach (mean: 92%) (p < 0.01). There were no differences in DHI (p = 0.14), V200 (p = 0.21), MSD (p = 0.7), and MCD (p = 0.8). Conclusions Compared to the non-template approach, the template approach offered significant shorter insertion and planning times with significantly improved dosimetric PTV-Eval coverage without significantly compromising organs at risk dosimetrically. PMID:25097558

  14. Management of myofascial pain by therapeutic ultrasound and transcutaneous electrical nerve stimulation: A comparative study

    PubMed Central

    Rai, Shalu; Ranjan, Vikash; Misra, Deepankar; Panjwani, Sapna

    2016-01-01

    Objective: The present comparative study was aimed to determine the effectiveness of Th US and TENS in the management of myofascial pain in TMD patients. Materials and Methods: The present randomized comparative study was on 90 patients who were further assigned in three different groups each having 30 patients; Group I was healthy control patients, Group II was receiving Th US therapy, and Group III was receiving TENS therapy. All the 90 patients were further evaluated for maximum inter incisor subjective evaluation regarding muscle pain, impediment to daily life, massage impression on visual analog scale (VAS) scale, and intensity and duration used in Th US massage. Results: The masseter muscle thickness in control group was 12.00 (standard deviation [SD] ±1.1) mm when compared with TMD patient of 13.00 (SD ± 1.1) mm before treatment. Statistical significant findings on VAS score of muscle pain, impediment to daily life, and massage impression were observed in Th US. After treatment, the anechoic areas disappeared or were reduced in Th US group by 95.6% and in TENS by 74.4%. Conclusion: Th US appeared to be subjectively better which was related to VAS score of massage impression, muscle pain, and impediment to daily life after treatment as well as sonographically related to existence of anechoic areas. PMID:27011739

  15. The Automated Breast Volume Scanner (ABVS): initial experiences in lesion detection compared with conventional handheld B-mode ultrasound: a pilot study of 50 cases.

    PubMed

    Wojcinski, Sebastian; Farrokh, Andre; Hille, Ursula; Wiskirchen, Jakub; Gyapong, Samuel; Soliman, Amr A; Degenhardt, Friedrich; Hillemanns, Peter

    2011-01-01

    The idea of an automated whole breast ultrasound was developed three decades ago. We present our initial experiences with the latest technical advance in this technique, the automated breast volume scanner (ABVS) ACUSON S2000(™). Volume data sets were collected from 50 patients and a database containing 23 women with no detectable lesions in conventional ultrasound (BI-RADS(®)-US 1), 13 women with clearly benign lesions (BI-RADS(®)-US 2), and 14 women with known breast cancer (BI-RADS(®)-US 5) was created. An independent examiner evaluated the ABVS data on a separate workstation without any prior knowledge of the patients' histories. The diagnostic accuracy for the experimental ABVS was 66.0% (95% confidence interval [CI]: 52.9-79.1). The independent examiner detected all breast cancers in the volume data resulting in a calculated sensitivity of 100% in the described setting (95% CI: 73.2%-100%). After the ABVS examination, there were a high number of requests for second-look ultrasounds in 47% (95% CI: 30.9-63.5) of the healthy women (with either a clearly benign lesion or no breast lesions at all in conventional handheld ultrasound). Therefore, the specificity remained at 52.8% (95% CI: 35.7-69.2). When comparing the concordance of the ABVS with the gold standard (conventional handheld ultrasound), Cohen's Kappa value as an estimation of the inter-rater reliability was κ = 0.37, indicating fair agreement. In conclusion, the ABVS must still be regarded as an experimental technique for breast ultrasound, which definitely needs to undergo further evaluation studies. PMID:22114526

  16. The Automated Breast Volume Scanner (ABVS): initial experiences in lesion detection compared with conventional handheld B-mode ultrasound: a pilot study of 50 cases

    PubMed Central

    Wojcinski, Sebastian; Farrokh, Andre; Hille, Ursula; Wiskirchen, Jakub; Gyapong, Samuel; Soliman, Amr A; Degenhardt, Friedrich; Hillemanns, Peter

    2011-01-01

    The idea of an automated whole breast ultrasound was developed three decades ago. We present our initial experiences with the latest technical advance in this technique, the automated breast volume scanner (ABVS) ACUSON S2000™. Volume data sets were collected from 50 patients and a database containing 23 women with no detectable lesions in conventional ultrasound (BI-RADS®-US 1), 13 women with clearly benign lesions (BI-RADS®-US 2), and 14 women with known breast cancer (BI-RADS®-US 5) was created. An independent examiner evaluated the ABVS data on a separate workstation without any prior knowledge of the patients’ histories. The diagnostic accuracy for the experimental ABVS was 66.0% (95% confidence interval [CI]: 52.9–79.1). The independent examiner detected all breast cancers in the volume data resulting in a calculated sensitivity of 100% in the described setting (95% CI: 73.2%–100%). After the ABVS examination, there were a high number of requests for second-look ultrasounds in 47% (95% CI: 30.9–63.5) of the healthy women (with either a clearly benign lesion or no breast lesions at all in conventional handheld ultrasound). Therefore, the specificity remained at 52.8% (95% CI: 35.7–69.2). When comparing the concordance of the ABVS with the gold standard (conventional handheld ultrasound), Cohen’s Kappa value as an estimation of the inter-rater reliability was κ = 0.37, indicating fair agreement. In conclusion, the ABVS must still be regarded as an experimental technique for breast ultrasound, which definitely needs to undergo further evaluation studies. PMID:22114526

  17. Lab-on-fiber platforms for ultrasound detection: a comparative study

    NASA Astrophysics Data System (ADS)

    Giaquinto, M.; Ricciardi, A.; Cutolo, A.; Cusano, A.

    2015-09-01

    Sub-wavelength metallo-dielectric gratings integrated on optical fibers tip and supporting plasmonic resonances were numerically investigated in their behavior as acousto-optical transducers. Different configurations have been analyzed and compared among them in terms of sensitivity, defined as reflectivity intensity variation (at fixed wavelength) with respect to dielectric layer thickness changes. Our results demonstrate that the maximum sensitivity is obtained when an interaction between different plasmonic modes occurs. Sensitivity enhancement up to a factor of 3 with respect to Fabry- Perot cavity like transducer with same materials and sizes can be achieved.

  18. 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. PMID:21914564

  19. Prostate Ultrasound

    MedlinePlus

    ... waves. Ultrasound imaging, also called ultrasound scanning or sonography , involves the use of a small transducer (probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the ...

  20. Hip Ultrasound

    MedlinePlus

    ... waves. Ultrasound imaging, also called ultrasound scanning or sonography , involves the use of a small transducer (probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the ...

  1. Ultrasound -- Vascular

    MedlinePlus

    ... waves. Ultrasound imaging, also called ultrasound scanning or sonography , involves the use of a small transducer (probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the ...

  2. Musculoskeletal Ultrasound

    MedlinePlus

    ... waves. Ultrasound imaging, also called ultrasound scanning or sonography , involves the use of a small transducer (probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the ...

  3. Ultrasound - Scrotum

    MedlinePlus

    ... waves. Ultrasound imaging, also called ultrasound scanning or sonography , involves the use of a small transducer (probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the ...

  4. A comparative sonochemical reaction that is independent of the intensity of ultrasound and the geometry of the exposure apparatus.

    PubMed

    Sostaric, Joe Z

    2008-09-01

    Sonolysis of aqueous solutions of n-alkyl anionic surfactants results in the formation of secondary carbon-centered radicals (-*CH-). The yield of -*CH- depends on the bulk surfactant concentration up to a maximum attainable radical yield (the 'plateau yield') where an increasing surfactant concentration (below the critical micelle concentration) no longer affects the -*CH- yield. In an earlier study it was found that the ratio of -*CH- detected following sonolysis of aqueous solutions of sodium pentane sulfonate (SPSo) to that of sodium dodecyl sulfate (SDS) (i.e. CH(SPSo)/CH(SDS)) depended on the frequency of sonolysis, but was independent of the ultrasound intensity, at the plateau concentrations [J.Z. Sostaric, P. Riesz, Adsorption of surfactants at the gas/solution interface of cavitation bubbles: an ultrasound intensity-independent frequency effect in sonochemistry, J. Phys. Chem. B 106 (2002) 12537-12548]. In the current study, it was found that the CH(SPSo)/CH(SDS) ratio depended only on the ultrasound frequency and did not depend on the geometry of the ultrasound exposure apparatus considered. PMID:18472292

  5. Diagnostic value of CT compared to ultrasound in the evaluation of acute abdominal pain in children younger than 10 years old.

    PubMed

    Simanovsky, Natalia; Dola, Tamar; Hiller, Nurith

    2016-02-01

    To assess the diagnostic value of ultrasound compared to CT in evaluating acute abdominal pain of different causes in children 10 years of age and under, hospital records and imaging files of 4052 patients under age of 10 who had imaging for abdominal pain were reviewed. One-hundred-thirty-two patients (3 %), (74 males/58 females) who underwent ultrasound and CT within 24 h were divided by age: group I, ages 0-48 months (25 patients); group II, 49-84 months (53 patients); and group III, 85-120 months (54 patients). Diagnoses at ultrasound, CT, and discharge were compared. Cases of a change in diagnosis following CT and impact of the changed diagnosis on patient management were assessed. Non-diagnostic ultrasound or a diagnostic conundrum was present in a small percentage (3 %) of our patients. In the group of patients imaged with two modalities, CT changed the diagnosis in 73/132 patients (55.3 %). Patient management changed in 63/132 patients (47.7 %). CT changed the diagnosis in 46/64 patients with surgical conditions (71.8 %, p < 0.001). Among patients with surgical conditions, the difference between ultrasonography (US) and CT diagnoses was significant in groups 2 (p = 0.046) and 3 (p =  .001). The impact of the change in diagnosis in surgical patients imaged with two modalities was significant in the group as a whole and in each age group separately. Non-diagnostic or equivocal US in a small percentage of patients is probably sufficient to justify the additional radiation burden. PMID:26453370

  6. Comparative study of the effects of low-intensity pulsed ultrasound and low-level laser therapy on bone defects in tibias of rats.

    PubMed

    Fávaro-Pípi, Elaine; Feitosa, Suellen Maurin; Ribeiro, Daniel Araki; Bossini, Paulo; Oliveira, Poliani; Parizotto, Nivaldo A; Renno, Ana Claudia Muniz

    2010-09-01

    The aim of this study was to investigate and to compare the effects of low intensity ultra-sound (LIPUS) and low-level laser therapy (LLLT) during the process of bone healing by means of histopathological and morphometric analysis. The animals were randomly distributed into three groups of 30 animals each: the control group (bone defect without treatment); the laser-treated group: (bone defect treated with laser), and the LIPUS-treated (bone defect treated with ultrasound). Each group was further divided into three different subgroups (n = 10) and on days 7, 13, and 25 post-injury, rats were killed with an intra-peritoneal injection of general anesthetic. The rats were treated with a 30-mW/cm(2) low-intensity pulsed ultrasound and a 830-nm laser at 50 J/cm(2). The results showed intense new bone formation surrounded by highly vascularized connective tissue presenting a slight osteogenic activity, with primary bone deposition being observed in the group exposed to laser in the intermediary (13 days) and late stages of repair (25 days). This was confirmed by morphometric analysis in which significant statistical differences (p < 0.05) were noticed when compared to the control. No remarkable differences were noticed in the specimens treated with ultrasound with regard to the amount of newly formed bone in comparison to the control group. Taken together, our results indicate that laser therapy improves bone repair in rats as depicted by histopathological and morphometric analysis, mainly at the late stages of recovery. Moreover, it seems that this therapy was more effective than US to accelerate bone healing. PMID:20521077

  7. Disaster Response Team FAST Skills Training with a Portable Ultrasound Simulator Compared to Traditional Training: Pilot Study

    PubMed Central

    Paddock, Michael T.; Bailitz, John; Horowitz, Russ; Khishfe, Basem; Cosby, Karen; Sergel, Michelle J.

    2015-01-01

    Introduction Pre-hospital focused assessment with sonography in trauma (FAST) has been effectively used to improve patient care in multiple mass casualty events throughout the world. Although requisite FAST knowledge may now be learned remotely by disaster response team members, traditional live instructor and model hands-on FAST skills training remains logistically challenging. The objective of this pilot study was to compare the effectiveness of a novel portable ultrasound (US) simulator with traditional FAST skills training for a deployed mixed provider disaster response team. Methods We randomized participants into one of three training groups stratified by provider role: Group A. Traditional Skills Training, Group B. US Simulator Skills Training, and Group C. Traditional Skills Training Plus US Simulator Skills Training. After skills training, we measured participants’ FAST image acquisition and interpretation skills using a standardized direct observation tool (SDOT) with healthy models and review of FAST patient images. Pre- and post-course US and FAST knowledge were also assessed using a previously validated multiple-choice evaluation. We used the ANOVA procedure to determine the statistical significance of differences between the means of each group’s skills scores. Paired sample t-tests were used to determine the statistical significance of pre- and post-course mean knowledge scores within groups. Results We enrolled 36 participants, 12 randomized to each training group. Randomization resulted in similar distribution of participants between training groups with respect to provider role, age, sex, and prior US training. For the FAST SDOT image acquisition and interpretation mean skills scores, there was no statistically significant difference between training groups. For US and FAST mean knowledge scores, there was a statistically significant improvement between pre- and post-course scores within each group, but again there was not a statistically

  8. One-pot synthesis of indenonaphthopyrans catalyzed by copper(II) triflate: a comparative study of reflux and ultrasound methods.

    PubMed

    Turhan, Kadir; Ozturkcan, S Arda; Uluer, Mehmet; Turgut, Zuhal

    2014-01-01

    An effective and environment-friendly protocol for the synthesis of indenonaphthopyrans has been developed by one-pot reaction of 2-naphthol, various aromatic aldehydes and 1,3-indandione, in the presence of copper(II) triflate as the catalyst while using reflux (Method A) and ultrasound (Method B). The Method B approach offers the advantages of a simple reaction method, short reaction time, excellent yield, and showcases the economic importance of the catalysts for such processes. PMID:25286219

  9. COMPARATIVE STUDY OF THE EFFECTS OF LOW-LEVEL LASER AND LOW-INTENSITY ULTRASOUND ASSOCIATED WITH BIOSILICATE® ON THE PROCESS OF BONE REPAIR IN THE RAT TIBIA

    PubMed Central

    Oliveira, Poliani de; Fernandes, Kelly Rosseti; Sperandio, Evandro Fornias; Pastor, Fabio Alexandre Casarin; Nonaka, Keico Okino; Parizotto, Nivaldo Antonio; Renno, Ana Claudia Muniz

    2015-01-01

    Objective: Verify the effects of the association between Biosilicate® and ultrasound and, Biosilicate® and laser in bone consolidation process of rats, through the biomechanical and histological analysis. Methods: Forthy male rats were used. The animals were randomized into four groups (n=10): control group fracture no treated (CGF); group treated with Biosilicate® (BG); group treated with Biosilicate® and laser (BLG); group treated with Biosilicate® and ultrasound (BUG). Results: The biomechanical analysis showed no significant difference among any groups after 14 days post-surgery. In the morphometric analysis, the control group showed moderate presence of new formed bone tissue inside the defects areas and the Biosilicate® group showed similar results. Despite those facts, the biomaterial osteogenic potential was demonstrated by the great amount of cells and bone tissue around the particles. Curiously, the Biosilicate® plus laser or ultrasound groups showed lower amounts of bone tissue deposition when compared with control fracture and Biosilicate® groups. Conclusion: The data from this study can conclude that Biosilicate® was able to accelerate and optimized the bone consolidation, through the modulation of the inflammatory process and the stimulation of new bone formation. However, when resources were associated, there are no positive results. PMID:27027088

  10. A comparative study of ultrasound and laser light diffraction techniques for particle size determination in dairy beverages

    NASA Astrophysics Data System (ADS)

    Meyer, S.; Berrut, S.; Goodenough, T. I. J.; Rajendram, V. S.; Pinfield, V. J.; Povey, M. J. W.

    2006-02-01

    The particle size distribution (PSD) of milkfat droplets of raw and homogenized milk was determined by a diagnostic ultrasound technique that was initially calibrated with colloidal silica. The quality of the fit between ultrasound theory and experiment is discussed and provides a basis for comparison with the reference laser light scattering technique. The predicted ultrasonic attenuation was determined from the ECAH (Epstein P S and Carhart R R 1953 J. Acoust. Soc. Am. 25 553-65, Allegra J R and Hawley S A 1972 J. Acoust. Soc. Am. 51 1545-64) model using thermophysical data for milkfat and milk serum. New thermophysical properties of milkfat were established. The experimental data were obtained with the Ultrasizer spectrometer. Both techniques were affected by the milk proteins and could provide only qualitative milkfat PSD for the raw and the homogenized milk samples. Therefore, they showed their limitations to characterize multiple emulsions. However, preliminary results are shown for the ultrasound technique that account for the impact of the protein on the measured data and hence obtain quantitative results for the milkfat size distributions.

  11. A comparative sonochemical reaction that is independent of the intensity of ultrasound and the geometry of the exposure apparatus

    PubMed Central

    Sostaric, Joe Z.

    2009-01-01

    Sonolysis of aqueous solutions of n-alkyl anionic surfactants results in the formation of secondary carbon-centered radicals (—•CH—). The yield of —•CH— depends on the bulk surfactant concentration up to a maximum attainable radical yield (the ‘plateau yield’) where an increasing surfactant concentration (below the critical micelle concentration) no longer affects the —•CH— yield. In an earlier study it was found that the ratio of —•CH— detected following sonolysis of aqueous solutions of sodium pentane sulfonate (SPSo) to that of sodium dodecyl sulfate (SDS) (i.e., CHSPSo/CHSDS) depended on the frequency of sonolysis, but was independent of the ultrasound intensity, at the plateau concentrations (J. Phys. Chem. B 106 (2002) 12537-12548). In the current study, it was found that the CHSPSo/CHSDS ratio depended only on the ultrasound frequency and did not depend on the geometry of the ultrasound exposure apparatus considered. PMID:18472292

  12. Endoscopic ultrasound

    MedlinePlus

    Endoscopic ultrasound is a type of imaging test. It is used to see organs in and near the digestive ... Ultrasound is a way to see the inside of the body using high-frequency sound waves. Endoscopic ...

  13. Scrotal ultrasound

    MedlinePlus

    ... the scrotal sac to help transmit the sound waves. A handheld probe (the ultrasound transducer) is then ... The ultrasound machine sends out high-frequency sound waves. These waves reflect off areas in the scrotum ...

  14. Pregnancy ultrasound

    MedlinePlus

    ... 3D ultrasound References Richards DS. Obstetrical ultrasound: Imaging, dating, and growth. In: Gabbe SG, Niebyl JR, Simpson ... the first to achieve this important distinction for online health information and services. Learn more about A. ...

  15. Added value of semi-quantitative breast-specific gamma imaging in the work-up of suspicious breast lesions compared to mammography, ultrasound and 3-T MRI

    PubMed Central

    Seymer, A; Keinrath, P; Holzmannhofer, J; Pirich, C; Hergan, K; Meissnitzer, M W

    2015-01-01

    Objective: To prospectively analyse the diagnostic value of semi-quantitative breast-specific gamma imaging (BSGI) in the work-up of suspicious breast lesions compared with that of mammography (MG), breast ultrasound and MRI of the breast. Methods: Within a 15-month period, 67 patients with 92 breast lesions rated as Category IV or V according to the breast imaging reporting and data system detected with MG and/or ultrasound were included into the study. After the injection of 740–1110 MBq of Technetium-99m (99mTc) SestaMIBI intravenously, scintigrams were obtained in two projections comparable to MG. The BSGI was analysed visually and semi-quantitatively by calculating a relative uptake factor (X). With the exception of two patients with cardiac pacemakers, all patients underwent 3-T breast MRI. Biopsy results were obtained as the reference standard in all patients. Sensitivity, specificity, positive- and negative-predictive values, accuracy and area under the curve were calculated for each modality. Results: Among the 92 lesions, 67 (72.8%) were malignant. 60 of the 67 cancers of any size were detected by BSGI with an overall sensitivity of 90%, only exceeded by ultrasound with a sensitivity of 99%. The sensitivity of BSGI for lesions <1 cm declined significantly to 60%. Overall specificity of ultrasound was only 20%. Specificity, accuracy and positive-predictive value were the highest for BSGI (56%, 80% and 85%, respectively). X was significantly higher for malignant lesions (mean, 4.27) and differed significantly between ductal types (mean, 4.53) and the other histopathological entities (mean, 3.12). Conclusion: Semi-quantitative BSGI with calculation of the relative uptake factor (X) can help to characterize breast lesions. BSGI negativity may obviate the need for biopsy of breast lesions >1 cm with low or intermediate prevalence for malignancy. Advances in knowledge: Compared with morphological imaging modalities, specificity, positive

  16. A comparative study on the contour tracking algorithms in ultrasound tongue images with automatic re-initialization.

    PubMed

    Xu, Kele; Gábor Csapó, Tamás; Roussel, Pierre; Denby, Bruce

    2016-05-01

    The feasibility of an automatic re-initialization of contour tracking is explored by using an image similarity-based method in the ultrasound tongue sequences. To this end, the re-initialization method was incorporated into current state-of-art tongue tracking algorithms, and a quantitative comparison was made between different algorithms by computing the mean sum of distances errors. The results demonstrate that with automatic re-initialization, the tracking error can be reduced from an average of 5-6 to about 4 pixels, a result obtained by using a large number of hand-labeled frames and similarity measurements to extract the contours, which results in improved performance. PMID:27250201

  17. Ultrasound transmission attenuation tomography using energy-scaled amplitude ratios

    NASA Astrophysics Data System (ADS)

    Chen, Ting; Shin, Junseob; Huang, Lianjie

    2016-04-01

    Ultrasound attenuation of breast tumors is related to their types and pathological states, and can be used to detect and characterize breast cancer. Particularly, ultrasound scattering attenuation can infer the margin properties of breast tumors. Ultrasound attenuation tomography quantitatively reconstructs the attenuation properties of the breast. Our synthetic-aperture breast ultrasound tomography system with two parallel transducer arrays records both ultrasound reflection and transmission signals. We develop an ultrasound attenuation tomography method using ultrasound energy-scaled amplitude decays of ultrasound transmission signals and conduct ultrasound attenuation tomography using a known sound-speed model. We apply our ultrasound transmission attenuation tomography method to a breast phantom dataset, and compare the ultrasound attenuation tomography results with conventional beamforming ultrasound images obtained using reflection signals. We show that ultrasound transmission attenuation tomography complements beamforming images in identifying breast lesions.

  18. Interventional ultrasound

    SciTech Connect

    Holm, H.H.; Kristensen, J.K.

    1985-01-01

    This book discusses: Introduction to interventional ultrasound/handling of aspirated material/general principles of fine needle aspiration cytology/procedure and principles in ultrasonically guided puncture/puncture of focal liver lesions/intraoperative puncture of the liver guided by ultrasound/Interventional ultrasound in cancer therapy/Interventional echocardiography/Fine-needle aspiration biopsy: Are there any risks./Puncture of renal mass lesions/Intrauterine needle diagnosis/Percutaneous nephrolithotomy.

  19. Infrared thermography and ultrasound C-scan for non-destructive evaluation of 3D carbon fiber materials: a comparative study

    NASA Astrophysics Data System (ADS)

    Zhang, Hai; Genest, Marc; Robitaille, Francois; Maldague, Xavier; West, Lucas; Joncas, Simon; Leduc, Catherine

    2015-05-01

    3D Carbon fiber polymer matrix composites (3D CF PMCs) are increasingly used for aircraft construction due to their exceptional stiffness and strength-to-mass ratios. However, defects are common in the 3D combining areas and are challenging to inspect. In this paper, Stitching is used to decrease these defects, but causes some new types of defects. Infrared NDT (non-destructive testing) and ultrasound NDT are used. In particular, a micro-laser line thermography technique (micro-LLT) and a micro-laser spot thermography (micro-LST) with locked-in technique are used to detect the micro-defects. In addition, a comparative study is conducted by using pulsed thermography (PT), vibrothermography (VT). In order to confirm the types of the defects, microscopic inspection is carried out before NDT work, after sectioning and polishing a small part of the sample..

  20. Clinical Applicability of Assessment of Jugular Flow over the Individual Cardiac Cycle Compared with Current Ultrasound Methodology.

    PubMed

    Sisini, Francesco; Tessari, Mirko; Menegatti, Erica; Vannini, Maria Elena; Gianesini, Sergio; Tavoni, Valentina; Gadda, Giacomo; Gambaccini, Mauro; Taibi, Angelo; Zamboni, Paolo

    2016-08-01

    There is growing interest in measuring cerebral venous outflow with ultrasound (US). However, results obtained with the current US Doppler methodology, which uses just a single value of cross-sectional area (CSA) of the vessel, are highly variable and inconclusive. The product of CSA and time-averaged velocity in the case of pulsatile vessels may be a possible source of error, particularly for a pulsatile vein like the internal jugular vein (IJV), where the cardiac pump transmits a sequence of well-established waves along the conduit. We herein propose a novel technique for US IJV flow assessment that accurately accounts for IJV CSA variations during the cardiac cycle. Five subjects were investigated with a high-resolution real-time B-mode video, synchronized with an electrocardiography trace. In this approach, CSA variations representing the pulsatility of the IJV are overlapped with the velocity curve obtained by the usual spectral Doppler trace. The overlap is then phased point by point using the electrocardiography pacemaker. This allows us to experimentally measure the velocity variation in relation to the change in CSA precisely, ultimately enabling calculation of IJV flow. (i) The sequence of CSA variation with respect to the electrocardiography waves corresponds exactly to the jugular venous pulse as measured in physiology. (ii) The methodology permits us to phase the velocity and CSA, which is ultimately what is currently lacking to precisely calculate the flow in the IJV with US. (iii) The time-averaged flow, calculated with the described technique, is very close to that calculated assuming a constant IJV CSA, whereas the time-dependent flow shows differs as much as 40%. (iv) Finally, we tested the accuracy of the technique with a methodology that may allow for universal assessment of the accuracy of each personal US-based evaluation of flow rate. PMID:27108038

  1. A comparative approach of four different image registration techniques for quantitative assessment of coronary artery calcium lesions using intravascular ultrasound.

    PubMed

    Araki, Tadashi; Ikeda, Nobutaka; Dey, Nilanjan; Chakraborty, Sayan; Saba, Luca; Kumar, Dinesh; Godia, Elisa Cuadrado; Jiang, Xiaoyi; Gupta, Ajay; Radeva, Petia; Laird, John R; Nicolaides, Andrew; Suri, Jasjit S

    2015-02-01

    In IVUS imaging, constant linear velocity and a constant angular velocity of 1800 rev/min causes displacement of the calcium in subsequent image frames. To overcome this error in intravascular ultrasound video, IVUS image frames must be registered prior to the lesion quantification. This paper presents a comprehensive comparison of four registration methods, namely: Rigid, Affine, B-Splines and Demons on five set of calcium lesion quantification parameters namely: (i) the mean lesion area, (ii) mean lesion arc, (iii) mean lesion span, (iv) mean lesion length, and (v) mean lesion distance from catheter. Using our IRB approved data of 100 patient volumes, our results shows that all four registrations showed a decrease in five calcium lesion parameters as follows: for Rigid registration, the values were: 4.92%, 5.84%, 5.89%, 5.27%, and 4.57%, respectively, for Affine registration the values were: 6.06%, 6.51%, 7.28%, 6.50%, and 5.94%, respectively, for B-Splines registration the values were: 7.35%, 8.03%, 9.54%, 8.18%, and 7.62%, respectively, and for Demons registration the five parameters were 7.32%, 8.02%, 10.11%, 7.94%, and 8.92% respectively. The relative overlap of identified lesions decreased by 5.91% in case of Rigid registration, 6.23% in case of Affine registration, 4.48% for Demons registration, whereas it increased by 3.05% in case of B-Splines registration. Rigid and Affine transformation-based registration took only 0.1936 and 0.2893 s per frame, respectively. Demons and B-Splines framework took only 0.5705 and 0.9405 s per frame, respectively, which were significantly slower than Rigid and Affine transformation based image registration. PMID:25523233

  2. Comparative study of ultrasound-guided paravertebral block with ropivacaine versus bupivacaine for post-operative pain relief in children undergoing thoracotomy for patent ductus arteriosus ligation surgery

    PubMed Central

    Chalam, Kolli S; Patnaik, Sathya Swaroop; Sunil, C; Bansal, Tripti

    2015-01-01

    Background and Aims: Thoracotomy incision following patent ductus arteriosus (PDA) ligation surgery is often associated with severe post-operative pain that has deleterious effects on respiratory function. We aimed to assess pain relief with thoracic paravertebral block using either bupivacaine or ropivacaine in these surgeries. Methods: One hundred paediatric patients of age group between 2 and 10 years undergoing PDA ligation surgery were randomised either to bupivacaine or ropivacaine group in this prospective double-blinded study. After induction of general anaesthesia, the ultrasound-guided paravertebral block was carried out using 0.25% bupivacaine 0.4 ml/kg in Group B patients and 0.2% ropivacaine 0.4 ml/kg in Group R patients. Monitoring included minimum mandatory monitoring with pulse rate, pulseoximetry (SpO2), electrocardiogram, blood pressure, temperature during surgery and also in Intensive Care Unit (ICU). Additionally, modified objective pain score (MOPS) was used in ICU for assessment of pain for 12 h after surgery. Incidence of complications was noted. Results: Mean values of MOPSs were comparable in both the groups. The time to rescue analgesic was 8 to 10 h in over 80% of patients in both the groups. More patients had hypotension and bradycardia in bupivacaine group compared to ropivacaine group. Conclusion: Paravertebral injection of 0.4 ml/kg of either 0.2% ropivacaine or 0.25% bupivacaine provided equipotent analgesia, but ropivacaine had a better side effect profile. Ultrasound-guided paravertebral block is a safe and effective mode of analgesia in paediatric patients undergoing thoracotomy. PMID:26379293

  3. Comparative study of linear and curvilinear ultrasound probes to assess quadriceps rectus femoris muscle mass in healthy subjects and in patients with chronic respiratory disease

    PubMed Central

    Mandal, S; Suh, E; Thompson, A; Connolly, B; Ramsay, M; Harding, R; Puthucheary, Z; Moxham, J; Hart, N

    2016-01-01

    Introduction Ultrasound measurements of rectus femoris cross-sectional area (RFCSA) are clinically useful measurements in chronic obstructive pulmonary disease (COPD) and critically ill patients. Technical considerations as to the type of probe used, which affects image resolution, have limited widespread clinical application. We hypothesised that measurement of RFCSA would be similar with linear and curvilinear probes. Methods Four studies were performed to compare the use of the curvilinear probe in measuring RFCSA. Study 1 investigated agreement of RFCSA measurements using linear and curvilinear probes in healthy subjects, and in patients with chronic respiratory disease. Study 2 investigated the intra-rater and inter-rater agreement using the curvilinear probe. Study 3 investigated the agreement of RFCSA measured from whole and spliced images using the linear probe. Study 4 investigated the applicability of ultrasound in measuring RFCSA during the acute and recovery phases of an exacerbation of COPD. Results Study 1 showed demonstrated no difference in the measurement of RFCSA using the curvilinear and linear probes (308±104 mm2 vs 320±117 mm2, p=0.80; intraclass correlation coefficient (ICC)>0.97). Study 2 demonstrated high intra-rater and inter-rater reliability of RFCSA measurement with ICC>0.95 for both. Study 3 showed that the spliced image from the linear probe was similar to the whole image RFCSA (308±103.5 vs 263±147 mm2, p=0.34; ICC>0.98). Study 4 confirmed the clinical acceptability of using the curvilinear probe during an exacerbation of COPD. There were relationships observed between admission RFCSA and body mass index (r=+0.65, p=0.018), and between RFCSA at admission and physical activity levels at 4 weeks post-hospital discharge (r=+0.75, p=0.006). Conclusions These studies have demonstrated that clinicians can employ whole and spliced images from the linear probe or use images from the curvilinear probe, to measure RFCSA. This will extend

  4. Randomized Trial Comparing the Flexible 19G and 25G Needles for Endoscopic Ultrasound-Guided Fine Needle Aspiration of Solid Pancreatic Mass Lesions

    PubMed Central

    Ramesh, Jayapal; Bang, Ji Young; Hebert-Magee, Shantel; Trevino, Jessica; Eltoum, Isam; Frost, Andra; Hasan, Muhammad K.; Logue, Amy; Hawes, Robert; Varadarajulu, Shyam

    2015-01-01

    Objectives Although a large gauge needle can procure more tissue at endoscopic ultrasound-guided fine needle aspiration (EUS-FNA), its advantage over smaller needles is unclear. This study compared flexible 19G and 25G needles for EUS-FNA of solid pancreatic masses. Methods This was a randomized trial of patients undergoing EUS-FNA of pancreatic masses using flexible 19G or 25G needle. Main outcome measure was to compare median number of passes for on-site diagnosis. Secondary measures were to compare specimen bloodiness, complications, technical failures, and histological core tissue procurement. Results One hundred patients were randomized to EUS-FNA using flexible 19G or 25G needle. Median of 1 pass was required to achieve on-site diagnosis of 96% and 92% (P = 0.68) in 19G and 25G cohorts. There was no significant difference in technical failure (0% vs 2%, P = 0.99) or adverse events (2% vs 0%, P = 0.99) between 19G and 25G cohorts. Although histological core tissue procurement was significantly better with flexible 19G needle (88% vs 44%, P < 0.001), specimens were bloodier (severe bloodiness, 36% vs 4%; P < 0.001). Conclusions As there is no significant difference in the performance of flexible 19G and 25G needles, needle choice for sampling pancreatic masses should be based on endoscopist preference and need for histology. PMID:25232713

  5. Ultrasound-guided Central Line Insertion and Standard Peripherally Inserted Catheter Placement in Preterm Infants: Comparing Results from Prospective Study in a Single-center

    PubMed Central

    Al Hamod, Dany Antanios; Zeidan, Smart; Al Bizri, Ayah; Baaklini, Georges; Nassif, Yolla

    2016-01-01

    Background: Among preterm infants, the peripherally inserted central catheter (PICC) is the standard line for central venous access; however, its placement exposes them to hypothermia and pain. Ultrasound (US)-guided central line insertion may be less morbid than standard PICC line. Aims: To determine the ease, success rate, and morbidity associated with US-guided central line insertion in the internal jugular vein (IJV) by comparing it to the standard PICC line placement. Materials and Methods: This is a single-center nonrandomized prospective study evaluating preterm infants between October 2013 and June 2014. Patients were allocated into two groups: The standard group (control group) who underwent blind PICC line insertion and the intervention group who underwent a percutaneous US-guided central line insertion in the IJV. The epicutaneo-cava-catheter was used in both groups. Results: Fifty neonates were enrolled on study. A statistically difference in favor of US-IJV insertion was noted concerning the rate of successful first attempt (P < 0.001), insertion (P = 0.001), and procedure duration (P < 0.001) and number of trials (P < 0.001) compared to PICC. No difference in complications (P = 1.000) was noted. Conclusion: US guided catheterization of the IJV technique is faster than PICC line insertion with higher rates of successful first attempt and insertion, less procedure duration and fewer number of trials compared to PICC line insertion. There were no differences in complications. PMID:27298814

  6. Three-Dimensional Assessment of Automated Breast Volume Scanner Compared with Handheld Ultrasound in Pre-Operative Breast Invasive Ductal Carcinomas: A Pilot Study of 51 Cases.

    PubMed

    Xu, Chaoli; Wei, Shuping; Xie, Yingdong; Guan, Xiaoxiang; Yang, Bin

    2016-09-01

    The aim of the work described here was to compare the accuracy of conventional handheld ultrasound (HHUS) with that of an automated breast volume scanner (ABVS) in 3-D assessment of pre-operative invasive ductal carcinomas. HHUS and ABVS were used in 51 patients to obtain the largest tumor diameter, tumor volume and tumor surface area. The volumetric measurement was also obtained from ABVS data with medical software. With tumor size and volume on pathology as the gold standard, Bland-Altman analysis was used to compare variability. Correlation coefficients and receiver operating characteristic curves were established for all measurements for T2 classification. The correlation coefficients of all ABVS measurements were stronger than those of HHUS measurements, with the ABVS volumetric measurement significantly different with a higher accuracy of 88.24% (45/51) and predicting T-classification with higher area under the receiver operating characteristic curves (0.936). Therefore, 3-D measurements provide stronger correlations with pathology in tumor size measurement. However, more clinical trials are needed to confirm our findings. PMID:27339762

  7. Comparative study of ultrasound-guided abdominal field blocks versus port infiltration in laparoscopic cholecystectomies for post-operative pain relief

    PubMed Central

    Saxena, Ruchi; Joshi, Saurabh; Srivastava, Kuldeep; Tiwari, Shashank; Sharma, Nitin; Valecha, Umesh K

    2016-01-01

    Background and Aims: Post-operative pain is a major concern for day care surgeries like laparoscopic cholecystectomy. This study aimed to compare the efficacy of ultrasound guided abdominal field blocks (USAFB) with port site infiltrations for post-operative analgesia in terms of quality of pain relief, opioid consumption and patient satisfaction for day care surgeries Methods: Eighty patients presenting for laparoscopic cholecystectomy were randomly allocated to two groups either to receive port-site infiltration of local anaesthetic (n = 40, Group A) or USAFB (n = 40, Group B group). Numeric rating scores (NRS) were measured postoperatively to primarily assess the pain severity and opioid requirements. Data were analysed using Chi-Square test/Fisher's exact test for categorical data and Mann–Whitney test/unpaired t-test for quantitative data. Results: The study group (Group B) had significantly reduced NRS and opioid consumption over 24 h. The overall fentanyl consumption in patients receiving port infiltrations was approximately twice (200 ΁ 100 μg) as compared to patients in USAFB group (120 ΁ 74 μg) (P < 0.0001). Maximum fentanyl consumption was 400 μg (Group A) and 262 μg (Group B) over 24 h and the minimum requirement was 50 μg and zero, respectively. Conclusion: Superior post-operative analgesia was observed with USAFB which may help in minimising opioid-related adverse effects and facilitating faster recovery.

  8. Ultrasound Biomicroscopy and Scheimpflug Imaging in Anterior Megalophthalmos: Changes Seen after Cataract Surgery.

    PubMed

    Nawani, Nishant; Jain, Arun K; Singh, Ramandeep

    2015-01-01

    Purpose. With this report we describe ultrasound biomicroscopic (UBM) findings in a patient with anterior megalophthalmos before and after undergoing phacoemulsification with posterior chamber intraocular lens implantation. Methods. Phacoemulsification was carried out for nuclear sclerosis in both eyes of a patient diagnosed with anterior megalophthalmos. The patient was subjected to detailed ophthalmic examination including ultrasound biomicroscopy and Scheimpflug imaging prior to and after surgery. Preoperative ultrasound biomicroscopy revealed a deep anterior chamber with posterior bowing of the midperipheral iris in both eyes. The ciliary processes were inserted on the posterior surface of the iris. UBM was repeated postoperatively as well. Results. Phacoemulsification and posterior chamber intraocular lens implantation (IOL) were carried out successfully in both eyes. The IOLs were well centered and captured within the anterior capsulorhexis. The anterior chambers were hyperdeep, 6.24 mm (OD) and 6.08 mm (OS), respectively. The posterior bowing of the midperipheral iris was absent, with the iris having a more flat profile. Conclusion. UBM findings in anterior megalophthalmos seemed to partially resolve after cataract surgery. The anterior chamber deepens appreciably as well. PMID:26064734

  9. Ultrasound - Breast

    MedlinePlus

    ... discharge) and to characterize potential abnormalities seen on mammography or breast magnetic resonance imaging (MRI). Ultrasound imaging ... supply in breast lesions . Supplemental Breast Cancer Screening Mammography is the only screening tool for breast cancer ...

  10. Transvaginal ultrasound

    MedlinePlus

    ... germ cell neoplasms, sex-cord stromal tumors. In: Lentz GM, Lobo RA, Gershenson DM, Katz VL, eds. ... oviduct, ovary, ultrasound imaging of pelvic structures. In: Lentz GM, Lobo RA, Gershenson DM, Katz VL, eds. ...

  11. Abdominal Ultrasound

    MedlinePlus

    ... collects the sounds that bounce back and a computer then uses those sound waves to create an ... Ultrasound scanners consist of a console containing a computer and electronics, a video display screen and a ...

  12. Obstetrical Ultrasound

    MedlinePlus

    ... collects the sounds that bounce back and a computer then uses those sound waves to create an ... Ultrasound scanners consist of a console containing a computer and electronics, a video display screen and a ...

  13. Thyroid ultrasound

    MedlinePlus

    ... Performed Ultrasound is a painless method that uses sound waves to create images of the inside of the ... neck to help with the transmission of the sound waves. Next, the technician moves a wand, called a ...

  14. Breast ultrasound

    MedlinePlus

    ... JavaScript. Breast ultrasound is a test that uses sound waves to examine the breasts. How the Test is ... to the left or right. The device sends sound waves to the breast tissue. The sound waves help ...

  15. Pregnancy ultrasound

    MedlinePlus

    ... findings that might indicate an increased risk for Down syndrome A pregnancy ultrasound may also be done in ... weeks of pregnancy to look for signs of Down syndrome or other problems in the developing baby. This ...

  16. [Interventional ultrasound].

    PubMed

    Blázquez Sánchez, N; Fernández Canedo, I; Valdés Vilches, L; de Troya Martín, M

    2015-11-01

    High-frequency ultrasound has become increasingly used in dermatology. This technique is accessible, non-invasive, and rapid and provides information in real time. Consequently, it has become of great diagnostic value in dermatology. However, high-frequency ultrasound also has a promising future as a complementary technique in interventional diagnostic procedures, even though its application in this field has been little studied by dermatologists. PMID:26895944

  17. Cranial Ultrasound/Head Ultrasound

    MedlinePlus

    ... collects the sounds that bounce back and a computer then uses those sound waves to create an ... Ultrasound scanners consist of a console containing a computer and electronics, a video display screen and a ...

  18. A comparative study on the effect of conventional thermal pasteurisation, microwave and ultrasound treatments on the antioxidant activity of five fruit juices.

    PubMed

    Saikia, Sangeeta; Mahnot, Nikhil Kumar; Mahanta, Charu Lata

    2016-06-01

    A comparative study on the effect of conventional thermal pasteurisation, microwave and ultrasound treatments on the phytochemical and antioxidant activities of juices from carambola (Averrhoa carambola L.), black jamun (Syzygium cumuni L.Skeels.), watermelon (Citrullus lanatus var lanatus), pineapple (Ananas comosus L. Merr) and litchi (Litchi chinensis Sonn.) was carried out. Depending on the type of fruit sample and treatment, increase or decrease in phytochemical values was observed. Overall, sonication had a positive effect on the total flavonoid content in all the juice samples followed by microwave treatment with exceptions in some cases. High-performance liquid chromatography study showed the presence of different phenolic acids depending on the sample type. The phenolic acids in some processed carambola juice samples showed decrease or complete destruction, while in some cases, an increase or appearance of newer phenolic acid originally not detected in the fresh juice was observed as seen in conventional thermal pasteurisation, microwaved at 600 W and sonicated juices. Both microwaved and sonicated samples were found to have positive effect on the phenolic content and antioxidant activity with exceptions in some cases. Therefore, microwave and sonication treatment could be used in place of thermal pasteurisation depending on the sample requirements. PMID:26190045

  19. Comparative study of multi-enzyme production from typical agro-industrial residues and ultrasound-assisted extraction of crude enzyme in fermentation with Aspergillus japonicus PJ01.

    PubMed

    Li, Pei-jun; Xia, Jin-lan; Shan, Yang; Nie, Zhen-yuan

    2015-10-01

    Submerged fermentation (SmF) and solid-state fermentation (SSF) of Aspergillus japonicus PJ01 for multi-enzyme complexes (MEC) production were comparatively studied. The results showed that orange peel and wheat bran were the best substrates for MEC production in SmF and SSF, respectively. After 72 h of cultivation under SmF, the maximal pectinase, CMCase, and xylanase activities reached 2610, 85, and 335 U/gds (units/gram dry substrate), respectively; while after 72 h of cultivation under SSF, these three enzymes' activities reached 966, 58, and 1004 U/gds, respectively. Effects of ultrasound on extraction of crude enzymes from SSF medium were determined, the maximal activities of pectinase, CMCase, and xylanase increased to 1.20, 1.48, and 1.30-fold, respectively. Apparent different mycelia growths of SSF and SmF were observed by scanning electron microscopy; and different isoforms of the crude enzyme extracts from SSF and SmF were presented by zymogram analysis. PMID:26260269

  20. A comparative study of contrast enhanced ultrasound and contrast enhanced magnetic resonance imaging for the detection and characterization of hepatic hemangiomas.

    PubMed

    Fang, Liang; Zhu, Zheng; Huang, Beijian; Ding, Hong; Mao, Feng; Li, Chaolun; Zeng, Mengsu; Zhou, Jianjun; Wang, Ling; Wang, Wenping; Chen, Yue

    2015-04-01

    This study aims to compare contrast enhanced ultrasound (CEUS) and contrast enhanced magnetic resonance imaging (CEMRI) for the detection and characterization of hepatic hemangiomas. Included in this retrospective study were 83 histopathologically confirmed lesions of hemangioma in 66 hospitalized patients who underwent both CEUS and CEMRI and received surgery. The enhancement patterns on CEUS and CEMRI in each lesion were compared and analyzed. In addition, data obtained by the two modalities were then compared with the pathological findings to determine their value in differential diagnosis of hepatic hemangiomas. CEUS diagnosed 78 lesions of hemangioma against 80 by CEMRI. There were no statistical significant differences in the diagnostic value between CEUS and CEMRI in terms of sensitivity (88.0% vs. 92.8%), specificity (99.0% vs. 99.4%), accuracy (97.3% vs. 98.4%), positive predictive value (93.6% vs. 96.3%), and negative predictive value (98.0% vs. 98.8%) (p > 0.05, all). In the arterial phase, the main enhancement pattern on both CEUS and CEMRI was peripheral nodular enhancement (73 vs. 76), but lesions with diffuse enhancement on CEUS outnumbered those on CEMRI (3 vs. 1) and lesions with circular enhancement on CEMRI outnumbered those on CEUS (3 vs. 2). In the portal venous phase and delayed phase, the main enhancement pattern was hyperechoic change on CEUS and hyperintense on CEMRI (66 vs. 65), some lesions presented isoechoic change (12 vs. 15). These results suggested CEUS, an equivalent to CEMRI, may have an added diagnostic value in hemangiomas. PMID:25971695

  1. Endoscopic ultrasound-guided puncture suture device versus metal clip for gastric defect closure after endoscopic full-thickness resection: A randomized, comparative, porcine study

    PubMed Central

    Sun, Beibei; Guo, Jintao; Ge, Nan; Sun, Siyu; Wang, Sheng; Liu, Xiang; Wang, Guoxin; Feng, Linlin

    2016-01-01

    Objective: The secure closure of the wall defect is a critical stage of endoscopic full-thickness resection (EFTR). The aim of this study was to compare the closure of post-EFTR defects using an endoscopic ultrasound-guided puncture suture device (PSD) with the metal clip (MC) technique in a randomized, comparative, porcine study. Methods: We performed a randomized comparative survival study that included 18 pigs. The circular EFTR defects with a diameter of approximately 20 mm were closed with either a PSD or MC. Serum levels of interleukin-6 (IL-6) were determined preoperatively and on a postoperative day (POD) 1, 3, and 7. Three animals from each group were sacrificed at the end of the 7th, 14th, and 30th POD. Tissue samples retrieved from the closure sites were examined macroscopically and microscopically. Results: Resection and closure were performed in 18 pigs (100%) without major perioperative complications. The mean closure time was significantly longer in the MC group than in the PSD group (25.00 ± 3.16 min vs. 1.56 ± 0.39 min; P < 0.05). Preoperative and POD 7 serum levels of IL-6 did not differ between the two groups. However, on POD 1, the IL-6 levels were observed to be significantly greater in the MC group than in the PSD group (P < 0.005). No significant differences between the PSD and MC groups were observed at necropsy. Conclusion: In this in vivo porcine model, PSD is a feasible device that achieves post-EFTR defect closure with a much shorter closure time and with less immunological responses than the MC technique. PMID:27503160

  2. Ultrasound focusing images in superlattices

    NASA Astrophysics Data System (ADS)

    Narita, Michiko; Tanaka, Yukihiro; Tamura, Shin-ichiro

    2002-03-01

    We study theoretically ultrasound focusing in periodic multilayered structures, or superlattices, by solving the wave equation with the Green function method and calculating the transmitted ultrasound amplitude images of both the longitudinal and transverse modes. The constituent layers assumed are elastically isotropic but the periodically stacked structure is anisotropic. Thus anisotropy of ultrasound propagation is predicted even at low frequencies and it is enhanced significantly at higher frequencies due to the zone-folding effect of acoustic dispersion relations. An additional effect studied is the interference of ultrasound (known as the internal diffraction), which can be recognized when the propagation distance is comparable to the ultrasound wavelength. Numerical examples are developed for millimetre-scale Al/polymer multilayers used recently for imaging experiment with surface acoustic waves.

  3. [Quantitative ultrasound].

    PubMed

    Barkmann, R; Glüer, C-C

    2006-10-01

    Methods of quantitative ultrasound (QUS) can be used to obtain knowledge about bone fragility. Comprehensive study results exist showing the power of QUS for the estimation of osteoporotic fracture risk. Nevertheless, the variety of technologies, devices, and variables as well as different degrees of validation of the single devices have to be taken into account. Using methods to simulate ultrasound propagation, the complex interaction between ultrasound and bone could be understood and the propagation could be visualized. Preceding widespread clinical use, it has to be clarified if patients with low QUS values will profit from therapy, as it has been shown for DXA. Moreover, the introduction of quality assurance measures is essential. The user should know the limitations of the methods and be able to interpret the results correctly. Applied in an adequate manner QUS methods could then, due to lower costs and absence of ionizing radiation, become important players in osteoporosis management. PMID:16896637

  4. Comparatively studying the ultrasound present in a mild two-stage approach on the content of functional groups in modified MWCNT

    NASA Astrophysics Data System (ADS)

    Tian, Run; Liang, Shaolei; Li, Guangfen; Zhang, Yanxia; Shi, Le

    2016-04-01

    A two-stage approach assisted with ultrasound for oxidation of multiwalled carbon nanotubes (MWCNT) with ultra-high content of functional groups was utilized. The effect of ultrasound on the content of functional groups of the modified MWCNTs from different stages was analyzed by FE-SEM, HR-TEM, FTIR, Raman, TGA, XPS and triple double-backward titration method. The results confirm that more oxygen-containing functional groups were grafted on MWCNT with little damage to the structure integrity of nanotubes. The particle size distribution and the dispersion photography of MWCNTs in water and in ethanol further show a better dispersion of modified MWCNTs in polar solvent.

  5. Ultrasound Despeckling for Contrast Enhancement

    PubMed Central

    Tay, Peter C.; Garson, Christopher D.; Acton, Scott T.; Hossack, John A.

    2010-01-01

    Images produced by ultrasound systems are adversely hampered by a stochastic process known as speckle. A despeckling method based upon removing outlier is proposed. The method is developed to contrast enhance B-mode ultrasound images. The contrast enhancement is with respect to decreasing pixel variations in homogeneous regions while maintaining or improving differences in mean values of distinct regions. A comparison of the proposed despeckling filter is compared with the other well known despeckling filters. The evaluations of despeckling performance are based upon improvements to contrast enhancement, structural similarity, and segmentation results on a Field II simulated image and actual B-mode cardiac ultrasound images captured in vivo. PMID:20227984

  6. Ultrasound despeckling for contrast enhancement.

    PubMed

    Tay, Peter C; Garson, Christopher D; Acton, Scott T; Hossack, John A

    2010-07-01

    Images produced by ultrasound systems are adversely hampered by a stochastic process known as speckle. A despeckling method based upon removing outlier is proposed. The method is developed to contrast enhance B-mode ultrasound images. The contrast enhancement is with respect to decreasing pixel variations in homogeneous regions while maintaining or improving differences in mean values of distinct regions. A comparison of the proposed despeckling filter is compared with the other well known despeckling filters. The evaluations of despeckling performance are based upon improvements to contrast enhancement, structural similarity, and segmentation results on a Field II simulated image and actual B-mode cardiac ultrasound images captured in vivo. PMID:20227984

  7. Doppler ultrasound surveillance in deep tunneling compressed-air work with Trimix breathing: bounce dive technique compared to saturation-excursion technique.

    PubMed

    Vellinga, T P van Rees; Sterk, W; de Boer, A G E M; van der Beek, A J; Verhoeven, A C; van Dijk, F J H

    2008-01-01

    The Western Scheldt Tunneling Project in The Netherlands provided a unique opportunity to evaluate two deep-diving techniques with Doppler ultrasound surveillance. Divers used the bounce diving techniques for repair and maintenance of the TBM. The tunnel boring machine jammed at its deepest depth. As a result the work time was not sufficient. The saturation diving technique was developed and permitted longer work time at great depth. Thirty-one divers were involved in this project. Twenty-three divers were examined using Doppler ultrasound. Data analysis addressed 52 exposures to Trimix at 4.6-4.8 bar gauge using the bounce technique and 354 exposures to Trimix at 4.0-6.9 bar gauge on saturation excursions. No decompression incidents occurred with either technique during the described phase of the project. Doppler ultrasound revealed that the bubble loads assessed in both techniques were generally low. We find out, that despite longer working hours, shorter decompression times and larger physical workloads, the saturation-excursion technique was associated with significant lower bubble grades than in the bounce technique using Doppler Ultrasound. We conclude that the saturation-excursion technique with Trimix is a good option for deep and long exposures in caisson work. The Doppler technique proved valuable, and it should be incorporated in future compressed-air work. PMID:19175196

  8. A prospective, randomized, controlled trial comparing the effects of noncontact, low-frequency ultrasound to standard care in healing venous leg ulcers.

    PubMed

    Gibbons, Gary W; Orgill, Dennis P; Serena, Thomas E; Novoung, Aksone; O'Connell, Jessica B; Li, William W; Driver, Vickie R

    2015-01-01

    Current scientific evidence suggests venous leg ulcers (VLUs) that do not respond to guideline-defined care may have a wound microenvironment that is out of physiological balance. A prospective, randomized, controlled, multicenter trial was conducted to compare percent wound size reduction, proportions healed, pain, and quality-of-life (QOL) outcomes in patients randomized to standard care (SC) alone or SC and 40 kHz noncontact, low-frequency ultrasound (NLFU) treatments 3 times per week for 4 weeks. One hundred, twelve (112) eligible participants with documented venous stasis, a VLU >30 days' duration, measuring 4 cm2 to 50 cm2, and demonstrated arterial flow were enrolled. Of these, 81 reduced <30% in size during the 2-week run-in study phase and were randomized (SC, n = 40; NLFU+SC, n = 41). Median age of participants was 59 years; 83% had multiple complex comorbidities. Index ulcers were 56% recurrent, with a median duration of 10.3 months (range 1 month to 204.5 months) and median ulcer area of 11.0 cm2 (range 3.7 cm2-41.3 cm2). All participants received protocol-defined SC compression (30-40 mm Hg), dressings to promote a moist wound environment, and sharp debridement at the bedside for a minimum of 1 time per week. Ulcer measurements were obtained weekly using digital planimetry. Pain and QOL scores were assessed at baseline and after 4 weeks of treatment using the Visual Analog Scale and the Short Form-36 Health Survey. After 4 weeks of treatment, average wound size reduction was 61.6% ± 28.9 in the NLFU+SC compared to 45% ± 32.5 in the SC group (P = 0.02). Reductions in median (65.7% versus 44.4%, P = 0.02) and absolute wound area (9.0 cm2 versus 4.1 cm2, P = 0.003) as well as pain scores (from 3.0 to 0.6 versus 3.0 to 2.4, P = 0.01) were also significant. NLFU therapy with guideline-defined standard VLU care should be considered for healing VLUs not responding to SC alone. The results of this study warrant further research on barriers to healing and the

  9. SU-E-J-76: Incorporation of Ultrasound Elastography in Target Volume Delineation for Partial Breast Radiotherapy Planning: A Comparative Study

    SciTech Connect

    Juneja, P; Harris, E; Bamber, J

    2014-06-01

    Purpose: There is substantial observer variability in the delineation of target volumes for post-surgical partial breast radiotherapy because the tumour bed has poor x-ray contrast. This variability may result in substantial variations in planned dose distribution. Ultrasound elastography (USE) has an ability to detect mechanical discontinuities and therefore, the potential to image the scar and distortion in breast tissue architecture. The goal of this study was to compare USE techniques: strain elastography (SE), shear wave elastography (SWE) and acoustic radiation force impulse (ARFI) imaging using phantoms that simulate features of the tumour bed, for the purpose of incorporating USE in breast radiotherapy planning. Methods: Three gelatine-based phantoms (10% w/v) containing: a stiff inclusion (gelatine 16% w/v) with adhered boundaries, a stiff inclusion (gelatine 16% w/v) with mobile boundaries and fluid cavity inclusion (to mimic seroma), were constructed and used to investigate the USE techniques. The accuracy of the elastography techniques was quantified by comparing the imaged inclusion with the modelled ground-truth using the Dice similarity coefficient (DSC). For two regions of interest (ROI), the DSC measures their spatial overlap. Ground-truth ROIs were modelled using geometrical measurements from B-mode images. Results: The phantoms simulating stiff scar tissue with adhered and mobile boundaries and seroma were successfully developed and imaged using SE and SWE. The edges of the stiff inclusions were more clearly visible in SE than in SWE. Subsequently, for all these phantoms the measured DSCs were found to be higher for SE (DSCs: 0.91–0.97) than SWE (DSCs: 0.68–0.79) with an average relative difference of 23%. In the case of seroma phantom, DSC values for SE and SWE were similar. Conclusion: This study presents a first attempt to identify the most suitable elastography technique for use in breast radiotherapy planning. Further analysis will

  10. Comparative study of the effects of low-intensity pulsed ultrasound and low-level laser therapy on injured muscle repair

    NASA Astrophysics Data System (ADS)

    Renno, Ana Claudia Muniz; Toma, Renata Luri; Feitosa, Suellen Maurin; Fernandes, Kelly; de Oliveira, Poliani; Parizotto, N.; Ribeiro, Daniel Araki

    2011-03-01

    Muscle tissue is one of the most frequently affected by injury, whether during sports activities, or work activities. In this context, biochemical and biophysical resources have been studied to minimize the time of muscle regeneration. Among these, low intensity pulsed ultrasound (US) and low level laser therapy (LLLT) may be highlighted. Despite a series of evidences about the positive effects of these resources in the process of tissue regeneration, the cellular and morphological changes triggered by LLLT and U.S. are still largely unknown. Thus, the aim of this study was to investigate the effects of US and LLLT on muscle repair after cryolesion by means of histopathological analysis and immunohistochemistry for COX-2. A total of thirty five male Wistar rats were randomly distributed into 4 groups: intact control group; injured control group: muscle injured animals without any treatment; laser treated group: muscle injured animals treated with 830 nm laser and ultra-sound treated group: muscle injured animals treated with US. The treatments started 24 hours post-surgery and were performed during 6 sessions. The animals exposed to lasertherapy pointed out minor degenerative changes of muscle tissue. In the same way, exposure to ultrasound was able to reduce tissue injuries induced by cryolesion, but less intense than laser therapy. Strong COX-2 positive cells were found in rats submitted to cryolesion only, whereas COX-2 immunoexpression was lower in laser treated or ultrasound treated groups. In summary, this study reveals that both lasertherapy and ultrasound have positive effects on muscle repair in rats.

  11. Ultrasound Annual, 1984

    SciTech Connect

    Sanders, R.C.; Hill, M.C.

    1984-01-01

    The 1984 edition of Ultrasound Annual explores new applications of ultrasound in speech and swallowing and offers guidelines on the use of ultrasound and nuclear medicine in thyroid and biliary tract disease. Other areas covered include Doppler sonography of the abdomen, intraoperative abdominal ultrasound, sonography of the placenta, ultrasound of the neonatal head and abdomen, and sonographic echo patterns created by fat.

  12. [Ultrasound guided percutaneous nephrolithotripsy].

    PubMed

    Guliev, B G

    2014-01-01

    The study was aimed to the evaluation of the effectiveness and results of ultrasound guided percutaneous nephrolithotripsy (PNL) for the treatment of patients with large stones in renal pelvis. The results of PNL in 138 patients who underwent surgery for kidney stones from 2011 to 2013 were analyzed. Seventy patients (Group 1) underwent surgery with combined ultrasound and radiological guidance, and 68 patients (Group 2)--only with ultrasound guidance. The study included patients with large renal pelvic stones larger than 2.2 cm, requiring the formation of a single laparoscopic approach. Using the comparative analysis, the timing of surgery, the number of intra- and postoperative complications, blood loss and length of stay were evaluated. Percutaneous access was successfully performed in all patients. Postoperative complications (exacerbation of chronic pyelonephritis, gross hematuria) were observed in 14.3% of patients in Group 1 and in 14.7% of patients in Group 2. Bleeding requiring blood transfusion, and injuries of adjacent organs were not registered. Efficacy of PNL in the Group 1 was 95.7%; 3 (4.3%) patients required additional interventions. In Group 2, the effectiveness of PNL was 94.1%, 4 (5.9%) patients additionally underwent extracorporeal lithotripsy. There were no significant differences in the effectiveness of PNL, the volume of blood loss and duration of hospitalization. Ultrasound guided PNL can be performed in large pelvic stones and sufficient expansion of renal cavities, thus reducing radiation exposure of patients and medical staff. PMID:25807772

  13. Venous Ultrasound (Extremities)

    MedlinePlus

    ... waves. Ultrasound imaging, also called ultrasound scanning or sonography , involves the use of a small transducer (probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the ...

  14. Tracked ultrasound elastography (TRUE)

    NASA Astrophysics Data System (ADS)

    Foroughi, Pezhman

    Medical ultrasound research has experienced a renaissance in the past decade leading to innovations in flow mapping, elasticity and thermal imaging, measurement of optical properties, beamforming, and image enhancement. In this thesis, we focus on ultrasound elastography, an emerging imaging modality with great potential to become a part of several ultrasound diagnostic applications. Elastography images the stiffness of soft tissue by applying a mechanical stimulus and estimating the disturbance created by this stimulus. In freehand elastography, soft tissue is palpated by hand using the ultrasound transducer. The elastography image is generated by comparing the pre- and post-compression images to form a displacement map which is then differentiated to produce the final strain map. To achieve the best result in freehand elastography, the sonographer must compress and decompress the tissue uniformly in a specific direction with adequate compression. This can be a difficult task even for trained users. A small rotational or out-of-plane motion in the collected ultrasound frames can render them unusable for elastography. This has made freehand elastography highly qualitative and user-dependent. We tackle this issue by incorporating the extra information from a position sensor attached to the ultrasound transducer. Our aim is to show that the localization information of ultrasound images may be utilized to improve the quality and reliability of freehand elastography. For this purpose, we have developed a frame selection scheme that finds pairs of images with optimal compression and minimal lateral and out-of-plane displacement. Relying on the localization information, our algorithm merges multiple strain images computed from the selected frame pairs. This method is applicable to both 2D and 3D elastography. Our 3D elastography does not require for the transducer to be held still during the acquisition of each volume. Instead, the sonographer freely palpates the tissue

  15. Assessment of carotid plaque neovascularization by contrast-enhanced ultrasound and high sensitivity C-reactive protein test in patients with acute cerebral infarction: a comparative study.

    PubMed

    Xu, Rong; Yin, Xiaohua; Xu, Weixin; Jin, Lin; Lu, Min; Wang, Yingchun

    2016-07-01

    Vulnerable carotid plaque easily ruptures and causes cerebral infarction. Plaque inflammation and neovascularization have both been shown as important characteristics in vulnerable plaque. We assessed neovascularization within carotid plaque using contrast-enhanced ultrasound, and also assessed inflammation, using high sensitivity C-reactive protein (hs-CRP) testing, in acute cerebral infarction patients. A total of 106 patients with acute cerebral infarction and 40 controls were enrolled in the study. All subjects had been previously found to have carotid atherosclerotic plaques, and the plaques were classified as soft plaque, hard plaque, mixed plaque, and calcified plaque, using carotid artery ultrasound. Contrast-enhanced ultrasound was performed on the plaques for quantitative analysis and hs-CRP levels were measured. The results showed that plaque enhancement was present in 81.1 % of cerebral infarction patients and 40.0 % of controls. The contrast parameters for cerebral infarction patients were significantly different from controls. For cerebral infarction patients, soft plaque showed the highest enhanced percentage, 95.1 %, with contrast parameters significantly different to other types of plaque. The hs-CRP levels of enhanced cerebral infarction patients were higher than in non-enhanced patients. Correlation analysis in cerebral infarction patients showed that hs-CRP levels were closely related to the contrast parameters. Acute cerebral infarction patients showed intense contrast enhancement and inflammation in carotid plaque, and different types of plaque had various degrees of enhancement, suggesting that contrast-enhanced ultrasound and hs-CRP might be used for plaque risk stratification. PMID:27021564

  16. A study comparing ultrasound images of tongue movements between open bite children and normal children in the early mixed dentition period.

    PubMed

    Kikyo, T; Saito, M; Ishikawa, M

    1999-09-01

    The tongue surface movement of young patients with or without open bite was evaluated by ultrasound images taken on the posterior part of the tongue on the frontal plane to determine whether there is any relationship between the tongue movement and open bite malocclusion in the early mixed dentition period. The standardized reproducible ultrasound images were obtained using ultrasound diagnostic equipment that was fabricated in a cephalostat unit having a probe stabilizer. At the central portion of the tongue, no significant differences were detected in the duration or the momentum of tongue surface movement on a frontal plane was detected between the patients with and without open bite during swallowing. The farther the region was from the central portion, however, the longer the duration and the bigger the momentum of the tongue surface movement was found in the open bite group. Based on this evidence, it is suggested that an open-bite child swallows by using a tongue thrust motion that forms using a large depressed area in the tongue, whereas a normal child without tongue thrust forms a rather narrow groove in the central portion of the tongue when swallowing. PMID:12160259

  17. Eye and orbit ultrasound

    MedlinePlus

    Echography - eye orbit; Ultrasound - eye orbit; Ocular ultrasonography; Orbital ultrasonography ... ophthalmology department of a hospital or clinic. Your eye is numbed with medicine (anesthetic drops). The ultrasound ...

  18. Ultrasound Fracture Diagnosis in Space

    NASA Technical Reports Server (NTRS)

    Dulchavsky, Scott A.; Amponsah, David; Sargsyan, Ashot E.; Garcia, Kathleen M.; Hamilton, Douglas R.; vanHolsbeeck, Marnix

    2010-01-01

    Introduction: This ground-based investigation accumulated high-level clinical evidence on the sensitivity and specificity of point of care ultrasound performed by expert and novice users for the rapid diagnosis of musculoskeletal (MSK) injuries. We developed preliminary educational methodologies to provide just-in-time training of novice users by creating multi-media training tools and imaging procedures for non expert operators and evaluated the sensitivity and specificity of non-expert performed musculoskeletal ultrasound to diagnose acute injuries in a Level 1 Trauma Center. Methods: Patients with potential MSK injuries were identified in the emergency room. A focused MSK ultrasound was performed by expert operators and compared to standard radiographs. A repeat examination was performed by non-expert operators who received a short, just-in-time multimedia education aid. The sensitivity and specificity of the expert and novice ultrasound examinations were compared to gold standard radiography. Results: Over 800 patients were enrolled in this study. The sensitivity and specificity of expert performed ultrasound exceeded 98% for MSK injuries. Novice operators achieved 97% sensitivity and 99% specificity for targeted examinations with the greatest error in fractures involving the hand and foot. Conclusion: Point of care ultrasound is a sensitive and specific diagnostic test for MSK injury when performed by experts and just-in-time trained novice operators.

  19. High definition 3D ultrasound imaging.

    PubMed

    Morimoto, A K; Krumm, J C; Kozlowski, D M; Kuhlmann, J L; Wilson, C; Little, C; Dickey, F M; Kwok, K S; Rogers, B; Walsh, N

    1997-01-01

    We have demonstrated high definition and improved resolution using a novel scanning system integrated with a commercial ultrasound machine. The result is a volumetric 3D ultrasound data set that can be visualized using standard techniques. Unlike other 3D ultrasound images, image quality is improved from standard 2D data. Image definition and bandwidth is improved using patent pending techniques. The system can be used to image patients or wounded soldiers for general imaging of anatomy such as abdominal organs, extremities, and the neck. Although the risks associated with x-ray carcinogenesis are relatively low at diagnostic dose levels, concerns remain for individuals in high risk categories. In addition, cost and portability of CT and MRI machines can be prohibitive. In comparison, ultrasound can provide portable, low-cost, non-ionizing imaging. Previous clinical trials comparing ultrasound to CT were used to demonstrate qualitative and quantitative improvements of ultrasound using the Sandia technologies. Transverse leg images demonstrated much higher clarity and lower noise than is seen in traditional ultrasound images. An x-ray CT scan was provided of the same cross-section for comparison. The results of our most recent trials demonstrate the advantages of 3D ultrasound and motion compensation compared with 2D ultrasound. Metal objects can also be observed within the anatomy. PMID:10168958

  20. Ultrasound annual, 1986

    SciTech Connect

    Sanders, R.C.; Hill, M.C.

    1986-01-01

    This book provides an analyses of developments in the field of diagnostic ultrasound. Endoscopic ultrasound and ultrasound-guided aspiration of ovarian follicles for in vitro fertilization are addressed. The use of Doppler ultrasound to measure blood flow in obstetrics is also examined.

  1. Ultrasound and Therapy

    NASA Astrophysics Data System (ADS)

    Lafon, Cyril

    This paper begins with an overview and a description of the interactions between ultrasound and biological tissues encountered during treatment protocols. In a second part of this seminar, two clinical applications of therapeutic ultrasound will be described in details: -Kidney stone destruction by ultrasound (lithotripsy) and High Intensity Focused Ultrasound for treating prostate cancer (HIFU).

  2. Ultrasound in Space Medicine

    NASA Technical Reports Server (NTRS)

    Dulchavsky, Scott A.; Sargsyan, A.E.

    2009-01-01

    This slide presentation reviews the use of ultrasound as a diagnostic tool in microgravity environments. The goals of research in ultrasound usage in space environments are: (1) Determine accuracy of ultrasound in novel clinical conditions. (2) Determine optimal training methodologies, (3) Determine microgravity associated changes and (4) Develop intuitive ultrasound catalog to enhance autonomous medical care. Also uses of Ultrasound technology in terrestrial applications are reviewed.

  3. Case Study Using Ultrasound to Treat /[turned r]/

    ERIC Educational Resources Information Center

    Modha, Geetanjalee; Bernhardt, B. May; Church, Robyn; Bacsfalvi, Penelope

    2008-01-01

    Background: Ultrasound has shown promise as visual feedback in remediation of /[turned r]/.Aims: To compare treatment for [turned r] with and without ultrasound.Methods & Procedures: A Canadian English-speaking adolescent participated in a case study with a no treatment baseline, alternating treatment blocks with and without ultrasound and a final…

  4. Prostate Focused Ultrasound Therapy.

    PubMed

    Chapelon, Jean-Yves; Rouvière, Olivier; Crouzet, Sébastien; Gelet, Albert

    2016-01-01

    The tremendous progress in engineering and computing power coupled with ultrasound transducer technology and imaging modalities over the past 20 years have encouraged a revival of clinical interest in ultrasound therapy, mainly in High-Intensity Focused Ultrasound (HIFU). So far, the most extensive results from HIFU obtained in urology involve transrectal prostate ablation, which appears to be an effective therapeutic alternative for patients with malignant prostate tumors. Prostate cancer (PCa) is one of the most frequently diagnosed cancers in men. Several treatment options with different therapeutic approaches exist, including HIFU for localized PCa that has been in use for over 15 years. Since the early 2000s, two systems have been marketed for this application, and other devices are currently in clinical trials. HIFU treatment can be used either alone or in combination with (before- or after-) external beam radiotherapy (EBRT) (before or after HIFU) and can be repeated multiple times. HIFU treatment is performed under real-time monitoring with ultrasound or guided by MRI. Two indications are validated today: Primary care treatment and EBRT failure. The results of HIFU for primary care treatment are similar to standard conformal EBRT, even though no randomized comparative studies have been performed and no 10-year follow up data is yet available for HIFU. Salvage HIFU after EBRT failure is increasing with oncological outcomes, similar to those achieved with surgery but with the advantage of fewer adverse effects. HIFU is an evolving technology perfectly adapted for focal treatment. Thus, HIFU focal therapy is another pathway that must be explored when considering the accuracy and reliability for PCa mapping techniques. HIFU would be particularly suited for such a therapy since it is clear that HIFU outcomes and toxicity are relative to the volume of prostate treated. PMID:26486330

  5. Molecular Ultrasound Imaging: Current Status and Future Directions

    PubMed Central

    Deshpande, Nirupama; Needles, Andrew; Willmann, Jürgen K.

    2011-01-01

    Targeted contrast-enhanced ultrasound (molecular ultrasound) is an emerging imaging strategy that combines ultrasound technology with novel molecularly-targeted ultrasound contrast agents for assessing biological processes at the molecular level. Molecular ultrasound contrast agents are nano- or micro-sized particles that are targeted to specific molecular markers by adding high-affinity binding ligands onto the surface of the particles. Following intravenous administration, these targeted ultrasound contrast agents accumulate at tissue sites overexpressing specific molecular markers, thereby enhancing the ultrasound imaging signal. High spatial and temporal resolution, real-time imaging, non-invasiveness, relatively low costs, lack of ionizing irradiation and wide availability of ultrasound systems are advantages compared to other molecular imaging modalities. In this article we review current concepts and future directions of molecular ultrasound imaging, including different classes of molecular ultrasound contrast agents, ongoing technical developments of preclinical and clinical ultrasound systems , the potential of molecular ultrasound for imaging different diseases at the molecular level, and the translation of molecular ultrasound into the clinic. PMID:20541656

  6. High definition ultrasound imaging for battlefield medical applications

    SciTech Connect

    Kwok, K.S.; Morimoto, A.K.; Kozlowski, D.M.; Krumm, J.C.; Dickey, F.M.; Rogers, B; Walsh, N.

    1996-06-23

    A team has developed an improved resolution ultrasound system for low cost diagnostics. This paper describes the development of an ultrasound based imaging system capable of generating 3D images showing surface and subsurface tissue and bone structures. We include results of a comparative study between images obtained from X-Ray Computed Tomography (CT) and ultrasound. We found that the quality of ultrasound images compares favorably with those from CT. Volumetric and surface data extracted from these images were within 7% of the range between ultrasound and CT scans. We also include images of porcine abdominal scans from two different sets of animal trials.

  7. Ultrasound Annual, 1983

    SciTech Connect

    Sanders, R.C.; Hill, M.C.

    1983-01-01

    The 1983 edition of Ultrasound Annual features a state-of-the-art assessment of real-time ultrasound technology and a look at improvements in real-time equipment. Chapters discuss important new obstetric applications of ultrasound in measuring fetal umbilical vein blood flow and monitoring ovarian follicular development in vivo and in vitro fertilization. Other topics covered include transrectal prostate ultrasound using a linear array system; ultrasound of the common bile duct; ultrasound in tropical diseases; prenatal diagnosis of craniospinal anomalies; scrotal ultrasonography; opthalmic ultrasonography; and sonography of the upper abdominal venous system.

  8. Breast Ultrasound: Indications and Findings.

    PubMed

    Gundry, Kathleen R

    2016-06-01

    Breast ultrasound is a widely used adjuvant to mammography for the detection of breast cancer. This chapter will review some of the basic ultrasound technical factors and techniques, describe findings on ultrasound with an emphasis on the Breast Imaging Reporting and Data System terminology, and present the indications for breast ultrasound. New innovations in breast ultrasound, such as elastography, ultrasound contrast, 3-dimensional, and automated whole-breast ultrasound, will be reviewed. Ultrasound-guided breast procedures are also presented. PMID:26974219

  9. Prenatal ultrasound - slideshow

    MedlinePlus

    ... page: //medlineplus.gov/ency/presentations/100197.htm Prenatal ultrasound - series To use the sharing features on this ... Editorial team. Related MedlinePlus Health Topics Prenatal Testing Ultrasound A.D.A.M., Inc. is accredited by ...

  10. 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 ...

  11. 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 ...

  12. Medical Ultrasound Imaging.

    ERIC Educational Resources Information Center

    Hughes, Stephen

    2001-01-01

    Explains the basic principles of ultrasound using everyday physics. Topics include the generation of ultrasound, basic interactions with material, and the measurement of blood flow using the Doppler effect. (Author/MM)

  13. Comparing focused ultrasound and uterine artery embolization for uterine fibroids – Rationale and Design of the Fibroid Interventions: Reducing Symptoms Today and Tomorrow (FIRSTT) trial

    PubMed Central

    Bouwsma, Esther V.A.; Hesley, Gina K.; Woodrum, David A.; Weaver, Amy L.; Leppert, Phyllis C.; Peterson, Lisa G.; Stewart, Elizabeth A.

    2011-01-01

    Objective To present the rational, design and methodology of the FIRSTT study (Fibroid Interventions: Reducing Symptoms Today and Tomorrow, NCT00995878, clinicaltrials.gov). Design Randomized Clinical Trial (RCT) Setting Two Academic Medical Centers Patient(s) Premenopausal women with symptomatic uterine fibroids. Intervention(s) Participants are randomized to two FDA-approved minimally invasive treatments for uterine leiomyomas: uterine artery embolization (UAE) and MRI guided focused ultrasound (MRgFUS). Main Outcome Measure(s) The primary endpoint is defined as the need for an additional intervention for fibroid symptoms following treatment. Secondary outcomes consist of group differences in symptom alleviation, recovery trajectory, health related quality of life, impairment of ovarian reserve, treatment complications and the economic impact of these issues. Results The trial is currently in the phase of active recruitment. Conclusions This RCT will provide important evidence-based information for patients and health care providers regarding optimal minimally invasive treatment approach for women with symptomatic uterine leiomyomas. PMID:21794858

  14. Ultrasound Imaging System Video

    NASA Technical Reports Server (NTRS)

    2002-01-01

    In this video, astronaut Peggy Whitson uses the Human Research Facility (HRF) Ultrasound Imaging System in the Destiny Laboratory of the International Space Station (ISS) to image her own heart. The Ultrasound Imaging System provides three-dimension image enlargement of the heart and other organs, muscles, and blood vessels. It is capable of high resolution imaging in a wide range of applications, both research and diagnostic, such as Echocardiography (ultrasound of the heart), abdominal, vascular, gynecological, muscle, tendon, and transcranial ultrasound.

  15. Mist separation and sonochemiluminescence under pulsed ultrasound.

    PubMed

    Tuziuti, Toru

    2012-04-12

    Differences in the amount of water-mist separation and the intensity of luminol chemiluminescence for pulsed and continuous-wave (CW) ultrasound at 135 kHz have been investigated. The amount of mist generated is estimated using the cooling rate of a copper plate sprayed with the mist. For pulsed operation with an appropriate duty cycle, the cooling rate and the cooling rate per input power to the transducer are higher by 4 and 12 times compared to CW operation, respectively. This is due to the amplitude of the pulsed ultrasound being higher than that for CW ultrasound. Relatively low power pulsed operation can successfully produce both a higher sonochemiluminescence (SCL) intensity and cooling rate than those for CW ultrasound. The sonochemical reaction for pulsed ultrasound occurs at the same input power threshold as that for mist separation, whereas for CW ultrasound, the former threshold is lower than the latter. A higher number of large bubbles is produced with CW ultrasound than that with pulsed ultrasound. To achieve a sound pressure amplitude sufficient for mist separation near the surface of a liquid, it is necessary to expel these bubbles by changing the sound field from resonant standing waves to progressive waves that give rise to capillary waves on the liquid surface. PMID:22443489

  16. Synthetic aperture imaging in ultrasound calibration

    NASA Astrophysics Data System (ADS)

    Ameri, Golafsoun; Baxter, John S. H.; McLeod, A. Jonathan; Jayaranthe, Uditha L.; Chen, Elvis C. S.; Peters, Terry M.

    2014-03-01

    Ultrasound calibration allows for ultrasound images to be incorporated into a variety of interventional applica­ tions. Traditional Z- bar calibration procedures rely on wired phantoms with an a priori known geometry. The line fiducials produce small, localized echoes which are then segmented from an array of ultrasound images from different tracked probe positions. In conventional B-mode ultrasound, the wires at greater depths appear blurred and are difficult to segment accurately, limiting the accuracy of ultrasound calibration. This paper presents a novel ultrasound calibration procedure that takes advantage of synthetic aperture imaging to reconstruct high resolution ultrasound images at arbitrary depths. In these images, line fiducials are much more readily and accu­ rately segmented, leading to decreased calibration error. The proposed calibration technique is compared to one based on B-mode ultrasound. The fiducial localization error was improved from 0.21mm in conventional B-mode images to 0.15mm in synthetic aperture images corresponding to an improvement of 29%. This resulted in an overall reduction of calibration error from a target registration error of 2.00mm to 1.78mm, an improvement of 11%. Synthetic aperture images display greatly improved segmentation capabilities due to their improved resolution and interpretability resulting in improved calibration.

  17. Accelerated heavy ions and the lens. IV. Biomicroscopic and cytopathological analyses of the lenses of mice irradiated with 600 MeV/amu sup 56 Fe ions

    SciTech Connect

    Worgul, B.V.; Medvedovsky, C.; Powers-Risius, P.; Alpen, E. )

    1989-11-01

    The lenses of mice exposed to 600 MeV/amu iron ions were evaluated by slit-lamp biomicroscopy and cytopathological analyses. The doses ranged from 0.05 to 1.6 Gy, and the lenses were assessed at several intervals postirradiation. Cataract, the development of which is dependent on both time and dose, is significantly more advanced in all of the exposed mice when compared to the unirradiated controls. The great difference between the severity of the cataracts caused by 0.05 Gy (the lowest dose used) and those that developed spontaneously in the control animals is an indication that 0.05 Gy may far exceed the threshold dose for the production of cataracts by accelerated iron ions. Cytopathologically, a similar dose dependence was observed for a number of end points including micronucleation, interphase death, and meridional row disorganization. In addition the exposure to the 56Fe ions produced a long-term effect on the mitotic population and a pronounced focal loss of epithelial cytoarchitecture. The microscopic changes support the view that the mechanism of heavy-ion-induced cataractogenesis is the same as that for cataracts caused by low-LET radiation.

  18. Temperature estimation with ultrasound

    NASA Astrophysics Data System (ADS)

    Daniels, Matthew

    Hepatocelluar carcinoma is the fastest growing type of cancer in the United States. In addition, the survival rate after one year is approximately zero without treatment. In many instances, patients with hepatocelluar carcinoma may not be suitable candidates for the primary treatment options, i.e. surgical resection or liver transplantation. This has led to the development of minimally invasive therapies focused on destroying hepatocelluar by thermal or chemical methods. The focus of this dissertation is on the development of ultrasound-based image-guided monitoring options for minimally invasive therapies such as radiofrequency ablation. Ultrasound-based temperature imaging relies on relating the gradient of locally estimated tissue displacements to a temperature change. First, a realistic Finite Element Analysis/ultrasound simulation of ablation was developed. This allowed evaluation of the ability of ultrasound-based temperature estimation algorithms to track temperatures for three different ablation scenarios in the liver. It was found that 2-Dimensional block matching and a 6 second time step was able to accurately track the temperature over a 12 minute ablation procedure. Next, a tissue-mimicking phantom was constructed to determine the accuracy of the temperature estimation method by comparing estimated temperatures to that measured using invasive fiber-optic temperature probes. The 2-Dimensional block matching was able to track the temperature accurately over the entire 8 minute heating procedure in the tissue-mimicking phantom. Finally, two separate in-vivo experiments were performed. The first experiment examined the ability of our algorithm to track frame-to-frame displacements when external motion due to respiration and the cardiac cycle were considered. It was determined that a frame rate between 13 frames per second and 33 frames per second was sufficient to track frame-to-frame displacements between respiratory cycles. The second experiment examined

  19. Obstetric ultrasound simulation.

    PubMed

    Nitsche, Joshua F; Brost, Brian C

    2013-06-01

    Obstetric ultrasound is becoming an increasingly important part of the practice of maternal-fetal medicine. Thus, it is important to develop rigorous and effective training curricula for obstetrics and gynecology residents and maternal-fetal medicine fellows. Traditionally, this training has come almost entirely from exposure to ultrasound in the clinical setting. However, with the increased complexity of modern ultrasound and advent of duty-hour restrictions, a purely clinical training model is no longer viable. With the advent of high-fidelity obstetric ultrasound simulators, a significant amount of training can occur in a non-clinical setting which allows learners to obtain significant skill prior to their first patient ultrasound encounter and obtain proficiency in a shorter period of time. In this manuscript we discuss the available obstetric ultrasound simulators and ways to construct a comprehensive ultrasound training curricula to meet the increasing demands of modern maternal-fetal medicine. PMID:23721777

  20. Schlemm’s Canal and Trabecular Meshwork in Eyes with Primary Open Angle Glaucoma: A Comparative Study Using High-Frequency Ultrasound Biomicroscopy

    PubMed Central

    Yan, Xiaoqin; Li, Mu; Chen, Zhiqi; Zhu, Ying; Song, Yinwei; Zhang, Hong

    2016-01-01

    We investigated in vivo changes in Schlemm’s canal and the trabecular meshwork in eyes with primary open angle glaucoma (POAG). Relationships between Schlemm’s canal diameter, trabecular meshwork thickness, and intraocular pressure (IOP) were examined. Forty POAG patients and 40 normal individuals underwent 80-MHz Ultrasound Biomicroscopy examinations. The Schlemm’s canal and trabecular meshwork were imaged in superior, inferior, nasal and temporal regions. Normal individuals had an observable Schlemm’s canal in 80.3% of sections, a meridional canal diameter of 233.0±34.5 μm, a coronal diameter of 44.5±12.6 μm and a trabecular meshwork thickness of 103.9±11.1 μm, in POAG patients, Schlemm’s canal was observable in 53.1% of sections, a meridional canal diameter of 195.6±31.3 μm, a coronal diameter of 35.7±8.0 μm, and a trabecular meshwork thickness of 88.3±13.2 μm, which significantly differed from normal (both p <0.001). Coronal canal diameter (r = -0.623, p < 0.001) and trabecular meshwork thickness (r = -0.663, p < 0.001) were negatively correlated with IOP, but meridional canal diameter was not (r = -0.160, p = 0.156). Schlemm’s canal was observable in 50.5% and 56.6% of POAG patients with normal (<21 mmHg) and elevated (>21 mmHg) IOP, respectively (χ = 1.159, p = 0.282). Coronal canal diameter was significantly lower in the elevated IOP group (32.6±4.9 μm) than in the normal IOP group (35.7±8.0 μm, p < 0.001). This was also true of trabecular meshwork thickness (81.9±10.0 μm vs. 97.1±12.0 μm, p < 0.001). In conclusion, eyes with POAG had fewer sections with an observable Schlemm’s canal. Canal diameter and trabecular meshwork thickness were also lower than normal in POAG patients. Schlemm’s canal coronal diameter and trabecular meshwork thickness were negatively correlated with IOP. PMID:26726880

  1. Schlemm's Canal and Trabecular Meshwork in Eyes with Primary Open Angle Glaucoma: A Comparative Study Using High-Frequency Ultrasound Biomicroscopy.

    PubMed

    Yan, Xiaoqin; Li, Mu; Chen, Zhiqi; Zhu, Ying; Song, Yinwei; Zhang, Hong

    2016-01-01

    We investigated in vivo changes in Schlemm's canal and the trabecular meshwork in eyes with primary open angle glaucoma (POAG). Relationships between Schlemm's canal diameter, trabecular meshwork thickness, and intraocular pressure (IOP) were examined. Forty POAG patients and 40 normal individuals underwent 80-MHz Ultrasound Biomicroscopy examinations. The Schlemm's canal and trabecular meshwork were imaged in superior, inferior, nasal and temporal regions. Normal individuals had an observable Schlemm's canal in 80.3% of sections, a meridional canal diameter of 233.0±34.5 μm, a coronal diameter of 44.5±12.6 μm and a trabecular meshwork thickness of 103.9±11.1 μm, in POAG patients, Schlemm's canal was observable in 53.1% of sections, a meridional canal diameter of 195.6±31.3 μm, a coronal diameter of 35.7±8.0 μm, and a trabecular meshwork thickness of 88.3±13.2 μm, which significantly differed from normal (both p <0.001). Coronal canal diameter (r = -0.623, p < 0.001) and trabecular meshwork thickness (r = -0.663, p < 0.001) were negatively correlated with IOP, but meridional canal diameter was not (r = -0.160, p = 0.156). Schlemm's canal was observable in 50.5% and 56.6% of POAG patients with normal (<21 mmHg) and elevated (>21 mmHg) IOP, respectively (χ = 1.159, p = 0.282). Coronal canal diameter was significantly lower in the elevated IOP group (32.6±4.9 μm) than in the normal IOP group (35.7±8.0 μm, p < 0.001). This was also true of trabecular meshwork thickness (81.9±10.0 μm vs. 97.1±12.0 μm, p < 0.001). In conclusion, eyes with POAG had fewer sections with an observable Schlemm's canal. Canal diameter and trabecular meshwork thickness were also lower than normal in POAG patients. Schlemm's canal coronal diameter and trabecular meshwork thickness were negatively correlated with IOP. PMID:26726880

  2. Aesthetic ultrasound therapy

    NASA Astrophysics Data System (ADS)

    Barthe, Peter G.; Slayton, Michael H.

    2012-10-01

    Ultrasound provides key benefits in aesthetic surgery compared to laser and RF based energy sources. We present results of research, development, pre-clinical and clinical studies, regulatory clearance and commercialization of a revolutionary non-invasive aesthetic ultrasound imaging and therapy system. Clinical applications for this platform include non-invasive face-lifts, brow-lifts, and neck-lifts achieved through fractionated treatment of the superficial musculoaponeurotic system (SMAS) and subcutaneous tissue. Treatment consists of placing a grid of micro-coagulative lesions on the order of 1 mm3 at depths in skin of 1 to 6 mm, source energy levels of 0.1 to 3 J, and spacing on the order of 1.5 mm, from 4 to 10 MHz dual-mode image/treat transducers. System details are described, as well as a regulatory pathway consisting of acoustic and bioheat simulations, source characterization (hydrophone, radiation force, and Schlieren), pre-clinical studies (porcine skin ex vivo, in vivo, and human cadaver), human safety studies (treat and resect) and efficacy trials which culminated in FDA clearance (2009) under a new device classification and world-wide usage. Clinical before and after photographs are presented which validate the clinical approach.

  3. Neonatal urological ultrasound: diagnostic inaccuracies and pitfalls.

    PubMed Central

    Clarke, N W; Gough, D C; Cohen, S J

    1989-01-01

    Ninety one patients with urinary tract abnormalities diagnosed before birth were reviewed. Diagnoses based on prenatal and postnatal ultrasound scans alone were compared with the final diagnoses after full urological investigations, with operative or necropsy confirmation in 79 cases. The results confirmed that ultrasound examination before birth usually detects nonspecific abnormalities and although scanning after birth is more accurate it is not absolutely reliable. A diagnosis of "multicystic kidney' made on ultrasound scan alone is especially prone to error. Such mistakes can be avoided if full urological investigation is undertaken in every case. PMID:2665660

  4. Ultrasound-accelerated enzymatic synthesis of sugar esters in nonaqueous solvents.

    PubMed

    Xiao, Yong-mei; Wu, Qi; Cai, Ying; Lin, Xian-fu

    2005-09-26

    Comparative studies of enzymatic synthesis of glucose esters under ultrasound and shaking were carried out in nonaqueous media. The influence of solvents, enzymes, chain length of the acyl donors, the power of the ultrasound bath, and intermittent ultrasound on the enzymatic synthesis was investigated. Among the eight solvents selected, pyridine was the most appropriate with alkaline protease from Bacillus subtilis whether under ultrasound or shaking. The acceleration effect of ultrasound with Novozym 435 and the alkaline protease from B. subtilis-catalyzed transesterification increased with the chain length of acyl donors, decreasing from C(10) to C(4). We also investigated the influence of the power (50, 100, and 120 W) of the ultrasound irradiation and the manner of operation (continuous ultrasound, 10 min ultrasound/20 min shaking without ultrasound) on the transesterification. The results showed that higher power and continual operational gave the better acceleration. Ultrasound did not change the character and selectivity of the enzyme in the transesterification. PMID:16040020

  5. 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.

  6. Ultrasound-assisted temperature-controlled ionic-liquid dispersive liquid-phase microextraction method for simultaneous determination of anethole, estragole, and para-anisaldehyde in different plant extracts and human urine: a comparative study.

    PubMed

    Rajabi, Maryam; Haji-Esfandiari, Sudabeh; Barfi, Behruz; Ghanbari, Hanieh

    2014-07-01

    In this study, the performances of four ionic-liquid-based microextraction methods, ionic-liquid-based dispersive liquid-liquid microextraction (IL-DLLME), ionic-liquid-based ultrasound-assisted emulsification microextraction (IL-USA-ME), temperature-controlled ionic-liquid dispersive liquid-phase microextraction (TC-IL-DLME), and ultrasound-assisted temperature-controlled ionic-liquid dispersive liquid-phase microextraction (USA-TC-IL-DLME), were investigated for extraction of three bioactive compounds (anethole, estragole, and anisaldehyde) from different plant extracts and human urine. Anethole and estragole were chosen because they can alter cellular processes positively or negatively, and an efficient method is needed for their extraction and sensitive determination in the samples mentioned. Because there is no previous report on the separation of anethole and estragole (structural isomers), first, simultaneous gradient elution and flow programming were used. The microextraction methods were then applied and compared for analysis of these compounds in plant extracts and human urine by use of high-performance liquid chromatography (HPLC). The effect of conditions on extraction efficiency was studied and under the optimum conditions, the best enrichment factors (58-64), limits of detection (14-18 ng mL(-1)), limits of quantification (47-60 ng mL(-1)), and recovery (94.4-101.7 %) were obtained by use of USA-TC-IL-DLME. The optimized conditions were used to determine anethole, estragole, and para-anisaldehyde in fennel, anise, and tarragon extracts and in human urine. PMID:24817361

  7. Diagnostic and interventional musculoskeletal ultrasound: part 2. Clinical applications.

    PubMed

    Smith, Jay; Finnoff, Jonathan T

    2009-02-01

    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 neurological and musculoskeletal disorders. After reviewing this article, physicians should be able to (1) list the advantages and disadvantages of ultrasound compared to 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 difference ultrasound appearances of tendons, nerves, muscles, ligaments, blood vessels, and bones; and (5) identify multiple applications for diagnostic and interventional musculoskeletal ultrasound. Part 2 of this 2-part article will focus on the clinical applications of musculoskeletal ultrasound in clinical practice, including the ultrasonographic appearance of normal and abnormal tissues as well as specific diagnostic and interventional applications in major body regions. PMID:19627890

  8. Ultrasound of the Thyroid Gland

    MedlinePlus

    ... waves. Ultrasound imaging, also called ultrasound scanning or sonography , involves the use of a small transducer (probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the ...

  9. Medical ultrasound imaging.

    PubMed

    Jensen, Jørgen Arendt

    2007-01-01

    The paper gives an introduction to current medical ultrasound imaging systems. The basics of anatomic and blood flow imaging are described. The properties of medical ultrasound and its focusing are described, and the various methods for two- and three-dimensional imaging of the human anatomy are shown. Systems using both linear and non-linear propagation of ultrasound are described. The blood velocity can also be non-invasively visualized using ultrasound and the basic signal processing for doing this is introduced. Examples for spectral velocity estimation, color flow imaging and the new vector velocity images are presented. PMID:17092547

  10. Ultrasound elastography: principles, techniques, and clinical applications.

    PubMed

    Dewall, Ryan J

    2013-01-01

    Ultrasound elastography is an emerging set of imaging modalities used to image tissue elasticity and are often referred to as virtual palpation. These techniques have proven effective in detecting and assessing many different pathologies, because tissue mechanical changes often correlate with tissue pathological changes. This article reviews the principles of ultrasound elastography, many of the ultrasound-based techniques, and popular clinical applications. Originally, elastography was a technique that imaged tissue strain by comparing pre- and postcompression ultrasound images. However, new techniques have been developed that use different excitation methods such as external vibration or acoustic radiation force. Some techniques track transient phenomena such as shear waves to quantitatively measure tissue elasticity. Clinical use of elastography is increasing, with applications including lesion detection and classification, fibrosis staging, treatment monitoring, vascular imaging, and musculoskeletal applications. PMID:23510006

  11. Intravascular ultrasound imaging following balloon angioplasty.

    PubMed

    Tobis, J M; Mahon, D J; Moriuchi, M; Honye, J; McRae, M

    1991-01-01

    Despite its long history and reliability, contrast angiography has several inherent limitations. Because it is a two-dimensional projection image of the lumen contour, the wall thickness cannot be measured and the plaque itself is not visualized. This results in an underestimation of the amount of atherosclerotic disease by angiography. An assessment of atherosclerosis could be improved by an imaging modality: (1) that has an inherent larger magnification than angiography and (2) that directly visualizes the plaque. Intravascular ultrasound fulfils these criteria. This presentation will provide evidence that intravascular ultrasound may prove complimentary or even superior to angiography as an imaging modality. Intravascular ultrasound demonstrates excellent representations of lumen and plaque morphology of in vitro specimens compared with histology. There is very close intraobserver and interobserver variability of measurements made from intravascular ultrasound images. Phantom studies of stenoses in a tube model demonstrate that angiography can misrepresent the severity of stenosis when the lumen contour is irregular and not a typical ellipse, whereas intravascular ultrasound reproduces the cross-sectional morphology more accurately since it images the artery from within. In vitro studies of the atherosclerotic plaque tissue characteristics compare closely with the echo representation of fibrosis, calcification, and lipid material. In addition, in vitro studies of balloon angioplasty demonstrate that intravascular ultrasound accurately represents the changes in the structure of artery segments following balloon dilatation. PMID:1833473

  12. Ultrasound assisted biogas production from landfill leachate

    SciTech Connect

    Oz, Nilgün Ayman Yarimtepe, Canan Can

    2014-07-15

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

  13. Ultrasound in placental disorders.

    PubMed

    D'Antonio, Francesco; Bhide, Amar

    2014-04-01

    The definition of placenta previa based on ultrasound findings is more practical, and the traditional definition (implantation of the placenta in the lower uterine segment) needs to be revised. The term 'placenta previa' should only be used when the placental edge overlaps or is within 2 cm of the internal cervical orifice in late pregnancy. If the placental edge is located further than 2 cm but within 3.5 cm from the internal cervical orifice, the placenta should be termed 'low-lying'. Unless the placental edge at least reaches the internal orifice at mid-trimester, symptomatic placenta previa in the third trimester will not be encountered. Caesarean section is the recommended mode of delivery for placenta previa at term. Attempt at vaginal delivery is appropriate for low-lying placenta, but the possibility of post-partum haemorrhage should be kept in mind. The incidence of invasive placentation, such as placenta accrete, has progressively risen in the past 3 decades, possibly as a consequence of increasing caesarean section rates. Ultrasound has a sensitivity of 91% and a specificity of 97% for the identification of all forms of invasive placentation. Chorioangiomas are benign non-trophoblastic placental tumours with excessive vascular proliferation within the stroma of chronic villi. They are usually asymptomatic, although occasionally can be associated with adverse fetal outcomes. Chorioangiomas usually appear as well-circumscribed, rounded, hypo-echoic lesions next to the chorionic surface. Iatrogenic delivery or prenatal intervention are two options, if fetal compromise is present. Prenatal detection leads to a dramatic increase in survival compared with those cases unsuspected antenatally. PMID:24461676

  14. 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

  15. Assisted ultrasound applications for the production of safe foods.

    PubMed

    Sango, D M; Abela, D; McElhatton, A; Valdramidis, V P

    2014-05-01

    Ultrasound requires high power and longer treatment times to inactivate micro-organisms when compared to ultrasound combined with other technologies. Previous reports have shown that the effectiveness of ultrasound as a decontamination technology can be increased by combining it with another treatment such as pressure, heat and antimicrobial solutions. Assisted ultrasound, the combination of ultrasound with another technology, is more energy efficient, and it has less impact on the food properties. In this review paper, the power ultrasound antimicrobial mechanisms of action, the antimicrobial effects of ultrasound in combination with other physical processes and antimicrobial solutions are comprehensively discussed. Furthermore, the present interest on using these technologies as alternative processing and decontamination methods is presented. Research outputs on the application of ultrasound combined with physical processes are showcased including applications of thermosonication, manosonication, manothermosonication and osmosonication. Antimicrobial efficacy, energy requirements and optimal operation conditions of the different assisted ultrasound technologies are critically discussed, and their impact on the food industry for future applications is presented. Overall, this review paper highlights the importance and recent developments of assisted ultrasound for enhancing food safety. PMID:24506803

  16. 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. PMID:19627875

  17. 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

  18. Musculoskeletal Ultrasound in Pediatrics.

    PubMed

    Harcke, H. Theodore

    1998-01-01

    Ultrasound is ideally suited to the evaluation of the pediatric musculoskeletal system because of the increased ratio of cartilage to bone in the immature skeleton. The purpose of this article is to review the current uses of musculoskeletal ultrasound in pediatric patients. Hip sonography is widely accepted; other applications are increasing in popularity. PMID:11387111

  19. Ultrasound skin imaging.

    PubMed

    Alfageme Roldán, F

    2014-12-01

    The interaction of high-frequency ultrasound waves with the skin provides the basis for noninvasive, fast, and accessible diagnostic imaging. This tool is increasingly used in skin cancer and inflammatory conditions as well as in cosmetic dermatology. This article reviews the basic principles of skin ultrasound and its applications in the different areas of dermatology. PMID:24838227

  20. Effects of ultrasound and sodium lauryl sulfate on the transdermal delivery of hydrophilic permeants: Comparative in vitro studies with full-thickness and split-thickness pig and human skin.

    PubMed

    Seto, Jennifer E; Polat, Baris E; Lopez, Renata F V; Blankschtein, Daniel; Langer, Robert

    2010-07-01

    The simultaneous application of ultrasound and the surfactant sodium lauryl sulfate (referred to as US/SLS) to skin enhances transdermal drug delivery (TDD) in a synergistic mechanical and chemical manner. Since full-thickness skin (FTS) and split-thickness skin (STS) differ in mechanical strength, US/SLS treatment may have different effects on their transdermal transport pathways. Therefore, we evaluated STS as an alternative to the well-established US/SLS-treated FTS model for TDD studies of hydrophilic permeants. We utilized the aqueous porous pathway model to compare the effects of US/SLS treatment on the skin permeability and the pore radius of pig and human FTS and STS over a range of skin electrical resistivity values. Our findings indicate that the US/SLS-treated pig skin models exhibit similar permeabilities and pore radii, but the human skin models do not. Furthermore, the US/SLS-enhanced delivery of gold nanoparticles and quantum dots (two model hydrophilic macromolecules) is greater through pig STS than through pig FTS, due to the presence of less dermis that acts as an artificial barrier to macromolecules. In spite of greater variability in correlations between STS permeability and resistivity, our findings strongly suggest the use of 700microm-thick pig STS to investigate the in vitro US/SLS-enhanced delivery of hydrophilic macromolecules. PMID:20346994

  1. [Ultrasound imaging of Dupuytren's contracture].

    PubMed

    Créteur, V; Madani, A; Gosset, N

    2010-06-01

    Dupuytren's contracture is characterized by two underlying lesions, nodules and cords. These involve the palmar fascia at the distal palmar crease, especially at the level of the third and fourth rays with progressive disabling finger contracture. The superficial palmar aponeurosis appears as a thin echogenic lamellar structure overlying the flexor tendons. The demonstration of hypoechoic bands adhering to the marging of the flexor tendons and deep surface of the dermis appears to be pathognomonic of the disease. Compared to tendons, early nodules are hypoechoic and typically hypervascular whereas older nodules are iso- to hyperechoic, without hypervascular Doppler signal. Ultrasound can sometimes demonstrate arterial encasement by fibrous or scarring tissue. Ultrasound therefore is very useful for the differential diagnosis of pathologies involving the palmar surface of the hand, for the early detection of Dupuytren's contracture, and for the detection of complication, especially vascular. These data may have an impact on management. PMID:20808269

  2. A novel de-noising method for B ultrasound images

    NASA Astrophysics Data System (ADS)

    Tian, Da-Yong; Mo, Jia-qing; Yu, Yin-Feng; Lv, Xiao-Yi; Yu, Xiao; Jia, Zhen-Hong

    2015-12-01

    B ultrasound as a kind of ultrasonic imaging, which has become the indispensable diagnosis method in clinical medicine. However, the presence of speckle noise in ultrasound image greatly reduces the image quality and interferes with the accuracy of the diagnosis. Therefore, how to construct a method which can eliminate the speckle noise effectively, and at the same time keep the image details effectively is the research target of the current ultrasonic image de-noising. This paper is intended to remove the inherent speckle noise of B ultrasound image. The novel algorithm proposed is based on both wavelet transformation of B ultrasound images and data fusion of B ultrasound images, with a smaller mean squared error (MSE) and greater signal to noise ratio (SNR) compared with other algorithms. The results of this study can effectively remove speckle noise from B ultrasound images, and can well preserved the details and edge information which will produce better visual effects.

  3. ULTRASOUND INCREASES THE RATE OF BACTERIAL CELL GROWTH

    PubMed Central

    Pitt, William G.; Ross, S. Aaron

    2006-01-01

    Ultrasound was employed to increase the growth rate of bacterial cells attached to surfaces. Staphylococcus epidermidis, Pseudomonas aeruginosa and Escherichia coli cells adhered to and grew on a polyethylene surface in the presence of ultrasound. It was found that low frequency ultrasound (70 kHz) of low acoustic intensity (<2 W/cm2) increased the growth rate of the cells compared to growth without ultrasound. However, at high intensity levels, cells were partially removed from the surface. Ultrasound also enhanced planktonic growth of S. epidermidis and other planktonic bacteria. It is hypothesized that ultrasound increases the rate of transport of oxygen and nutrients to the cells and increases the rate of transport of waste products away from the cells, thus enhancing their growth. PMID:12790676

  4. Simplified stereo-optical ultrasound plane calibration

    NASA Astrophysics Data System (ADS)

    Hoßbach, Martin; Noll, Matthias; Wesarg, Stefan

    2013-03-01

    Image guided therapy is a natural concept and commonly used in medicine. In anesthesia, a common task is the injection of an anesthetic close to a nerve under freehand ultrasound guidance. Several guidance systems exist using electromagnetic tracking of the ultrasound probe as well as the needle, providing the physician with a precise projection of the needle into the ultrasound image. This, however, requires additional expensive devices. We suggest using optical tracking with miniature cameras attached to a 2D ultrasound probe to achieve a higher acceptance among physicians. The purpose of this paper is to present an intuitive method to calibrate freehand ultrasound needle guidance systems employing a rigid stereo camera system. State of the art methods are based on a complex series of error prone coordinate system transformations which makes them susceptible to error accumulation. By reducing the amount of calibration steps to a single calibration procedure we provide a calibration method that is equivalent, yet not prone to error accumulation. It requires a linear calibration object and is validated on three datasets utilizing di erent calibration objects: a 6mm metal bar and a 1:25mm biopsy needle were used for experiments. Compared to existing calibration methods for freehand ultrasound needle guidance systems, we are able to achieve higher accuracy results while additionally reducing the overall calibration complexity. Ke

  5. Ultrasound-mediated gastrointestinal drug delivery

    PubMed Central

    Schoellhammer, Carl M.; Schroeder, Avi; Maa, Ruby; Lauwers, Gregory Yves; Swiston, Albert; Zervas, Michael; Barman, Ross; DiCiccio, Angela M.; Brugge, William R.; Anderson, Daniel G.; Blankschtein, Daniel; Langer, Robert; Traverso, Giovanni

    2016-01-01

    There is a significant clinical need for rapid and efficient delivery of drugs directly to the site of diseased tissues for the treatment of gastrointestinal (GI) pathologies, in particular, Crohn’s and ulcerative colitis. However, complex therapeutic molecules cannot easily be delivered through the GI tract because of physiologic and structural barriers. We report the use of ultrasound as a modality for enhanced drug delivery to the GI tract, with an emphasis on rectal delivery. Ultrasound increased the absorption of model therapeutics inulin, hydrocortisone, and mesalamine two- to tenfold in ex vivo tissue, depending on location in the GI tract. In pigs, ultrasound induced transient cavitation with negligible heating, leading to an order of magnitude enhancement in the delivery of mesalamine, as well as successful systemic delivery of a macromolecule, insulin, with the expected hypoglycemic response. In a rodent model of chemically induced acute colitis, the addition of ultrasound to a daily mesalamine enema (compared to enema alone) resulted in superior clinical and histological scores of disease activity. In both animal models, ultrasound treatment was well tolerated and resulted in minimal tissue disruption, and in mice, there was no significant effect on histology, fecal score, or tissue inflammatory cytokine levels. The use of ultrasound to enhance GI drug delivery is safe in animals and could augment the efficacy of GI therapies and broaden the scope of agents that could be delivered locally and systemically through the GI tract for chronic conditions such as inflammatory bowel disease. PMID:26491078

  6. Portable ultrasound: the next generation arrives.

    PubMed

    Ault, Mark J; Rosen, Bradley T

    2010-07-01

    PURPOSE: A new category of handheld devices has recently emerged that are even smaller than current portable models, with their main advantages being increased portability and affordability relative to their counterparts. However, these new devices have not yet been thoroughly evaluated in the clinical setting. METHODS: A prospective, non-blinded, three-phase study was designed to evaluate a handheld ultrasound device as compared to a common compact ultrasound machine for the performance of paracenteses and thoracenteses on human patients. RESULTS: For the vast majority of straight-forward evaluations, the handheld device was sufficient to safely complete the procedure without further imaging. For difficult cases with smaller fluid collections or anatomic aberrations, further localization with the common compact machine continued to be useful to improve the operator's confidence in the findings. CONCLUSION: This novice handheld device represents only one of what appears to be a growing number of new ultra-portable ultrasound devices on the market. These devices represent a new and exciting form of ultrasound technology that may benefit patients and physicians in multiple venues. While they are unlikely to replace standard ultrasound devices for many of the more complex applications, their extreme portability allows for ultrasound imaging in more diverse situations that has previously been practical. Based on our limited experience, the image quality is adequate and the learning curve is reasonable. Future integration of PDA technology could further the utility of these devices and additional study will be important to further define their appropriate niche and clinical utility. PMID:21151494

  7. Quantitative Ultrasound Assessment of the Rat Cervix

    PubMed Central

    McFarlin, Barbara L.; O’Brien, William D.; Oelze, Michael L.; Zachary, James F.; White-Traut, Rosemary C.

    2009-01-01

    Objective The purpose of this research was to detect cervical ripening with a new quantitative ultrasound technique. Methods Cervices of 13 nonpregnant and 65 timed pregnant (days 15, 17, 19, 20, and 21 of pregnancy) Sprague Dawley rats were scanned ex vivo with a 70-MHz ultrasound transducer. Ultrasound scatterer property estimates (scatterer diameter [SD], acoustic concentration [AC], and scatterer strength factor [SSF]) from the cervices were quantified and then compared to hydroxyproline and water content. Insertion loss (attenuation) was measured in 3 rats in each of the 6 groups. Discriminant analysis was used to predict gestational age group (cervical ripening) from the ultrasound variables SD, SSF, and AC. Results Differences were observed between the groups (SD, AC, and SSF; P < .0001). Quantitative ultrasound measures changed as the cervix ripened: (1) SD increased from days 15 to 21; (2) AC decreased from days 15 to 21; and (3) SSF was the greatest in the nonpregnant group and the least in the day 21 group. Cervix hydroxyproline content increased as pregnancy progressed (P < .003) and correlated with group, SD, AC, and SSF (P < .001). Discriminant analysis of ultrasound variables predicted 56.4% of gestational group assignment (P < .001) and increased to 77% within 2 days of the predicted analysis. Cervix insertion loss was greatest for the nonpregnant group and least for the day 21 group. Conclusions Quantitative ultrasound predicted cervical ripening in the rat cervix, but before use in humans, quantitative ultrasound will need to predict gestational age in the later days of gestation with more precision. PMID:16870896

  8. Ultrasound simulation in bone.

    PubMed

    Kaufman, Jonathan J; Luo, Gangming; Siffert, Robert S

    2008-01-01

    The manner in which ultrasound interacts with bone is of key interest in therapy and diagnosis alike. These may include applications directly to bone, as, for example, in treatment to accelerate the healing of bone fractures and in assessment of bone density in osteoporosis, or indirectly in diagnostic imaging of soft tissue with interest in assessing exposure levels to nearby bone. Because of the lack of analytic solutions to virtually every "practical problem" encountered clinically, ultrasound simulation has become a widely used technique for evaluating ultrasound interactions in bone. This paper provides an overview of the use of ultrasound simulation in bone. A brief description of the mathematical model used to characterize ultrasound propagation in bone is first provided. A number of simulation examples are then presented that explain how simulation may be utilized in a variety of practical configurations. The focus of this paper in terms of examples presented is on diagnostic applications in bone, and, in particular, for assessment of osteoporosis. However, the use of simulation in other areas of interest can easily be extrapolated from the examples presented. In conclusion, this paper describes the use of ultrasound simulation in bone and demonstrates the power of computational methods for ultrasound research in general and tissue and bone applications in particular. PMID:18599409

  9. Beating the blues: is there any music in fighting cyanobacteria with ultrasound?

    PubMed

    Lürling, Miquel; Tolman, Yora

    2014-12-01

    The hypothesis that cyanobacteria can be controlled by commercially available ultrasound transducers was tested in laboratory experiments with cultures of the cyanobacteria Anabaena sp., Cylindrospermopsis raciborskii and Microcystis aeruginosa and the green alga Scenedesmus obliquus that were grown in the absence or presence of ultrasound (mix of 20, 28 and 44 kHz). The Scenedesmus experiment also included a treatment with the zooplankton grazer Daphnia magna. Chlorophyll-a and biovolume-based growth of Anabaena was significantly lower in ultrasound exposed cultures than in controls. Particle based growth rates were higher in ultrasound treatments. Filaments were significantly shorter in ultrasound exposed cultures reflecting filament breakage. Photosystem II efficiency was not affected by ultrasound. In Cylindrospermopsis chlorophyll-a based growth rates and photosystem II efficiencies were similar in controls and ultrasound treatments, but biovolume-based growth was significantly lower in ultrasound exposed cultures compared to controls. Despite biovolume growth rates of the filamentous cyanobacteria were reduced in ultrasound treatments compared to controls, growth remained positive implying still a population increase. In Microcystis and Scenedesmus growth rates were similar in controls and ultrasound treatments. Hence, no effect of ultrasound on these phytoplankton species was found. Ultrasound should not be viewed "environmental friendly" as it killed all Daphnia within 15 min, releasing Scenedesmus from grazing control in the cultures. Based on our experiments and critical literature review, we conclude that there is no music in controlling cyanobacteria in situ with the commercially available ultrasound transducers we have tested. PMID:25240117

  10. Ultrasound Techniques for Space Applications

    NASA Technical Reports Server (NTRS)

    Rooney, James A.

    1985-01-01

    Ultrasound has proven to be a safe non-invasive technique for imaging organs and measuring cardiovascular function. It has unique advantages for application to problems with man in space including evaluation of cardiovascular function both in serial studies and during critical operations. In addition, specialized instrumentation may be capable of detecting the onset of decompression sickness during EVA activities. A spatial location and three-dimensional reconstruction system is being developed to improve the accuracy and reproducibility for serial comparative ultrasound studies of cardiovascular function. The three-dimensional method permits the acquisition of ultrasonic images from many views that can be recombined into a single reconstruction of the heart or vasculature. In addition to conventional imaging and monitoring systems, it is sometimes necessary or desirable to develop instrumentation for special purposes. One example of this type of development is the design of a pulsed-Doppler system to monitor cerebral blood flow during critical operations such as re-entry. A second example is the design of a swept-frequency ultrasound system for the detection of bubbles in the circulatory system and/or soft tissues as an early indication of the onset of decompression sickness during EVA activities. This system exploits the resonant properties of bubbles and can detect both fundamental and second harmonic emissions from the insonified region.

  11. Ultrasound assessment of schistosomiasis.

    PubMed

    Richter, J; Botelho, M C; Holtfreter, M C; Akpata, R; El Scheich, T; Neumayr, A; Brunetti, E; Hatz, C; Dong, Y; Dietrich, C F

    2016-07-01

    In 2000, the World Health Organization (WHO) issued an ultrasound field protocol for assessing the morbidity due to Schistosoma (S.) haematobium and S. mansoni. The experience with this classification has recently been reviewed systematically. The WHO protocol was well accepted worldwide. Here we review the use of ultrasound to assess the morbidity due to schistosomiasis with emphasis on easy, quick, and reproducible ways that can be used in the field. Findings obtained with high-end ultrasound scanners in the hospital setting that might eventually have applications in the field are also described. PMID:27429103

  12. Abdominal ultrasound (image)

    MedlinePlus

    Abdominal ultrasound is a scanning technique used to image the interior of the abdomen. Like the X- ... use high frequency sound waves to produce an image and do not expose the individual to radiation. ...

  13. Measurements in ultrasound

    SciTech Connect

    Goldberg, B.B.; Kurtz, A.B.; Goldberg, P.

    1988-01-01

    This book gathers all published and original data pertaining to anatomical measurements as projected on ultrasound scans. It covers all major anatomic regions and organ systems, including abdomen, pelvic, obstetrical, head and neck, and heart.

  14. Ultrasound in pregnancy (image)

    MedlinePlus

    The ultrasound has become a standard procedure used during pregnancy. It can demonstrate fetal growth and can detect increasing ... abnormalities, hydrocephalus, anencephaly, club feet, and other ... does not produce ionizing radiation and is considered ...

  15. Eye and orbit ultrasound

    MedlinePlus

    ... the eye (vitreous hemorrhage) Cancer of the retina ( retinoblastoma ), under the retina, or in other parts of ... Cataract removal Melanoma of the eye Retinal detachment Retinoblastoma Ultrasound Update Date 2/23/2015 Updated by: ...

  16. Ultrasound: Pelvis (For Parents)

    MedlinePlus

    ... pelvic area and images are recorded on a computer. The black-and-white images show the internal ... the images can be seen clearly on the computer screen. A technician (sonographer) trained in ultrasound imaging ...

  17. Ultrasound: Infant Hip

    MedlinePlus

    ... hip area, and images are recorded on a computer. The black-and-white images show the internal ... the images can be seen clearly on the computer screen. A technician (sonographer) trained in ultrasound imaging ...

  18. Ultrasound: Abdomen (For Parents)

    MedlinePlus

    ... abdominal area and images are recorded on a computer. The black-and-white images show the internal ... the images can be seen clearly on the computer screen. A technician (sonographer) trained in ultrasound imaging ...

  19. Ultrasound: Head (For Parents)

    MedlinePlus

    ... the head and images are recorded on a computer. The black-and-white images show the internal ... the images can be seen clearly on the computer screen. A technician (sonographer) trained in ultrasound imaging ...

  20. Ultrasound: Bladder (For Parents)

    MedlinePlus

    ... bladder area and images are recorded on a computer. The black-and-white images show the internal ... the images can be seen clearly on the computer screen. A technician (sonographer) trained in ultrasound imaging ...

  1. Ultrasound in perinatology

    SciTech Connect

    Maklad, N.F.

    1986-01-01

    This 19th volume in the series Clinics in Diagnostic Ultrasound provides an overview and update of some of the recent applications of ultrasound (US) in the pernatal period. Prenatal topics include estimation of gestational age; evaluation of intrauterine growth retardation, non-immune hydrops, and fetal urinary abnormalities; fetal echocardiography; and biophysical scoring. The discussion of postnatal topics includes US studies of the head and abdomen, echocardiography, and interventional procedures.

  2. Breast ultrasound tomography with total-variation regularization

    SciTech Connect

    Huang, Lianjie; Li, Cuiping; Duric, Neb

    2009-01-01

    Breast ultrasound tomography is a rapidly developing imaging modality that has the potential to impact breast cancer screening and diagnosis. A new ultrasound breast imaging device (CURE) with a ring array of transducers has been designed and built at Karmanos Cancer Institute, which acquires both reflection and transmission ultrasound signals. To extract the sound-speed information from the breast data acquired by CURE, we have developed an iterative sound-speed image reconstruction algorithm for breast ultrasound transmission tomography based on total-variation (TV) minimization. We investigate applicability of the TV tomography algorithm using in vivo ultrasound breast data from 61 patients, and compare the results with those obtained using the Tikhonov regularization method. We demonstrate that, compared to the Tikhonov regularization scheme, the TV regularization method significantly improves image quality, resulting in sound-speed tomography images with sharp (preserved) edges of abnormalities and few artifacts.

  3. Resonant nonlinear ultrasound spectroscopy

    DOEpatents

    Johnson, Paul A.; TenCate, James A.; Guyer, Robert A.; Van Den Abeele, Koen E. A.

    2001-01-01

    Components with defects are identified from the response to strains applied at acoustic and ultrasound frequencies. The relative resonance frequency shift .vertline..DELTA..function./.function..sub.0.vertline., is determined as a function of applied strain amplitude for an acceptable component, where .function..sub.0 is the frequency of the resonance peak at the lowest amplitude of applied strain and .DELTA..function. is the frequency shift of the resonance peak of a selected mode to determine a reference relationship. Then, the relative resonance frequency shift .vertline..DELTA..function./.function..sub.0 is determined as a function of applied strain for a component under test, where fo .function..sub.0 the frequency of the resonance peak at the lowest amplitude of applied strain and .DELTA..function. is the frequency shift of the resonance peak to determine a quality test relationship. The reference relationship is compared with the quality test relationship to determine the presence of defects in the component under test.

  4. METRIC (MREnterography or ulTRasound in Crohn’s disease): a study protocol for a multicentre, non-randomised, single-arm, prospective comparison study of magnetic resonance enterography and small bowel ultrasound compared to a reference standard in those aged 16 and over

    PubMed Central

    2014-01-01

    Background Crohn’s disease (CD) is a lifelong, relapsing and remitting inflammatory condition of the intestine. Medical imaging is crucial for diagnosis, phenotyping, activity assessment and detecting complications. Diverse small bowel imaging tests are available but a standard algorithm for deployment is lacking. Many hospitals employ tests that impart ionising radiation, of particular concern to this young patient population. Magnetic resonance enterography (MRE) and small bowel ultrasound (USS) are attractive options, as they do not use ionising radiation. However, their comparative diagnostic accuracy has not been compared in large head to head trials. METRIC aims to compare the diagnostic efficacy, therapeutic impact and cost effectiveness of MRE and USS in newly diagnosed and relapsing CD. Methods METRIC (ISRCTN03982913) is a multicentre, non-randomised, single-arm, prospective comparison study. Two patient cohorts will be recruited; those newly diagnosed with CD, and those with suspected relapse. Both will undergo MRE and USS in addition to other imaging tests performed as part of clinical care. Strict blinding protocols will be enforced for those interpreting MRE and USS. The Harvey Bradshaw index, C-reactive protein and faecal calprotectin will be collected at recruitment and 3 months, and patient experience will be assessed via questionnaires. A multidisciplinary consensus panel will assess all available clinical and imaging data up to 6 months after recruitment of each patient and will define the standard of reference for the presence, localisation and activity of disease against which the diagnostic accuracy of MRE and USS will be judged. Diagnostic impact of MRE and USS will be evaluated and cost effectiveness will be assessed. The primary outcome measure is the difference in per patient sensitivity between MRE and USS for the correct identification and localisation of small bowel CD. Discussion The trial is open at 5 centres with 46 patients

  5. High-resolution imaging with a real-time synthetic aperture ultrasound system: a phantom study

    NASA Astrophysics Data System (ADS)

    Huang, Lianjie; Labyed, Yassin; Simonetti, Francesco; Williamson, Michael; Rosenberg, Robert; Heintz, Philip; Sandoval, Daniel

    2011-03-01

    It is difficult for ultrasound to image small targets such as breast microcalcifications. Synthetic aperture ultrasound imaging has recently developed as a promising tool to improve the capabilities of medical ultrasound. We use two different tissueequivalent phantoms to study the imaging capabilities of a real-time synthetic aperture ultrasound system for imaging small targets. The InnerVision ultrasound system DAS009 is an investigational system for real-time synthetic aperture ultrasound imaging. We use the system to image the two phantoms, and compare the images with those obtained from clinical scanners Acuson Sequoia 512 and Siemens S2000. Our results show that synthetic aperture ultrasound imaging produces images with higher resolution and less image artifacts than Acuson Sequoia 512 and Siemens S2000. In addition, we study the effects of sound speed on synthetic aperture ultrasound imaging and demonstrate that an accurate sound speed is very important for imaging small targets.

  6. The ultrasound-assisted aqueous extraction of rice bran oil.

    PubMed

    Khoei, Maryam; Chekin, Fereshteh

    2016-03-01

    In this work, aqueous extraction of rice bran oil was done without and with ultrasound pretreatment. Key factors controlling the extraction and optimal operating conditions were identified. The highest extraction efficiency was found at pH=12, temperature of 45°C, agitation speed of 800rpm and agitation time of 15min, ultrasound treatment time of 70min and ultrasound treatment temperature of 25°C. Moreover, extraction yields were compared to ultrasound-assisted aqueous extraction and Soxhlet extraction. The results showed that the yield of rice bran oil at ultrasound-assisted aqueous extraction was close to the yield of oil extracted by hexane Soxhlet extraction. This result implied that the yield of rice bran oil was significantly influenced by ultrasound. With regard to quality, the oil extracted by ultrasound-assisted aqueous process had a lower content of free fatty acid and lower color imparting components than the hexane-extracted oil. Also, effect of parboiling of paddy on hexane and ultrasound-assisted aqueous extraction was studied. Both extraction methods gives higher percentage of oil from par boiled rice bran compared with raw rice bran. This may be due to the fact that parboiling releases the oil. PMID:26471585

  7. Comparing cost-effectiveness between endoscopic ultrasound and endoscopic retrograde cholangiopancreatography in diagnosis of common bile duct stone in patients with predefined risks: A study from a developing country

    PubMed Central

    Netinatsunton, Nisa; Attasaranya, Siriboon; Sottisuporn, Jaksin; Witeerungrot, Teepawit; Jongboonyanuparp, Theeratus; Piratvisuth, Teerha; Ovartlarnporn, Bancha

    2016-01-01

    Background and Objectives: Endoscopic ultrasound (EUS) achieves results comparable to endoscopic retrograde cholangiopancreatography (ERCP) in the diagnosis of common bile duct (CBD) stone, but studies from the western have shown EUS to be less expensive in patients with intermediate risk for CBD stones. The aim of this study was to compare the costs of EUS and ERCP in the diagnosis of CBD stones in a developing country. Materials and Methods: A prospective study was done with 141 patients with suspected CBD stones, categorized as having high or intermediate risk for CBD stone. All underwent EUS, and the high-risk patients had ERCP after the EUS. For intermediate-risk patients, an ERCP was done at the discretion of the attending physician. The CBD stone was confirmed by ERCP in patients who underwent both EUS and ERCP. Patients who received EUS only were followed up every 3 months for 1 year. The false negative rate in patients with EUS and ERCP was estimated in the clinical follow-up. Result: One hundred and forty-one patients (141: 83 females, 58 males) with a mean age ± standard deviation (SD) of 55.71 ±18.68 years were recruited. Ninety-four (94) patients underwent both EUS and ERCP. ERCP confirmed the diagnosis in 83 of 85 patients (97.6%) with CBD stone detected by EUS. Forty-seven (47) patients with a negative EUS and no ERCP done were symptom-free during the follow-up. The overall sensitivity, specificity, positive predictive value, and negative predictive value of EUS were 97.6%, 80%, 97.6%, and 80% respectively. An EUS-based strategy for high-risk patients was 15% more expensive than an ERCP-based strategy, but the EUS-based strategy reduced the cost to 37.78% less than the ERCP-based strategy in intermediate-risk patients. The EUS-based strategy was cost-saving when the CBD stone prevalence was less than 52.5%. Conclusion: EUS is safer and less costly than ERCP for CBD stone diagnosis in patients with intermediate risk. PMID:27386473

  8. Pocket ultrasound devices for focused echocardiography

    PubMed Central

    2012-01-01

    Pocket ultrasound devices have recently been developed and may be particularly useful for emergency assessment. These devices can be stored in a pocket but share only some technical features with conventional echocardiographic machines. Two-dimensional imaging and color flow mode are available, with possible adjustments of global gain and depth, but Doppler features are lacking. These devices are particularly fitted for focused echocardiography. In this issue, a trial compares a pocket ultrasound device with a conventional echocardiographic machine for focused echocardiography in patients admitted to the emergency department. This commentary will put these findings into perspective. PMID:22748159

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

    PubMed

    Bigelow, Timothy A

    2009-01-01

    High-Intensity Focused Ultrasound (HIFU) is quickly becoming one of the best methods to thermally ablate tissue noninvasively. Unlike RF or Laser ablation, the tissue can be destroyed without inserting any probes into the body minimizing the risk of secondary complications such as infections. In this study, the heating efficiency of HIFU sources is improved by altering the excitation of the ultrasound source to take advantage of nonlinear propagation. For ultrasound, the phase velocity of the ultrasound wave depends on the amplitude of the wave resulting in the generation of higher harmonics. These higher harmonics are more efficiently converted into heat in the body due to the frequency dependence of the ultrasound absorption in tissue. In our study, the generation of the higher harmonics by nonlinear propagation is enhanced by transmitting an ultrasound wave with both the fundamental and a higher harmonic component included. Computer simulations demonstrated up to a 300% increase in temperature increase compared to transmitting at only the fundamental for the same acoustic power transmitted by the source. PMID:19963801

  10. Endoscopic ultrasound using ultrasound probes for the diagnosis of early esophageal and gastric cancers.

    PubMed

    Yoshinaga, Shigetaka; Oda, Ichiro; Nonaka, Satoru; Kushima, Ryoji; Saito, Yutaka

    2012-06-16

    Endoscopic ultrasound (EUS) devices were first designed and manufactured more than 30 years ago, and since then investigators have reported EUS is effective for determining both the staging and the depth of invasion of esophageal and gastric cancers. We review the present status, the methods, and the findings of EUS when used to diagnose and stage early esophageal and gastric cancer. EUS using high-frequency ultrasound probes is more accurate than conventional EUS for the evaluation of the depth of invasion of superficial esophageal carcinoma. The rates of accurate evaluation of the depth of invasion by EUS using high-frequency ultrasound probes were 70%-88% for intramucosal cancer, and 83%-94% for submucosal invasive cancer. But the sensitivity of EUS using high-frequency ultrasound probes for the diagnosis of submucosal invasive cancer was relatively low, making it difficult to confirm minute submucosal invasion. The accuracy of EUS using high-frequency ultrasound probes for early gastric tumor classification can be up to 80% compared with 63% for conventional EUS, although the accuracy of EUS using high-frequency ultrasound probes relatively decreases for those patients with depressed-type lesions, undifferentiated cancer, concomitant ulceration, expanded indications, type 0-I lesions, and lesions located in the upper-third of the stomach. A 92% overall accuracy rate was achieved when both the endoscopic appearance and the findings from EUS using high-frequency ultrasound probes were considered together for tumor classification. Although EUS using high-frequency ultrasound probes has limitations, it has a high depth of invasion accuracy and is a useful procedure to distinguish lesions in the esophagus and stomach that are indicated for endoscopic resection. PMID:22720122

  11. AMUM LECTURE: Therapeutic ultrasound

    NASA Astrophysics Data System (ADS)

    Crum, Lawrence A.

    2004-01-01

    The use of ultrasound in medicine is now quite commonplace, especially with the recent introduction of small, portable and relatively inexpensive, hand-held diagnostic imaging devices. Moreover, ultrasound has expanded beyond the imaging realm, with methods and applications extending to novel therapeutic and surgical uses. These applications broadly include: tissue ablation, acoustocautery, lipoplasty, site-specific and ultrasound mediated drug activity, extracorporeal lithotripsy, and the enhancement of natural physiological functions such as wound healing and tissue regeneration. A particularly attractive aspect of this technology is that diagnostic and therapeutic systems can be combined to produce totally non-invasive, imageguided therapy. This general lecture will review a number of these exciting new applications of ultrasound and address some of the basic scientific questions and future challenges in developing these methods and technologies for general use in our society. We shall particularly emphasize the use of High Intensity Focused Ultrasound (HIFU) in the treatment of benign and malignant tumors as well as the introduction of acoustic hemostasis, especially in organs which are difficult to treat using conventional medical and surgical techniques.

  12. Medical ultrasound systems

    PubMed Central

    Powers, Jeff; Kremkau, Frederick

    2011-01-01

    Medical ultrasound imaging has advanced dramatically since its introduction only a few decades ago. This paper provides a short historical background, and then briefly describes many of the system features and concepts required in a modern commercial ultrasound system. The topics addressed include array beam formation, steering and focusing; array and matrix transducers; echo image formation; tissue harmonic imaging; speckle reduction through frequency and spatial compounding, and image processing; tissue aberration; Doppler flow detection; and system architectures. It then describes some of the more practical aspects of ultrasound system design necessary to be taken into account for today's marketplace. It finally discusses the recent explosion of portable and handheld devices and their potential to expand the clinical footprint of ultrasound into regions of the world where medical care is practically non-existent. Throughout the article reference is made to ways in which ultrasound imaging has benefited from advances in the commercial electronics industry. It is meant to be an overview of the field as an introduction to other more detailed papers in this special issue. PMID:22866226

  13. Ultrasound of Peripheral Nerves

    PubMed Central

    Suk, Jung Im; Walker, Francis O.; Cartwright, Michael S.

    2013-01-01

    Over the last decade, neuromuscular ultrasound has emerged as a useful tool for the diagnosis of peripheral nerve disorders. This article reviews sonographic findings of normal nerves including key quantitative ultrasound measurements that are helpful in the evaluation of focal and possibly generalized peripheral neuropathies. It also discusses several recent papers outlining the evidence base for the use of this technology, as well as new findings in compressive, traumatic, and generalized neuropathies. Ultrasound is well suited for use in electrodiagnostic laboratories where physicians, experienced in both the clinical evaluation of patients and the application of hands-on technology, can integrate findings from the patient’s history, physical examination, electrophysiological studies, and imaging for diagnosis and management. PMID:23314937

  14. Ultrasound in space

    NASA Technical Reports Server (NTRS)

    Martin, David S.; South, Donna A.; Garcia, Kathleen M.; Arbeille, Philippe

    2003-01-01

    Physiology of the human body in space has been a major concern for space-faring nations since the beginning of the space era. Ultrasound (US) is one of the most cost effective and versatile forms of medical imaging. As such, its use in characterizing microgravity-induced changes in physiology is being realized. In addition to the use of US in related ground-based studies, equipment has also been modified to fly in space. This involves alteration to handle the stresses of launch and different power and cooling requirements. Study protocols also have been altered to accommodate the microgravity environment. Ultrasound studies to date have shown a pattern of adaptation to microgravity that includes changes in cardiac chamber sizes and vertebral spacing. Ultrasound has been and will continue to be an important component in the investigation of physiological and, possibly, pathologic changes occurring in space or as a result of spaceflight.

  15. Ultrasound waveform tomography with the second-order total-generalized-variation regularization

    NASA Astrophysics Data System (ADS)

    Lin, Youzuo; Huang, Lianjie

    2016-03-01

    Ultrasound waveform tomography with the total-variation regularization could improve reconstructions of tumor margins, but the reconstructions usually contain unwanted blocky artifacts. We develop a new ultrasound waveform tomography method with a second-order total-generalized-variation regularization scheme to improve tomographic reconstructions of breast tumors and remove blocky artifacts in reconstruction results. We validate our new method using numerical phantom data and real phantom data acquired using our synthetic-aperture breast ultrasound tomography system with two parallel transducer arrays. Compared to reconstructions of ultrasound waveform tomography with modified total-variation regularization, our new ultrasound waveform tomography yields accurate sound-speed reconstruction results with significantly reduced artifacts.

  16. [Lung ultrasound in the newborn].

    PubMed

    Yousef, N

    2016-03-01

    Lung ultrasound (LU) is becoming a bedside point-of-care technique in critical care and emergency medicine as it is performed and immediately interpreted by the clinician. LU is quick, easy, relatively inexpensive, and provides accurate diagnostic information when compared with conventional lung imaging methods, such as CT scans and chest radiographs, with the additional advantage of being non-irradiating, adapted to bedside use, and easily repeatable with no side effects for the patient. LU is easy to learn, does not require sophisticated ultrasound machines or settings, and shows low intra- and interobserver variability when a standardized approach is used. A comprehensive and standardized ultrasound semiology has been described and validated in both adults and children. In summary, LU allows for quick easy recognition of a normally aerated lung in contrast to an interstitial or alveolar pattern. Recognition of these patterns may be even easier in neonates due to their small size and the absence of obesity and heavy musculature. Specific LU findings have been described for some types of neonatal lung injury, such as neonatal respiratory distress syndrome, transient tachypnea of the neonate, meconium aspiration syndrome, and neonatal pneumonia. In the newborn, LU has proved its usefulness in predicting the need for hospital admission and/or intubation based on simple LU patterns. A recently proposed LU score, adapted for the neonate, correlates well with oxygenation status, independently of gestational age and underlying respiratory condition. The score reliably predicts the need for surfactant treatment in preterm babies less than 34 weeks gestation treated with nasal CPAP from birth. LU is a promising tool with numerous potential applications that warrant future studies. However, like every technique, LU has its limitations and should not completely replace standard radiography. LU can nevertheless largely reduce exposure to ionizing radiation by limiting the

  17. Focused Ultrasound and Lithotripsy.

    PubMed

    Ikeda, Teiichiro; Yoshizawa, Shin; Koizumi, Norihiro; Mitsuishi, Mamoru; Matsumoto, Yoichiro

    2016-01-01

    Shock wave lithotripsy has generally been a first choice for kidney stone removal. The shock wave lithotripter uses an order of microsecond pulse durations and up to a 100 MPa pressure spike triggered at approximately 0.5-2 Hz to fragment kidney stones through mechanical mechanisms. One important mechanism is cavitation. We proposed an alternative type of lithotripsy method that maximizes cavitation activity to disintegrate kidney stones using high-intensity focused ultrasound (HIFU). Here we outline the method according to the previously published literature (Matsumoto et al., Dynamics of bubble cloud in focused ultrasound. Proceedings of the second international symposium on therapeutic ultrasound, pp 290-299, 2002; Ikeda et al., Ultrasound Med Biol 32:1383-1397, 2006; Yoshizawa et al., Med Biol Eng Comput 47:851-860, 2009; Koizumi et al., A control framework for the non-invasive ultrasound the ragnostic system. Proceedings of 2009 IEEE/RSJ International Conference on Intelligent Robotics and Systems (IROS), pp 4511-4516, 2009; Koizumi et al., IEEE Trans Robot 25:522-538, 2009). Cavitation activity is highly unpredictable; thus, a precise control system is needed. The proposed method comprises three steps of control in kidney stone treatment. The first step is control of localized high pressure fluctuation on the stone. The second step is monitoring of cavitation activity and giving feedback on the optimized ultrasound conditions. The third step is stone tracking and precise ultrasound focusing on the stone. For the high pressure control we designed a two-frequency wave (cavitation control (C-C) waveform); a high frequency ultrasound pulse (1-4 MHz) to create a cavitation cloud, and a low frequency trailing pulse (0.5 MHz) following the high frequency pulse to force the cloud into collapse. High speed photography showed cavitation collapse on a kidney stone and shock wave emission from the cloud. We also conducted in-vitro erosion tests of model and natural

  18. Cardiac 4D Ultrasound Imaging

    NASA Astrophysics Data System (ADS)

    D'hooge, Jan

    Volumetric cardiac ultrasound imaging has steadily evolved over the last 20 years from an electrocardiography (ECC) gated imaging technique to a true real-time imaging modality. Although the clinical use of echocardiography is still to a large extent based on conventional 2D ultrasound imaging it can be anticipated that the further developments in image quality, data visualization and interaction and image quantification of three-dimensional cardiac ultrasound will gradually make volumetric ultrasound the modality of choice. In this chapter, an overview is given of the technological developments that allow for volumetric imaging of the beating heart by ultrasound.

  19. Wavelet-based ultrasound image denoising: performance analysis and comparison.

    PubMed

    Rizi, F Yousefi; Noubari, H Ahmadi; Setarehdan, S K

    2011-01-01

    Ultrasound images are generally affected by multiplicative speckle noise, which is mainly due to the coherent nature of the scattering phenomenon. Speckle noise filtering is thus a critical pre-processing step in medical ultrasound imaging provided that the diagnostic features of interest are not lost. A comparative study of the performance of alternative wavelet based ultrasound image denoising methods is presented in this article. In particular, the contourlet and curvelet techniques with dual tree complex and real and double density wavelet transform denoising methods were applied to real ultrasound images and results were quantitatively compared. The results show that curvelet-based method performs superior as compared to other methods and can effectively reduce most of the speckle noise content of a given image. PMID:22255196

  20. Ultrasound stylet for non-image-guided ventricular catheterization.

    PubMed

    Coulson, Nathaniel K; Chiarelli, Peter A; Su, David K; Chang, Jason J; MacConaghy, Brian; Murthy, Revathi; Toms, Peter; Robb, Terrence L; Ellenbogen, Richard G; Browd, Samuel R; Mourad, Pierre D

    2015-10-01

    OBJECT Urgent ventriculostomy placement can be a lifesaving procedure in the setting of hydrocephalus or elevated intracranial pressure. While external ventricular drain (EVD) insertion is common, there remains a high rate of suboptimal drain placement. Here, the authors seek to demonstrate the feasibility of an ultrasound-based guidance system that can be inserted into an existing EVD catheter to provide a linear ultrasound trace that guides the user toward the ventricle. METHODS The ultrasound stylet was constructed as a thin metal tube, with dimensions equivalent to standard catheter stylets, bearing a single-element, ceramic ultrasound transducer at the tip. Ultrasound backscatter signals from the porcine ventricle were processed by custom electronics to offer real-time information about ventricular location relative to the catheter. Data collected from the prototype device were compared with reference measurements obtained using standard clinical ultrasound imaging. RESULTS A study of porcine ventricular catheterization using the experimental device yielded a high rate of successful catheter placement after a single pass (10 of 12 trials), despite the small size of pig ventricles and the lack of prior instruction on porcine ventricular architecture. A characteristic double-peak signal was identified, which originated from ultrasound reflections off of the near and far ventricular walls. Ventricular dimensions, as obtained from the width between peaks, were in agreement with standard ultrasound reference measurements (p < 0.05). Furthermore, linear ultrasound backscatter data permitted in situ measurement of the stylet distance to the ventricular wall (p < 0.05), which assisted in catheter guidance. CONCLUSIONS The authors have demonstrated the ability of the prototype ultrasound stylet to guide ventricular access in the porcine brain. The alternative design of the device makes it potentially easy to integrate into the standard workflow for bedside EVD

  1. Information contained in the radiating ultrasound during ultrasonic welding

    PubMed

    Masuzawa; Ohdaira

    2000-03-01

    During ultrasonic welding, unnecessary ultrasound together with audible sound is radiated into the air. Audible sound is noisy and uncomfortable, and ultrasound may have bed effects on adjacent equipment. However, it is considered that these sounds potentially contain useful information such as welding state. This article reports the relationship between radiated ultrasound and the change of the welding state during ultrasonic welding. It is known that the welding state can be presumed from the change of the mechanical load impedance, which can be calculated from resonant frequency, motional voltage and the driving current of the vibrating system for the welder when a constant-velocity motional-feedback power oscillator is used. In this study, radiated ultrasound picked up with a microphone and an amplifier is recorded and analyzed with a personal computer. Analyzed results are compared with the change of the mechanical load impedance that is also calculated from the recorded data of the resonant frequency, motional voltage and the driving current of the vibrating system for the welding. Experiments were made on the ultrasonic welding of plastic rods. The relationship between the parameters of radiated ultrasound and the electrical parameters of the vibrating system were compared. The peak amplitude of the radiated ultrasound and the mechanical impedance versus time were very similar. It is shown in this study that radiated ultrasound contains lots of useful information. PMID:10829736

  2. Ultrasound induced green solvent extraction of oil from oleaginous seeds.

    PubMed

    Sicaire, Anne-Gaëlle; Vian, Maryline Abert; Fine, Frédéric; Carré, Patrick; Tostain, Sylvain; Chemat, Farid

    2016-07-01

    Ultrasound-assisted extraction of rapeseed oil was investigated and compared with conventional extraction for energy efficiency, throughput time, extraction yield, cleanness, processing cost and product quality. A multivariate study enabled us to define optimal parameters (7.7 W/cm(2) for ultrasonic power intensity, 40 °C for processing temperature, and a solid/liquid ratio of 1/15) for ultrasound-assisted extraction of oil from oilseeds to maximize lipid yield while reducing solvent consumption and extraction time using response surface methodology (RSM) with a three-variable central composite design (CCD). A significant difference in oil quality was noted under the conditions of the initial ultrasound extraction, which was later avoided using ultrasound in the absence of oxygen. Three concepts of multistage cross-current extraction were investigated and compared: conventional multistage maceration, ultrasound-assisted maceration and a combination, to assess the positive impact of using ultrasound on the seed oil extraction process. The study concludes that ultrasound-assisted extraction of oil is likely to reduce both economic and ecological impacts of the process in the fat and oil industry. PMID:26964955

  3. Recent advances in medical ultrasound

    NASA Astrophysics Data System (ADS)

    Crum, Lawrence

    2014-03-01

    Ultrasound has become one of the most widely used imaging modalities in medicine; yet, before ultrasound-imaging systems became available, high intensity ultrasound was used as early as the 1950s to ablate regions in the brains of human patients. Recently, a variety of novel applications of ultrasound have been developed that include site-specific and ultrasound-mediated drug delivery, acoustocautery, lipoplasty, histotripsy, tissue regeneration, and bloodless surgery, among many others. This lecture will review several new applications of therapeutic ultrasound and address some of the basic scientific questions and future challenges in developing these methods and technologies for general use in our society. We shall particularly emphasize the use of High Intensity Focused Ultrasound (HIFU) in the treatment of benign and malignant tumors.

  4. 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…

  5. Validity and reliability of an ultrasound system for estimating adipose tissue.

    PubMed

    Loenneke, Jeremy P; Barnes, Jeremy T; Wagganer, Jason D; Wilson, Jacob M; Lowery, Ryan P; Green, Cody E; Pujol, Thomas J

    2014-03-01

    When health professionals measure the fitness levels of clients, body composition is usually estimated. In field settings, body composition is commonly estimated with skinfolds or bioelectrical impedance analysis. Recently, a portable ultrasound device has been manufactured to estimate what percentage of body mass is composed of adipose tissue (AT%). A reported advantage of using ultrasound is that inter- and intrarater variations may be minimized when compared with the skinfold technique. Therefore, the purpose of this pilot study was twofold; 1) to determine the validity of a portable ultrasound device compared with skinfolds and 2) determine the reliability of the portable ultrasound device. Participants had their measurements taken in the following order: urine specific gravity, body mass, height, skinfolds and ultrasound determined. Participants had their urine specific gravity and ultrasound determined AT% estimates measured again 48 h later. The current pilot study found that the ultrasound was not a valid estimate of AT% when compared with the skinfold estimate (TE > 4%). In addition, the 1-site estimate from the ultrasound was more reliable than the 3-site estimate of AT%. These data are of importance to practitioners because it demonstrates that while the ultrasound is not a valid estimate compared with skinfolds, the 1-site estimate may be able to track changes in AT% over time, making the ultrasound an option for assessing changes in body composition. PMID:23879395

  6. Neural network ultrasound image analysis

    NASA Astrophysics Data System (ADS)

    Schneider, Alexander C.; Brown, David G.; Pastel, Mary S.

    1993-09-01

    Neural network based analysis of ultrasound image data was carried out on liver scans of normal subjects and those diagnosed with diffuse liver disease. In a previous study, ultrasound images from a group of normal volunteers, Gaucher's disease patients, and hepatitis patients were obtained by Garra et al., who used classical statistical methods to distinguish from among these three classes. In the present work, neural network classifiers were employed with the same image features found useful in the previous study for this task. Both standard backpropagation neural networks and a recently developed biologically-inspired network called Dystal were used. Classification performance as measured by the area under a receiver operating characteristic curve was generally excellent for the back propagation networks and was roughly comparable to that of classical statistical discriminators tested on the same data set and documented in the earlier study. Performance of the Dystal network was significantly inferior; however, this may be due to the choice of network parameter. Potential methods for enhancing network performance was identified.

  7. Ultrasound enhanced thrombolysis in acute arterial ischemia.

    PubMed

    Tsivgoulis, Georgios; Culp, William C; Alexandrov, Andrei V

    2008-08-01

    In vitro and animal studies have shown that thrombolysis with intravenous tissue plasminogen activator (tPA) can be enhanced with ultrasound. Ultrasound delivers mechanical pressure waves to the clot, thus exposing more thrombus surface to circulating drug. Moreover, intravenous gaseous microspheres with ultrasound have been shown to be a potential alternative to fibrinolytic agents to recanalize discrete peripheral thrombotic arterial occlusions or acute arteriovenous graft thromboses. Small phase I-II randomized and non-randomized clinical trials have shown promising results concerning the potential applications of ultrasound-enhanced thrombolysis in the setting of acute cerebral ischemia. CLOTBUST was an international four-center phase II trial, which demonstrated that, in patients with acute ischemic stroke, transcranial Doppler (TCD) monitoring augments tPA-induced arterial recanalization (sustained complete recanalization rates: 38% vs. 13%) with a non-significant trend toward an increased rate of clinical recovery from stroke, as compared with placebo. The rates of symptomatic intracerebral hemorrhage (sICH) were similar in the active and placebo group (4.8% vs. 4.8%). Smaller single-center clinical trials using transcranial color-coded sonography (TCCD) reported recanalization rates ranging from 27% to 64% and sICH rates of 0-18%. A separate clinical trial evaluating the safety and efficacy of therapeutic low-frequency ultrasound was discontinued because of a concerning sICH rate of 36% in the active group. To further enhance the ability of tPA to break up thrombi, current ongoing clinical trials include phase II studies of a single beam 2 MHz TCD with perflutren-lipid microspheres. Moreover, potential enhancement of intra-arterial tPA delivery is being clinically tested with 1.7-2.1 MHz pulsed wave ultrasound (EKOS catheter) in ongoing phase II-III clinical trials. Intravenous platelet-targeted microbubbles with low-frequency ultrasound are currently

  8. Studies on the use of power ultrasound in leather dyeing.

    PubMed

    Sivakumar, Venkatasubramanian; Rao, Paruchuri Gangadhar

    2003-03-01

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

  9. Laser ultrasound technology for fault detection on carbon fiber composites

    NASA Astrophysics Data System (ADS)

    Seyrkammer, Robert; Reitinger, Bernhard; Grün, Hubert; Sekelja, Jakov; Burgholzer, Peter

    2014-05-01

    The marching in of carbon fiber reinforced polymers (CFRPs) to mass production in the aeronautic and automotive industry requires reliable quality assurance methods. Laser ultrasound (LUS) is a promising nondestructive testing technique for sample inspection. The benefits compared to conventional ultrasound (US) testing are couplant free measurements and an easy access to complex shapes due to remote optical excitation and detection. Here the potential of LUS is present on composite test panels with relevant testing scenarios for industry. The results are evaluated in comparison to conventional ultrasound used in the aeronautic industry.

  10. Ultrasound propagation in the micropores of track membranes

    NASA Astrophysics Data System (ADS)

    Gómez Álvarez-Arenas, T. E.; González, B.; Apel, P. Yu.; Orelovitch, O. L.; Mitrofanov, A. V.

    2005-09-01

    Air-coupled and high-frequency ultrasonic spectroscopy is used to study ultrasound transmission through track membranes (TMs). Observed behavior, anomalous compared to that observed for other membranes, suggests independent ultrasound propagation through the pores. This is proved experimentally by studying frequency dependence of some acoustical parameters and by closing the pore aperture at the TM surface. This changes boundary conditions so that such wave is inhibited. Ultrasound propagation in such small pores opens up a new way to investigate gas behavior under rarefied conditions and provides a new technique to characterize TMs.

  11. A resonance-free nano-film airborne ultrasound emitter

    NASA Astrophysics Data System (ADS)

    Daschewski, Maxim; Harrer, Andrea; Prager, Jens; Kreutzbruck, Marc; Beck, Uwe; Lange, Thorid; Weise, Matthias

    2013-01-01

    In this contribution we present a novel thermo-acoustic approach for the generation of broad band airborne ultrasound and investigate the applicability of resonance-free thermo-acoustic emitters for very short high pressure airborne ultrasound pulses. We report on measurements of thermo-acoustic emitter consisting of a 30 nm thin metallic film on a usual soda-lime glass substrate, generating sound pressure values of more than 140 dB at 60 mm distance from the transducer and compare the results with conventional piezoelectric airborne ultrasound transducers. Our experimental investigations show that such thermo-acoustic devices can be used as broad band emitters using pulse excitation.

  12. Breast ultrasound waveform tomography: using both transmission and reflection data, and numerical virtual point sources

    NASA Astrophysics Data System (ADS)

    Huang, Lianjie; Lin, Youzuo; Zhang, Zhigang; Labyed, Yassin; Tan, Sirui; Nguyen, Nghia; Hanson, Kenneth; Sandoval, Daniel; Williamson, Michael

    2014-03-01

    Ultrasound transmission tomography usually generates low-resolution breast images. We improve sound-speed reconstructions using ultrasound waveform tomography with both transmission and reflection data. We validate the improvement using computer-generated synthetic-aperture ultrasound transmission and reflection data for numerical breast phantoms. Our tomography results demonstrate that using both transmission and reflection data in ultrasound waveform tomography greatly enhances the resolution and accuracy of tomographic reconstructions compared to ultrasound waveform tomography using either transmission data or reflection data alone. To verify the capability of our novel ultrasound waveform tomography, we design and manufacture a new synthetic-aperture breast ultrasound tomography system with two parallel transducer arrays for clinical studies. The distance of the two transducer arrays is adjustable for accommodating different sizes of the breast. The parallel transducer arrays also allow us to easily scan the axillary region to evaluate the status of axillary lymph nodes and detect breast cancer in the axillary region. However, synthetic-aperture ultrasound reflection data acquired by firing each transducer element sequentially are usually much weaker than transmission data, and have much lower signal-to-noise ratios than the latter. We develop a numerical virtual-point-source method to enhance ultrasound reflection data using synthetic-aperture ultrasound data acquired by firing each transducer element sequentially. Synthetic-aperture ultrasound reflection data for a breast phantom obtained using our numerical virtual-point-source method reveals many coherent ultrasound reflection waveforms that are weak or invisible in the original synthetic-aperture ultrasound data. Ultrasound waveform tomography using both transmission and reflection data together with numerical virtual-point-source method has great potential to produce high-resolution tomographic

  13. Ultrasound Effect on Cancerous versus Non-Cancerous Cells.

    PubMed

    Azagury, Aharon; Amar-Lewis, Eliz; Yudilevitch, Yana; Isaacson, Carol; Laster, Brenda; Kost, Joseph

    2016-07-01

    Previous studies have found that cancer cells whose metastatic potential is low are more vulnerable to mechanical stress-induced trauma to their cytoskeleton compared with benign cells. Because ultrasound induces mechanical stresses on cells and tissues, it is postulated that there may be a way to apply ultrasound to tumors to reduce their ability to metastasize. The difference between low-malignant-potential cancer cells and benign cells could be a result of their different responses to the mechanical stress insonation induced. This hypothesis was tested in vitro and in vivo. Low-malignant-potential cells were found to be more sensitive to insonation, resulting in a significantly higher mortality rate compared with that of benign cells, 89% versus 21%, respectively. This effect can be controlled by varying ultrasound parameters: intensity, duration, and duty cycle. Thus, the results presented in this study suggest the application of ultrasound to discriminate between benign and malignant cells. PMID:27067417

  14. 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).

  15. Tumor Functional and Molecular Imaging Utilizing Ultrasound and Ultrasound-Mediated Optical Techniques

    PubMed Central

    Yuan, Baohong; Rychak, Joshua

    2014-01-01

    Tumor functional and molecular imaging has significantly contributed to cancer preclinical research and clinical applications. Among typical imaging modalities, ultrasonic and optical techniques are two commonly used methods; both share several common features such as cost efficiency, absence of ionizing radiation, relatively inexpensive contrast agents, and comparable maximum-imaging depth. Ultrasonic and optical techniques are also complementary in imaging resolution, molecular sensitivity, and imaging space (vascular and extravascular). The marriage between ultrasonic and optical techniques takes advantages of both techniques. This review introduces tumor functional and molecular imaging using microbubble-based ultrasound and ultrasound-mediated optical imaging techniques. PMID:23219728

  16. Ultrasound-mediated nail drug delivery system.

    PubMed

    Abadi, Danielle; Zderic, Vesna

    2011-12-01

    A novel ultrasound-mediated drug delivery system has been developed for treatment of a nail fungal disorder (onychomycosis) by improving delivery to the nail bed using ultrasound to increase the permeability of the nail. The slip-in device consists of ultrasound transducers and drug delivery compartments above each toenail. The device is connected to a computer, where a software interface allows users to select their preferred course of treatment. In in vitro testing, canine nails were exposed to 3 energy levels (acoustic power of 1.2 W and exposure durations of 30, 60, and 120 seconds). A stereo -microscope was used to determine how much of a drug-mimicking compound was delivered through the nail layers by measuring brightness on the cross section of each nail tested at each condition, where brightness level decreases coincide with increases in permeability. Each of the 3 energy levels tested showed statistical significance when compared to the control (P < .05) with a permeability factor of 1.3 after 30 seconds of exposure, 1.3 after 60 seconds, and 1.5 after 120 seconds, where a permeability factor of 1 shows no increase in permeability. Current treatments for onychomycosis include systemic, topical, and surgical. Even when used all together, these treatments typically take a long time to result in nail healing, thus making this ultrasound-mediated device a promising alternative. PMID:22124008

  17. Nanobubbles for enhanced ultrasound imaging of tumors.

    PubMed

    Yin, Tinghui; Wang, Ping; Zheng, Rongqin; Zheng, Bowen; Cheng, Du; Zhang, Xinling; Shuai, Xintao

    2012-01-01

    The fabrication and initial applications of nanobubbles (NBs) have shown promising results in recent years. A small particle size is a basic requirement for ultrasound contrast-enhanced agents that penetrate tumor blood vessel pores to allow for targeted imaging and therapy. However, the nanoscale size of the particles used has the disadvantage of weakening the imaging ability of clinical diagnostic ultrasound. In this work, we fabricated a lipid NBs contrast-enhanced ultrasound agent and evaluated its passive targeting ability in vivo. The results showed that the NBs were small (436.8 ± 5.7 nm), and in vitro ultrasound imaging suggested that the ultrasonic imaging ability is comparable to that of microbubbles (MBs). In vivo experiments confirmed the ability of NBs to passively target tumor tissues. The NBs remained in the tumor area for a longer period because they exhibited enhanced permeability and retention. Direct evidence was obtained by direct observation of red fluorescence-dyed NBs in tumor tissue using confocal laser scanning microscopy. We have demonstrated the ability to fabricate NBs that can be used for the in vivo contrast-enhanced imaging of tumor tissue and that have potential for drug/gene delivery. PMID:22393289

  18. Ultrasound-enhanced enzymatic hydrolysis of poly(ethylene terephthalate).

    PubMed

    Pellis, Alessandro; Gamerith, Caroline; Ghazaryan, Gagik; Ortner, Andreas; Herrero Acero, Enrique; Guebitz, Georg M

    2016-10-01

    The application of ultrasound was found to enhance enzymatic hydrolysis of poly(ethylene terephthalate) (PET). After a short activation phase up to 6.6times increase in the amount of released products was found. PET powder with lower crystallinity of 8% was hydrolyzed faster when compared to PET with 28% crystallinity. Ultrasound activation was found to be around three times more effective on powders vs. films most likely due to a larger surface area accessible to the enzyme. PMID:27481467

  19. [High frequency ultrasound].

    PubMed

    Sattler, E

    2015-07-01

    Diagnostic ultrasound has become a standard procedure in clinical dermatology. Devices with intermediate high frequencies of 7.5-15 MHz are used in dermato-oncology for the staging and postoperative care of skin tumor patients and in angiology for improved vessel diagnostics. In contrast, the high frequency ultrasound systems with 20-100 MHz probes offer a much higher resolution, yet with a lower penetration depth of about 1 cm. The main indications are the preoperative measurements of tumor thickness in malignant melanoma and other skin tumors and the assessment of inflammatory and soft tissue diseases, offering information on the course of these dermatoses and allowing therapy monitoring. This article gives an overview on technical principles, devices, mode of examination, influencing factors, interpretation of the images, indications but also limitations of this technique. PMID:25636803

  20. Ultrasound-Assisted Freezing

    NASA Astrophysics Data System (ADS)

    Delgado, A. E.; Sun, Da-Wen

    Freezing is a well-known preservation method widely used in the food industry. The advantages of freezing are to a certain degree counterbalanced by the risk of damage caused by the formation and size of ice crystals. Over recent years new approaches have been developed to improve and control the crystallization process, and among these approaches sonocrystallization has proved to be very useful, since it can enhance both the nucleation rate and the crystal growth rate. Although ultrasound has been successfully used for many years in the evaluation of various aspects of foods and in medical applications, the use of power ultrasound to directly improve processes and products is less popular in food manufacturing. Foodstuffs are very complex materials, and research is needed in order to define the specific sound parameters that aid the freezing process and that can later be used for the scale-up and production of commercial frozen food products.

  1. Ultrasound promoted catalytic liquid-phase dehydrogenation of isopropanol for Isopropanol-Acetone-Hydrogen chemical heat pump.

    PubMed

    Xu, Min; Xin, Fang; Li, Xunfeng; Huai, Xiulan; Liu, Hui

    2015-03-01

    The apparent kinetic of the ultrasound assisted liquid-phase dehydrogenation of isopropanol over Raney nickel catalyst was determined in the temperature range of 346-353 K. Comparison of the effects of ultrasound and mechanical agitation on the isopropanol dehydrogenation was investigated. The ultrasound assisted dehydrogenation rate was significantly improved when relatively high power density was used. Moreover, the Isopropanol-Acetone-Hydrogen chemical heat pump (IAH-CHP) with ultrasound irradiation, in which the endothermic reaction is exposure to ultrasound, was proposed. A mathematical model was established to evaluate its energy performance in term of the coefficient of performance (COP) and the exergy efficiency, into which the apparent kinetic obtained in this work was incorporated. The operating performances between IAH-CHP with ultrasound and mechanical agitation were compared. The results indicated that the superiority of the IAH-CHP system with ultrasound was present even if more than 50% of the power of the ultrasound equipment was lost. PMID:25246094

  2. Manipulating neuronal activity with low frequency transcranial ultrasound

    NASA Astrophysics Data System (ADS)

    Moore, Michele Elizabeth

    Stimulation of the rodent cerebral cortex is used to investigate the underlying biological basis for the restorative effects of slow wave sleep. Neuronal activation by optogenetic and ultrasound stimulation elicits changes in action potentials across the cerebral cortex that are recorded as electroencephalograms. Optogenetic stimulation requires an invasive implantation procedure limiting its application in human studies. We sought to determine whether ultrasound stimulation could be as effective as optogenetic techniques currently used, in an effort to further understand the physiological and metabolic requirements of sleep. We successfully recorded electroencephalograms in response to transcranial ultrasound stimulation of the barrel cortex at 1 and 7 Hz frequencies, comparing them to those recorded in response to optogenetic stimuli applied at the same frequencies. Our results showed application of a 473 nm blue LED positioned 6 cm above the skull and ultrasound stimulation at an output voltage of 1000 mVpp produced electroencephalograms with physiological responses of similar amplitude. We concluded that there exists an intensity-proportionate response in the optogenetic stimulation, but not with ultrasound stimulation at the frequencies we surveyed. Activation of neuronal cells in response to optogenetic stimulation in a Thy1-ChR2 transgenic mouse line is specifically targeted to pyramidal cells in the cerebral cortex. ChR2 responses to optogenetic stimulation are mediated by a focal activation of neuronal ion channels. We measured electrophysiological responses to ultrasound stimulation, comparing them to those recorded from optogenetic stimuli. Our results show striking similarities between ultrasound-induced responses and optogenetically-induced responses, which may indicate that transcranial ultrasound stimulation is also mediated by ion channel dependent processes in cerebral cortical neurons. The biophysical substrates for electrical excitability of

  3. Tissue identification by ultrasound

    NASA Technical Reports Server (NTRS)

    Lecroissette, D. H.; Heyser, R. C.; Gammell, P. M.; Wilson, R. L.

    1978-01-01

    The ultrasonic properties of animal and human soft tissue were measured over the frequency range of 1.5 to 10.0 MHz. The method employed a swept-frequency, coherent technique known as time delay spectrometry. Measurements of attenuation versus frequency on liver, backfat, kidney, pancreas, spleen, breast, and other tissue were made. Considerable attention was paid to tissue handling and in determining the effects of fixing on the attenuation of ultrasound in the tissue.

  4. Clinical ophthalmic ultrasound improvements

    NASA Technical Reports Server (NTRS)

    Garrison, J. B.; Piro, P. A.

    1981-01-01

    The use of digital synthetic aperture techniques to obtain high resolution ultrasound images of eye and orbit was proposed. The parameters of the switched array configuration to reduce data collection time to a few milliseconds to avoid eye motion problems in the eye itself were established. An assessment of the effects of eye motion on the performance of the system was obtained. The principles of synthetic techniques are discussed. Likely applications are considered.

  5. Black Endobronchial Ultrasound.

    PubMed

    Dhillon, Samjot S; Harris, Kassem; Ylagan, Lourdes

    2015-10-01

    The infrequent bronchoscopic finding of black airway pigmentation due to a variety of causes has been labeled as "Black Bronchoscopy." Black bronchioalveolar lavage has been sometimes described in tobacco, marijuana, and crack cocaine smokers. To add to this interesting panorama of bronchoscopic findings, we describe cases of black endobronchial ultrasound-guided transbronchial needle aspirates due to metastatic melanoma and anthracotic lymph nodes. PMID:26348692

  6. Ultrasound mediated gene transfection

    NASA Astrophysics Data System (ADS)

    Williamson, Rene G.; Apfel, Robert E.; Brandsma, Janet L.

    2002-05-01

    Gene therapy is a promising modality for the treatment of a variety of human diseases both inherited and acquired, such as cystic fibrosis and cancer. The lack of an effective, safe method for the delivery of foreign genes into the cells, a process known as transfection, limits this effort. Ultrasound mediated gene transfection is an attractive method for gene delivery since it is a noninvasive technique, does not introduce any viral particles into the host and can offer very good temporal and spatial control. Previous investigators have shown that sonication increases transfection efficiency with and without ultrasound contrast agents. The mechanism is believed to be via a cavitation process where collapsing bubble nuclei permeabilize the cell membrane leading to increased DNA transfer. The research is focused on the use of pulsed wave high frequency focused ultrasound to transfect DNA into mammalian cells in vitro and in vivo. A better understanding of the mechanism behind the transfection process is also sought. A summary of some in vitro results to date will be presented, which includes the design of a sonication chamber that allows us to model the in vivo case more accurately.

  7. Obstetric Ultrasound Simulator With Task-Based Training and Assessment.

    PubMed

    Liu, Li; Kutarnia, Jason; Belady, Petra; Pedersen, Peder C

    2015-10-01

    The increasing use of point-of-care (POC) ultrasound presents a challenge in providing efficient training to POC ultrasound users for whom formal training is not readily available. In response to this need, we developed an affordable compact laptop-based obstetric ultrasound training simulator. It offers a realistic scanning experience, task-based training, and performance assessment. The position and orientation of the sham transducer are tracked with 5 DoF on an abdomen-sized scan surface with the shape of a cylindrical segment. On the simulator, user interface is rendered a virtual torso whose body surface models the abdomen of the pregnant scan subject. A virtual transducer scans the virtual torso by following the sham transducer movements on the scan surface. A given 3-D training image volume is generated by combining several overlapping 3-D ultrasound sweeps acquired from the pregnant scan subject using a Markov random field-based approach. Obstetric ultrasound training is completed through a series of tasks, guided by the simulator and focused on three aspects: basic medical ultrasound, orientation to obstetric space, and fetal biometry. The scanning performance is automatically evaluated by comparing user-identified anatomical landmarks with reference landmarks preinserted by sonographers. The simulator renders 2-D ultrasound images in real time with 30 frames/s or higher with good image quality; the training procedure follows standard obstetric ultrasound protocol. Thus, for learners without access to formal sonography programs, the simulator is intended to provide structured training in basic obstetrics ultrasound. PMID:25993700

  8. Comparison of Thresholds for Pulmonary Capillary Hemorrhage Induced by Pulsed-wave and B-mode Ultrasound

    NASA Astrophysics Data System (ADS)

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

    Pulsed ultrasound was found to induce pulmonary capillary hemorrhage (PCH) in mice about 25 years ago but remains a poorly understood risk factor for pulmonary diagnostic ultrasound. In early research using laboratory fixed beam ultrasound, thresholds for PCH had frequency variation from 1-4 MHz similar to the Mechanical Index. In recent research, thresholds for B mode diagnostic ultrasound from 1.5-12 MHz had little dependence on frequency. To compare the diagnostic ultrasound method to laboratory pulsed exposure, thresholds for fixed beam ultrasound were determined using comparable methods at 1.5 and 7.5 MHz. PCH thresholds were lower for simple fixed-beam pulse modes than for B mode and in approximate agreement with early research. However, for comparable timing parameters, PCH thresholds had little dependence on ultrasonic frequency. These findings suggest that the MI may not be directly useful as a dosimetric parameter for safety guidance in pulmonary ultrasound.

  9. Smart Ultrasound Remote Guidance Experiment (SURGE)- Concept of Operations Evaluation for Using Remote Guidance Ultrasound for Planetary Space Flight

    NASA Technical Reports Server (NTRS)

    Hurst, Victor, IV; Peterson, Sean; Garcia, Kathleen; Sargsyan, Ashot; Ebert, Douglas; Ham, David; Amponsah, David; Dulchavsky, Scott

    2010-01-01

    Introduction Use of remote guidance (RG) techniques aboard the International Space Station (ISS) has enabled astronauts to collect diagnostic-level ultrasound images. Exploration class missions will require this cohort of (typically) non-formally trained sonographers to operate with greater autonomy given the longer communication delays (2 seconds for ISS vs. >6 seconds for missions beyond the Moon) and communication blackouts. To determine the feasibility and training requirements for autonomous ultrasound image collection by non-expert ultrasound operators, ultrasound images were collected from a similar cohort using three different image collection protocols: RG only, RG with a computer-based learning tool (LT), and autonomous image collection with LT. The groups were assessed for both image quality and time to collect the images. Methods Subjects were randomized into three groups: RG only, RG with LT, and autonomous with LT. Each subject received 10 minutes of standardized training before the experiment. The subjects were tasked with making the following ultrasound assessments: 1) bone fracture and 2) focused assessment with sonography in trauma (FAST) to assess a patient s abdomen. Human factors-related questionnaire data were collected immediately after the assessments. Results The autonomous group did not out-perform the two groups that received RG. The mean time for the autonomous group to collect images was less than the RG groups, however the mean image quality for the autonomous group was less compared to both RG groups. Discussion Remote guidance continues to produce higher quality ultrasound images than autonomous ultrasound operation. This is likely due to near-instant feedback on image quality from the remote guider. Expansion in communication time delays, however, diminishes the capability to provide this feedback, thus requiring more autonomous ultrasound operation. The LT has the potential to be an excellent training and coaching component for

  10. Intraventricular haemorrhage and periventricular leucomalacia: ultrasound and autopsy correlation.

    PubMed Central

    Trounce, J Q; Fagan, D; Levene, M I

    1986-01-01

    The brains of 30 infants who died after at least one real time ultrasound scan were examined after fixation. The ultrasound diagnosis of either periventricular haemorrhage or periventricular leucomalacia was compared with the macroscopic and histological appearances. Each hemisphere was considered separately for both periventricular haemorrhage and periventricular leucomalacia. The accuracy of ultrasound diagnosis for periventricular haemorrhage was 88%, with sensitivity of 91% and specificity of 85%. The accuracy for periventricular leucomalacia was 90%, with sensitivity of 85% and specificity of 93%. Ultrasound was shown to diagnose the entire range of periventricular leucomalacia lesions. Three hemispheres showed the appearance of prolonged flare, and this correlated with extensive spongiosis and microcalcification of the periventricular white matter, although no macroscopic lesion was seen. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:3545096

  11. Screening MR imaging versus screening ultrasound: pros and cons.

    PubMed

    Mahoney, Mary C; Newell, Mary S

    2013-08-01

    Data support greater sensitivity of MR imaging compared with mammography and ultrasound in high-risk populations, in particular BRCA 1 and BRCA 2 carriers. Screening ultrasound improves cancer yield versus mammography alone in high-risk patients and in patients with dense breasts and is less expensive. Drawbacks include low positive predictive value, operator dependence, and significant physician time expenditure. Advances, such as refinement of automated whole-breast ultrasound, new outcomes data from ultrasound-detected masses in BI-RADS 3 and 4a categories, and development of new MR imaging sequences that allow rapid screening, potentially without use of contrast, will likely reveal the most appropriate tool over time. PMID:23928240

  12. Numerical simulation of piezoelectric effect of bone under ultrasound irradiation

    NASA Astrophysics Data System (ADS)

    Hosokawa, Atsushi

    2015-07-01

    The piezoelectric effect of bone under ultrasound irradiation was numerically simulated using an elastic finite-difference time-domain method with piezoelectric constitutive equations (PE-FDTD method). First, to demonstrate the validity of the PE-FDTD method, the ultrasound propagation in piezoelectric ceramics was simulated and then compared with the experimental results. The simulated and experimental waveforms propagating through the ceramics were in good agreement. Next, the piezoelectric effect of human cortical bone on the ultrasound propagation was investigated by PE-FDTD simulation. The simulated result showed that the difference between the waveforms propagating through the bone without and with piezoelectricity was negligible. Finally, the spatial distributions of the electric fields in a human femur induced by ultrasound irradiation were simulated. The electric fields were changed by a bone fracture, which depended on piezoelectric anisotropy. In conclusion, the PE-FDTD method is considered to be useful for investigating the piezoelectric effect of bone.

  13. American Institute of Ultrasound in Medicine

    MedlinePlus

    ... In | My Account | Renew | Join About Us Leadership History Awards Committees Mission & Constitution Join/Renew Communities Basic Science and Instrumentation Cardiovascular Ultrasound Contrast-Enhanced Ultrasound Dermatology ...

  14. Emergency ultrasound in the prehospital setting: the impact of environment on examination outcomes.

    PubMed

    Snaith, B; Hardy, M; Walker, A

    2011-12-01

    This study aimed to compare ultrasound examinations performed within a land ambulance (stationary and moving) with those completed in a simulated emergency department (ED) to determine the feasibility of undertaking ultrasound examinations within the UK prehospital care environment. The findings suggest that abdominal aortic aneurysm and extended focused assessment with sonography in trauma emergency ultrasound examinations can be performed in the stationary or moving land ambulance environment to a standard consistent with those performed in the hospital ED. PMID:21450758

  15. Quantitative determination of fatty tissue on body surface in obese children by ultrasound method.

    PubMed

    Czinner, A; Várady, M

    1992-01-01

    Authors compared a new ultrasound method with the recognized anthropometrical examination in obese children. Between the two methods the determination of body fat did not indicate any divergence. In extreme obesity they considered the advantage of ultrasound examination more reliable. A further advantage of the ultrasound method is that it is well documentable, reproducible and is not invasive. In this way the therapeutic result is well followable. PMID:1560996

  16. Combined ultrasound and MR imaging to guide focused ultrasound therapies in the brain

    NASA Astrophysics Data System (ADS)

    Arvanitis, Costas D.; Livingstone, Margaret S.; McDannold, Nathan

    2013-07-01

    Several emerging therapies with potential for use in the brain, harness effects produced by acoustic cavitation—the interaction between ultrasound and microbubbles either generated during sonication or introduced into the vasculature. Systems developed for transcranial MRI-guided focused ultrasound (MRgFUS) thermal ablation can enable their clinical translation, but methods for real-time monitoring and control are currently lacking. Acoustic emissions produced during sonication can provide information about the location, strength and type of the microbubble oscillations within the ultrasound field, and they can be mapped in real-time using passive imaging approaches. Here, we tested whether such mapping can be achieved transcranially within a clinical brain MRgFUS system. We integrated an ultrasound imaging array into the hemisphere transducer of the MRgFUS device. Passive cavitation maps were obtained during sonications combined with a circulating microbubble agent at 20 targets in the cingulate cortex in three macaques. The maps were compared with MRI-evident tissue effects. The system successfully mapped microbubble activity during both stable and inertial cavitation, which was correlated with MRI-evident transient blood-brain barrier disruption and vascular damage, respectively. The location of this activity was coincident with the resulting tissue changes within the expected resolution limits of the system. While preliminary, these data clearly demonstrate, for the first time, that it is possible to construct maps of stable and inertial cavitation transcranially, in a large animal model, and under clinically relevant conditions. Further, these results suggest that this hybrid ultrasound/MRI approach can provide comprehensive guidance for targeted drug delivery via blood-brain barrier disruption and other emerging ultrasound treatments, facilitating their clinical translation. We anticipate that it will also prove to be an important research tool that will

  17. Ultrasound Detection of Lung Hepatization

    PubMed Central

    Durant, Andrea; Nagdev, Arun

    2010-01-01

    Bedside ultrasound interrogation of the thorax can aide the clinician in determining the cause of the respiratory dysfunction. Often plain radiographs are not sufficient to differentiate pathology. We present a case in which bedside ultrasound defined the pathology without the need for further imaging. PMID:21079701

  18. Real-time ultrasound elastography

    NASA Astrophysics Data System (ADS)

    Bae, Unmin; Kim, Yongmin

    2007-03-01

    Ultrasound elastography can provide tissue stiffness information that is complementary to the anatomy and blood flow information offered by conventional ultrasound machines, but it is computationally challenging due to many time-consuming modules and a large amount of data. To facilitate real-time implementations of ultrasound elastography, we have developed new methods that can significantly reduce the computational burden of common processing components in ultrasound elastography, such as the crosscorrelation analysis and spatial filtering applied to displacement and strain estimates. Using the new correlation-based search algorithm, the computational requirement of correlation-based search does not increase with the correlation window size. For typical parameters used in ultrasound elastography, the computation in correlation-based search can be reduced by a factor of more than 30. Median filtering is often performed to suppress the spike-like noise that results from correlation-based search. For fast median filtering, we have developed a method that efficiently finds a new median value utilizing the sort result of the previous pixel. With careful mapping of the new algorithms on digital signal processors, our work has led to development of a clinical ultrasound machine supporting real-time elastography. Our methods can help real-time implementations of various applications including ultrasound elastography, which could lead to increased use of ultrasound elastography in the clinic.

  19. Addressing Phonological Questions with Ultrasound

    ERIC Educational Resources Information Center

    Davidson, Lisa

    2005-01-01

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

  20. Endobronchial ultrasound elastography

    PubMed Central

    Dietrich, Christoph F.; Jenssen, Christian; Herth, Felix J. F.

    2016-01-01

    Elastographic techniques have recently become available as advanced diagnostic tools for tissue characterization. Strain elastography is a real-time technique used with transcutaneous ultrasound (US) and endoscopic US. Convincing evidence is available demonstrating a significant value of strain elastography for the discrimination of benign and malignant lymph nodes (LNs). This paper reviews preliminary data demonstrating the feasibility of performing real-time elastography during endobronchial US (EBUS) and a potential application of this technique for selection of LNs for EBUS-guided transbronchial needle aspiration in patients with lung cancer and extrathoracic malignancies. PMID:27503154

  1. Therapeutic Endoscopic Ultrasound

    PubMed Central

    Cheriyan, Danny

    2015-01-01

    Endoscopic ultrasound (EUS) technology has evolved dramatically over the past 20 years, from being a supplementary diagnostic aid available only in large medical centers to being a core diagnostic and therapeutic tool that is widely available. Although formal recommendations and practice guidelines have not been developed, there are considerable data supporting the use of EUS for its technical accuracy in diagnosing pancreaticobiliary and gastrointestinal pathology. Endosonography is now routine practice not only for pathologic diagnosis and tumor staging but also for drainage of cystic lesions and celiac plexus neurolysis. In this article, we cover the use of EUS in biliary and pancreatic intervention, ablative therapy, enterostomy, and vascular intervention. PMID:27118942

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

    PubMed Central

    2013-01-01

    Background 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. Methods 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. Results 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. Conclusions Focused

  3. What's new in urologic ultrasound?

    PubMed

    Lal, Anupam; Naranje, Priyanka; Pavunesan, Santhosh Kumar

    2015-01-01

    Ultrasound is an imaging technology that has evolved swiftly and has come a long way since its beginnings. It is a commonly used initial diagnostic imaging modality as it is rapid, effective, portable, relatively inexpensive, and causes no harm to human health. In the last few decades, there have been significant technological improvements in the equipment as well as the development of contrast agents that allowed ultrasound to be even more widely adopted for urologic imaging. Ultrasound is an excellent guidance tool for an array of urologic interventional procedures and also has therapeutic application in the form of high-intensity focused ultrasound (HIFU) for tumor ablation. This article focuses on the recent advances in ultrasound technology and its emerging clinical applications in urology. PMID:26166960

  4. Endoscopic ultrasound in mediastinal tuberculosis

    PubMed Central

    Sharma, Malay; Ecka, Ruth Shifa; Somasundaram, Aravindh; Shoukat, Abid; Kirnake, Vijendra

    2016-01-01

    Background: Tubercular lymphadenitis is the commonest extra pulmonary manifestation in cervical and mediastinal locations. Normal characteristics of lymph nodes (LN) have been described on ultrasonography as well as by Endoscopic Ultrasound. Many ultrasonic features have been described for evaluation of mediastinal lymph nodes. The inter and intraobserver agreement of the endosonographic features have not been uniformly established. Methods and Results: A total of 266 patients underwent endoscopic ultrasound guided fine needle aspiration and 134 cases were diagnosed as mediastinal tuberculosis. The endoscopic ultrasound location and features of these lymph nodes are described. Conclusion: Our series demonstrates the utility of endoscopic ultrasound guided fine needle aspiration as the investigation of choice for diagnosis of mediastinal tuberculosis and also describes various endoscopic ultrasound features of such nodes. PMID:27051097

  5. Doppler ultrasound studies in pelvic inflammatory disease.

    PubMed

    Tinkanen, H; Kujansuu, E

    1992-01-01

    Ten women with tubo-ovarian abscess caused by pelvic inflammatory disease (PID) were investigated by transvaginal Doppler ultrasound during the acute and healing phases of the infection. The pulsatility index (PI) of the uterine arteries was measured and compared with the values obtained from 19 healthy women. Each control patient was investigated three times during a single menstrual cycle. In PID patients, the PI values were significantly lower than in controls in the same phase of the menstrual cycle. When C-reactive protein was > 50, the PI values were lowest and reverted to normal values when the infection subsided. In a case of chronic infection, the PI did not rise to normal despite normal infection parameters. Doppler ultrasound seems to offer a new method of assessing PID. PMID:1487185

  6. Accuracy of ED Bedside Ultrasound for Identification of gallstones: retrospective analysis of 575 studies

    PubMed Central

    Scruggs, William; Fox, J. Christian; Potts, Brian; Zlidenny, Alexander; McDonough, JoAnne; Anderson, Craig L.; Larson, Jarrod; Barajas, Graciela; Langdorf, Mark I.

    2008-01-01

    Study Objective To determine the ability of emergency department (ED) physicians to diagnose cholelithiasis with bedside ultrasound. Methods ED gallbladder ultrasounds recorded over 37 months were compared to radiology ultrasound interpretation. Results Of 1,690 ED gallbladder ultrasound scans performed during this period, radiology ultrasound was performed in 575/1690 (34%) cases. ED physician bedside interpretation was 88% sensitive [95% CI, 84–91] and 87% specific [95% CI, 82–91], while positive predictive value (PPV) was 91% [88–94%] and negative predictive value (NPV) was 83% [78–87%], using radiology interpretation as the criterion reference. Conclusion ED physician ultrasound of the gallbladder for cholelithiasis is both sensitive and specific. PMID:19561694

  7. Procedural ultrasound in pediatric patients: techniques and tips for accuracy and safety.

    PubMed

    Lin, Sophia

    2016-06-01

    Point-of-care ultrasound is becoming more prevalent in pediatric emergency departments as a critical adjunct to both diagnosis and procedure guidance. It is cost-effective, safe for unstable patients, and easily repeatable as a patient's clinical status changes. Point-of-care ultrasound does not expose the patient to ionizing radiation and may care ultrasound in pediatric emergency medicine is relatively new, the body of literature evaluating its utility is small, but growing. Data from adult emergency medicine, radiology, critical care, and anesthesia evaluating the utility of ultrasound guidance must be extrapolated to pediatric emergency medicine. This issue will review the adult literature and the available pediatric literature comparing ultrasound guidance to more traditional approaches. Methods for using ultrasound guidance to perform various procedures, and the pitfalls associated with each procedure, will also be described. PMID:27232771

  8. [The efficacy of ultrasound-guided infraorbital nerve block with hockey stick typed probe].

    PubMed

    Iwase, Naoto; Fukui, Hidekimi; Yuunaiyama, Youko; Kaneko, Kouki; Ohseto, Kiyoshige; Uchino, Hiroyuki

    2013-10-01

    We report a case of ultrasound-guided infraorbital nerve block with a hockey stick typed probe in plane approach. Individual difference of infraorbital anatomy makes it difficult to puncture the infraorbital for a man, and the risks include bleeding, double vision and paranasal sinus puncture. The advantage of ultrasound-guided nerve block has been reported. Compared with conventional land mark method approach, ultrasound technique is thought to be easy to perform, more quickly and safely without any complications. From our results, we have demonstrated that ultrasound-guided infraorbital nerve block assisted by hockey stick typed probe could become one of the safe methods for this purpose. PMID:24228458

  9. Clinical workflow for spinal curvature measurement with portable ultrasound

    NASA Astrophysics Data System (ADS)

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

    2016-03-01

    PURPOSE: Spinal curvature monitoring is essential in making treatment decisions in scoliosis. Monitoring entails radiographic examinations, however repeated ionizing radiation exposure has been shown to increase cancer risk. Ultrasound does not emit ionizing radiation and is safer for spinal curvature monitoring. We investigated a clinical sonography protocol and challenges associated with position-tracked ultrasound in spinal curvature measurement in scoliosis. METHODS: Transverse processes were landmarked along each vertebra using tracked ultrasound snapshots. The transverse process angle was used to determine the orientation of each vertebra. We tested our methodology on five patients in a local pediatric scoliosis clinic, comparing ultrasound to radiographic curvature measurements. RESULTS: Despite strong correlation between radiographic and ultrasound curvature angles in phantom studies, we encountered new challenges in the clinical setting. Our main challenge was differentiating transverse processes from ribs and other structures during landmarking. We observed up to 13° angle variability for a single vertebra and a 9.85° +/- 10.81° difference between ultrasound and radiographic Cobb angles for thoracic curvatures. Additionally, we were unable to visualize anatomical landmarks in the lumbar region where soft tissue depth was 25-35mm. In volunteers with large Cobb angles (greater than 40° thoracic and 60° lumbar), we observed spinal protrusions resulting in incomplete probe-skin contact and partial ultrasound images not suitable for landmarking. CONCLUSION: Spinal curvature measurement using tracked ultrasound is viable on phantom spine models. In the clinic, new challenges were encountered which must be resolved before a universal sonography protocol can be developed.

  10. Active ultrasound pattern injection system (AUSPIS) for interventional tool guidance.

    PubMed

    Guo, Xiaoyu; Kang, Hyun-Jae; Etienne-Cummings, Ralph; Boctor, Emad M

    2014-01-01

    Accurate tool tracking is a crucial task that directly affects the safety and effectiveness of many interventional medical procedures. Compared to CT and MRI, ultrasound-based tool tracking has many advantages, including low cost, safety, mobility and ease of use. However, surgical tools are poorly visualized in conventional ultrasound images, thus preventing effective tool tracking and guidance. Existing tracking methods have not yet provided a solution that effectively solves the tool visualization and mid-plane localization accuracy problem and fully meets the clinical requirements. In this paper, we present an active ultrasound tracking and guiding system for interventional tools. The main principle of this system is to establish a bi-directional ultrasound communication between the interventional tool and US imaging machine within the tissue. This method enables the interventional tool to generate an active ultrasound field over the original imaging ultrasound signals. By controlling the timing and amplitude of the active ultrasound field, a virtual pattern can be directly injected into the US machine B mode display. In this work, we introduce the time and frequency modulation, mid-plane detection, and arbitrary pattern injection methods. The implementation of these methods further improves the target visualization and guiding accuracy, and expands the system application beyond simple tool tracking. We performed ex vitro and in vivo experiments, showing significant improvements of tool visualization and accurate localization using different US imaging platforms. An ultrasound image mid-plane detection accuracy of ±0.3 mm and a detectable tissue depth over 8.5 cm was achieved in the experiment. The system performance is tested under different configurations and system parameters. We also report the first experiment of arbitrary pattern injection to the B mode image and its application in accurate tool tracking. PMID:25337784

  11. Active Ultrasound Pattern Injection System (AUSPIS) for Interventional Tool Guidance

    PubMed Central

    Guo, Xiaoyu; Kang, Hyun-Jae; Etienne-Cummings, Ralph; Boctor, Emad M.

    2014-01-01

    Accurate tool tracking is a crucial task that directly affects the safety and effectiveness of many interventional medical procedures. Compared to CT and MRI, ultrasound-based tool tracking has many advantages, including low cost, safety, mobility and ease of use. However, surgical tools are poorly visualized in conventional ultrasound images, thus preventing effective tool tracking and guidance. Existing tracking methods have not yet provided a solution that effectively solves the tool visualization and mid-plane localization accuracy problem and fully meets the clinical requirements. In this paper, we present an active ultrasound tracking and guiding system for interventional tools. The main principle of this system is to establish a bi-directional ultrasound communication between the interventional tool and US imaging machine within the tissue. This method enables the interventional tool to generate an active ultrasound field over the original imaging ultrasound signals. By controlling the timing and amplitude of the active ultrasound field, a virtual pattern can be directly injected into the US machine B mode display. In this work, we introduce the time and frequency modulation, mid-plane detection, and arbitrary pattern injection methods. The implementation of these methods further improves the target visualization and guiding accuracy, and expands the system application beyond simple tool tracking. We performed ex vitro and in vivo experiments, showing significant improvements of tool visualization and accurate localization using different US imaging platforms. An ultrasound image mid-plane detection accuracy of ±0.3 mm and a detectable tissue depth over 8.5 cm was achieved in the experiment. The system performance is tested under different configurations and system parameters. We also report the first experiment of arbitrary pattern injection to the B mode image and its application in accurate tool tracking. PMID:25337784

  12. Endocavity Ultrasound Probe Manipulators.

    PubMed

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

    2013-06-01

    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

  13. 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

  14. 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

  15. Ultrasound pretreatment for enhanced biogas production from olive mill wastewater.

    PubMed

    Oz, Nilgun Ayman; Uzun, Alev Cagla

    2015-01-01

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

  16. Frequency and number of ultrasound lung rockets (B-lines) using a regionally based lung ultrasound examination named vet BLUE (veterinary bedside lung ultrasound exam) in dogs with radiographically normal lung findings.

    PubMed

    Lisciandro, Gregory R; Fosgate, Geoffrey T; Fulton, Robert M

    2014-01-01

    Lung ultrasound is superior to lung auscultation and supine chest radiography for many respiratory conditions in human patients. Ultrasound diagnoses are based on easily learned patterns of sonographic findings and artifacts in standardized images. By applying the wet lung (ultrasound lung rockets or B-lines, representing interstitial edema) versus dry lung (A-lines with a glide sign) concept many respiratory conditions can be diagnosed or excluded. The ultrasound probe can be used as a visual stethoscope for the evaluation of human lungs because dry artifacts (A-lines with a glide sign) predominate over wet artifacts (ultrasound lung rockets or B-lines). However, the frequency and number of wet lung ultrasound artifacts in dogs with radiographically normal lungs is unknown. Thus, the primary objective was to determine the baseline frequency and number of ultrasound lung rockets in dogs without clinical signs of respiratory disease and with radiographically normal lung findings using an 8-view novel regionally based lung ultrasound examination called Vet BLUE. Frequency of ultrasound lung rockets were statistically compared based on signalment, body condition score, investigator, and reasons for radiography. Ten left-sided heart failure dogs were similarly enrolled. Overall frequency of ultrasound lung rockets was 11% (95% confidence interval, 6-19%) in dogs without respiratory disease versus 100% (95% confidence interval, 74-100%) in those with left-sided heart failure. The low frequency and number of ultrasound lung rockets observed in dogs without respiratory disease and with radiographically normal lungs suggests that Vet BLUE will be clinically useful for the identification of canine respiratory conditions. PMID:24382172

  17. Resolution enhancement in medical ultrasound imaging

    PubMed Central

    Ploquin, Marie; Basarab, Adrian; Kouamé, Denis

    2015-01-01

    Abstract. Image resolution enhancement is a problem of considerable interest in all medical imaging modalities. Unlike general purpose imaging or video processing, for a very long time, medical image resolution enhancement has been based on optimization of the imaging devices. Although some recent works purport to deal with image postprocessing, much remains to be done regarding medical image enhancement via postprocessing, especially in ultrasound imaging. We face a resolution improvement issue in the case of medical ultrasound imaging. We propose to investigate this problem using multidimensional autoregressive (AR) models. Noting that the estimation of the envelope of an ultrasound radio frequency (RF) signal is very similar to the estimation of classical Fourier-based power spectrum estimation, we theoretically show that a domain change and a multidimensional AR model can be used to achieve super-resolution in ultrasound imaging provided the order is estimated correctly. Here, this is done by means of a technique that simultaneously estimates the order and the parameters of a multidimensional model using relevant regression matrix factorization. Doing so, the proposed method specifically fits ultrasound imaging and provides an estimated envelope. Moreover, an expression that links the theoretical image resolution to both the image acquisition features (such as the point spread function) and a postprocessing feature (the AR model) order is derived. The overall contribution of this work is threefold. First, it allows for automatic resolution improvement. Through a simple model and without any specific manual algorithmic parameter tuning, as is used in common methods, the proposed technique simply and exclusively uses the ultrasound RF signal as input and provides the improved B-mode as output. Second, it allows for the a priori prediction of the improvement in resolution via the knowledge of the parametric model order before actual processing. Finally, to achieve

  18. 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.

  19. Enzymolysis kinetics and structural characteristics of rice protein with energy-gathered ultrasound and ultrasound assisted alkali pretreatments.

    PubMed

    Li, Suyun; Yang, Xue; Zhang, Yanyan; Ma, Haile; Qu, Wenjuan; Ye, Xiaofei; Muatasim, Rahma; Oladejo, Ayobami Olayemi

    2016-07-01

    This research investigated the structural characteristics and enzymolysis kinetics of rice protein which was pretreated by energy-gathered ultrasound and ultrasound assisted alkali. The structural characteristics of rice protein before and after the pretreatment were performed with surface hydrophobicity and Fourier transform infrared (FTIR). There was an increase in the intensity of fluorescence spectrum and changes in functional groups after the pretreatment on rice protein compared with the control (without ultrasound and ultrasound assisted alkali processed), thus significantly enhancing efficiency of the enzymatic hydrolysis. A simplified kinetic equation for the enzymolysis model with the impeded reaction of enzyme was deduced to successfully describe the enzymatic hydrolysis of rice protein by different pretreatments. The initial observed rate constants (Kin,0) as well as ineffective coefficients (kimp) were proposed and obtained based on the experimental observation. The results showed that the parameter of kin,0 increased after ultrasound and ultrasound assisted alkali pretreatments, which proved the effects of the pretreatments on the substrate enhancing the enzymolysis process and had relation to the structure changes of the pretreatments on the substrate. Furthermore, the applicability of the simplified model was demonstrated by the enzymatic hydrolysis process for other materials. PMID:26964926

  20. Ultrasound Strain Imaging Towards Verification and Guidance of Prostate Thermal Therapy with Catheter-Based Ultrasound Applicators

    NASA Astrophysics Data System (ADS)

    Sridhar-Keralapura, Mallika; Chubb, Nicole; Scott, Serena; Phipps, Natalie; Burdette, Clif; Diederich, Chris

    2010-03-01

    Ultrasound based transurethral and interstitial catheters have been developed and tested in vivo to thermally ablate prostate cancers. Treatment validation and accurate control of therapy is currently done using MR thermal imaging (±1° C, update: 5-15 s). MRTI is effective for real-time monitoring and guidance, but, cost, setup time, and accessibility can be limiting. Ultrasound imaging methods could be a practicable approach to monitoring. We investigated Ultrasound Strain Imaging (USI) as a tool towards verifying and controlling prostate treatments by developing a novel methodology for tissue compression using ultrasound phantoms and ex vivo tissue models. We estimate strain using quasi real-time estimation algorithms and added automatic segmentation features. The methodology involved inserting an ultrasound applicator into ex vivo liver or porcine muscle tissue, ablating it for 10 min at 15 W to create a well defined thermal lesion. After treatment, the tissue was compressed either externally (3-5%) using the probe or by deflating/inflating the applicator's coupling balloon internally. Ultrasound RF data was recorded during the compression and USI was computed within 20 seconds and compared with photographs of corresponding excised tissue sections. USI estimated post ablation using balloon and external methods yielded significant contrast that correlated well with measurements of excised tissue sections. From these preliminary studies, USI can become an effective feasible tool for verification and guidance of ablation regions with these devices. Balloon compressions could potentially allow computation USI in clinical treatments for confirmation and boundary control.

  1. Ultrasound has synergistic effects in vitro with tirofiban and heparin for thrombus dissolution.

    PubMed

    Birnbaum, Y; Atar, S; Luo, H; Nagai, T; Siegel, R J

    1999-12-15

    Previous studies have shown synergism between ultrasound and thrombolytic agents or microbubbles on blood clot dissolution. It has not been investigated whether heparin or glycoprotein IIb/IIIa blockers enhance clot lysis by ultrasound. We compared the blood clot dissolution effect of saline, heparin, tissue plasminogen activator (tPA), tirofiban, and an echocardiographic contrast media (Optison) without and with ultrasound application. Human blood clots from four donors, 2 to 4 hours old, were cut into 200- to 400-mg sections, weighed, and immersed for 2 minutes in 1 L of normal saline 0.9% solution containing either heparin 1000 U, tirofiban 150 microg, tPA 20 mg, Optison 0.5 mL, or normal saline alone. Clots were randomized to 2 minutes ultrasound application or immersion alone without ultrasound. Ultrasound was applied with a 19.5 KHz catheter. After treatment, the clots were weighed, and the absolute and percent difference in weight was calculated. Immersion in heparin, tirofiban, and tPA without ultrasound did not augment clot disruption relative to normal saline alone. Immersion in Optison (p = 0.07) tended to result in less lysis than saline alone. Ultrasound enhanced clot dissolution compared to immersion alone with: saline (48.1+/-15.3% vs. 26.0+/-13.8%, p<0.0000002); heparin (60.8+/-17.5% vs. 30.8+/-15.1%, p = 0.000001); tirofiban (61.8+/-13.6% vs. 30.1+/-12.2%, p<0.0000001); tPA (53.1+/-15.3% vs. 30.2+/-11.5%, p<0.000002); and Optison (47.8+/-16.0% vs. 18.4+/-11.5%, p<0.0000001). The combination of tirofiban with ultrasound, as well as heparin with ultrasound, was associated with a significant augmentation of clot dissolution compared with the saline plus ultrasound group (p = 0.002, 0.013, respectively). Ultrasound with tPA or with Optison had no significant augmentation of clot dissolution over the ultrasound + saline effect. This in vitro study of catheter-delivered high-intensity low-frequency ultrasound demonstrates that: (1) tirofiban and heparin

  2. Reflections on ultrasound image analysis.

    PubMed

    Alison Noble, J

    2016-10-01

    Ultrasound (US) image analysis has advanced considerably in twenty years. Progress in ultrasound image analysis has always been fundamental to the advancement of image-guided interventions research due to the real-time acquisition capability of ultrasound and this has remained true over the two decades. But in quantitative ultrasound image analysis - which takes US images and turns them into more meaningful clinical information - thinking has perhaps more fundamentally changed. From roots as a poor cousin to Computed Tomography (CT) and Magnetic Resonance (MR) image analysis, both of which have richer anatomical definition and thus were better suited to the earlier eras of medical image analysis which were dominated by model-based methods, ultrasound image analysis has now entered an exciting new era, assisted by advances in machine learning and the growing clinical and commercial interest in employing low-cost portable ultrasound devices outside traditional hospital-based clinical settings. This short article provides a perspective on this change, and highlights some challenges ahead and potential opportunities in ultrasound image analysis which may both have high impact on healthcare delivery worldwide in the future but may also, perhaps, take the subject further away from CT and MR image analysis research with time. PMID:27503078

  3. Droplets, Bubbles and Ultrasound Interactions.

    PubMed

    Shpak, Oleksandr; Verweij, Martin; de Jong, Nico; Versluis, Michel

    2016-01-01

    The interaction of droplets and bubbles with ultrasound has been studied extensively in the last 25 years. Microbubbles are broadly used in diagnostic and therapeutic medical applications, for instance, as ultrasound contrast agents. They have a similar size as red blood cells, and thus are able to circulate within blood vessels. Perfluorocarbon liquid droplets can be a potential new generation of microbubble agents as ultrasound can trigger their conversion into gas bubbles. Prior to activation, they are at least five times smaller in diameter than the resulting bubbles. Together with the violent nature of the phase-transition, the droplets can be used for local drug delivery, embolotherapy, HIFU enhancement and tumor imaging. Here we explain the basics of bubble dynamics, described by the Rayleigh-Plesset equation, bubble resonance frequency, damping and quality factor. We show the elegant calculation of the above characteristics for the case of small amplitude oscillations by linearizing the equations. The effect and importance of a bubble coating and effective surface tension are also discussed. We give the main characteristics of the power spectrum of bubble oscillations. Preceding bubble dynamics, ultrasound propagation is introduced. We explain the speed of sound, nonlinearity and attenuation terms. We examine bubble ultrasound scattering and how it depends on the wave-shape of the incident wave. Finally, we introduce droplet interaction with ultrasound. We elucidate the ultrasound-focusing concept within a droplets sphere, droplet shaking due to media compressibility and droplet phase-conversion dynamics. PMID:26486337

  4. Unpowered wireless ultrasound tomography system

    NASA Astrophysics Data System (ADS)

    Zahedi, Farshad; Huang, Haiying

    2016-04-01

    In this paper, an unpowered wireless ultrasound tomography system is presented. The system consists of two subsystems; the wireless interrogation unit (WIU) and three wireless nodes installed on the structure. Each node is designed to work in generation and sensing modes, but operates at a specific microwave frequency. Wireless transmission of the ultrasound signals between the WIU and the wireless nodes is achieved by converting ultrasound signals to microwave signals and vice versa, using a microwave carrier signal. In the generation mode, both a carrier signal and an ultrasound modulated microwave signal are transmitted to the sensor nodes. Only the node whose operating frequency matches the carrier signal will receive these signals and demodulate them to recover the original ultrasound signal. In the sensing mode, a microwave carrier signal with two different frequency components matching the operating frequencies of the sensor nodes is broadcasted by the WIU. The sensor nodes, in turn, receive the corresponding carrier signals, modulate it with the ultrasound sensing signal, and wirelessly transmit the modulated signal back to the WIU. The demodulation of the sensing signals is performed in the WIU using a digital signal processing. Implementing a software receiver significantly reduces the complexity and the cost of the WIU. A wireless ultrasound tomography system is realized by interchanging the carrier frequencies so that the wireless transducers can take turn to serve as the actuator and sensors.

  5. Overcoming biological barriers with ultrasound

    NASA Astrophysics Data System (ADS)

    Thakkar, Dhaval; Gupta, Roohi; Mohan, Praveena; Monson, Kenneth; Rapoport, Natalya

    2012-10-01

    Effect of ultrasound on the permeability of blood vessels and cell membranes to macromolecules and nanodroplets was investigated using mouse carotid arteries and tumor cells. Model macromolecular drug, FITC-dextran with molecular weight of 70,000 Da was used in experiments with carotid arteries. The effect of unfocused 1-MHz ultrasound and and perfluoro-15-crown-5-ether nanodroplets stabilized with the poly(ethylene oxide)-co-poly(D, L-lactide) block copolymer shells was studied. In cell culture experiments, ovarian carcinoma cells and Doxorubicin (DOX) loaded poly(ethylene oxide)-co-polycaprolactone nanodroplets were used. The data showed that the application of ultrasound resulted in permeabilization of all biological barriers tested. Under the action of ultrasound, not only FITC-dextran but also nanodroplets effectively penetrated through the arterial wall; the effect of continuous wave ultrasound was stronger than that of pulsed ultrasound. In cell culture experiments, ultrasound triggered DOX penetration into cell nuclei, presumably due to releasing the drug from the carrier. Detailed mechanisms of the observed effects require further study.

  6. [3-D ultrasound in gastroenterology].

    PubMed

    Zoller, W G; Liess, H

    1994-06-01

    Three-dimensional (3D) sonography represents a development of noninvasive diagnostic imaging by real-time two-dimensional (2D) sonography. The use of transparent rotating scans, comparable to a block of glass, generates a 3D effect. The objective of the present study was to optimate 3D presentation of abdominal findings. Additional investigations were made with a new volumetric program to determine the volume of selected findings of the liver. The results were compared with the estimated volumes of 2D sonography and 2D computer tomography (CT). For the processing of 3D images, typical parameter constellations were found for the different findings, which facilitated processing of 3D images. In more than 75% of the cases examined we found an optimal 3D presentation of sonographic findings with respect to the evaluation criteria developed by us for the 3D imaging of processed data. Great differences were found for the estimated volumes of the findings of the liver concerning the three different techniques applied. 3D ultrasound represents a valuable method to judge morphological appearance in abdominal findings. The possibility of volumetric measurements enlarges its potential diagnostic significance. Further clinical investigations are necessary to find out if definite differentiation between benign and malign findings is possible. PMID:7919882

  7. Safety Assurance in Obstetrical Ultrasound

    PubMed Central

    Miller, Douglas L

    2008-01-01

    Safety assurance for diagnostic ultrasound in obstetrics began with a tacit assumption of safety allowed by a federal law enacted in 1976 for then-existing medical ultrasound equipment. The implementation of the 510(k) pre-market approval process for diagnostic ultrasound resulted in the establishment of guideline upper limits for several examination categories in 1985. The obstetrical category has undergone substantial evolution from initial limits (I. e., 46 mW/cm2 spatial peak temporal average (SPTA) intensity) set in 1985. Thermal and mechanical exposure indices, which are displayed on-screen according to an Output Display Standard (ODS), were developed for safety assurance with relaxed upper limits. In 1992, with the adoption of the ODS, the allowable output for obstetrical ultrasound was increased both in terms of the average exposure (e. g. to a possible 720 mW/cm2 SPTA intensity) and of the peak exposure (via the Mechanical Index). There has been little or no subsequent research with the modern obstetrical ultrasound machines to systematically assess potential risks to the fetus using either relevant animal models of obstetrical exposure or human epidemiology studies. The assurance of safety for obstetrical ultrasound therefore is supported by three ongoing means: (I) review of a substantial but uncoordinated bioeffect research literature, (ii) the theoretical evaluation of diagnostic ultrasound exposure in terms of thermal and nonthermal mechanisms for bioeffects, and (iii) the skill and knowledge of professional sonographers. At this time, there is no specific reason to suspect that there is any significant health risk to the fetus or mother from exposure to diagnostic ultrasound in obstetrics. This assurance of safety supports the prudent use of diagnostic ultrasound in obstetrics by trained professionals for any medically indicated examination. PMID:18450141

  8. Safety assurance in obstetrical ultrasound.

    PubMed

    Miller, Douglas L

    2008-04-01

    Safety assurance for diagnostic ultrasound in obstetrics began with a tacit assumption of safety allowed by a federal law enacted in 1976 for then-existing medical ultrasound equipment. The implementation of the 510(k) pre-market-approval process for diagnostic ultrasound resulted in the establishment of guideline upper limits for several examination categories in 1985. The obstetrical category has undergone substantial evolution from initial limits (ie, 46 mW/cm2 spatial peak temporal average [SPTA] intensity) set in 1985. Thermal and mechanical exposure indices, which are displayed onscreen according to an Output Display Standard, were developed for safety assurance with relaxed upper limits. In 1992, with the adoption of the Output Display Standard, the allowable output for obstetrical ultrasound was increased in terms of both the average exposure (eg, to a possible 720 mW/cm2 SPTA intensity) and the peak exposure (via the Mechanical Index). There has been little or no subsequent research with the modern obstetrical ultrasound machines to systematically assess potential risks to the fetus using either relevant animal models of obstetrical exposure or human epidemiology studies. The assurance of safety for obstetrical ultrasound therefore is supported by three ongoing means: (1) review of a substantial but uncoordinated bioeffect research literature; (2) the theoretical evaluation of diagnostic ultrasound exposure in terms of thermal and nonthermal mechanisms for bioeffects; and (3) the skill and knowledge of professional sonographers. At this time, there is no specific reason to suspect that there is any significant health risk to the fetus or mother from exposure to diagnostic ultrasound in obstetrics. This assurance of safety supports the prudent use of diagnostic ultrasound in obstetrics by trained professionals for any medically indicated examination. PMID:18450141

  9. Value of Ultrasound in Rheumatologic Diseases

    PubMed Central

    Kang, Taeyoung; Horton, Laura; Emery, Paul

    2013-01-01

    The use of musculoskeletal ultrasound in rheumatology clinical practice has rapidly increased over the past decade. Ultrasound has enabled rheumatologists to diagnose, prognosticate and monitor disease outcome. Although international standardization remains a concern still, the use of ultrasound in rheumatology is expected to grow further as costs fall and the opportunity to train in the technique improves. We present a review of value of ultrasound, focusing on major applications of ultrasound in rheumatologic diseases. PMID:23580002

  10. Fuzzy similarity measures for ultrasound tissue characterization

    NASA Astrophysics Data System (ADS)

    Emara, Salem M.; Badawi, Ahmed M.; Youssef, Abou-Bakr M.

    1995-03-01

    Computerized ultrasound tissue characterization has become an objective means for diagnosis of diseases. It is difficult to differentiate diffuse liver diseases, namely cirrhotic and fatty liver from a normal one, by visual inspection from the ultrasound images. The visual criteria for differentiating diffused diseases is rather confusing and highly dependent upon the sonographer's experience. The need for computerized tissue characterization is thus justified to quantitatively assist the sonographer for accurate differentiation and to minimize the degree of risk from erroneous interpretation. In this paper we used the fuzzy similarity measure as an approximate reasoning technique to find the maximum degree of matching between an unknown case defined by a feature vector and a family of prototypes (knowledge base). The feature vector used for the matching process contains 8 quantitative parameters (textural, acoustical, and speckle parameters) extracted from the ultrasound image. The steps done to match an unknown case with the family of prototypes (cirr, fatty, normal) are: Choosing the membership functions for each parameter, then obtaining the fuzzification matrix for the unknown case and the family of prototypes, then by the linguistic evaluation of two fuzzy quantities we obtain the similarity matrix, then by a simple aggregation method and the fuzzy integrals we obtain the degree of similarity. Finally, we find that the similarity measure results are comparable to the neural network classification techniques and it can be used in medical diagnosis to determine the pathology of the liver and to monitor the extent of the disease.

  11. Simulation of ultrasound backscatter images from fish

    NASA Astrophysics Data System (ADS)

    Pham, An Hoai; Stage, Bjarne; Hemmsen, Martin Christian; Lundgren, Bo; Pedersen, Mads Møller; Pedersen, Tina Bock; Jensen, Jørgen Arendt

    2011-03-01

    The objective of this work is to investigate ultrasound (US) backscatter in the MHz range from fish to develop a realistic and reliable simulation model. The long term objective of the work is to develop the needed signal processing for fish species differentiation using US. In in-vitro experiments, a cod (Gadus morhua) was scanned with both a BK Medical ProFocus 2202 ultrasound scanner and a Toshiba Aquilion ONE computed tomography (CT) scanner. The US images of the fish were compared with US images created using the ultrasound simulation program Field II. The center frequency of the transducer is 10 MHz and the Full Width at Half Maximum (FWHM) at the focus point is 0.54 mm in the lateral direction. The transducer model in Field II was calibrated using a wire phantom to validate the simulated point spread function. The inputs to the simulation were the CT image data of the fish converted to simulated scatter maps. The positions of the point scatterers were assumed to be uniformly distributed. The scatter amplitudes were generated with a new method based on the segmented CT data in Hounsfield Units and backscatter data for the different types of tissues from the literature. The simulated US images reproduce most of the important characteristics of the measured US image.

  12. Doppler ultrasound--basics revisited.

    PubMed

    Eagle, Mary

    Palpation of pedal pulses alone is known to be an unreliable indicator for the presence of arterial disease. Using portable Doppler ultrasound to measure the resting ankle brachial pressure index is superior to palpation of peripheral pulses as an assessment of the adequacy pf the arterial supply in the lower limb. Revisiting basics, this article aims to aid the clinician to understand and perform hand-held Doppler ultrasound effectively while involving the client or patient in the process. The author describes the basics of Doppler ultrasound, how to select correct equipment for the process, and interpretation of results to further enhance clinicians' knowledge. PMID:16835512

  13. Heating of fetal bone by diagnostic ultrasound

    NASA Astrophysics Data System (ADS)

    Doody, Claire

    Most pregnant women in the Western world undergo an ultrasound examination and so it is important to ensure that exposure of the embryo or fetus does not produce unwanted effects. It is known that ultrasound can heat tissue, especially bone, and so this thesis explores the degree to which fetal bone might be heated during a pulsed Doppler examination. This is done both by carrying out measurements and by developing computer models. Thermal measurements on human fetal thoracic vertebrae of gestational age ranging from 14 to 39 weeks are reported. The bone samples were insonated in vitro with an ultrasound beam which had power and intensity values typical of those from a clinical scanner operating in pulsed Doppler mode. Temperature rises ranging from 0.6°C to 1.8°C were observed after five minutes, with approximately 75% of the temperature rise occurring in the first minute. Two approaches to computer modelling are described. These are the heated disc technique, which is commonly used to model the temperature rise generated by an ultrasound beam, and finite element modelling, a more general approach used to obtain solutions to differential equations. The degree to which our limited knowledge of the properties of fetal tissue affect our ability to make accurate predictions of in vivo heating is explored. It is shown that the present uncertainty in the value of the thermal conductivity and attenuation coefficient of fetal bone can lead to significant uncertainty in predictions of heating. The degree to which the simplifications inherent in the heated disc model affect the results will also be discussed. The results from the models are compared with the experimental measurements in order to estimate the attenuation coefficient of the bone.

  14. 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

  15. A Novel Nit Comb Concept Using Ultrasound Actuation: Preclinical Evaluation.

    PubMed

    Burgess, Mark N; Brunton, Elizabeth R; Burgess, Ian F

    2016-01-01

    Nit combing and removal of head louse, Pediculus humanus capitis De Geer (Anoplura: Pediculidae), eggs is a task made more difficult because "nit combs" vary in efficiency. There is currently no evidence that the binding of the eggshell to the hair can be loosened chemically and few hair treatments improve the slip of the louse eggs along the hair. Ultrasound, applied through the teeth of a nit comb, may facilitate the flow of fluids into the gap between the hair shaft and the tube of fixative holding louse eggs in place to improve lubrication. Ultrasound alone had little effect to initiate sliding, requiring a force of 121.5 ± 23.8 millinewtons (mN) compared with 125.8 ± 18.0 mN without ultrasound, but once the egg started to move it made the process easier. In the presence of a conditioner-like creamy lotion, ultrasound reduced the Peak force required to start movement to 24.3 ± 8.8 mN from 50.4 ± 13.0 mN without ultrasound. In contrast, some head louse treatments made removal of eggs more difficult, requiring approximately twice the Peak force to initiate movement compared with dry hair in the absence of ultrasound. However, following application of ultrasound, the forces required to initiate movement increased for an essential oil product, remained the same for isopropyl myristate and cyclomethicone, and halved for 4% dimeticone lotion. Fixing the nit comb at an estimated angle of 16.5° to the direction of pull gave an optimum effect to improve the removal process when a suitable lubricant was used. PMID:26545717

  16. Endobronchial Ultrasound Bronchoscope Damage.

    PubMed

    Patil, Monali; Harris, Kassem; Krishnan, Amita; Alraiyes, Abdul H; Dhillon, Samjot S

    2016-07-01

    Endobronchial ultrasound (EBUS)-guided transbronchial needle aspiration is an effective, safe, and cost-effective diagnostic bronchoscopy technique for the work-up of mediastinal lymphadenopathy. Concern has been raised, however, about the high cost of convex-probe EBUS bronchoscope repairs. The damage is usually due to breakage of the insertion tube (the flexible part that is advanced into the airways), moisture invasion and damages to the working channel, image guide bundle, or umbilical cord. Understanding the root cause of EBUS scope damage is important for its prevention. We describe 2 unusual cases of EBUS scope damage. In the first case, the distal black rubber covering of the EBUS scope insertion tube was damaged due to friction with the edge of an endotracheal tube and in the second case, the EBUS scope insertion tube was angulating laterally instead of vertically during the flexion maneuver, probably due to scope manipulation while wedged tightly in a segmental bronchus. PMID:27077640

  17. Resonant ultrasound spectroscopy

    DOEpatents

    Migliori, Albert

    1991-01-01

    A resonant ultrasound spectroscopy method provides a unique characterization of an object for use in distinguishing similar objects having physical differences greater than a predetermined tolerance. A resonant response spectrum is obtained for a reference object by placing excitation and detection transducers at any accessible location on the object. The spectrum is analyzed to determine the number of resonant response peaks in a predetermined frequency interval. The distribution of the resonance frequencies is then characterized in a manner effective to form a unique signature of the object. In one characterization, a small frequency interval is defined and stepped though the spectrum frequency range. Subsequent objects are similarly characterized where the characterizations serve as signatures effective to distinguish objects that differ from the reference object by more than the predetermined tolerance.

  18. Spatiotemporal Clutter Filtering of Ultrafast Ultrasound Data Highly Increases Doppler and fUltrasound Sensitivity.

    PubMed

    Demené, Charlie; Deffieux, Thomas; Pernot, Mathieu; Osmanski, Bruno-Félix; Biran, Valérie; Gennisson, Jean-Luc; Sieu, Lim-Anna; Bergel, Antoine; Franqui, Stéphanie; Correas, Jean-Michel; Cohen, Ivan; Baud, Olivier; Tanter, Mickael

    2015-11-01

    Ultrafast ultrasonic imaging is a rapidly developing field based on the unfocused transmission of plane or diverging ultrasound waves. This recent approach to ultrasound imaging leads to a large increase in raw ultrasound data available per acquisition. Bigger synchronous ultrasound imaging datasets can be exploited in order to strongly improve the discrimination between tissue and blood motion in the field of Doppler imaging. Here we propose a spatiotemporal singular value decomposition clutter rejection of ultrasonic data acquired at ultrafast frame rate. The singular value decomposition (SVD) takes benefits of the different features of tissue and blood motion in terms of spatiotemporal coherence and strongly outperforms conventional clutter rejection filters based on high pass temporal filtering. Whereas classical clutter filters operate on the temporal dimension only, SVD clutter filtering provides up to a four-dimensional approach (3D in space and 1D in time). We demonstrate the performance of SVD clutter filtering with a flow phantom study that showed an increased performance compared to other classical filters (better contrast to noise ratio with tissue motion between 1 and 10mm/s and axial blood flow as low as 2.6 mm/s). SVD clutter filtering revealed previously undetected blood flows such as microvascular networks or blood flows corrupted by significant tissue or probe motion artifacts. We report in vivo applications including small animal fUltrasound brain imaging (blood flow detection limit of 0.5 mm/s) and several clinical imaging cases, such as neonate brain imaging, liver or kidney Doppler imaging. PMID:25955583

  19. Introduction to ultrasound elastography.

    PubMed

    Nowicki, Andrzej; Dobruch-Sobczak, Katarzyna

    2016-06-01

    For centuries tissue palpation has been an important diagnostic tool. During palpation, tumors are felt as tissues harder than the surrounding tissues. The significance of palpation is related to the relationship between mechanical properties of different tissue lesions. The assessment of tissue stiffness through palpation is based on the fact that mechanical properties of tissues are changing as a result of various diseases. A higher tissue stiffness translates into a higher elasticity modulus. In the 90's, ultrasonography was extended by the option of examining the stiffness of tissue by estimating the difference in backscattering of ultrasound in compressed and non-compressed tissue. This modality is referred to as the static, compression elastography and is based on tracking the deformation of tissue subjected to the slowly varying compression through the recording of the backscattered echoes. The displacement is estimated using the methods of cross-correlation between consecutive ultrasonic lines of examined tissue, so calculating the degree of similarity of ultrasonic echoes acquired from tissue before and after the compression was applied. The next step in the development of ultrasound palpation was to apply the local remote tissue compression by using the acoustic radiation force generated through the special beam forming of the ultrasonic beam probing the tissue. The acoustic radiation force causes a slight deformation the tissue thereby forming a shear wave propagating in the tissue at different speeds dependent on the stiffness of the tissue. Shear wave elastography, carries great hopes in the field of quantitative imaging of tissue lesions. This article describes the physical basis of both elastographic methods: compression elastography and shear wave elastography. PMID:27446596

  20. Introduction to ultrasound elastography

    PubMed Central

    Dobruch-Sobczak, Katarzyna

    2016-01-01

    For centuries tissue palpation has been an important diagnostic tool. During palpation, tumors are felt as tissues harder than the surrounding tissues. The significance of palpation is related to the relationship between mechanical properties of different tissue lesions. The assessment of tissue stiffness through palpation is based on the fact that mechanical properties of tissues are changing as a result of various diseases. A higher tissue stiffness translates into a higher elasticity modulus. In the 90's, ultrasonography was extended by the option of examining the stiffness of tissue by estimating the difference in backscattering of ultrasound in compressed and non-compressed tissue. This modality is referred to as the static, compression elastography and is based on tracking the deformation of tissue subjected to the slowly varying compression through the recording of the backscattered echoes. The displacement is estimated using the methods of cross-correlation between consecutive ultrasonic lines of examined tissue, so calculating the degree of similarity of ultrasonic echoes acquired from tissue before and after the compression was applied. The next step in the development of ultrasound palpation was to apply the local remote tissue compression by using the acoustic radiation force generated through the special beam forming of the ultrasonic beam probing the tissue. The acoustic radiation force causes a slight deformation the tissue thereby forming a shear wave propagating in the tissue at different speeds dependent on the stiffness of the tissue. Shear wave elastography, carries great hopes in the field of quantitative imaging of tissue lesions. This article describes the physical basis of both elastographic methods: compression elastography and shear wave elastography. PMID:27446596

  1. Consequences of Intermodality Registration Errors for Intramodality 3D Ultrasound IGRT.

    PubMed

    van der Meer, Skadi; Seravalli, Enrica; Fontanarosa, Davide; Bloemen-van Gurp, Esther J; Verhaegen, Frank

    2016-08-01

    Intramodality ultrasound image-guided radiotherapy systems compare daily ultrasound to reference ultrasound images. Nevertheless, because the actual treatment planning is based on a reference computed tomography image, and not on a reference ultrasound image, their accuracy depends partially on the correct intermodality registration of the reference ultrasound and computed tomography images for treatment planning. The error propagation in daily patient positioning due to potential registration errors at the planning stage was assessed in this work. Five different scenarios were simulated involving shifts or rotations of ultrasound or computed tomography images. The consequences of several workflow procedures were tested with a phantom setup. As long as the reference ultrasound and computed tomography images are made to match, the patient will be in the correct treatment position. In an example with a phantom measurement, the accuracy of the performed manual fusion was found to be ≤2 mm. In clinical practice, manual registration of patient images is expected to be more difficult. Uncorrected mismatches will lead to a systematically incorrect final patient position because there will be no indication that there was a misregistration between the computed tomography and reference ultrasound images. In the treatment room, the fusion with the computed tomography image will not be visible and based on the ultrasound images the patient position seems correct. PMID:26048909

  2. Can pulsed ultrasound increase tissue damage during ischemia? A study of the effects of ultrasound on infarcted and non-infarcted myocardium in anesthetized pigs

    PubMed Central

    Olivecrona, Göran K; Härdig, Bjarne Madsen; Roijer, Anders; Block, Mattias; Grins, Edgars; Persson, Hans W; Johansson, Leif; Olsson, Bertil

    2005-01-01

    Background The same mechanisms by which ultrasound enhances thrombolysis are described in connection with non-beneficial effects of ultrasound. The present safety study was therefore designed to explore effects of beneficial ultrasound characteristics on the infarcted and non-infarcted myocardium. Methods In an open chest porcine model (n = 17), myocardial infarction was induced by ligating a coronary diagonal branch. Pulsed ultrasound of frequency 1 MHz and intensity 0.1 W/cm2 (ISATA) was applied during one hour to both infarcted and non-infarcted myocardial tissue. These ultrasound characteristics are similar to those used in studies of ultrasound enhanced thrombolysis. Using blinded assessment technique, myocardial damage was rated according to histopathological criteria. Results Infarcted myocardium exhibited a significant increase in damage score compared to non-infarcted myocardium: 6.2 ± 2.0 vs. 4.3 ± 1.5 (mean ± standard deviation), (p = 0.004). In the infarcted myocardium, ultrasound exposure yielded a further significant increase of damage scores: 8.1 ± 1.7 vs. 6.2 ± 2.0 (p = 0.027). Conclusion Our results suggest an instantaneous additive effect on the ischemic damage in myocardial tissue when exposed to ultrasound of stated characteristics. The ultimate damage degree remains to be clarified. PMID:15831106

  3. Ultrasound-Guided Breast Biopsy

    MedlinePlus

    ... the breast are often detected by physical examination, mammography, or other imaging studies. However, it is not ... full size with caption Related Articles and Media Mammography Ultrasound - Breast Breast Cancer Screening Breast Cancer Treatment ...

  4. Ultrasound-modulated bioluminescence tomography

    NASA Astrophysics Data System (ADS)

    Bal, Guillaume; Schotland, John C.

    2014-03-01

    We propose a method to reconstruct the density of a luminescent source in a highly scattering medium from ultrasound-modulated optical measurements. Our approach is based on the solution to a hybrid inverse source problem for the diffusion equation.

  5. Volume flow in arteriovenous fistulas using vector velocity ultrasound.

    PubMed

    Hansen, Peter Møller; Olesen, Jacob Bjerring; Pihl, Michael Johannes; Lange, Theis; Heerwagen, Søren; Pedersen, Mads Møller; Rix, Marianne; Lönn, Lars; Jensen, Jørgen Arendt; Nielsen, Michael Bachmann

    2014-11-01

    Volume flow in arteriovenous fistulas for hemodialysis was measured using the angle-independent ultrasound technique Vector Flow Imaging and compared with flow measurements using the ultrasound dilution technique during dialysis. Using an UltraView 800 ultrasound scanner (BK Medical, Herlev, Denmark) with a linear transducer, 20 arteriovenous fistulas were scanned directly on the most superficial part of the fistula just before dialysis. Vector Flow Imaging volume flow was estimated with two different approaches, using the maximum and the average flow velocities detected in the fistula. Flow was estimated to be 242 mL/min and 404 mL/min lower than the ultrasound dilution technique estimate, depending on the approach. The standard deviations of the two Vector Flow Imaging approaches were 175.9 mL/min and 164.8 mL/min compared with a standard deviation of 136.9 mL/min using the ultrasound dilution technique. The study supports that Vector Flow Imaging is applicable for volume flow measurements. PMID:25282482

  6. Filtering and detection of low contrast structures on ultrasound images

    NASA Astrophysics Data System (ADS)

    Vargas-Quintero, Lorena; Escalante-Ramírez, Boris; Arámbula, Fernando

    2012-06-01

    In this paper, we propose a detection method of low contrast structures in medical ultrasound images. Since noise speckle makes difficult the analysis of ultrasound images, two approaches based on the wavelet and Hermite-transforms for enhancement and noise reduction are compared. These techniques assume that speckle pattern is a random signal characterized by a Rayleigh distribution and affects the image as a multiplicative noise. For the wavelet-based approach, a Bayesian estimator at subband level for pixel classification is used. All the estimation parameters are calculated using an adjustment method derived from the first and second order statistical moments. The Hermite method computes a mask to find those pixels that are corrupted by speckle. In this work, we consider a statistical detection model that depends on the variable size and contrast of the image speckle. The algorithms have been evaluated using several real and synthetic ultrasound images. Combinations of the implemented methods can be helpful for automatic detection applications of tumors in mammographic ultrasound images. The employed filtering techniques are quantitatively and qualitatively compared with other previously published methods applied on ultrasound medical images.

  7. Ultrasound techniques in the evaluation of the mediastinum, part I: endoscopic ultrasound (EUS), endobronchial ultrasound (EBUS) and transcutaneous mediastinal ultrasound (TMUS), introduction into ultrasound techniques

    PubMed Central

    Annema, Jouke Tabe; Clementsen, Paul; Cui, Xin Wu; Borst, Mathias Maximilian; Jenssen, Christian

    2015-01-01

    Ultrasound imaging has gained importance in pulmonary medicine over the last decades including conventional transcutaneous ultrasound (TUS), endoscopic ultrasound (EUS), and endobronchial ultrasound (EBUS). Mediastinal lymph node staging affects the management of patients with both operable and inoperable lung cancer (e.g., surgery vs. combined chemoradiation therapy). Tissue sampling is often indicated for accurate nodal staging. Recent international lung cancer staging guidelines clearly state that endosonography (EUS and EBUS) should be the initial tissue sampling test over surgical staging. Mediastinal nodes can be sampled from the airways [EBUS combined with transbronchial needle aspiration (EBUS-TBNA)] or the esophagus [EUS fine needle aspiration (EUS-FNA)]. EBUS and EUS have a complementary diagnostic yield and in combination virtually all mediastinal lymph nodes can be biopsied. Additionally endosonography has an excellent yield in assessing granulomas in patients suspected of sarcoidosis. The aim of this review, in two integrative parts, is to discuss the current role and future perspectives of all ultrasound techniques available for the evaluation of mediastinal lymphadenopathy and mediastinal staging of lung cancer. A specific emphasis will be on learning mediastinal endosonography. Part I is dealing with an introduction into ultrasound techniques, mediastinal lymph node anatomy and diagnostic reach of ultrasound techniques and part II with the clinical work up of neoplastic and inflammatory mediastinal lymphadenopathy using ultrasound techniques and how to learn mediastinal endosonography. PMID:26543620

  8. Ultrasound-Mediated Polymeric Micelle Drug Delivery.

    PubMed

    Xia, Hesheng; Zhao, Yue; Tong, Rui

    2016-01-01

    The synthesis of multi-functional nanocarriers and the design of new stimuli-responsive means are equally important for drug delivery. Ultrasound can be used as a remote, non-invasive and controllable trigger for the stimuli-responsive release of nanocarriers. Polymeric micelles are one kind of potential drug nanocarrier. By combining ultrasound and polymeric micelles, a new modality (i.e., ultrasound-mediated polymeric micelle drug delivery) has been developed and has recently received increasing attention. A major challenge remaining in developing ultrasound-responsive polymeric micelles is the improvement of the sensitivity or responsiveness of polymeric micelles to ultrasound. This chapter reviews the recent advance in this field. In order to understand the interaction mechanism between ultrasound stimulus and polymeric micelles, ultrasound effects, such as thermal effect, cavitation effect, ultrasound sonochemistry (including ultrasonic degradation, ultrasound-initiated polymerization, ultrasonic in-situ polymerization and ultrasound site-specific degradation), as well as basic micellar knowledge are introduced. Ultrasound-mediated polymeric micelle drug delivery has been classified into two main streams based on the different interaction mechanism between ultrasound and polymeric micelles; one is based on the ultrasound-induced physical disruption of the micelle and reversible release of payload. The other is based on micellar ultrasound mechanochemical disruption and irreversible release of payload. PMID:26486348

  9. Ultrasonographic percutaneous anatomy of the atlanto-occipital region and indirect ultrasound-guided cisternal puncture in the dog and the cat.

    PubMed

    Etienne, A-L; Audigié, F; Peeters, D; Gabriel, A; Busoni, V

    2015-04-01

    Cisternal puncture in dogs and cats is commonly carried out. This article describes the percutaneous ultrasound anatomy of the cisternal region in the dog and the cat and an indirect technique for ultrasound-guided cisternal puncture. Ultrasound images obtained ex vivo and in vivo were compared with anatomic sections and used to identify the landmarks for ultrasound-guided cisternal puncture. The ultrasound-guided procedure was established in cadavers and then applied in vivo in seven dogs and two cats. The anatomic landmarks for the ultrasound-guided puncture are the cisterna magna, the spinal cord, the two occipital condyles on transverse images, the external occipital crest and the dorsal arch of the first cervical vertebra on longitudinal images. Using these ultrasound anatomic landmarks, an indirect ultrasound-guided technique for cisternal puncture is applicable in the dog and the cat. PMID:24712312

  10. Good sensitivity and specificity of ultrasound for detecting pseudotumors in 83 failed metal-on-metal hip replacements

    PubMed Central

    Lainiala, Olli; Elo, Petra; Reito, Aleksi; Pajamäki, Jorma; Puolakka, Timo; Eskelinen, Antti

    2015-01-01

    Background and purpose Ultrasound is used for imaging of pseudotumors associated with metal-on-metal (MoM) hips. Ultrasound has been compared with magnetic resonance imaging, but to date there have been no studies comparing ultrasound findings and revision findings. Methods We evaluated the sensitivity and specificity of preoperative ultrasound for detecting pseudotumors in 82 patients with MoM hip replacement (82 hips). Ultrasound examinations were performed by 1 of 3 musculoskeletal radiologists, and pseudotumors seen by ultrasound were retrospectively classified as fluid-filled, mixed-type, or solid. Findings at revision surgery were retrieved from surgical notes and graded according to the same system as used for ultrasound findings. Results Ultrasound had a sensitivity of 83% (95% CI: 63–93) and a specificity of 92% (CI: 82–96) for detecting trochanteric region pseudotumors, and a sensitivity of 79% (CI: 62–89) and a specificity of 94% (CI: 83–98) for detecting iliopsoas-region pseudotumors. Type misclassification of pseudotumors found at revision occurred in 8 of 23 hips in the trochanteric region and in 19 of 33 hips in the iliopsoas region. Interpretation Despite the discrepancy in type classification between ultrasound and revision findings, the presence of pseudotumors was predicted well with ultrasound in our cohort of failed MoM hip replacements. PMID:25582840

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

    PubMed

    Waghmare, Govind V; Rathod, Virendra K

    2016-09-01

    The present work demonstrates the hydrolysis of waste cooking oil (WCO) under solvent free condition using commercial available immobilized lipase (Novozyme 435) under the influence of ultrasound irradiation. The process parameters were optimized using a sequence of experimental protocol to evaluate the effects of temperature, molar ratios of substrates, enzyme loading, duty cycle and ultrasound intensity. It has been observed that ultrasound-assisted lipase-catalyzed hydrolysis of WCO would be a promising alternative for conventional methods. A maximum conversion of 75.19% was obtained at mild operating parameters: molar ratio of oil to water (buffer pH 7) 3:1, catalyst loading of 1.25% (w/w), lower ultrasound power 100W (ultrasound intensity - 7356.68Wm(-2)), duty cycle 50% and temperature (50°C) in a relatively short reaction time (2h). The activation energy and thermodynamic study shows that the hydrolysis reaction is more feasible when ultrasound is combined with mechanical agitation as compared with the ultrasound alone and simple conventional stirring technique. Application of ultrasound considerably reduced the reaction time as compared to conventional reaction. The successive use of the catalyst for repetitive cycles under the optimum experimental conditions resulted in a loss of enzymatic activity and also minimized the product conversion. PMID:27150746

  12. Endoscopic Ultrasound-Assisted Pancreaticobiliary Access.

    PubMed

    Weilert, Frank; Binmoeller, Kenneth F

    2015-10-01

    Endoscopic retrograde cholangiopancreatography (ERCP) is the primary approach to drain an obstructed pancreatic or biliary duct. Failed biliary drainage is traditionally referred for percutaneous transhepatic biliary drainage or surgical bypass, which carry significantly higher morbidity and mortality rates compared with ERCP and transpapillary drainage. Endoscopic ultrasound provides a real-time imaging platform to access and deliver therapy to organs and tissues outside of the bowel lumen. The bile and pancreatic ducts can be directly accessed from the stomach and duodenum, offering an alternative to ERCP when this fails or is not feasible. PMID:26431606

  13. A Prototype Ultrasound Instrument To Size Stone Fragments During Ureteroscopy

    NASA Astrophysics Data System (ADS)

    Sorensen, Mathew D.; Teichman, Joel M. H.; Bailey, Michael R.

    2008-09-01

    An intraoperative tool to measure the size of kidney stones or stone fragments during ureteroscopy would help urologists assess if a fragment is small enough to be removed through the ureter or ureteral access sheath. The goal of this study was to determine the accuracy and precision of a prototype ultrasound device used to measure in vitro stone fragments compared to caliper measurements. A 10-MHz, 10-french ultrasound transducer probe was used to send an ultrasound pulse and receive ultrasound reflections from the stone using two methods. In Method 1 the instrument was aligned over the stone and the ultrasound pulse traveled through the stone. The time between reflections from the proximal and the distal surface of the stone were used along with the sound speed to calculate the stone size. Although the sound speed varied between stones, it was unlikely to be known during surgery and thus was estimated at 3000 m/s for calculations. In Method 2 the instrument was aligned partially over the stone and the ultrasound pulse traveled through water with a sound speed of 1481 m/s. Time was determined between the reflection from the proximal stone surface and the reflection from the tissue phantom on which the stone rested. Methods 1 and 2 were compared by linear regression to caliper measurements of the size of 19 human stones of 3 different stone types. Accuracy was measured by the difference of the mean ultrasound and mean caliper measurement and precision was measured as the standard deviation in the ultrasound measurements. For Method 1, the correlation between caliper-determined stone size and ultrasound-determined stone size was r2 = 0.71 (p<0.0001). In all but two stones accuracy and precision were less than 1 mm. For Method 2, the correlation was r2 = 0.99 (p<0.0001) and measurements were accurate and precise to within 0.25 mm. We conclude that the prototype device and either method measure stone size with good accuracy.

  14. [Ultrasound of the Thyroid].

    PubMed

    Dietrich, C F; Bojunga, J

    2016-02-01

    Thyroid nodules and thyroid abnormalities are common findings in the general population. Ultrasonography is the most important imaging tool for diagnosing thyroid disease. In the majority of cases a correct diagnosis can already be made in synopsis of the sonographic together with clinical findings and basal thyroid hormone parameters and an appropriate therapy can be initiated thereafter. A differentiation of hormonally active vs. inactive nodes, and in particular benign vs. malignant nodules is sonographically, however, not reliably possible. In this context, radioscanning has its clinical significance predominantly in diagnosing hormonal activity of thyroid nodules. Efforts of the past years aimed to improve sonographic risk stratification to predict malignancy of thyroid nodules through standardized diagnostic assessment of evaluated risk factors in order to select patients, who need further diagnostic work up. According to the "Breast Imaging Reporting and Data System" (BI-RADS), "Thyroid Imaging Reporting and Data Systems" (TI-RADS) giving standardized categories with rates of malignancy were evaluated as a basis for further clinical management. Recent technological developments, such as elastography, also showpromising data and could gain entrance into clinical practice. The ultrasound-guided fineneedle aspiration is the key element in the diagnosis of sonographically suspicious thyroid nodules and significantly contributes to the diagnosis of malignancy versus benignity. PMID:26859730

  15. Endoscopic Ultrasound: Indian Perspective.

    PubMed

    Vora, Agam

    2015-09-01

    Mediastinoscopy is a minimally invasive surgical procedure that allows visualization and tissue sampling of mediastinal nodes. Mediastinoscopy has been extremely valuable in the evaluation and staging of lung cancer and therefore has been considered the gold standard for this purpose for over 30 years. Historically, this procedure has been associated with a low morbidity and mortality and a high sensitivity for diagnosing lung cancer with certain procedural limitations. Recently, it has been reported that not only is mediastinoscopy use limited in community practice, concomitant biopsy rates are limited as well.1 While mediastinoscopy does provide a tissue diagnosis, the procedure has its limitations. Cervical mediastinoscopy allows access to nodal stations 2, 3, 4 and 7, leaving out commonly involved pulmonary ligament and aortopulmonary window nodes.1 It requires general anesthesia and has a morbidity of 1% and a mortality of 0.2%. The procedure adds considerable expense to the staging workup. The estimated current cost is $1,700 for the procedure alone and $7,500 for a mediastinoscopy with a 2-day hospital stay. This prompted the development of endobronchial ultrasound(EBUS) in the 1990s.2. PMID:27608860

  16. Resonant ultrasound spectrometer

    DOEpatents

    Migliori, Albert; Visscher, William M.; Fisk, Zachary

    1990-01-01

    An ultrasound resonant spectrometer determines the resonant frequency spectrum of a rectangular parallelepiped sample of a high dissipation material over an expected resonant response frequency range. A sample holder structure grips corners of the sample between piezoelectric drive and receive transducers. Each transducer is mounted on a membrane for only weakly coupling the transducer to the holder structure and operatively contacts a material effective to remove system resonant responses at the transducer from the expected response range. i.e., either a material such as diamond to move the response frequencies above the range or a damping powder to preclude response within the range. A square-law detector amplifier receives the response signal and retransmits the signal on an isolated shield of connecting cabling to remove cabling capacitive effects. The amplifier also provides a substantially frequency independently voltage divider with the receive transducer. The spectrometer is extremely sensitive to enable low amplitude resonance to be detected for use in calculating the elastic constants of the high dissipation sample.

  17. Direct visualization of microalgae rupture by ultrasound-driven bubbles

    NASA Astrophysics Data System (ADS)

    Pommella, Angelo; Harun, Irina; Pouliopoulos, Antonis; Choi, James J.; Hellgardt, Klaus; Garbin, Valeria

    2015-11-01

    Cell rupture induced by ultrasound is central to applications in biotechnology. For instance, cell disruption is required in the production of biofuels from microalgae (unicellular species of algae). Ultrasound-induced cavitation, bubble collapse and jetting are exploited to induce sufficiently large viscous stresses to cause rupture of the cell membranes. It has recently been shown that seeding the flow with bubbles that act as cavitation nuclei significantly reduces the energy cost for cell processing. However, a fundamental understanding of the conditions for rupture of microalgae in the complex flow fields generated by ultrasound-driven bubbles is currently lacking. We perform high-speed video microscopy to visualize the miscroscale details of the interaction of Chlamydomonas reinhardtii , microalgae of about 10 μm in size, with ultrasound-driven microbubbles of 2-200 μm in diameter. We investigate the efficiency of cell rupture depending on ultrasound frequency and pressure amplitude (from 10 kPa up to 1 MPa), and the resulting bubble dynamics regimes. In particular we compare the efficiency of membrane rupture in the acoustic microstreaming flow induced by linear oscillations, with the case of violent bubble collapse and jetting. V.G. acknowledges partial support from the European Commission (FP7-PEOPLE-2013-CIG), Grant No. 618333.

  18. Candle soot nanoparticles-polydimethylsiloxane composites for laser ultrasound transducers

    NASA Astrophysics Data System (ADS)

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

    2015-10-01

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

  19. Quantitative Ultrasound Characterization of Cancer Radiotherapy Effects In Vitro

    SciTech Connect

    Vlad, Roxana M.; Alajez, Nehad M.; Giles, Anoja B.Sc.; Kolios, Michael C.; Czarnota, Gregory J.

    2008-11-15

    Purpose: Currently, no routinely used imaging modality is available to assess tumor responses to cancer treatment within hours to days after radiotherapy. In this study, we demonstrate the preclinical application of quantitative ultrasound methods to characterize the cellular responses to cancer radiotherapy in vitro. Methods and Materials: Three different cell lines were exposed to radiation doses of 2-8 Gy. Data were collected with an ultrasound scanner using frequencies of 10-30 MHz. As indicators of response, ultrasound integrated backscatter and spectral slope were determined from the cell samples. These parameters were corrected for ultrasonic attenuation by measuring the attenuation coefficient. Results: A significant increase in the ultrasound integrated backscatter of 4-7 dB (p < 0.001) was found for radiation-treated cells compared with viable cells at all radiation doses. The spectral slopes decreased in the cell samples that predominantly underwent mitotic arrest/catastrophe after radiotherapy, consistent with an increase in cell size. In contrast, the spectral slopes did not change significantly in the cell samples that underwent a mix of cell death (apoptosis and mitotic arrest), with no significant change in average cell size. Conclusion: The changes in ultrasound integrated backscatter and spectral slope were direct consequences of cell and nuclear morphologic changes associated with cell death. The results indicate that this combination of quantitative ultrasonic parameters has the potential to assess the cell responses to radiation, differentiate between different types of cell death, and provide a preclinical framework to monitor tumor responses in vivo.

  20. The feasibility of non-contact ultrasound for medical imaging

    NASA Astrophysics Data System (ADS)

    Clement, G. T.; Nomura, H.; Adachi, H.; Kamakura, T.

    2013-09-01

    High intensity focused ultrasound in air may provide a means for medical and biological imaging without direct coupling of an ultrasound probe. In this study, an approach based on highly focused ultrasound in air is described and the feasibility of the technique is assessed. The overall method is based on the observations that (1) ultrasound in air has superior focusing ability and stronger nonlinear harmonic generation as compared to tissue propagation and (2) a tightly focused field directed into tissue causes point-like spreading that may be regarded as a source for generalized diffraction tomography. Simulations of a spherically-curved transducer are performed, where the transducer's radiation pattern is directed from air into tissue. It is predicted that a focal pressure of 162 dB (2.5 kPa) is sufficient to direct ultrasound through the body, and provide a small but measurable signal (∼1 mPa) upon exit. Based on the simulations, a 20 cm diameter array consisting of 298 transducers is constructed. For this feasibility study, a 40 kHz resonance frequency is selected based on the commercial availability of such transducers. The array is used to focus through water and acrylic phantoms, and the time history of the exiting signal is evaluated. Sufficient data are acquired to demonstrate a low-resolution tomographic reconstruction. Finally, to demonstrate the feasibility to record a signal in vivo, a 75 mm × 55 mm section of a human hand is imaged in a C-mode configuration.

  1. Lung recruitment maneuvers using direct ultrasound guidance: a case study.

    PubMed

    Du, Jiang; Tan, Jiuting; Yu, Kanglong; Wang, Ruilan

    2015-05-01

    Previous studies have shown that lung recruitment maneuvers are important means of treating ARDS. Although computed tomography (CT) scans and pressure-volume curves are the most common ways to evaluate lung recruitment, there are still many disadvantages. Not only do the scans have to take place in a CT room, but the patient is exposed to large doses of radiation through the multiple scans necessary to define the optimal PEEP. Pressure-volume curves require deep sedation and muscle relaxation. Thus, bedside lung ultrasound may be considered to be a safer and easier alternative to CT scans or pressure-volume curves. In our case, we evaluated the effectiveness of lung recruitment with a bedside ultrasound on a patient who was suffering from life-threatening hypoxemia. Bedside ultrasound is a faster and more convenient imaging method because it reduces the need for patient transport compared with CT scan and requires no muscle relaxation. This case supports that ultrasound may become an alternative imaging tool to guide and evaluate alveolar recruitment in patients with ARDS. Additionally, we have also included a brief review of lung recruitment evaluation by ultrasound to supplement this case study. PMID:25406343

  2. Growth factor and ultrasound-assisted bioreactor synergism for human mesenchymal stem cell chondrogenesis

    PubMed Central

    Thakurta, Sanjukta Guha; Budhiraja, Gaurav

    2015-01-01

    Ultrasound at 5.0 MHz was noted to be chondro-inductive, with improved SOX-9 gene and COL2A1 protein expression in constructs that allowed for cell-to-cell contact. To achieve tissue-engineered cartilage using macroporous scaffolds, it is hypothesized that a combination of ultrasound at 5.0 MHz and transforming growth factor-β3 induces human mesenchymal stem cell differentiation to chondrocytes. Expression of miR-145 was used as a metric to qualitatively assess the efficacy of human mesenchymal stem cell conversion. Our results suggest that in group 1 (no transforming growth factor-β3, no ultrasound), as anticipated, human mesenchymal stem cells were not efficiently differentiated into chondrocytes, judging by the lack of decrease in the level of miR-145 expression. Human mesenchymal stem cells differentiated into chondrocytes in group 2 (transforming growth factor-β3, no ultrasound) and group 3 (transforming growth factor-β3, ultrasound) with group 3 having a 2-fold lower miR-145 when compared to group 2 at day 7, indicating a higher conversion to chondrocytes. Transforming growth factor-β3–induced chondrogenesis with and without ultrasound stimulation for 14 days in the ultrasound-assisted bioreactor was compared and followed by additional culture in the absence of growth factors. The combination of growth factor and ultrasound stimulation (group 3) resulted in enhanced COL2A1, SOX-9, and ACAN protein expression when compared to growth factor alone (group 2). No COL10A1 protein expression was noted. Enhanced cell proliferation and glycosaminoglycan deposition was noted with the combination of growth factor and ultrasound stimulation. These results suggest that ultrasound at 5.0 MHz could be used to induce chondrogenic differentiation of mesenchymal stem cells for cartilage tissue engineering. PMID:25610590

  3. Antenatal Ultrasound and Risk of Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    Grether, Judith K.; Li, Sherian Xu; Yoshida, Cathleen K.; Croen, Lisa A.

    2010-01-01

    We evaluated antenatal ultrasound (U/S) exposure as a risk factor for autism spectrum disorders (ASD), comparing affected singleton children and control children born 1995-1999 and enrolled in the Kaiser Permanente health care system. Among children with ASD (n = 362) and controls (n = 393), 13% had no antenatal exposure to U/S examinations;…

  4. Antibacterial effect of zinc oxide nanoparticles combined with ultrasound

    NASA Astrophysics Data System (ADS)

    Seil, Justin T.; Webster, Thomas J.

    2012-12-01

    Using Staphylococcus aureus (S. aureus), the present study investigated the antibacterial effect of ZnO nanoparticles both in the absence and presence of ultrasound stimulation. While the antibacterial effect of control nanoparticle chemistries (Al2O3) alone was either weak or unobservable under the conditions tested, the antibacterial effect of ZnO alone was significant, providing over a four log reduction (equivalent to antibiotics) compared to no treatment after just 8 h. The antibacterial effect was enhanced as ZnO particle diameter decreased. Specifically, when testing the antibacterial effect against bacteria populations relevant to infection, a 500 μg ml-1 dose of zinc oxide nanoparticles with a diameter of 20 nm reduced S. aureus populations by four orders of magnitude after 8 and 24 h, compared to control groups with no nanoparticles. This was accomplished without the use of antibiotics, to which bacteria are developing a resistance anyway. The addition of ultrasound stimulation further reduced the number of viable colony-forming units present in a planktonic cell suspension by 76% compared to nanoparticles alone. Lastly, this study provided a mechanism for how ZnO nanoparticles in the presence of ultrasound decrease bacteria functions by demonstrating greater hydrogen peroxide generation by S. aureus compared to controls. These results indicated that small-diameter ZnO nanoparticles exhibited strong antibacterial properties that can be additionally enhanced in the presence of ultrasound and, thus, should be further studied for a wide range of medical device anti-infection applications.

  5. Ultrasound elastography using carotid artery pulsation in the differential diagnosis of sonographically indeterminate thyroid nodules.

    PubMed

    Choi, Woo Jung; Park, Jeong Seon; Koo, Hye Ryoung; Kim, Soo-Yeon; Chung, Min Sung; Tae, Kyung

    2015-02-01

    OBJECTIVE. The purpose of this study was to evaluate the diagnostic performance of gray-scale ultrasound and a new method of thyroid ultrasound elastography using carotid artery pulsation in the differential diagnosis of sonographically indeterminate thyroid nodules. MATERIALS AND METHODS. A total of 102 thyroid nodules with indeterminate gray-scale ultrasound features from 102 patients (20 males and 82 females; age range, 16-74 years; mean age, 51 years) were included. The gray-scale ultrasound images of each nodule were reviewed and assigned a score from 1 (low) to 5 (high) according to the possibility of malignancy. Ultrasound elastography was performed using carotid pulsation as the compression source. The elasticity contrast index (ECI), which quantifies local strain contrast within a nodule, was automatically calculated. The radiologist reassessed the scores after concurrently reviewing gray-scale ultrasound and elastography. ROC curve analysis was used to evaluate the diagnostic performances of each dataset and to compare the AUC (Az) values of gray-scale ultrasound score alone, ECI alone, and a combined assessment. RESULTS. Significantly more malignant thyroid nodules were hypoechoic than benign nodules (p = 0.014). The ECI was significantly higher in malignant nodules than in benign thyroid nodules. The Az values of each dataset were 0.755 (95% CI, 0.660-0.835) for gray-scale ultrasound score, 0.835 (0.748-0.901) for ECI, and 0.853 (0.769-0.915) for a combined assessment. The Az value for a combined assessment of the gray-scale ultrasound score and the ECI was significantly higher than that for the gray-scale ultrasound score alone (p = 0.022). CONCLUSION. Combined assessment with gray-scale ultrasound and elastography using carotid artery pulsation is helpful for characterizing sonographically indeterminate thyroid nodules as benign or malignant. PMID:25615763

  6. Investigating ultrasound imaging in the frequency domain for tissue characterisation

    NASA Astrophysics Data System (ADS)

    Stromer, Jeremy; Ladani, Leila

    2016-07-01

    The potential of ultrasound imaging for use in distinguishing structures present in soft materials is investigated. In this study, images were reconstructed using non-standard parameters, which have been shown to vary according to different tissue structures. Due to the previously determined dependence on material microstructure, we investigate the possibility of these parameters as a basis for imaging soft materials. The feasibility of imaging methods was first tested on a large scale using 0.5-MHz ultrasound transducers. Imaging was then extended to a smaller scale using small-diameter 25-MHz transducers. The resulting images were compared to conventional C-scans with minimal data processing and were found to be of at least similar quality. These initial results show the possibility of using nonconventional ultrasound measurements as another means of imaging tissue and other soft materials for the presence of internal inclusions.

  7. Disruption of microalgal cells using high-frequency focused ultrasound.

    PubMed

    Wang, Meng; Yuan, Wenqiao; Jiang, Xiaoning; Jing, Yun; Wang, Zhuochen

    2014-02-01

    The objective of this study was to evaluate the effectiveness of high-frequency focused ultrasound (HFFU) in microalgal cell disruption. Two microalgal species including Scenedesmus dimorphus and Nannochloropsis oculata were treated by a 3.2-MHz, 40-W focused ultrasound and a 100-W, low-frequency (20kHz) non-focused ultrasound (LFNFU). The results demonstrated that HFFU was effective in the disruption of microalgal cells, indicated by significantly increased lipid fluorescence density, the decrease of cell sizes, and the increase of chlorophyll a fluorescence density after treatments. Compared with LFNFU, HFFU treatment was more energy efficient. The combination of high and low frequency treatments was found to be even more effective than single frequency treatment at the same processing time, indicating that frequency played a critical role in cell disruption. In both HFFU and LFNFU treatments, the effectiveness of cell disruption was found to be dependent on the cell treated. PMID:24374364

  8. Determination of glass thickness using laser-based ultrasound

    NASA Astrophysics Data System (ADS)

    Shih, Frank J.; Pouet, Bruno F.; Klein, Marvin B.; McKie, Andrew D. W.

    2001-04-01

    Thickness measurements of glass plates and glass bottles using laser-based ultrasound (LBU) are described. Ultrasound in the glass specimens was generated thermoelastically with either a pulsed CO2 laser, or a Q-switched Nd:YAG laser in the case of colored glass filters. The detection of ultrasound was accomplished by one of the following methods; a spherical Fabry-Pérot interferometer system or a photo-refractive interferometer based on two-wave mixing. A self-interference effect, utilizing the partial reflection from the front and back faces of a glass plate was also demonstrated to have sufficient sensitivity under certain conditions. The thickness of the glass plates and colored glass bottles was determined using the fundamental reverberation frequency obtained from the time-domain waveform data. LBU results were compared to physical thickness measurements and showed excellent agreement.

  9. Ultrasound echoes as biometric navigators.

    PubMed

    Schwartz, Benjamin M; McDannold, Nathan J

    2013-04-01

    We demonstrate a new method of using ultrasound data to achieve prospective motion compensation in MRI, especially for respiratory motion during interventional MRI procedures in moving organs such as the liver. The method relies on fingerprint-like biometrically distinct ultrasound echo patterns produced by different locations in tissue, which are collated with geometrical information from MRI during a training stage to form a mapping table that relates ultrasound measurements to positions. During prospective correction, the system makes frequent ultrasound measurements and uses the map to determine the corresponding position. Results in motorized linear motion phantoms and freely breathing animals indicate that the system performs well. Apparent motion is reduced by up to 97.8%, and motion artifacts are reduced or eliminated in two-dimensional spoiled gradient-echo images. The motion compensation is sufficient to permit MRI thermometry of focused ultrasound heating during respiratory-like motion, with results similar to those obtained in the absence of motion. This new technique may have applications for MRI thermometry and other dynamic imaging in the abdomen during free breathing. PMID:22648783

  10. Ultrasound Device Approved to Treat Essential Tremor

    MedlinePlus

    ... page: https://medlineplus.gov/news/fullstory_159817.html Ultrasound Device Approved to Treat Essential Tremor Uses MRI ... U.S. Food and Drug Administration to deliver focused ultrasound to destroy small bits of brain tissue that ...

  11. Therapeutic ultrasound: Recent trends and future perspectives

    NASA Astrophysics Data System (ADS)

    Crum, Lawrence; Bailey, Michael; Hwang, Joo Ha; Khokhlova, Vera; Sapozhnikov, Oleg

    2010-01-01

    Before ultrasound-imaging systems became widely available, ultrasound therapy devices showed great promise for general use in medicine. However, it is only in the last decade that ultrasound therapy has begun to obtain clinical acceptance. Recently, a variety of novel applications of therapeutic ultrasound have been developed that include sonothrombolysis, site-specific and ultrasound-mediated drug delivery, shock wave therapy, lithotripsy, tumor ablation, acoustic hemostasis and several others. This paper reviews a few selected applications of therapeutic ultrasound. It will address some of the basic scientific questions and future challenges in developing these methods and technologies for general use in our society. As a plenary presentation, its audience is intended for the ultrasound scientist or engineer, and thus is not presented at the level of the experienced medical ultrasound professional.

  12. Ultrasound Research Interface - Cancer Imaging Program

    Cancer.gov

    The ultrasound research interface permits extensive instrument parameter control of a commercially available scanner that allows access to, and export of, the beam-formed signal data while simultaneously displaying the ultrasound system-processed data as a clinical image.

  13. Role of Guided Ultrasound in the Treatment of De Quervain Tenosynovitis by Local Steroid Infiltration.

    PubMed

    Danda, Raja Shekar; Kamath, Jagannath; Jayasheelan, Nikil; Kumar, Prashanth

    2016-04-01

    Ultrasound guidance for steroid injection in de Quervain disease is useful in identifying the presence of subcompartments and effectively injecting the drug into tendon sheath. We prospectively studied 50 patients with features of de Quervain disease to determine the effectiveness of ultrasound in positioning of needle for steroid injection and effectiveness of single versus multiple injections in the presence of subcompartments. Scalp vein set was inserted into the tendon sheath under ultrasound guidance and sterile conditions. Mixture containing 1 mL of methylprednisolone 40 mg with 1 mL of 2% lignocaine was injected and the patient followed for 6 months. In patients having subcompartments, improvement was better when two separate injections into each subcompartment were given compared with single. Ultrasound guidance is helpful in identifying the existence of subcompartment and injecting the subcompartments separately. Scalp vein set may be very effective in ultrasound-guided injection. This is a level III study. PMID:27616825

  14. Object identification accuracy under ultrasound enhanced virtual reality for minimally invasive cardiac surgery

    NASA Astrophysics Data System (ADS)

    Wiles, Andrew D.; Moore, John; Linte, Cristian A.; Wedlake, Christopher; Ahmad, Anis; Peters, Terry M.

    2008-03-01

    A 2D ultrasound enhanced virtual reality surgical guidance system has been under development for some time in our lab. The new surgical guidance platform has been shown to be effective in both the laboratory and clinical settings, however, the accuracy of the tracked 2D ultrasound has not been investigated in detail in terms of the applications for which we intend to use it (i.e., mitral valve replacement and atrial septal defect closure). This work focuses on the development of an accuracy assessment protocol specific to the assessment of the calibration methods used to determine the rigid transformation between the ultrasound image and the tracked sensor. Specifically, we test a Z-bar phantom calibration method and a phantomless calibration method and compared the accuracy of tracking ultrasound images from neuro, transesophageal, intracardiac and laparoscopic ultrasound transducers. This work provides a fundamental quantitative description of the image-guided accuracy that can be obtained with this new surgical guidance system.

  15. Sound Packing DNA: packing open circular DNA with low-intensity ultrasound

    NASA Astrophysics Data System (ADS)

    Park, Donghee; Jung, Bong-Kwang; Park, Hyunjin; Lee, Hyungbeen; Lee, Gyudo; Park, Jingam; Shin, Unchul; Won, Jong Ho; Jo, Yong Jun; Chang, Jin Woo; Lee, Sangwoo; Yoon, Daesung; Seo, Jongbum; Kim, Chul-Woo

    2015-04-01

    Supercoiling DNA (folding DNA into a more compact molecule) from open circular forms requires significant bending energy. The double helix is coiled into a higher order helix form; thus it occupies a smaller footprint. Compact packing of DNA is essential to improve the efficiency of gene delivery, which has broad implications in biology and pharmaceutical research. Here we show that low-intensity pulsed ultrasound can pack open circular DNA into supercoil form. Plasmid DNA subjected to 5.4 mW/cm2 intensity ultrasound showed significant (p-values <0.001) supercoiling compared to DNA without exposure to ultrasound. Radiation force induced from ultrasound and dragging force from the fluid are believed to be the main factors that cause supercoiling. This study provides the first evidence to show that low-intensity ultrasound can directly alter DNA topology. We anticipate our results to be a starting point for improved non-viral gene delivery.

  16. Diffraction and coherence in breast ultrasound tomography: a study with a toroidal array

    SciTech Connect

    Huang, Lianjie; Simonetti, Francesco; Duric, Neb; Littrup, Peter

    2008-01-01

    Ultrasound is commonly used as an adjunct to mammography for diagnostic evaluation of suspicions arising from breast cancer screening. As an alternative to conventional sonography that uses hand-held transducers, toroidal array probes that encircle the breast immersed in a water bath have been investigated for ultrasound tomography. In this paper, two sets of experiments performed with a prototype ultrasound scanner on a phantom and a human breast in vivo are used to investigate the effects of diffraction and coherence in ultrasound tomography. Reconstructions obtained with transmission diffraction tomography (TDT) are compared with conventional reflection imaging and computerized ultrasound tomography showing a substantial improvement. The in vivo tests demonstrate that TDT can image the complex boundary of a cancer mass and suggest that it can reveal the anatomy of milk ducts and Cooper's ligaments.

  17. Sound Packing DNA: packing open circular DNA with low-intensity ultrasound

    PubMed Central

    Park, DongHee; Jung, Bong-Kwang; Park, Hyunjin; Lee, Hyungbeen; Lee, Gyudo; Park, Jingam; Shin, Unchul; Won, Jong Ho; Jo, Yong Jun; Chang, Jin Woo; Lee, Sangwoo; Yoon, Daesung; Seo, Jongbum; Kim, Chul-Woo

    2015-01-01

    Supercoiling DNA (folding DNA into a more compact molecule) from open circular forms requires significant bending energy. The double helix is coiled into a higher order helix form; thus it occupies a smaller footprint. Compact packing of DNA is essential to improve the efficiency of gene delivery, which has broad implications in biology and pharmaceutical research. Here we show that low-intensity pulsed ultrasound can pack open circular DNA into supercoil form. Plasmid DNA subjected to 5.4 mW/cm2 intensity ultrasound showed significant (p-values <0.001) supercoiling compared to DNA without exposure to ultrasound. Radiation force induced from ultrasound and dragging force from the fluid are believed to be the main factors that cause supercoiling. This study provides the first evidence to show that low-intensity ultrasound can directly alter DNA topology. We anticipate our results to be a starting point for improved non-viral gene delivery. PMID:25892035

  18. Characterization of vascular strain during in-vitro angioplasty with high-resolution ultrasound speckle tracking

    PubMed Central

    2010-01-01

    Background Ultrasound elasticity imaging provides biomechanical and elastic properties of vascular tissue, with the potential to distinguish between tissue motion and tissue strain. To validate the ability of ultrasound elasticity imaging to predict structurally defined physical changes in tissue, strain measurement patterns during angioplasty in four bovine carotid artery pathology samples were compared to the measured physical characteristics of the tissue specimens. Methods Using computational image-processing techniques, the circumferences of each bovine artery specimen were obtained from ultrasound and pathologic data. Results Ultrasound-strain-based and pathology-based arterial circumference measurements were correlated with an R2 value of 0.94 (p = 0.03). The experimental elasticity imaging results confirmed the onset of deformation of an angioplasty procedure by indicating a consistent inflection point where vessel fibers were fully unfolded and vessel wall strain initiated. Conclusion These results validate the ability of ultrasound elasticity imaging to measure localized mechanical changes in vascular tissue. PMID:20727172

  19. Behavior of Propagation and Heating Due to Absorption of Ultrasound in Medium

    NASA Astrophysics Data System (ADS)

    Yamaya, Chiaki; Inoue, Hiroshi

    2006-05-01

    Recently, ultrasound waves have been put to practical use not only in diagnostic equipment but also in thermotherapy that uses the effect of ultrasound waves in a living body. The analysis of temperature rise due to the absorption of ultrasound in a soft tissue medium is an important analyzing object for the clarification of the effect of ultrasound waves in biological tissues and the estimation of medium constants. Three-dimensional simulations by the finite-difference time-domain (FDTD) method which used the equations that considers the absorption attenuation based on acoustic basic equations (ABEs) and the Westervelt equation have been performed. The consistency between the ABEs and the Westervelt equation is confirmed. The results of temperature measurement that uses glycerin as the absorbing medium of ultrasound are compared with those of FDTD simulation. The temperature distribution obtained by FDTD simulation almost corresponds to that obtained by experiment.

  20. Ionic liquid-based ultrasound-assisted extraction of fangchinoline and tetrandrine from Stephaniae tetrandrae.

    PubMed

    Zhang, Lijin; Geng, Yanling; Duan, Wenjuan; Wang, Daijie; Fu, Maorun; Wang, Xiao

    2009-10-01

    An ionic liquid-based ultrasound-assisted extraction method has been developed for the effective extraction of fangchinoline and tetrandrine from Stephaniae tetrandrae. The effects of some ultrasound-assisted extraction parameters including the concentration of [BMIM][BF(4)], pH, ultrasonic power and time were investigated to optimize the ultrasound-assisted extraction conditions. Compared to the regular ultrasound-assisted extraction and traditional refluent extraction, the proposed [BMIM][BF(4)]-based ultrasound-assisted extraction offered shorter extraction times (from 6 h to 40 min) and remarkable higher efficiencies (approximately 30% improved), which supported the suitability of the proposed approach. In addition, the proposed approach was confirmed by the good correlation coefficient (R(2)), recovery and reproducibility (RSD, n = 5), which were in the range of 0.9992-0.9995, 85.5-101.1%, and 1.87-4.33%, respectively. PMID:19764054

  1. Are Live Ultrasound Models Replaceable? Traditional versus Simulated Education Module for FAST Exam

    PubMed Central

    Bentley, Suzanne; Mudan, Gurpreet; Strother, Christopher; Wong, Nelson

    2015-01-01

    Introduction The focused assessment with sonography for trauma (FAST) is a commonly used and life-saving tool in the initial assessment of trauma patients. The recommended emergency medicine (EM) curriculum includes ultrasound and studies show the additional utility of ultrasound training for medical students. EM clerkships vary and often do not contain formal ultrasound instruction. Time constraints for facilitating lectures and hands-on learning of ultrasound are challenging. Limitations on didactics call for development and inclusion of novel educational strategies, such as simulation. The objective of this study was to compare the test, survey, and performance of ultrasound between medical students trained on an ultrasound simulator versus those trained via traditional, hands-on patient format. Methods This was a prospective, blinded, controlled educational study focused on EM clerkship medical students. After all received a standardized lecture with pictorial demonstration of image acquisition, students were randomized into two groups: control group receiving traditional training method via practice on a human model and intervention group training via practice on an ultrasound simulator. Participants were tested and surveyed on indications and interpretation of FAST and training and confidence with image interpretation and acquisition before and after this educational activity. Evaluation of FAST skills was performed on a human model to emulate patient care and practical skills were scored via objective structured clinical examination (OSCE) with critical action checklist. Results There was no significant difference between control group (N=54) and intervention group (N=39) on pretest scores, prior ultrasound training/education, or ultrasound comfort level in general or on FAST. All students (N=93) showed significant improvement from pre- to post-test scores and significant improvement in comfort level using ultrasound in general and on FAST (p<0.001). There

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

    PubMed

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

    2014-04-01

    The acceptance of broadband ultrasound attenuation for the assessment of osteoporosis suffers from a limited understanding of ultrasound wave propagation through cancellous bone. It has recently been proposed that the ultrasound wave propagation can be described by a concept of parallel sonic rays. This concept approximates the detected transmission signal to be the superposition of all sonic rays that travel directly from transmitting to receiving transducer. The transit time of each ray is defined by the proportion of bone and marrow propagated. An ultrasound transit time spectrum describes the proportion of sonic rays having a particular transit time, effectively describing lateral inhomogeneity of transit times over the surface of the receiving ultrasound transducer. The aim of this study was to provide a proof of concept that a transit time spectrum may be derived from digital deconvolution of input and output ultrasound signals. We have applied the active-set method deconvolution algorithm to determine the ultrasound transit time spectra in the three orthogonal directions of four cancellous bone replica samples and have compared experimental data with the prediction from the computer simulation. The agreement between experimental and predicted ultrasound transit time spectrum analyses derived from Bland-Altman analysis ranged from 92% to 99%, thereby supporting the concept of parallel sonic rays for ultrasound propagation in cancellous bone. In addition to further validation of the parallel sonic ray concept, this technique offers the opportunity to consider quantitative characterisation of the material and structural properties of cancellous bone, not previously available utilising ultrasound. PMID:24598434

  3. Noninvasive measurement of acoustic field inside mother's uterus generated by ultrasound scanning

    NASA Astrophysics Data System (ADS)

    Antonets, V. A.; Kazakov, V. V.

    2015-07-01

    Sounds in the audible range arising in mother's uterus during conventional ultrasound scanning were recorded noninvasively for the first time. It was found that their level is comparable with the level of spoken language.

  4. Comparison of ultrasound-assisted cloud point extraction and ultrasound-assisted dispersive liquid liquid microextraction for copper coupled with spectrophotometric determination

    NASA Astrophysics Data System (ADS)

    Yang, Shengchun; Fang, Xiang; Duan, Liju; Yang, Shu; Lei, Zirong; Wen, Xiaodong

    2015-09-01

    In this work, ultrasound-assisted cloud point extraction (UA-CPE) and ultrasound-assisted dispersive liquid liquid microextraction (UA-DLLME) were investigated and compared firstly as ultrasound-assisted liquid phase microextraction methods, which were coupled with spectrophotometer for copper preconcentration and detection. Compared to conventional CPE and DLLME, the extraction patterns were changed and improved by the effect of ultrasound. As novel methods, their applications were expanded and the analytical performance of spectrophotometric determination for copper was considerably improved. The influence factors of UA-CPE and UA-DLLME were studied in detail. Under the optimal conditions, the limits of detection (LODs) for copper were 0.7 μg L-1 of UA-CPE and 0.8 μg L-1 of UA-DLLME with sensitivity enhancement factors (EFs) of 17 and 16. The developed methods were applied to the determination of trace copper in real water samples with satisfactory analytical results.

  5. Effect of ultrasound on cyprid footprint and juvenile barnacle adhesion on a fouling release material.

    PubMed

    Guo, Shifeng; Khoo, Boo Cheong; Teo, Serena Lay Ming; Zhong, Shaoping; Lim, Chwee Teck; Lee, Heow Pueh

    2014-03-01

    In our earlier studies, we have demonstrated that low and high intensity ultrasound can prevent barnacle cyprid settlement. In this study, we found that ultrasound treatment reduced the adhesion of newly metamorphosed barnacles up to 2 days' old. This was observed in the reduction of adhesion strength of the newly settled barnacles from ultrasound treated cyprids on silicone substrate compared to the adhesion strength of barnacles metamorphosed from cyprids not exposed to ultrasound. Atomic force microscopy (AFM) was used to analyze the effect of ultrasound on barnacle cyprid footprints (FPs), which are protein adhesives secreted when the larvae explore surfaces. The ultrasound treated cyprids were found to secrete less FPs, which appeared to spread a larger area than those generated by untreated cyprids. The evidence from this study suggests that ultrasound treatment results in a reduced cyprid settlement and footprint secretion, and may affect the subsequent recruitment of barnacles onto fouling release surfaces by reducing the ability of early settlement stage of barnacles (up to 2 days' old) from firmly adhering to the substrates. Ultrasound therefore can be used in combination with fouling release coatings to offer a more efficient antifouling strategy. PMID:24333559

  6. Antitumor effects of combining tumor radiation with the antivascular action of ultrasound stimulated microbubbles

    PubMed Central

    Ji, Yanlei; Han, Zhen; Shao, Limei; Zhao, Yuehuan

    2015-01-01

    Objective: More and more evidence indicates tumor vasculature plays an important role in tumor radiation response. In this study, we investigated ultrasound stimulated microbubbles to enhance the effects of radiation. Methods: Human bladder cancer HT-1376 xenografts in severe combined immuno-deficient mice were used. High-frequency (25 MHz) ultrasound was used to image tumor responses caused by ultrasound-stimulated microbubbles in combination with radiation. Human bladder xenografts grown in severe combined immunodeficiency (SCID) mice were treated using microbubbles stimulated with ultrasound at 250, 570, or 750 kPa, and exposed to 0, 2, or 8 Gy of radiation. Tumors were imaged prior to treatment and 24 hours after treatment. Spectral analysis of images acquired from treated tumors revealed overall increases in ultrasound backscatter intensity and the spectral intercept parameter. Results: There existed a synergistic effect in vivo with combined single treatments of ultrasound-stimulated microbubble vascular perturbation and radiation inducing an over 10-fold greater cell kill with combined treatments. We further demonstrate that induction of ceramide-related endothelial cell apoptosis, leading to vascular disruption, is a causative mechanism. In vivo experiments with ultrasound and bubbles permit radiation doses to be decreased significantly for comparable effect. Conclusion: We envisage this unique combined ultrasound-based vascular perturbation and radiation treatment method being used to enhance the effects of radiation in a tumor, leading to greater tumor eradication. PMID:26617705

  7. Acoustically active liposome-nanobubble complexes for enhanced ultrasonic imaging and ultrasound-triggered drug delivery.

    PubMed

    Nguyen, An T; Wrenn, Steven P

    2014-01-01

    Ultrasound is well known as a safe, reliable imaging modality. A historical limitation of ultrasound, however, was its inability to resolve structures at length scales less than nominally 20 µm, which meant that classical ultrasound could not be used in applications such as echocardiography and angiogenesis where one requires the ability to image small blood vessels. The advent of ultrasound contrast agents, or microbubbles, removed this limitation and ushered in a new wave of enhanced ultrasound applications. In recent years, the microbubbles have been designed to achieve yet another application, namely ultrasound-triggered drug delivery. Ultrasound contrast agents are thus tantamount to 'theranostic' vehicles, meaning they can do both therapy (drug delivery) and imaging (diagnostics). The use of ultrasound contrast agents as drug delivery vehicles, however, is perhaps less than ideal when compared to traditional drug delivery vehicles (e.g., polymeric microcapsules and liposomes) which have greater drug carrying capacities. The drawback of the traditional drug delivery vehicles is that they are not naturally acoustically active and cannot be used for imaging. The notion of a theranostic vehicle is sufficiently intriguing that many attempts have been made in recent years to achieve a vehicle that combines the echogenicity of microbubbles with the drug carrying capacity of liposomes. The attempts can be classified into three categories, namely entrapping, tethering, and nesting. Of these, nesting is the newest-and perhaps the most promising. PMID:24459007

  8. Heel Ultrasound Scan in Detecting Osteoporosis in Low Trauma Fracture Patients

    PubMed Central

    Hashmi, Faiz R.; Elfandi, Khaled O.

    2016-01-01

    Osteoporosis is the most common metabolic disease with significant impact on the morbidity and mortality of affected patients. Osteoporosis has a significant impact on the economy worldwide. The aim of this study was to find out whether heel ultrasound is as good as central bone densitometry scanning in diagnosing osteoporosis in patients who are at high risk of osteoporosis. This was a prospective study of patients comparing heel ultrasound to central bone densitometry scanning (dual X-ray absorptiometry, DEXA) in patients. The recruited patients attended for a DEXA scan of the left hip and lumbar spine. All subjects had an ultrasound of the left heel using the quantitative heel ultrasound machine. The results of DEXA scan were blinded from the results of ultrasound and vice versa. There were 59 patients who took part in the study, 12 men and 47 women. The mean age was 66 years (SD 11.9) and mean weight was 62.5 kg (SD 10.7). The sensitivity and specificity of the ultrasound heel test to predict osteoporosis were 53% (95%CI: 29-77) and 86% (95%CI: 75-96) respectively. Specificity for predicting bone mineral density (BMD)-defined osteoporosis was high (86%), but sensitivity was low (53%). A heel ultrasound result in the osteoporotic range was highly predictive of BMD-defined osteoporosis. A positive ultrasound heel test in high risk patients is more useful in ruling in osteoporosis than a negative test to rule out osteoporosis. PMID:27433300

  9. Projection-reflection ultrasound images using PE-CMOS sensor: a preliminary bone fracture study

    NASA Astrophysics Data System (ADS)

    Lo, Shih-Chung B.; Liu, Chu-Chuan; Freedman, Matthew T.; Mun, Seong-Ki; Kula, John; Lasser, Marvin E.; Lasser, Bob; Wang, Yue Joseph

    2008-03-01

    In this study, we investigated the characteristics of the ultrasound reflective image obtained by a CMOS sensor array coated with piezoelectric material (PE-CMOS). The laboratory projection-reflection ultrasound prototype consists of five major components: an unfocused ultrasound transducer, an acoustic beam splitter, an acoustic compound lens, a PE-CMOS ultrasound sensing array (Model I400, Imperium Inc. Silver Spring, MD), and a readout circuit system. The prototype can image strong reflective materials such as bone and metal. We found this projection-reflection ultrasound prototype is able to reveal hairline bone fractures with and without intact skin and tissue. When compared, the image generated from a conventional B-scan ultrasound on the same bone fracture is less observable. When it is observable with the B-scan system, the fracture or crack on the surface only show one single spot of echo due to its scan geometry. The corresponding image produced from the projection-reflection ultrasound system shows a bright blooming strip on the image clearly indicating the fracture on the surface of the solid material. Speckles of the bone structure are also observed in the new ultrasound prototype. A theoretical analysis is provided to link the signals as well as speckles detected in both systems.

  10. Low-Power 2-MHz Pulsed-Wave Transcranial Ultrasound Reduces Ischemic Brain Damage in Rats.

    PubMed

    Alexandrov, Andrei V; Barlinn, Kristian; Strong, Roger; Alexandrov, Anne W; Aronowski, Jaroslaw

    2011-09-01

    It is largely unknown whether prolonged insonation with ultrasound impacts the ischemic brain tissue by itself. Our goal was to evaluate safety and the effect of high-frequency ultrasound on infarct volume in rats. Thirty-two Long-Evans rats with permanent middle cerebral and carotid artery occlusions received either 2-MHz ultrasound at two levels of insonation power (128 or 10 mW) or no ultrasound (controls). We measured cerebral hemorrhage, indirect and direct infarct volume as well as edema volume at 24 h. No cerebral hemorrhages were detected in all animals. Exposure to low-power (10 mW) ultrasound resulted in a significantly decreased indirect infarct volume (p = 0.0039), direct infarct volume (p = 0.0031), and brain edema volume (p = 0.01) compared with controls. High-power (128 mW) ultrasound had no significant effects. An additional experiment with India ink showed a greater intravascular penetration of dye into ischemic tissues exposed to low-power ultrasound. Insonation with high-frequency, low-power ultrasound reduces ischemic brain damage in rat. Its effect on edema reduction and possible promotion of microcirculation could be used to facilitate drug and nutrient delivery to ischemic areas. PMID:24323655

  11. Heel Ultrasound Scan in Detecting Osteoporosis in Low Trauma Fracture Patients.

    PubMed

    Hashmi, Faiz R; Elfandi, Khaled O

    2016-06-27

    Osteoporosis is the most common metabolic disease with significant impact on the morbidity and mortality of affected patients. Osteoporosis has a significant impact on the economy worldwide. The aim of this study was to find out whether heel ultrasound is as good as central bone densitometry scanning in diagnosing osteoporosis in patients who are at high risk of osteoporosis. This was a prospective study of patients comparing heel ultrasound to central bone densitometry scanning (dual X-ray absorptiometry, DEXA) in patients. The recruited patients attended for a DEXA scan of the left hip and lumbar spine. All subjects had an ultrasound of the left heel using the quantitative heel ultrasound machine. The results of DEXA scan were blinded from the results of ultrasound and vice versa. There were 59 patients who took part in the study, 12 men and 47 women. The mean age was 66 years (SD 11.9) and mean weight was 62.5 kg (SD 10.7). The sensitivity and specificity of the ultrasound heel test to predict osteoporosis were 53% (95%CI: 29-77) and 86% (95%CI: 75-96) respectively. Specificity for predicting bone mineral density (BMD)-defined osteoporosis was high (86%), but sensitivity was low (53%). A heel ultrasound result in the osteoporotic range was highly predictive of BMD-defined osteoporosis. A positive ultrasound heel test in high risk patients is more useful in ruling in osteoporosis than a negative test to rule out osteoporosis. PMID:27433300

  12. Design of a Thermoacoustic Sensor for Low Intensity Ultrasound Measurements Based on an Artificial Neural Network.

    PubMed

    Xing, Jida; Chen, Jie

    2015-01-01

    In therapeutic ultrasound applications, accurate ultrasound output intensities are crucial because the physiological effects of therapeutic ultrasound are very sensitive to the intensity and duration of these applications. Although radiation force balance is a benchmark technique for measuring ultrasound intensity and power, it is costly, difficult to operate, and compromised by noise vibration. To overcome these limitations, the development of a low-cost, easy to operate, and vibration-resistant alternative device is necessary for rapid ultrasound intensity measurement. Therefore, we proposed and validated a novel two-layer thermoacoustic sensor using an artificial neural network technique to accurately measure low ultrasound intensities between 30 and 120 mW/cm2. The first layer of the sensor design is a cylindrical absorber made of plexiglass, followed by a second layer composed of polyurethane rubber with a high attenuation coefficient to absorb extra ultrasound energy. The sensor determined ultrasound intensities according to a temperature elevation induced by heat converted from incident acoustic energy. Compared with our previous one-layer sensor design, the new two-layer sensor enhanced the ultrasound absorption efficiency to provide more rapid and reliable measurements. Using a three-dimensional model in the K-wave toolbox, our simulation of the ultrasound propagation process demonstrated that the two-layer design is more efficient than the single layer design. We also integrated an artificial neural network algorithm to compensate for the large measurement offset. After obtaining multiple parameters of the sensor characteristics through calibration, the artificial neural network is built to correct temperature drifts and increase the reliability of our thermoacoustic measurements through iterative training about ten seconds. The performance of the artificial neural network method was validated through a series of experiments. Compared to our previous

  13. Design of a Thermoacoustic Sensor for Low Intensity Ultrasound Measurements Based on an Artificial Neural Network

    PubMed Central

    Xing, Jida; Chen, Jie

    2015-01-01

    In therapeutic ultrasound applications, accurate ultrasound output intensities are crucial because the physiological effects of therapeutic ultrasound are very sensitive to the intensity and duration of these applications. Although radiation force balance is a benchmark technique for measuring ultrasound intensity and power, it is costly, difficult to operate, and compromised by noise vibration. To overcome these limitations, the development of a low-cost, easy to operate, and vibration-resistant alternative device is necessary for rapid ultrasound intensity measurement. Therefore, we proposed and validated a novel two-layer thermoacoustic sensor using an artificial neural network technique to accurately measure low ultrasound intensities between 30 and 120 mW/cm2. The first layer of the sensor design is a cylindrical absorber made of plexiglass, followed by a second layer composed of polyurethane rubber with a high attenuation coefficient to absorb extra ultrasound energy. The sensor determined ultrasound intensities according to a temperature elevation induced by heat converted from incident acoustic energy. Compared with our previous one-layer sensor design, the new two-layer sensor enhanced the ultrasound absorption efficiency to provide more rapid and reliable measurements. Using a three-dimensional model in the K-wave toolbox, our simulation of the ultrasound propagation process demonstrated that the two-layer design is more efficient than the single layer design. We also integrated an artificial neural network algorithm to compensate for the large measurement offset. After obtaining multiple parameters of the sensor characteristics through calibration, the artificial neural network is built to correct temperature drifts and increase the reliability of our thermoacoustic measurements through iterative training about ten seconds. The performance of the artificial neural network method was validated through a series of experiments. Compared to our previous

  14. Ultrasound in assisted reproductive technology.

    PubMed

    Porter, Misty Blanchette

    2008-05-01

    Transvaginal ultrasound-guided oocyte retrieval is the gold standard for in vitro fertilization (IVF) treatment. Despite its relative safety, oocyte retrieval is associated with risk to the adjacent pelvic organs, bleeding, and pelvic infection. The embryo transfer (ET) procedure is considered a crucial step in an IVF cycle. The success of the ET is dependent upon multiple factors including embryo quality, proper endometrial receptivity, and the technique by which the embryos are transferred. Optimizing the technique of ET would therefore provide the best chance for pregnancy. No standard evidence-based protocol exists, but ET with ultrasound guidance has been shown to significantly increase the chance of embryo implantation, an ongoing pregnancy, and a live birth and to improve the ease of transfer. Identifying appropriate ultrasound-guided simulation training techniques in ET would ensure adequate fellowship training without affecting the outcome of assisted reproductive technology cycles. PMID:18504701

  15. Power ultrasound in meat processing.

    PubMed

    Alarcon-Rojo, A D; Janacua, H; Rodriguez, J C; Paniwnyk, L; Mason, T J

    2015-09-01

    Ultrasound has a wide range of applications in various agricultural sectors. In food processing, it is considered to be an emerging technology with the potential to speed up processes without damaging the quality of foodstuffs. Here we review the reports on the applications of ultrasound specifically with a view to its use in meat processing. Emphasis is placed on the effects on quality and technological properties such as texture, water retention, colour, curing, marinating, cooking yield, freezing, thawing and microbial inhibition. After the literature review it is concluded that ultrasound is a useful tool for the meat industry as it helps in tenderisation, accelerates maturation and mass transfer, reduces cooking energy, increases shelf life of meat without affecting other quality properties, improves functional properties of emulsified products, eases mould cleaning and improves the sterilisation of equipment surfaces. PMID:25974043

  16. Ultrasound: From Earth to Space

    PubMed Central

    Law, Jennifer; Macbeth, Paul. B.

    2011-01-01

    Ultrasonography is a versatile imaging modality that offers many advantages over radiography, computed tomography, and magnetic resonance imaging. On Earth, the use of ultrasound has become standard in many areas of medicine including diagnosis of medical and surgical diseases, management of obstetric and gynecologic conditions, assessment of critically ill patients, and procedural guidance. Advances in telecommunications have enabled remotely-guided ultrasonography for both geographically isolated populations and astronauts aboard the International Space Station. While ultrasound has traditionally been used in spaceflight to study anatomical and physiological adaptations to microgravity and evaluate countermeasures, recent years have seen a growth of applications adapted from terrestrial techniques. Terrestrial, remote, and space applications for ultrasound are reviewed in this paper. PMID:22399873

  17. Neuromuscular Ultrasound of Cranial Nerves

    PubMed Central

    Tawfik, Eman A.; Cartwright, Michael S.

    2015-01-01

    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. PMID:25851889

  18. Clinical applications of doppler ultrasound

    SciTech Connect

    Taylor, K.J.W.; Burns, P.N.; Well, P.N.T.

    1987-01-01

    This book introduces a guide to the physical principles and instrumentation of duplex Doppler ultrasound and its applications in obstetrics, gynecology, neonatology, gastroentology, and evaluation of peripheral vascular disease. The book provides information needed to perform Doppler ultrasound examinations and interpret the results. An introduction to Doppler physics and instrumentation is followed by a thorough review of hemodynamics, which explains the principles underlying interpretation of Doppler signals. Of special note is the state-of-the-art coverage of new applications of Doppler in recognition of high-risk pregnancy, diagnosis of intrauterine growth retardation, investigation of neonatal blood flow, evaluation of first-trimester pregnancy, and diagnosis of gastrointestinal disease. The book also offers guidelines on the use of Doppler ultrasound in diagnosing carotid disease, deep venous thrombosis, and aorta/femoral disease.

  19. Ultrasound technology: A decision-making tool

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An ultrasound demonstration was conducted for participants (~ 110 people) of the Arkansas Cattle Grower’s Conference, Hope, AR. Evaluation of live animals with ultrasound technology allows beef producers the ability to make selection and management decisions. Specifically, ultrasound at the conclu...

  20. 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)

  1. Ultrasound of wrist and hand masses.

    PubMed

    Guerini, H; Morvan, G; Vuillemin, V; Campagna, R; Thevenin, F; Larousserie, F; Leclercq, C; Le Viet, D; Drapé, J-L

    2015-12-01

    Ultrasound is a useful tool to investigate soft tissue masses in the wrist and hand. In most situations ultrasound helps distinguish between a cyst and a tissue mass. This article provides a simple clinical approach to the use of ultrasound imaging for the diagnosis and preoperative assessment of wrist and hand masses. PMID:26625731

  2. 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

  3. Ultrasound improves the renneting properties of milk.

    PubMed

    Liu, Zheng; Juliano, Pablo; Williams, Roderick P W; Niere, Julie; Augustin, Mary Ann

    2014-11-01

    The effects of ultrasound application on skim milk (10% w/w total solids at natural pH 6.7 or alkali-adjusted to pH 8.0) prior to the renneting of milk at pH 6.7 were examined. Skim milk, made by reconstituting skim milk powder, was sonicated at 20kHz and 30°C (dissipated power density 286kJkg(-1)) in an ultrasonic reactor. The rennet gelation time, curd firming rate, curd firmness, and the connectivity of the rennet gel network were improved significantly in rennet gels made from milk ultrasonicated at pH 8.0 and re-adjusted back to pH 6.7 compared to those made from milk sonicated at pH 6.7. These renneting properties were also improved in milk sonicated at pH 6.7 compared to those of the non-sonicated control milk. The improvements in renneting behavior were related to ultrasound-induced changes to the proteins in the milk. This study showed that ultrasonication has potential to be used as an intervention to manipulate the renneting properties of milk for more efficient manufacturing of cheese. PMID:24751292

  4. Ultrasound beamforming using compressed data.

    PubMed

    Li, Yen-Feng; Li, Pai-Chi

    2012-05-01

    The rapid advancements in electronics technologies have made software-based beamformers for ultrasound array imaging feasible, thus facilitating the rapid development of high-performance and potentially low-cost systems. However, one challenge to realizing a fully software-based system is transferring data from the analog front end to the software back end at rates of up to a few gigabits per second. This study investigated the use of data compression to reduce the data transfer requirements and optimize the associated trade-off with beamforming quality. JPEG and JPEG2000 compression techniques were adopted. The acoustic data of a line phantom were acquired with a 128-channel array transducer at a center frequency of 3.5 MHz, and the acoustic data of a cyst phantom were acquired with a 64-channel array transducer at a center frequency of 3.33 MHz. The receive-channel data associated with each transmit event are separated into 8 × 8 blocks and several tiles before JPEG and JPEG2000 data compression is applied, respectively. In one scheme, the compression was applied to raw RF data, while in another only the amplitude of baseband data was compressed. The maximum compression ratio of RF data compression to produce an average error of lower than 5 dB was 15 with JPEG compression and 20 with JPEG2000 compression. The image quality is higher with baseband amplitude data compression than with RF data compression; although the maximum overall compression ratio (compared with the original RF data size), which was limited by the data size of uncompressed phase data, was lower than 12, the average error in this case was lower than 1 dB when the compression ratio was lower than 8. PMID:22434817

  5. New Ultrasound Modalities in Rheumatology.

    PubMed

    Gutierrez, Marwin; Okano, Tadashi; Reginato, Anthony M; Cazenave, Tomas; Ventura-Rios, Lucio; Bertolazzi, Chiara; Pineda, Carlos

    2015-12-01

    Over the years, ultrasound (US) has accumulated important evidence supporting its relevant role for the assessment of inflammatory processes of different rheumatologic diseases, as well as in the follow-up in assessing the response to different therapeutic approaches. This has been possible because of the increase in training, competency, and knowledge, as well as the rapid progress in the US technologies.Currently, some US machines can be equipped by sophisticated software modalities (i.e., 3-dimensional US, elastosonography, automated cardiovascular software, and fusion imaging) that can augment US traditional role as a safe, fast, and easy-to-perform modality and giving it new life and increased relevance in rheumatology. In this article, we evaluated the US developments, from conventional B-mode to more sophisticated technologies, and their potential clinical impact in the field of rheumatology.Three-dimensional US can improve the accuracy of the assessment of bone erosions and the quantification of power Doppler because of its multiplanar view including coronal, axial and sagital view. Elastosonography is still looking for its role in rheumatology. Preliminary works induce us to consider it as a promise tool for the assessment of tendon pathology and skin of patients with connective tissue disorders. The automated method for the measurement of carotid intima-media thickness permits a rapid and accurate assessment. The preliminary published data showed that it is reliable, and valid compared to the traditional method; they also support the future of rheumatologists as the direct operators in evaluating the cardiovascular risk in daily practice. Fusion imaging increases the diagnostic power of US, displaying simultaneously in the monitor, the US image, and the corresponding computed tomography/magnetic resonance imaging image. However, there are no sufficient data supporting its application in daily rheumatologic practice. PMID:26587854

  6. [Ultrasound examination of hidradenitis suppurativa].

    PubMed

    Martorell, A; Segura Palacios, J M

    2015-11-01

    Hidradenitis suppurativa is a debilitating chronic, recurrent, inflammatory cutaneous disease of the hair follicle that usually presents with painful, deep and inflamed lesions in the areas of the body with apocrine glands, most frequently the axillary, groin and anogenital regions. This entity is difficult to manage since it can be difficult to determine the true nature and extension of the lesions. Cutaneous ultrasound allows real-time visualization of the cutaneous structures under examination, defining the type of lesion, its anatomical extension, and the degree of inflammatory activity, which affects adequate patient management. The present review analyses the importance of ultrasound in the assessment of patients with hidradenitis suppurativa. PMID:26895939

  7. Enzyme activity determination using ultrasound

    NASA Astrophysics Data System (ADS)

    Holmes, M. J.; Southworth, T.; Watson, N. G.; Povey, M. J. W.

    2014-04-01

    Here are presented the results of a novel approach to the measurement of enzyme reaction rates in which ultrasound velocity measurement is used. Our results show enzyme activity is observable, in the acoustic context, and that furthermore this offers the potential to estimate the rate of reaction over different substrate concentrations and temperatures. Findings are corroborated with optical microscopy and rheological measurements. Ultrasound velocity measurement can be performed without the need for aliquot extraction and offers an efficient, non-invasive and dynamic method to monitor enzyme activity.

  8. Vaginal ultrasound in assisted reproduction.

    PubMed

    Wikland, M

    1992-06-01

    Vaginal scanning of the ovaries and the uterus is a diagnostic and monitoring tool of utmost importance in assisted conception. Although the value of ultrasound for monitoring follicular growth has been questioned, few groups working on assisted conception do not use it. Follicle aspiration under the guidance of vaginal sonography is the method of choice. With such a simple and safe technique available, using laparoscopy for retrieving oocytes for assisted conception cannot be justified. The introduction of ultrasound-guided transvaginal retrograde tubal catheterization has meant that laparoscopic GIFT and ZIFT procedures will probably soon be unnecessary. Vaginal sonography is one of the most clinically important diagnostic instruments in assisted conception. PMID:1424325

  9. Geometric reconstruction using tracked ultrasound strain imaging

    NASA Astrophysics Data System (ADS)

    Pheiffer, Thomas S.; Simpson, Amber L.; Ondrake, Janet E.; Miga, Michael I.

    2013-03-01

    The accurate identification of tumor margins during neurosurgery is a primary concern for the surgeon in order to maximize resection of malignant tissue while preserving normal function. The use of preoperative imaging for guidance is standard of care, but tumor margins are not always clear even when contrast agents are used, and so margins are often determined intraoperatively by visual and tactile feedback. Ultrasound strain imaging creates a quantitative representation of tissue stiffness which can be used in real-time. The information offered by strain imaging can be placed within a conventional image-guidance workflow by tracking the ultrasound probe and calibrating the image plane, which facilitates interpretation of the data by placing it within a common coordinate space with preoperative imaging. Tumor geometry in strain imaging is then directly comparable to the geometry in preoperative imaging. This paper presents a tracked ultrasound strain imaging system capable of co-registering with preoperative tomograms and also of reconstructing a 3D surface using the border of the strain lesion. In a preliminary study using four phantoms with subsurface tumors, tracked strain imaging was registered to preoperative image volumes and then tumor surfaces were reconstructed using contours extracted from strain image slices. The volumes of the phantom tumors reconstructed from tracked strain imaging were approximately between 1.5 to 2.4 cm3, which was similar to the CT volumes of 1.0 to 2.3 cm3. Future work will be done to robustly characterize the reconstruction accuracy of the system.

  10. Automatic assessment of ultrasound image usability

    NASA Astrophysics Data System (ADS)

    Valente, Luca; Funka-Lea, Gareth; Stoll, Jeffrey

    2011-03-01

    We present a novel and efficient approach for evaluating the quality of ultrasound images. Image acquisition is sensitive to skin contact and transducer orientation and requires both time and technical skill to be done properly. Images commonly suffer degradation due to acoustic shadows and signal attenuation, which present as regions of low signal intensity masking anatomical details and making the images partly or totally unusable. As ultrasound image acquisition and analysis becomes increasingly automated, it is beneficial to also automate the estimation of image quality. Towards this end, we present an algorithm that classifies regions of an image as usable or un-usable. Example applications of this algorithm include improved compounding of free-hand 3D ultrasound volumes by eliminating unusable data and improved automatic feature detection by limiting detection to only usable areas. The algorithm operates in two steps. First, it classifies the image into bright areas, likely to have image content, and dark areas, likely to have no content. Second, it classifies the dark areas into unusable (i.e. due to shadowing and/or signal loss) and usable (i.e. anatomically accurate dark regions, such as with a blood vessel) sub-areas. The classification considers several factors, including statistical information, gradient intensity and geometric properties such as shape and relative position. Relative weighting of factors was obtained through the training of a Support Vector Machine. Classification results for both human and phantom images are presented and compared to manual classifications. This method achieves 91% sensitivity and 91% specificity for usable regions of human scans.

  11. Bedside ultrasound can predict nonalcoholic fatty liver disease in the hands of clinicians using a prototype image.

    PubMed

    Riley, Thomas R; Mendoza, Alfredo; Bruno, Michael A

    2006-05-01

    This study was designed to test whether ultrasound can be used to diagnose nonalcoholic fatty liver disease (NAFLD) utilizing a prototype. We collected 115 ultrasounds. A prototype was chosen that represented NAFLD; 5 features of NAFLD prototype were described. Ultrasounds were read blinded to diagnosis as matching prototype or not. A 20-minute teaching session was made to a group of 15 providers. Ten ultrasounds were presented for comparison to prototype with intraobserver reliability measured. Of 20 patients shown by liver biopsy to have NAFLD, 16 were successfully predicted by comparison to the prototype (sensitivity 80%). In 94 of 95 cases, ultrasound predicted those without NAFLD (specificity 99%). The positive predictive value was 94% and negative predictive value 96%. Training results showed substantial agreement with a kappa score of 0.76 with 95% of cases identified correctly. In conclusion, physicians can apply a bedside ultrasound to identify NAFLD when compared to prototype. PMID:16783524

  12. CT and Ultrasound Guided Stereotactic High Intensity Focused Ultrasound (HIFU)

    SciTech Connect

    Wood, Bradford J.; Frenkel, V.; Viswanathan, A.; Dromi, S.; Oh, K.; Kam, A.; Li, K. C. P.; Yanof, J.; Bauer, C.; Kruecker, J.; Seip, R.

    2006-05-08

    To demonstrate the feasibility of CT and B-mode Ultrasound (US) targeted HIFU, a prototype coaxial focused ultrasound transducer was registered and integrated to a CT scanner. CT and diagnostic ultrasound were used for HIFU targeting and monitoring, with the goals of both thermal ablation and non-thermal enhanced drug delivery. A 1 megahertz coaxial ultrasound transducer was custom fabricated and attached to a passive position-sensing arm and an active six degree-of-freedom robotic arm via a CT stereotactic frame. The outer therapeutic transducer with a 10 cm fixed focal zone was coaxially mounted to an inner diagnostic US transducer (2-4 megahertz, Philips Medical Systems). This coaxial US transducer was connected to a modified commercial focused ultrasound generator (Focus Surgery, Indianapolis, IN) with a maximum total acoustic power of 100 watts. This pre-clinical paradigm was tested for ability to heat tissue in phantoms with monitoring and navigation from CT and live US. The feasibility of navigation via image fusion of CT with other modalities such as PET and MRI was demonstrated. Heated water phantoms were tested for correlation between CT numbers and temperature (for ablation monitoring). The prototype transducer and integrated CT/US imaging system enabled simultaneous multimodality imaging and therapy. Pre-clinical phantom models validated the treatment paradigm and demonstrated integrated multimodality guidance and treatment monitoring. Temperature changes during phantom cooling corresponded to CT number changes. Contrast enhanced or non-enhanced CT numbers may potentially be used to monitor thermal ablation with HIFU. Integrated CT, diagnostic US, and therapeutic focused ultrasound bridges a gap between diagnosis and therapy. Preliminary results show that the multimodality system may represent a relatively inexpensive, accessible, and simple method of both targeting and monitoring HIFU effects. Small animal pre-clinical models may be translated to large

  13. CT and Ultrasound Guided Stereotactic High Intensity Focused Ultrasound (HIFU)

    NASA Astrophysics Data System (ADS)

    Wood, Bradford J.; Yanof, J.; Frenkel, V.; Viswanathan, A.; Dromi, S.; Oh, K.; Kruecker, J.; Bauer, C.; Seip, R.; Kam, A.; Li, K. C. P.

    2006-05-01

    To demonstrate the feasibility of CT and B-mode Ultrasound (US) targeted HIFU, a prototype coaxial focused ultrasound transducer was registered and integrated to a CT scanner. CT and diagnostic ultrasound were used for HIFU targeting and monitoring, with the goals of both thermal ablation and non-thermal enhanced drug delivery. A 1 megahertz coaxial ultrasound transducer was custom fabricated and attached to a passive position-sensing arm and an active six degree-of-freedom robotic arm via a CT stereotactic frame. The outer therapeutic transducer with a 10 cm fixed focal zone was coaxially mounted to an inner diagnostic US transducer (2-4 megahertz, Philips Medical Systems). This coaxial US transducer was connected to a modified commercial focused ultrasound generator (Focus Surgery, Indianapolis, IN) with a maximum total acoustic power of 100 watts. This pre-clinical paradigm was tested for ability to heat tissue in phantoms with monitoring and navigation from CT and live US. The feasibility of navigation via image fusion of CT with other modalities such as PET and MRI was demonstrated. Heated water phantoms were tested for correlation between CT numbers and temperature (for ablation monitoring). The prototype transducer and integrated CT/US imaging system enabled simultaneous multimodality imaging and therapy. Pre-clinical phantom models validated the treatment paradigm and demonstrated integrated multimodality guidance and treatment monitoring. Temperature changes during phantom cooling corresponded to CT number changes. Contrast enhanced or non-enhanced CT numbers may potentially be used to monitor thermal ablation with HIFU. Integrated CT, diagnostic US, and therapeutic focused ultrasound bridges a gap between diagnosis and therapy. Preliminary results show that the multimodality system may represent a relatively inexpensive, accessible, and simple method of both targeting and monitoring HIFU effects. Small animal pre-clinical models may be translated to large

  14. Measurement of corneal tangent modulus using ultrasound indentation.

    PubMed

    Wang, Li-Ke; Huang, Yan-Ping; Tian, Lei; Kee, Chea-Su; Zheng, Yong-Ping

    2016-09-01

    Biomechanical properties are potential information for the diagnosis of corneal pathologies. An ultrasound indentation probe consisting of a load cell and a miniature ultrasound transducer as indenter was developed to detect the force-indentation relationship of the cornea. The key idea was to utilize the ultrasound transducer to compress the cornea and to ultrasonically measure the corneal deformation with the eyeball overall displacement compensated. Twelve corneal silicone phantoms were fabricated with different stiffness for the validation of measurement with reference to an extension test. In addition, fifteen fresh porcine eyes were measured by the developed system in vitro. The tangent moduli of the corneal phantoms calculated using the ultrasound indentation data agreed well with the results from the tensile test of the corresponding phantom strips (R(2)=0.96). The mean tangent moduli of the porcine corneas measured by the proposed method were 0.089±0.026MPa at intraocular pressure (IOP) of 15mmHg and 0.220±0.053MPa at IOP of 30mmHg, respectively. The coefficient of variation (CV) and intraclass correlation coefficient (ICC) of tangent modulus were 14.4% and 0.765 at 15mmHg, and 8.6% and 0.870 at 30mmHg, respectively. The preliminary study showed that ultrasound indentation could be applied to the measurement of corneal tangent modulus with good repeatability and improved measurement accuracy compared to conventional surface displacement-based measurement method. The ultrasound indentation can be a potential tool for the corneal biomechanical properties measurement in vivo. PMID:27262352

  15. Cumulative phase delay imaging - A new contrast enhanced ultrasound modality

    SciTech Connect

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

    2015-10-28

    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{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.

  16. 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.

  17. Quantitative Ultrasound: Transition from the Laboratory to the Clinic

    NASA Astrophysics Data System (ADS)

    Hall, Timothy

    2014-03-01

    There is a long history of development and testing of quantitative methods in medical ultrasound. From the initial attempts to scan breasts with ultrasound in the early 1950's, there was a simultaneous attempt to classify tissue as benign or malignant based on the appearance of the echo signal on an oscilloscope. Since that time, there has been substantial improvement in the ultrasound systems used, the models to describe wave propagation in random media, the methods of signal detection theory, and the combination of those models and methods into parameter estimation techniques. One particularly useful measure in ultrasonics is the acoustic differential scattering cross section per unit volume in the special case of the 180° (as occurs in pulse-echo ultrasound imaging) which is known as the backscatter coefficient. The backscatter coefficient, and parameters derived from it, can be used to objectively measure quantities that are used clinically to subjectively describe ultrasound images. For example, the ``echogenicity'' (relative ultrasound image brightness) of the renal cortex is commonly compared to that of the liver. Investigating the possibility of liver disease, it is assumed the renal cortex echogenicity is normal. Investigating the kidney, it is assumed the liver echogenicity is normal. Objective measures of backscatter remove these assumptions. There is a 30-year history of accurate estimates of acoustic backscatter coefficients with laboratory systems. Twenty years ago that ability was extended to clinical imaging systems with array transducers. Recent studies involving multiple laboratories and a variety of clinical imaging systems has demonstrated system-independent estimates of acoustic backscatter coefficients in well-characterized media (agreement within about 1.5dB over about a 1-decade frequency range). Advancements that made this possible, transition of this and similar capabilities into medical practice and the prospects for quantitative image

  18. A super-resolution ultrasound method for brain vascular mapping

    PubMed Central

    O'Reilly, Meaghan A.; Hynynen, Kullervo

    2013-01-01

    Purpose: High-resolution vascular imaging has not been achieved in the brain due to limitations of current clinical imaging modalities. The authors present a method for transcranial ultrasound imaging of single micrometer-size bubbles within a tube phantom. Methods: Emissions from single bubbles within a tube phantom were mapped through an ex vivo human skull using a sparse hemispherical receiver array and a passive beamforming algorithm. Noninvasive phase and amplitude correction techniques were applied to compensate for the aberrating effects of the skull bone. The positions of the individual bubbles were estimated beyond the diffraction limit of ultrasound to produce a super-resolution image of the tube phantom, which was compared with microcomputed tomography (micro-CT). Results: The resulting super-resolution ultrasound image is comparable to results obtained via the micro-CT for small tissue specimen imaging. Conclusions: This method provides superior resolution to deep-tissue contrast ultrasound and has the potential to be extended to provide complete vascular network imaging in the brain. PMID:24320408

  19. Ultrasound in differential diagnosis of periapical radiolucencies: A radiohistopathological study

    PubMed Central

    Khambete, Neha; Kumar, Rahul

    2015-01-01

    Objectives: To evaluate the efficacy of ultrasound in differential diagnosis of periapical radiolucencies. Materials and Methods: Ten patients aged between 19 years and 40 years with periapical lesions associated with anterior maxillary or mandibular teeth were selected and consented for the study. Pre-operative periapical radiographs were obtained. Measurements and provisional diagnoses of the apical areas were made by two specialist observers on two separate occasions. Preoperative ultrasound examinations with Doppler flowmetry were then performed and the images assessed by two specialist observers for the size, contents, vascular supply and a provisional diagnosis made as to whether the lesion was a cyst or granuloma. Endodontic surgery was performed including curettage of the apical tissues to enable histopathological investigation, which provided the gold standard diagnosis. All measurements and findings were compared and statistically analyzed. Results: Total 10 lesions were identified in 10 patients. On periapical radiographs, lesions were readily identified but observers were unable to differentiate granuloma from cyst using either modality. Where sufficient buccal cortical bone had been resorbed, ultrasound imaging was simple but underestimated the size of the lesions compared with periapical radiographs. In all cases, the ultrasound diagnosis agreed with the histopathological gold standard. Conclusion: Ultrasonography (USG) can provide accurate information about the nature of intraosseous lesions of the jaws before any surgical procedure. It is proposed that USG with Doppler flowmetry can provide an additional diagnostic tool without invasive surgery, where treatment option is nonsurgical. PMID:25657525

  20. 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

  1. 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. PMID:26547634

  2. Effects of deep heating provided by therapeutic ultrasound on demyelinating nerves

    PubMed Central

    Aydin, Elif; Tastaban, Engin; Omurlu, Imran Kurt; Turan, Yasemin; Şendur, Ömer Faruk

    2016-01-01

    [Purpose] Physiotherapeutic heating agents are classified into two groups: superficial-heating agents and deep-heating agents. Therapeutic ultrasound is a deep-heating agent used to treat various musculosketal disorders. Numerous studies have attempted to determine the impact of ultrasound on healthy nerve conduction parameters. However, the instantaneous effects of deep heating via ultrasound on demyelinating nerves do not appear to have been described previously. The present study aimed to assess and compare the impact of ultrasound on demyelinating nerve and healthy nerve conduction parameters. [Subjects and Methods] Carpal tunnel syndrome was used as a focal demyelination model. Thirty-two hands of 25 participants with carpal tunnel syndrome were enrolled in the study. Ultrasound parameters were 3.3 MHz, 1.0 W/cm2, 8 minutes, and continuous wave. Electrodiagnostic studies were performed initially, at the midpoint (4th min), and immediately after (8th min) ultrasound application. [Results] Reduced motor conduction velocity was found in demyelinating nerves at the 4th and 8th minutes. Ulnar nerve onset latency was significantly prolonged in the 8th minute recording, compared to the initial value. There were no significant differences in relative velocity and latency changes between demyelinating and normal nerves. [Conclusion] Deep heating via ultrasound may inversely affect conduction velocity in demyelinating nerves. PMID:27190467

  3. Combination effect of ultrasound and shake as a mechanical action for textile cleaning.

    PubMed

    Gotoh, Keiko; Harayama, Kokoro; Handa, Keiko

    2015-01-01

    The ultrasonic cleaning of artificially soiled fabrics with and without shake was carried out in an aqueous anionic surfactant solution. The polyester, cotton and polyester/cotton (65/35) fabrics were soiled with oleic acid or carbon black as a model soil, and cleaned together with their original fabrics with applying ultrasound for 5min. The detergency and the soil redeposition were determined from the change in the Kubelka-Munk function of the soiled and original fabric surfaces due to the cleaning. For any fabric, the removal of oleic acid and carbon black from the soiled fabric and their redeposition onto the original fabric increased with increasing electric power consumption of ultrasound. When ultrasound and shake were applied at the same time, the detergency further increased for any electric power consumption. The maximum detergency obtained with combination of ultrasound 340W and shake 160spm was compared with detergency obtained with Wascator, a horizontal axis drum type washer. It was found that the ultrasound/shake combination cleaning enabled efficient removal of both soils from any fabric and the detergency of the polyester fabrics was comparable to that with Wascator. The mechanical action during the washing was evaluated by two mechanical action test pieces commercially available, which indicated that the ultrasound/shake combination cleaning provided gentle mechanical action to the fabric in comparison with the drum type washer. The SEM observations showed the damage of the fabric and fiber surfaces was negligibly small after the ultrasound/shake combination washing. PMID:24910442

  4. Flat HIFU transducer with a sawtooth-shaped ultrasound radiation face

    NASA Astrophysics Data System (ADS)

    Son, Keon-Ho; Cho, Young-Ki; Kim, Dae-Seung; Kim, Myung-Deok; Kang, Kook-Jin

    2013-10-01

    High-intensity focused ultrasound (HIFU) transducers are spherically-curved in order to obtain a high intensity gain of the converged ultrasound energy at the geometrical focus. Ultrasound imaging devices monitor the procedure of HIFU treatment in ultrasound-guided HIFU systems where the image probe is positioned at the apex of the HIFU transducer, which has a spherical surface. However, the remote image probe's location yields a poor image quality compared to that obtained using conventional ultrasound imaging where the image probe is in direct contact with the surface. A phased array HIFU transducer with a new structure is suggested to overcome this limitation. The centers of the array elements are distributed over the flat surface of the transducer. However, the elements are tilted to form a geometrical focus, like a transducer with a spherically-curved surface, to obtain a high focal gain. The cross-section of the ultrasound radiation face of the transducer resembles the teeth of a saw. The acoustic field emitted from this transducer was simulated in order to design and produce the transducer. The simulation was compared with the measured sound field to verify that the transducer was correctly manufactured and designed; subsequently, the acoustic power was measured, and ultrasound images were obtained through the installation of an image probe on the transducer, which confirmed the application of this transducer to HIFU treatment.

  5. Application of Ultrasound in Medicine

    PubMed Central

    Carovac, Aladin; Smajlovic, Fahrudin; Junuzovic, Dzelaludin

    2011-01-01

    Ultrasound device, essentially, consists of a transducer, transmitter pulse generator, compensating amplifiers, the control unit for focusing, digital processors and systems for display. It is used in cases of: abdominal, cardiac, maternity, gynecological, urological and cerebrovascular examination, breast examination, and small pieces of tissue as well as in pediatric and operational review. PMID:23408755

  6. Application of ultrasound in medicine.

    PubMed

    Carovac, Aladin; Smajlovic, Fahrudin; Junuzovic, Dzelaludin

    2011-09-01

    Ultrasound device, essentially, consists of a transducer, transmitter pulse generator, compensating amplifiers, the control unit for focusing, digital processors and systems for display. It is used in cases of: abdominal, cardiac, maternity, gynecological, urological and cerebrovascular examination, breast examination, and small pieces of tissue as well as in pediatric and operational review. PMID:23408755

  7. Medical ultrasound education for bioengineers

    NASA Astrophysics Data System (ADS)

    Vaezy, Shahram

    2005-04-01

    The widespread adoption of ultrasound technologies in medicine has necessitated the development of educational programs to address the growing demand for trained expertise in both academia and industry. The demand has been especially great in the field of therapeutic ultrasound that has experienced a significant level of research and development activities in the past decade. The applications cover a wide range including cancer treatment, hemorrhage control, cardiac ablation, gene therapy, and cosmetic surgery. A comprehensive educational program in ultrasound is well suited for bioengineering departments at colleges and universities. Our educational program for students in Bioengineering at the University of Washington includes a year-long coursework covering theory and practice of ultrasound, conducting research projects, attending and presenting at weekly seminars on literature survey, presentations at scientific meetings, and attending specialized workshops offered by various institutions for specific topics. An important aspect of this training is its multi-disciplinary approach, encompassing science, engineering, and medicine. The students are required to build teams with expertise in these disciplines. Our experience shows that these students are well prepared for careers in academia, conducting cutting edge research, as well as industry, being involved in the transformation of research end-products to commercially viable technology.

  8. Diagnostic ultrasound exposure in man.

    PubMed

    Gramiak, R

    1975-09-01

    In his review of the AAPM statement on ultrasound, the author feels that allowing "some" research or demonstration on normal persons in the face of cautionary statements on as yet unknown side effects is an inconsistent position. The use of videotapes and the development of simulators hacked by data banks are offered in place of tissue phantoms. PMID:1153790

  9. Ultrasound-Guided Hip Procedures.

    PubMed

    Payne, Jeffrey M

    2016-08-01

    This article describes the techniques for performing ultrasound-guided procedures in the hip region, including intra-articular hip injection, iliopsoas bursa injection, greater trochanter bursa injection, ischial bursa injection, and piriformis muscle injection. The common indications, pitfalls, accuracy, and efficacy of these procedures are also addressed. PMID:27468669

  10. Ultrasound mediated nanoparticle drug delivery

    NASA Astrophysics Data System (ADS)

    Mullin, Lee B.

    Ultrasound is not only a powerful diagnostic tool, but also a promising therapeutic technology that can be used to improve localized drug delivery. Microbubble contrast agents are micron sized encapsulated gas filled bubbles that are administered intravenously. Originally developed to enhance ultrasound images, microbubbles are highly echogenic due to the gas core that provides a detectable impedance difference from the surrounding medium. The core also allows for controlled response of the microbubbles to ultrasound pulses. Microbubbles can be pushed using acoustic radiation force and ruptured using high pressures. Destruction of microbubbles can increase permeability at the cellular and vascular level, which can be advantageous for drug delivery. Advances in drug delivery methods have been seen with the introduction of nanoparticles, nanometer sized objects often carrying a drug payload. In chemotherapy, nanoparticles can deliver drugs to tumors while limiting systemic exposure due to abnormalities in tumor vasculature such large gaps between endothelial cells that allow nanoparticles to enter into the interstitial space; this is referred to as the enhanced permeability and retention (EPR) effect. However, this effect may be overestimated in many tumors. Additionally, only a small percentage of the injected dose accumulates in the tumor, which most the nanoparticles accumulating in the liver and spleen. It is hypothesized that combining the acoustic activity of an ultrasound contrast agent with the high payload and extravasation ability of a nanoparticle, localized delivery to the tumor with reduced systemic toxicity can be achieved. This method can be accomplished by either loading nanoparticles onto the shell of the microbubble or through a coadministration method of both nanoparticles and microbubbles. The work presented in this dissertation utilizes novel and commercial nanoparticle formulations, combined with microbubbles and a variety of ultrasound systems

  11. 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…

  12. Ultrasound of Inherited vs. Acquired Demyelinating Polyneuropathies

    PubMed Central

    Zaidman, Craig M.; Harms, Matthew B.; Pestronk, Alan

    2013-01-01

    Introduction We compared features of nerve enlargement in inherited and acquired demyelinating neuropathies using ultrasound. Methods We measured median and ulnar nerve cross-sectional areas in proximal and distal regions in 128 children and adults with inherited (Charcot-Marie Tooth-1 (CMT-1) (n=35)) and acquired (Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) (n=55), Guillaine-Barre Syndrome (GBS) (n=21) and Multifocal Motor Neuropathy (MMN) (n=17)) demyelinating neuropathies. We classified nerve enlargement by degree and number of regions affected. We defined patterns of nerve enlargement as: none- no enlargement; mild-nerves enlarged but never more than twice normal; regional- nerves normal at at least one region and enlarged more than twice normal at atleast one region; diffuse- nerves enlarged at all four regions with atleast one region more than twice normal size. Results Nerve enlargement was commonly diffuse (89%) and generally more than twice normal size in CMT-1, but not (p<0.001) in acquired disorders which mostly had either no, mild or regional nerve enlargement (CIDP (64%), GBS (95%), and MMN (100%)). In CIDP, subjects treated within three months of disease onset had less nerve enlargement than those treated later. Discussion Ultrasound identified patterns of diffuse nerve enlargement can be used to screen patients suspected of having CMT-1. Normal, mildly, or regionally enlarged nerves in demyelinating polyneuropathy suggests an acquired etiology. Early treatment in CIDP may impede nerve enlargement. PMID:24101129

  13. Micro-ultrasound for preclinical imaging

    PubMed Central

    Foster, F. Stuart; Hossack, John; Adamson, S. Lee

    2011-01-01

    Over the past decade, non-invasive preclinical imaging has emerged as an important tool to facilitate biomedical discovery. Not only have the markets for these tools accelerated, but the numbers of peer-reviewed papers in which imaging end points and biomarkers have been used have grown dramatically. High frequency ‘micro-ultrasound’ has steadily evolved in the post-genomic era as a rapid, comparatively inexpensive imaging tool for studying normal development and models of human disease in small animals. One of the fundamental barriers to this development was the technological hurdle associated with high-frequency array transducers. Recently, new approaches have enabled the upper limits of linear and phased arrays to be pushed from about 20 to over 50 MHz enabling a broad range of new applications. The innovations leading to the new transducer technology and scanner architecture are reviewed. Applications of preclinical micro-ultrasound are explored for developmental biology, cancer, and cardiovascular disease. With respect to the future, the latest developments in high-frequency ultrasound imaging are described. PMID:22866232

  14. Hepatic lesions segmentation in ultrasound nonlinear imaging

    NASA Astrophysics Data System (ADS)

    Kissi, Adelaide A.; Cormier, Stephane; Pourcelot, Leandre; Tranquart, Francois

    2005-04-01

    Doppler has been used for many years for cardiovascular exploration in order to visualize the vessels walls and anatomical or functional diseases. The use of ultrasound contrast agents makes it possible to improve ultrasonic information. Nonlinear ultrasound imaging highlights the detection of these agents within an organ and hence is a powerful technique to image perfusion of an organ in real-time. The visualization of flow and perfusion provides important information for the diagnosis of various diseases as well as for the detection of tumors. However, the images are buried in noise, the speckle, inherent in the image formation. Furthermore at portal phase, there is often an absence of clear contrast between lesions and surrounding tissues because the organ is filled with agents. In this context, we propose a new method of automatic liver lesions segmentation in nonlinear imaging sequences for the quantification of perfusion. Our method of segmentation is divided into two stages. Initially, we developed an anisotropic diffusion step which raised the structural characteristics to eliminate the speckle. Then, a fuzzy competitive clustering process allowed us to delineate liver lesions. This method has been used to detect focal hepatic lesions (metastasis, nodular hyperplasia, adenoma). Compared to medical expert"s report obtained on 15 varied lesions, the automatic segmentation allows us to identify and delineate focal liver lesions during the portal phase which high accuracy. Our results show that this method improves markedly the recognition of focal hepatic lesions and opens the way for future precise quantification of contrast enhancement.

  15. 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

  16. Rock expansion caused by ultrasound

    NASA Astrophysics Data System (ADS)

    Hedberg, C.; Gray, A.

    2013-12-01

    It has during many years been reported that materials' elastic modulus decrease when exposed to influences like mechanical impacts, ultrasound, magnetic fields, electricity and even humidity. Non-perfect atomic structures like rocks, concrete, or damaged metals exhibit a larger effect. This softening has most often been recorded by wave resonance measurements. The motion towards equilibrium is slow - often taking hours or days, which is why the effect is called Slow Dynamics [1]. The question had been raised, if a material expansion also occurs. 'The most fundamental parameter to consider is the volume expansion predicted to occur when positive hole charge carriers become activated, causing a decrease of the electron density in the O2- sublattice of the rock-forming minerals. This decrease of electron density should affect essentially all physical parameters, including the volume.' [2]. A new type of configuration has measured expansion of a rock subjected to ultrasound. A PZT was used as a pressure sensor while the combined thickness of the rock sample and the PZT sensor was held fixed. The expansion increased the stress in both the rock and the PZT, which gave an out-put voltage from the PZT. Knowing its material properties then made it possible to calculate the rock expansion. The equivalent strain caused by the ultrasound was approximately 3 x 10-5. The temperature was monitored and accounted for during the tests and for the maximum expansion the increase was 0.7 C, which means the expansion is at least to some degree caused by heating of the material by the ultrasound. The fraction of bonds activated by ultrasound was estimated to be around 10-5. References: [1] Guyer, R.A., Johnson, P.A.: Nonlinear Mesoscopic Elasticity: The Complex Behaviour of Rocks, Soils, Concrete. Wiley-VCH 2009 [2] M.M. Freund, F.F. Freund, Manipulating the Toughness of Rocks through Electric Potentials, Final Report CIF 2011 Award NNX11AJ84A, NAS Ames 2012.

  17. Nonlinear acoustics in biomedical ultrasound

    NASA Astrophysics Data System (ADS)

    Cleveland, Robin O.

    2015-10-01

    Ultrasound is widely used to image inside the body; it is also used therapeutically to treat certain medical conditions. In both imaging and therapy applications the amplitudes employed in biomedical ultrasound are often high enough that nonlinear acoustic effects are present in the propagation: the effects have the potential to be advantageous in some scenarios but a hindrance in others. In the case of ultrasound imaging the nonlinearity produces higher harmonics that result in images of greater quality. However, nonlinear effects interfere with the imaging of ultrasound contrast agents (typically micron sized bubbles with a strong nonlinear response of their own) and nonlinear effects also result in complications when derating of pressure measurements in water to in situ values in tissue. High intensity focused ultrasound (HIFU) is emerging as a non-invasive therapeutic modality which can result in thermal ablation of tissue. For thermal ablation, the extra effective attenuation resulting from nonlinear effects can result in enhanced heating of tissue if shock formation occurs in the target region for ablation - a highly desirable effect. However, if nonlinearity is too strong it can also result in undesired near-field heating and reduced ablation in the target region. The disruption of tissue (histotripsy) and fragmentation of kidney stones (lithotripsy) exploits shock waves to produce mechanically based effects, with minimal heating present. In these scenarios it is necessary for the waves to be of sufficient amplitude that a shock exists when the waveform reaches the target region. This talk will discuss how underlying nonlinear phenomenon act in all the diagnostic and therapeutic applications described above.

  18. Visualizing ultrasound through computational modeling

    NASA Technical Reports Server (NTRS)

    Guo, Theresa W.

    2004-01-01

    The Doppler Ultrasound Hematocrit Project (DHP) hopes to find non-invasive methods of determining a person s blood characteristics. Because of the limits of microgravity and the space travel environment, it is important to find non-invasive methods of evaluating the health of persons in space. Presently, there is no well developed method of determining blood composition non-invasively. This projects hopes to use ultrasound and Doppler signals to evaluate the characteristic of hematocrit, the percentage by volume of red blood cells within whole blood. These non-invasive techniques may also be developed to be used on earth for trauma patients where invasive measure might be detrimental. Computational modeling is a useful tool for collecting preliminary information and predictions for the laboratory research. We hope to find and develop a computer program that will be able to simulate the ultrasound signals the project will work with. Simulated models of test conditions will more easily show what might be expected from laboratory results thus help the research group make informed decisions before and during experimentation. There are several existing Matlab based computer programs available, designed to interpret and simulate ultrasound signals. These programs will be evaluated to find which is best suited for the project needs. The criteria of evaluation that will be used are 1) the program must be able to specify transducer properties and specify transmitting and receiving signals, 2) the program must be able to simulate ultrasound signals through different attenuating mediums, 3) the program must be able to process moving targets in order to simulate the Doppler effects that are associated with blood flow, 4) the program should be user friendly and adaptable to various models. After a computer program is chosen, two simulation models will be constructed. These models will simulate and interpret an RF data signal and a Doppler signal.

  19. Ultrasound-Mediated Release of Hydrophilic and Lipophilic Agents From Echogenic Liposomes

    PubMed Central

    Kopechek, Jonathan A.; Abruzzo, Todd M.; Wang, Boyu; Chrzanowski, Stephen M.; Smith, Denise A. B.; Kee, Patrick H.; Huang, Shaoling; Collier, Joel H.; McPherson, David D.; Holland, Christy K.

    2010-01-01

    Objective To achieve ultrasound-controlled drug delivery using echogenic liposomes (ELIPs), we assessed ultrasound-triggered release of hydrophilic and lipophilic agents in vitro using color Doppler ultrasound delivered with a clinical 6-MHz compact linear array transducer. Methods Calcein, a hydrophilic agent, and papaverine, a lipophilic agent, were each separately loaded into ELIPs. Calcein-loaded ELIP (C-ELIP) and papaverine-loaded ELIP (P-ELIP) solutions were circulated in a flow model and treated with 6-MHz color Doppler ultrasound or Triton X-100. Treatment with Triton X-100 was used to release the encapsulated calcein or papaverine content completely. The free calcein concentration in the solution was measured directly by spectrofluorimetry. The free papaverine in the solution was separated from liposome-bound papaverine by spin column filtration, and the resulting papaverine concentration was measured directly by absorbance spectrophotometry. Dynamic changes in echogenicity were assessed with low-output B-mode ultrasound (mechanical index, 0.04) as mean digital intensity. Results Color Doppler ultrasound caused calcein release from C-ELIPs compared with flow alone (P < .05) but did not induce papaverine release from P-ELIPs compared with flow alone (P > .05). Triton X-100 completely released liposome-associated calcein and papaverine. Initial echogenicity was higher for C-ELIPs than P-ELIPs. Color Doppler ultrasound and Triton X-100 treatments reduced echogenicity for both C-ELIPs and P-ELIPs (P < .05). Conclusions The differential efficiency of ultrasound-mediated pharmaceutical release from ELIPs for water- and lipid-soluble compounds suggests that water-soluble drugs are better candidates for the design and development of ELIP-based ultrasound-controlled drug delivery systems. PMID:18946099

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

    SciTech Connect

    Yu, S; Hristov, D; Phillips, T

    2014-06-01

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

  1. Analgesic effect of extracorporeal shock wave therapy versus ultrasound therapy in chronic tennis elbow

    PubMed Central

    Lizis, Paweł

    2015-01-01

    [Purpose] This study compared the analgesic effects of extracorporeal shock wave therapy with those of ultrasound therapy in patients with chronic tennis elbow. [Subjects] Fifty patients with tennis elbow were randomized to receive extracorporeal shock wave therapy or ultrasound therapy. [Methods] The extracorporeal shock wave therapy group received 5 treatments once per week. Meanwhile, the ultrasound group received 10 treatments 3 times per week. Pain was assessed using the visual analogue scale during grip strength evaluation, palpation of the lateral epicondyle, Thomsen test, and chair test. Resting pain was also recorded. The scores were recorded and compared within and between groups pre-treatment, immediately post-treatment, and 3 months post-treatment. [Results] Intra- and intergroup comparisons immediately and 3 months post-treatment showed extracorporeal shock wave therapy decreased pain to a significantly greater extent than ultrasound therapy. [Conclusion] Extracorporeal shock wave therapy can significantly reduce pain in patients with chronic tennis elbow. PMID:26357440

  2. Ultrasound assisted biodiesel production from sesame (Sesamum indicum L.) oil using barium hydroxide as a heterogeneous catalyst: Comparative assessment of prediction abilities between response surface methodology (RSM) and artificial neural network (ANN).

    PubMed

    Sarve, Antaram; Sonawane, Shriram S; Varma, Mahesh N

    2015-09-01

    The present study estimates the prediction capability of response surface methodology (RSM) and artificial neural network (ANN) models for biodiesel synthesis from sesame (Sesamum indicum L.) oil under ultrasonication (20 kHz and 1.2 kW) using barium hydroxide as a basic heterogeneous catalyst. RSM based on a five level, four factor central composite design, was employed to obtain the best possible combination of catalyst concentration, methanol to oil molar ratio, temperature and reaction time for maximum FAME content. Experimental data were evaluated by applying RSM integrating with desirability function approach. The importance of each independent variable on the response was investigated by using sensitivity analysis. The optimum conditions were found to be catalyst concentration (1.79 wt%), methanol to oil molar ratio (6.69:1), temperature (31.92°C), and reaction time (40.30 min). For these conditions, experimental FAME content of 98.6% was obtained, which was in reasonable agreement with predicted one. The sensitivity analysis confirmed that catalyst concentration was the main factors affecting the FAME content with the relative importance of 36.93%. The lower values of correlation coefficient (R(2)=0.781), root mean square error (RMSE=4.81), standard error of prediction (SEP=6.03) and relative percent deviation (RPD=4.92) for ANN compared to those R(2) (0.596), RMSE (6.79), SEP (8.54) and RPD (6.48) for RSM proved better prediction capability of ANN in predicting the FAME content. PMID:25630700

  3. Ultrasound microscope: the new field in ultrasound diagnostics

    NASA Astrophysics Data System (ADS)

    Novyc'kyy, Victor V.; Lushchyk, Ulyana B.

    2001-06-01

    A device which is a new stage in the development of medical equipment has been developed. The device works as an ultrasound microscope in vivo and provides 4 up to 32 colored histological image. It gives possibility to estimate tissue acoustic density with the help of 4 up to 32 gradation coloring different tissues and enables tissue microcirculation visualization. With the help of the device a doctor can objectify fatty hepatitis and cirrhosis, edema of different organs and tissues as well as microcirculation in organs and tissues (e.g. muscles, myocard and bone system). New promising applications of ultrasound systems in diagnostics and for choosing individual treatment tactics, with pathogenesis being taken into account, may be developed with the help of the device.

  4. BBB disruption with unfocused ultrasound alone-A paradigm shift

    NASA Astrophysics Data System (ADS)

    Kyle, Al

    2012-10-01

    One paradigm for ultrasound-enabled blood brain barrier disruption uses image guided focused ultrasound and preformed microbubble agents to enable drug delivery to the brain. We propose an alternative approach: unguided, unfocused ultrasound with no adjunctive agent. Compared with the focused approach, the proposed method affects a larger region of the brain, and is aimed at treatment of regional neurological disease including glioblastoma multiforme (GBM). Avoidance of image guidance and focusing reduces cost for equipment and staff training. Avoidance of adjunctive agents also lowers cost and is enabled by a longer exposure time. Since 2004, our group has worked with two animal models, three investigators in four laboratories to safely deliver five compounds, increasing the concentration of large molecule markers in brain tissue two fold or more. Safety and effectiveness data for four studies have been presented at the Ultrasound Industry Association meetings in 2007 and 2010. This paper describes new safety and effectiveness results for a fifth study. We present evidence of delivery of large molecules - including Avastin-to the brains of a large animal model correlated with acoustic pressure, and summarize the advantages and disadvantages of this novel approach.

  5. An ultrasound personal locator for time-activity assessment.

    PubMed

    Allen-Piccolo, Gian; Rogers, Jamesine V; Edwards, Rufus; Clark, Michael C; Allen, T Tracy; Ruiz-Mercado, Ilse; Shields, Kyra N; Canuz, Eduardo; Smith, Kirk R

    2009-01-01

    The UC Berkeley Time-Activity Monitoring System (UCB-TAMS) was developed to measure time-activity in exposure studies. The system consists of small, light, inexpensive battery-operated 40-kHz ultrasound transmitters (tags) worn by participants and an ultrasound receiver (locator) attached to a datalogger fixed in an indoor location. Presence or absence of participants is monitored by distinguishing the unique ultrasound ID of each tag. Efficacy tests in rural households of highland Guatemala showed the system to be comparable to the gold-standard time-activity measure of direct observation by researchers, with an accuracy of predicting time-weighted averages of 90-95%, minute-by-minute accuracy of 80-85%, and sensitivity/specificity values of 86-89%/71-74% for one-minute readings on children 3-8 years-old. Additional controlled tests in modern buildings and in rural Guatemalan homes confirmed the performance of the system with the presence of other ultrasound sources, with multiple tags, covered by clothing, and in other non-ideal circumstances. PMID:19496478

  6. Ultrasound imaging techniques in density separation of polyolefin waste.

    PubMed

    Sanaee, Seyed Ali; Bakker, M C M

    2012-12-01

    Ultrasound imaging techniques are investigated using a multi-element sensor array for purposes of monitoring and measurement ofpolyolefin waste particles inside the black ferrous liquid ofa magnetic density separator (MDS). A medical ultrasound imaging system with real-time capability was adapted first to assess the potential of imaging technology inside the MDS. An image processing routine was developed to determine the depth distribution of the detected particles as they are carried by the flow in the MDS channel. This real-time information is vital for optimizing the splitter position, which directly influences quality and recovery of the MDS polyolefin products. Despite successes in the laboratory, the medical technology proved unsatisfactory for continuous high-quality image forming in the industrial set-up as it requires regular operator intervention. Therefore, research has been initiated into alternative imaging methods, which are also being investigated in other fields such as non-destructive testing and geophysics. The influence of different ultrasound datasets and related image-forming techniques were investigated, for which dedicated algorithms were implemented in Matlab. The main advantages and disadvantages of the different techniques are addressed. It is concluded that the alternative imaging methods may be more robust and deliver higher image quality compared to the commercial medical imager. In particular, sizing of polyolefin particles may improve significantly if the method takes into account the correct ultrasound velocities of both the ferrous liquid and the immersed polyolefin particles. PMID:23437658

  7. Nonlinear optical microscopy and ultrasound imaging of human cervical structure

    NASA Astrophysics Data System (ADS)

    Reusch, Lisa M.; Feltovich, Helen; Carlson, Lindsey C.; Hall, Gunnsteinn; Campagnola, Paul J.; Eliceiri, Kevin W.; Hall, Timothy J.

    2013-03-01

    The cervix softens and shortens as its collagen microstructure rearranges in preparation for birth, but premature change may lead to premature birth. The global preterm birth rate has not decreased despite decades of research, likely because cervical microstructure is poorly understood. Our group has developed a multilevel approach to evaluating the human cervix. We are developing quantitative ultrasound (QUS) techniques for noninvasive interrogation of cervical microstructure and corroborating those results with high-resolution images of microstructure from second harmonic generation imaging (SHG) microscopy. We obtain ultrasound measurements from hysterectomy specimens, prepare the tissue for SHG, and stitch together several hundred images to create a comprehensive view of large areas of cervix. The images are analyzed for collagen orientation and alignment with curvelet transform, and registered with QUS data, facilitating multiscale analysis in which the micron-scale SHG images and millimeter-scale ultrasound data interpretation inform each other. This novel combination of modalities allows comprehensive characterization of cervical microstructure in high resolution. Through a detailed comparative study, we demonstrate that SHG imaging both corroborates the quantitative ultrasound measurements and provides further insight. Ultimately, a comprehensive understanding of specific microstructural cervical change in pregnancy should lead to novel approaches to the prevention of preterm birth.

  8. Proposed standard thermal test object for medical ultrasound.

    PubMed

    Shaw, A; Pay, N M; Preston, R C; Bond, A D

    1999-01-01

    A general design for a thermal test object (TTO) is proposed. A number of novel features make the design particularly suitable for use as a standardised device for assessing the heating capability of diagnostic ultrasound beams. To assess performance, soft-tissue TTOs have been made containing thin-film thermocouples sandwiched between discs of tissue-mimicking gel. Installed in an appropriate measurement system, these TTOs exhibit excellent thermal and spatial resolution, allowing the ultrasound beam to be located rapidly and reproducibly. The measured temperature rise after 3 minutes of heating has been compared with theoretical predictions based on measured pressure distributions, and agreement is within 10%. Other studies have shown that soft-tissue- and bone-mimicking TTOs can be used to evaluate a wide range of ultrasound fields and that different physical tissue models can be simulated. It is concluded that this design would be suitable for providing reference assessments of the thermal hazard posed by diagnostic ultrasound under standardised conditions. PMID:10048809

  9. Protection Circuits for Very High Frequency Ultrasound Systems

    PubMed Central

    Shung, K. Kirk

    2014-01-01

    The purpose of protection circuits in ultrasound applications is to block noise signals from the transmitter from reaching the transducer and also to prevent unwanted high voltage signals from reaching the receiver. The protection circuit using a resistor and diode pair is widely used due to its simple architecture, however, it may not be suitable for very high frequency (VHF) ultrasound transducer applications (>100 MHz) because of its limited bandwidth. Therefore, a protection circuit using MOSFET devices with unique structure is proposed in this paper. The performance of the designed protection circuit was compared with that of other traditional protection schemes. The performance characteristics measured were the insertion loss (IL), total harmonic distortion (THD) and transient response time (TRT). The new protection scheme offers the lowest IL (−1.0 dB), THD (−69.8 dB) and TRT (78 ns) at 120 MHz. The pulse-echo response using a 120 MHz LiNbO3 transducer with each protection circuit was measured to validate the feasibility of the protection circuits in VHF ultrasound applications. The sensitivity and bandwidth of the transducer using the new protection circuit improved by 252.1 and 50.9 %, respectively with respect to the protection circuit using a resistor and diode pair. These results demonstrated that the new protection circuit design minimizes the IL, THD and TRT for VHF ultrasound transducer applications. PMID:24682684

  10. The Application of Ultrasound in 3D Bio-Printing.

    PubMed

    Zhou, Yufeng

    2016-01-01

    Three-dimensional (3D) bioprinting is an emerging and promising technology in tissue engineering to construct tissues and organs for implantation. Alignment of self-assembly cell spheroids that are used as bioink could be very accurate after droplet ejection from bioprinter. Complex and heterogeneous tissue structures could be built using rapid additive manufacture technology and multiple cell lines. Effective vascularization in the engineered tissue samples is critical in any clinical application. In this review paper, the current technologies and processing steps (such as printing, preparation of bioink, cross-linking, tissue fusion and maturation) in 3D bio-printing are introduced, and their specifications are compared with each other. In addition, the application of ultrasound in this novel field is also introduced. Cells experience acoustic radiation force in ultrasound standing wave field (USWF) and then accumulate at the pressure node at low acoustic pressure. Formation of cell spheroids by this method is within minutes with uniform size and homogeneous cell distribution. Neovessel formation from USWF-induced endothelial cell spheroids is significant. Low-intensity ultrasound could enhance the proliferation and differentiation of stem cells. Its use is at low cost and compatible with current bioreactor. In summary, ultrasound application in 3D bio-printing may solve some challenges and enhance the outcomes. PMID:27164066

  11. Temporal Healing in Rat Achilles Tendon: Ultrasound Correlations

    PubMed Central

    Chamberlain, Connie S.; Duenwald-Kuehl, Sarah E.; Okotie, Gregory; Brounts, Sabrina H.; Baer, Geoffrey S.; Vanderby, Ray

    2012-01-01

    The purpose of this study was to explore whether a new ultrasound-based technique correlates with mechanical and biological metrics that describe the tendon healing. Achilles tendons in 32 rats were unilaterally transected and allowed to heal without repair. At 7, 9, 14, or 29 days post-injury, tendons were collected and examined for healing via ultrasound image analysis, mechanical testing, and immunohistochemistry. Consistent with previous studies, we observe that the healing tendons are mechanically inferior (ultimate stress, ultimate load, and normalized stiffness) and biologically altered (cellular and ECM factors) compared to contralateral controls with an incomplete recovery over healing time. Unique to this study, we report: 1) Echo intensity (defined by gray-scale brightness in the ultrasound image) in the healing tissue is related to stress and normalized stiffness. 2) Elongation to failure is relatively constant so that tissue normalized stiffness is linearly correlated with ultimate stress. Together, 1 and 2 suggest a method to quantify mechanical compromise in healing tendons. 3) The amount and type of collagen in healing tendons associates with their strength and normalized stiffness as well as their ultrasound echo intensity. 4) A significant increase of periostin in the healing tissues suggests an important but unexplored role for this ECM protein in tendon healing. PMID:23149902

  12. Focusing of ferroelectret air-coupled ultrasound transducers

    NASA Astrophysics Data System (ADS)

    Gaal, Mate; Bartusch, Jürgen; Dohse, Elmar; Schadow, Florian; Köppe, Enrico

    2016-02-01

    Air-coupled ultrasound has been applied increasingly as a non-destructive testing method for lightweight construction in recent years. It is particularly appropriate for composite materials being used in automotive and aviation industry. Air-coupled ultrasound transducers mostly consist of piezoelectric materials and matching layers. However, their fabrication is challenging and their signal-to-noise ratio often not sufficient for many testing requirements. To enhance the efficiency, air-coupled ultrasound transducers made of cellular polypropylene have been developed. Because of its small density and sound velocity, this piezoelectric ferroelectret matches the small acoustic impedance of air much better than matching layers applied in conventional transducers. In our contribution, we present two different methods of spherical focusing of ferroelectret transducers for the further enhancement of their performance in NDT applications. Measurements on carbon-fiber-reinforced polymer (CFRP) samples and on metal adhesive joints performed with commercially available focused air-coupled ultrasound transducers are compared to measurements executed with self-developed focused ferroelectret transducers.

  13. Asynchronous compressed beamformer for portable diagnostic ultrasound systems.

    PubMed

    Zhou, Jun; Hoyos, Sebastian; Sadler, Brian

    2014-11-01

    State-of-the-art portable ultrasound imaging systems employ a small transducer array and a low carrier frequency to fit stringent constraints on power and form factor, and this tends to compromise the ultrasound imaging quality. In this paper, we present a low-complexity low-power asynchronous compressed beamformer (ACB) for portable diagnostic ultrasound. The proposed ACB integrates asynchronous sampling and compressive sensing (CS), and is capable of reducing data conversion power and handling a large data volume at the mixed-signal interface. A high-rate continuoustime ternary encoding (CT-TE) scheme eliminates the need for interpolation filters and coordinate rotation digital computer (CORDIC) units typically used in a conventional architecture. A split-projection least squares (SPLS) signal reconstruction algorithm is applied that replaces high-cost nonlinear signal recovery with a series of low-complexity and independent linear problems. Experiments with measured ultrasound data demonstrate the proposed ACB architecture, and the SPLS reconstruction algorithm achieves 9-fold data compression compared with Nyquist sampling. PMID:25389158

  14. Effects of ultrasound and ultrasound contrast agent on vascular tissue

    PubMed Central

    2012-01-01

    Background Ultrasound (US) imaging can be enhanced using gas-filled microbubble contrast agents. Strong echo signals are induced at the tissue-gas interface following microbubble collapse. Applications include assessment of ventricular function and virtual histology. Aim While ultrasound and US contrast agents are widely used, their impact on the physiological response of vascular tissue to vasoactive agents has not been investigated in detail. Methods and results In the present study, rat dorsal aortas were treated with US via a clinical imaging transducer in the presence or absence of the US contrast agent, Optison. Aortas treated with both US and Optison were unable to contract in response to phenylephrine or to relax in the presence of acetylcholine. Histology of the arteries was unremarkable. When the treated aortas were stained for endothelial markers, a distinct loss of endothelium was observed. Importantly, terminal deoxynucleotidyl transferase mediated dUTP nick-end-labeling (TUNEL) staining of treated aortas demonstrated incipient apoptosis in the endothelium. Conclusions Taken together, these ex vivo results suggest that the combination of US and Optison may alter arterial integrity and promote vascular injury; however, the in vivo interaction of Optison and ultrasound remains an open question. PMID:22805356

  15. Acoustic structure quantification by using ultrasound Nakagami imaging for assessing liver fibrosis

    PubMed Central

    Tsui, Po-Hsiang; Ho, Ming-Chih; Tai, Dar-In; Lin, Ying-Hsiu; Wang, Chiao-Yin; Ma, Hsiang-Yang

    2016-01-01

    Acoustic structure quantification (ASQ) is a recently developed technique widely used for detecting liver fibrosis. Ultrasound Nakagami parametric imaging based on the Nakagami distribution has been widely used to model echo amplitude distribution for tissue characterization. We explored the feasibility of using ultrasound Nakagami imaging as a model-based ASQ technique for assessing liver fibrosis. Standard ultrasound examinations were performed on 19 healthy volunteers and 91 patients with chronic hepatitis B and C (n = 110). Liver biopsy and ultrasound Nakagami imaging analysis were conducted to compare the METAVIR score and Nakagami parameter. The diagnostic value of ultrasound Nakagami imaging was evaluated using receiver operating characteristic (ROC) curves. The Nakagami parameter obtained through ultrasound Nakagami imaging decreased with an increase in the METAVIR score (p < 0.0001), representing an increase in the extent of pre-Rayleigh statistics for echo amplitude distribution. The area under the ROC curve (AUROC) was 0.88 for the diagnosis of any degree of fibrosis (≥F1), whereas it was 0.84, 0.69, and 0.67 for ≥F2, ≥F3, and ≥F4, respectively. Ultrasound Nakagami imaging is a model-based ASQ technique that can be beneficial for the clinical diagnosis of early liver fibrosis. PMID:27605260

  16. Acoustic structure quantification by using ultrasound Nakagami imaging for assessing liver fibrosis.

    PubMed

    Tsui, Po-Hsiang; Ho, Ming-Chih; Tai, Dar-In; Lin, Ying-Hsiu; Wang, Chiao-Yin; Ma, Hsiang-Yang

    2016-01-01

    Acoustic structure quantification (ASQ) is a recently developed technique widely used for detecting liver fibrosis. Ultrasound Nakagami parametric imaging based on the Nakagami distribution has been widely used to model echo amplitude distribution for tissue characterization. We explored the feasibility of using ultrasound Nakagami imaging as a model-based ASQ technique for assessing liver fibrosis. Standard ultrasound examinations were performed on 19 healthy volunteers and 91 patients with chronic hepatitis B and C (n = 110). Liver biopsy and ultrasound Nakagami imaging analysis were conducted to compare the METAVIR score and Nakagami parameter. The diagnostic value of ultrasound Nakagami imaging was evaluated using receiver operating characteristic (ROC) curves. The Nakagami parameter obtained through ultrasound Nakagami imaging decreased with an increase in the METAVIR score (p < 0.0001), representing an increase in the extent of pre-Rayleigh statistics for echo amplitude distribution. The area under the ROC curve (AUROC) was 0.88 for the diagnosis of any degree of fibrosis (≥F1), whereas it was 0.84, 0.69, and 0.67 for ≥F2, ≥F3, and ≥F4, respectively. Ultrasound Nakagami imaging is a model-based ASQ technique that can be beneficial for the clinical diagnosis of early liver fibrosis. PMID:27605260

  17. Ultrasound-induced hyperthermia for the spatio-temporal control of gene expression in bone repair

    NASA Astrophysics Data System (ADS)

    Wilson, Christopher; Padilla, Frédéric; Zhang, Man; Vilaboa, Nuria; Kripfgans, Oliver; Fowlkes, Brian; Franceschi, Renny

    2012-10-01

    Spatial and temporal control over the expression of growth/differentiation factors is of great interest for regeneration of bone, but technologies capable of providing tight and active control over gene expression remain elusive. We propose the use of focused ultrasound for the targeted activation of heat shock-sensitive expression systems in engineered bone. We report in vitro results with cells that express firefly luciferase (fLuc) under the control of a heat shock protein promoter. Cells were embedded in fibrin scaffolds and exposed to focused ultrasound, using a custom 3.3MHz transducer (focal length 4", f-number 1.33", focal dimension 1.2mm lateral FWHM) in CW mode for 2-20 minutes at intensities ISPTA=120-440 W/cm2. The kinetics of ultrasound-mediated activation of the cells was compared with that of strictly thermal activation. Bioluminescence imaging revealed fLuc expression in an area ≥2.5mm in diameter at the position of the ultrasound focus, and the diameter and intensity of the signal increased with the amplitude of the acoustic energy. We also found that ultrasound activated fLuc expression with substantially shorter exposures than thermal activation. Our results demonstrate the potential for focused ultrasound to selectively activate the expression of a gene of interest in an engineered tissue and suggest that focused ultrasound activates the heat shock pathway by a combination of thermal and non-thermal mechanisms.

  18. ULTRASOUND-INDUCED THERMAL ELEVATION IN CLOTTED BLOOD AND CRANIAL BONE

    PubMed Central

    Nahirnyak, Volodymyr; Mast, T. Douglas; Holland, Christy K.

    2007-01-01

    Ultrasound thermal effects have been hypothesized to contribute to ultrasound-assisted thrombolysis. To explore the thermal mechanism of ultrasound-enhanced thrombolysis with recombinant tissue plasminogen activator (rt-PA) for the treatment of ischemic stroke, a detailed investigation is needed of the heating produced in skull, brain and blood clots. A theoretical model is developed to provide an estimate for the worst-case scenario of the temperature increase in blood clots and on the surface of cranial bone exposed to 0.12- to 3.5-MHz ultrasound. Thermal elevation was also assessed experimentally in human temporal bone, human clots and porcine clots exposed to 0.12 to 3.5-MHz pulsed ultrasound in vitro with a peak-to-peak pressure of 0.25 MPa and 80% duty cycle. Blood clots exposed to 0.12-MHz pulsed ultrasound exhibited a small temperature increase (0.25° C) and bone exposed to 1.0-MHz pulsed ultrasound exhibited the highest temperature increase (1.0° C). These experimental results were compared with the predicted temperature elevations. PMID:17490808

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

    PubMed

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

    2014-01-01

    Recent ultrasound imaging evidence asserts that the diaphragm is an important multifunctional muscle to control breathing as well as stabilize the core and posture in humans. However, the validity and accuracy of ultrasound for the measurement of dynamic diaphragm movements during breathing and functional core activities have not been determined. The specific aim of this study was to validate the accuracy of ultrasound imaging measurements of diaphragm movements by concurrently comparing these measurements to the gold standard of radiographic imaging measurements. A total of 14 asymptomatic adults (9 males, 5 females; mean age =28.4 ± 3.0 years) were recruited to participate in the study. Ultrasound and radiographic images were used concurrently to determine diaphragm movement (inspiration, expiration, and excursion) during tidal breathing. Pearson correlation analysis showed strong correlations, ranging from r=0.78 to r=0.83, between ultrasound and radiographic imaging measurements of the diaphragm during inhalation, exhalation, and excursion. These findings suggest that ultrasound imaging measurement is useful to accurately evaluate diaphragm movements during tidal breathing. Clinically, ultrasound imaging measurements can be used to diagnose and treat diaphragm movement impairments in individuals with neuromuscular disorders including spinal cord injuries, stroke, and multiple sclerosis. PMID:24211983

  20. Controlling collagen fiber microstructure in three-dimensional hydrogels using ultrasound

    PubMed Central

    Garvin, Kelley A.; VanderBurgh, Jacob; Hocking, Denise C.; Dalecki, Diane

    2013-01-01

    Type I collagen is the primary fibrillar component of the extracellular matrix, and functional properties of collagen arise from variations in fiber structure. This study investigated the ability of ultrasound to control collagen microstructure during hydrogel fabrication. Under appropriate conditions, ultrasound exposure of type I collagen during polymerization altered fiber microstructure. Scanning electron microscopy and second-harmonic generation microscopy revealed decreased collagen fiber diameters in response to ultrasound compared to sham-exposed samples. Results of mechanistic investigations were consistent with a thermal mechanism for the effects of ultrasound on collagen fiber structure. To control collagen microstructure site-specifically, a high frequency, 8.3-MHz, ultrasound beam was directed within the center of a large collagen sample producing dense networks of short, thin collagen fibrils within the central core of the gel and longer, thicker fibers outside the beam area. Fibroblasts seeded onto these gels migrated rapidly into small, circularly arranged aggregates only within the beam area, and clustered fibroblasts remodeled the central, ultrasound-exposed collagen fibrils into dense sheets. These investigations demonstrate the capability of ultrasound to spatially pattern various collagen microstructures within an engineered tissue noninvasively, thus enhancing the level of complexity of extracellular matrix microenvironments and cellular functions achievable within three-dimensional engineered tissues. PMID:23927189

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

    NASA Astrophysics Data System (ADS)

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

    1999-11-01

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

  2. Prediction of trabecular bone principal structural orientation using quantitative ultrasound scanning

    PubMed Central

    Lin, Liangjun; Cheng, Jiqi; Lin, Wei; Qin, Yi-Xian

    2016-01-01

    Bone has the ability to adapt its structure in response to the mechanical environment as defined as Wolff’s Law. The alignment of trabecular structure is intended to adapt to the particular mechanical milieu applied to it. Due to the absence of normal mechanical loading, it will be extremely important to assess the anisotropic deterioration of bone during the extreme conditions, i.e., long term space mission and disease orientated disuse, to predict risk of fractures. The propagation of ultrasound wave in trabecular bone is substantially influenced by the anisotropy of the trabecular structure. Previous studies have shown that both ultrasound velocity and amplitude is dependent on the incident angle of the ultrasound signal into the bone sample. In this work, seven bovine trabecular bone balls were used for rotational ultrasound measurement around three anatomical axes to elucidate the ability of ultrasound to identify trabecular orientation. Both ultrasound attenuation (ATT) and fast wave velocity (UV) were used to calculate the principal orientation of the trabecular bone. By comparing to the mean intercept length (MIL) tensor obtained from μCT, the angle difference of the prediction by UV was 4.45°, while it resulted in 11.67° angle difference between direction predicted by μCT and the prediction by ATT. This result demonstrates the ability of ultrasound as a non-invasive measurement tool for the principal structural orientation of the trabecular bone. PMID:22560370

  3. An update around the evidence base for the lower extremity ultrasound regional block technique

    PubMed Central

    Fanelli, Andrea; Ghisi, Daniela; Melotti, Rita Maria

    2016-01-01

    Ultrasound guidance currently represents the gold standard for regional anesthesia. In particular for lower extremity blocks, despite the heterogeneity and the lack of large randomized controlled trials, current literature shows a modest improvement in block onset and quality compared with other localization techniques. This review aims to present the most recent findings on the application of ultrasound guidance for each single lower extremity approach. PMID:26918177

  4. Quantification and MRI Validation of Regional Contractile Dysfunction in Mice Post Myocardial Infarction Using High Resolution Ultrasound

    PubMed Central

    Li, Yinbo; Garson, Christopher D.; Xu, Yaqin; Beyers, Ronald J.; Epstein, Frederick H.; French, Brent A.; Hossack, John A.

    2007-01-01

    A versatile, computationally-efficient two-dimensional (2D) speckle-tracking method based on high resolution ultrasound imaging is proposed to quantify regional myocardial dysfunction in mice. Ultrasound scans were performed on the hearts of normal and post myocardial infarction (MI) mice with a Vevo770 scanner (VisualSonics, Toronto, Canada) operating at 30 MHz frequency. Regional myocardial motion was tracked using a 2D Minimum Sum of Absolute Differences (MSAD) block-matching algorithm. Motion analyses calculated from ultrasound images were compared to "gold-standard" analyses performed using small animal Magnetic Resonance Imaging (MRI). The radial and circumferential components of strain were compared between ultrasound and MRI short axis views and promising correlations were obtained (R = 0.90 and R = 0.85 for radial and circumferential strain, respectively). Therefore, ultrasound imaging, followed by 2D image tracking, provides an effective, low cost, mobile method to quantify murine cardiac function accurately and reliably. PMID:17434660

  5. Phased-array ultrasound technology enhances accuracy of dual frequency ultrasound measurements - towards improved ultrasound bone diagnostics.

    PubMed

    Linder, Hans; Malo, Markus K H; Liukkonen, Jukka; Jurvelin, Jukka S; Töyräs, Juha

    2016-08-01

    Overlying soft tissues attenuate ultrasound backscattered from bone, complicating diagnostics of osteoporosis at the most important fracture sites. Dual-frequency ultrasound technique (DFUS) has been proposed to solve this problem through determination of thickness and composition of overlying soft tissue. This study applies DFUS technique for the first time with a phased-array transducer to investigate if the thickness of two interfering layers (oil and water) can be accurately determined in a variety of configurations. Results indicate that DFUS may be used with phased-array ultrasound systems, making them a suitable combination to consider in future development of clinical in vivo ultrasound methodologies. PMID:27187271

  6. Ultrasound elastography for musculoskeletal applications

    PubMed Central

    Drakonaki, E E; Allen, G M; Wilson, D J

    2012-01-01

    Ultrasound elastography (EUS) is a method to assess the mechanical properties of tissue, by applying stress and detecting tissue displacement using ultrasound. There are several EUS techniques used in clinical practice; strain (compression) EUS is the most common technique that allows real-time visualisation of the elastographic map on the screen. There is increasing evidence that EUS can be used to measure the mechanical properties of musculoskeletal tissue in clinical practice, with the future potential for early diagnosis to both guide and monitor therapy. This review describes the various EUS techniques available for clinical use, presents the published evidence on musculoskeletal applications of EUS and discusses the technical issues, limitations and future perspectives of this method in the assessment of the musculoskeletal system. PMID:23091287

  7. Ultrasound diagnosis of uterine myomas.

    PubMed

    Fascilla, Fabiana D; Cramarossa, Paola; Cannone, Rossella; Olivieri, Claudiana; Vimercati, Antonella; Exacoustos, Caterina

    2016-06-01

    Myomas represent a large part of benign gynecological pathology, widely spread in fertile female population. First step to diagnose fibroids is ultrasound (US) that can be 2-dimensional (2D), 3-dimensional (3D), Color Doppler (CD) and sonohysterography (SHG). This review develops according to MUSA's sonographic features (Morphological Uterus Sonographic Assessment). One of the main topic of interest for ultrasonographer today is endo/myometrial junctional zone (JZ), because it may be useful to discern a diagnosis of myoma and adenomyosis. Another important aspect of ultrasound is the analysis of vascularization in front of a uterine lesion. Indeed, vascular pattern can be used to make differential diagnosis between myoma-adenomyosis and leiomyosarcomas. Myomas should be described accurately according to sonographic guidelines. Sonographic features correlated with symptoms should guide an appropriate surgical or medical treatment. PMID:27014801

  8. Enzyme extraction by ultrasound from sludge flocs.

    PubMed

    Yu, Guanghui; He, Pinjing; Shao, Liming; Zhu, Yishu

    2009-01-01

    Enzymes play essential roles in the biological processes of sludge treatment. In this article, the ultrasound method to extract enzymes from sludge flocs was presented. Results showed that using ultrasound method at 20 kHz could extract more types of enzymes than that at 40 kHz and ethylenediamine tetraacetic acid (EDTA) methods. The optimum parameters of ultrasound extraction at 20 kHz were duration of 10 min and intensity of 552 W/g TSS. Under the optimum condition, ultrasound could break the cells and extract both the extracellular and a small part of intercellular enzymes. Ultrasound intensity was apparently more susceptive to enzyme extraction than duration, suggesting that the control of intensity during ultrasound extraction was more important than that of duration. The Pearson correlation analysis between enzyme activities and cation contents revealed that the different types of enzymes had distinct cation binding characteristics. PMID:19402423

  9. Ultrasound: biological effects and industrial hygiene concerns

    SciTech Connect

    Wiernicki, C.; Karoly, W.J.

    1985-09-01

    Due to the increased use of high intensity ultrasonic devices, there is now a greater risk of worker exposure to ultrasonic radiation than there was in the past. Exposure to high power ultrasound may produce adverse biological effects. High power ultrasound, characterized by high intensity outputs at frequencies of 20-100 kHz, has a wide range of applications throughout industry. Future applications may involve equipment with higher energy outputs. Contact ultrasound, i.e., no air space between the energy source and the biological tissue, is significantly more hazardous than exposure to airborne ultrasound because air transmits less than one percent of the energy. This paper discusses biological effects associated with overexposure to ultrasound, exposure standards proposed for airborne and contact ultrasound industrial hygiene controls that can be employed to minimize exposure, and the instrumentation that is required for evaluating exposure.

  10. Sphericity determination using resonant ultrasound spectroscopy

    DOEpatents

    Dixon, R.D.; Migliori, A.; Visscher, W.M.

    1994-10-18

    A method is provided for grading production quantities of spherical objects, such as roller balls for bearings. A resonant ultrasound spectrum (RUS) is generated for each spherical object and a set of degenerate sphere-resonance frequencies is identified. From the degenerate sphere-resonance frequencies and known relationships between degenerate sphere-resonance frequencies and Poisson's ratio, a Poisson's ratio can be determined, along with a 'best' spherical diameter, to form spherical parameters for the sphere. From the RUS, fine-structure resonant frequency spectra are identified for each degenerate sphere-resonance frequency previously selected. From each fine-structure spectrum and associated sphere parameter values an asphericity value is determined. The asphericity value can then be compared with predetermined values to provide a measure for accepting or rejecting the sphere. 14 figs.

  11. Sphericity determination using resonant ultrasound spectroscopy

    DOEpatents

    Dixon, Raymond D.; Migliori, Albert; Visscher, William M.

    1994-01-01

    A method is provided for grading production quantities of spherical objects, such as roller balls for bearings. A resonant ultrasound spectrum (RUS) is generated for each spherical object and a set of degenerate sphere-resonance frequencies is identified. From the degenerate sphere-resonance frequencies and known relationships between degenerate sphere-resonance frequencies and Poisson's ratio, a Poisson's ratio can be determined, along with a "best" spherical diameter, to form spherical parameters for the sphere. From the RUS, fine-structure resonant frequency spectra are identified for each degenerate sphere-resonance frequency previously selected. From each fine-structure spectrum and associated sphere parameter values an asphericity value is determined. The asphericity value can then be compared with predetermined values to provide a measure for accepting or rejecting the sphere.

  12. [Use of ultrasound in labor].

    PubMed

    Koterová, K; Krofta, L; Velebil, P; Mechurová, A; Feyereisl, J

    2011-12-01

    In the managing of labor, the obstetrician gets often to the border situations especially at the end of the second stage of labor, where only accurate diagnosis allows the make correct decisions on how to end the delivery. Since clinical vaginal examination does not always give complete informations about station and rotation of the head, the intrapartum fetal ultrasound showing the fetus inside the birth canal can refine and document the diagnosis and help us to decide. PMID:22312841

  13. Three-dimensional obstetric ultrasound.

    PubMed

    Tache, Veronique; Tarsa, Maryam; Romine, Lorene; Pretorius, Dolores H

    2008-04-01

    Three-dimensional ultrasound has gained a significant popularity in obstetrical practice in recent years. The advantage of this modality in some cases is in question, however. This article provides a basic review of volume acquisition, mechanical positioning, and display modalities. Multiple uses of this technique in obstetrical care including first trimester applications and its utility in clarification of fetal anatomy such as brain, face, heart, and skeleton is discussed. PMID:18450140

  14. 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.

  15. Pelvic floor ultrasound: a review.

    PubMed

    Dietz, Hans Peter

    2010-04-01

    Imaging currently plays a limited role in the investigation of pelvic floor disorders. It is obvious that magnetic resonance imaging has limitations in urogynecology and female urology at present due to cost and access limitations and due to the fact that it is generally a static, not a dynamic, method. However, none of those limitations apply to sonography, a diagnostic method that is very much part of general practice in obstetrics and gynecology. Translabial or transperineal ultrasound is helpful in determining residual urine; detrusor wall thickness; bladder neck mobility; urethral integrity; anterior, central, and posterior compartment prolapse; and levator anatomy and function. It is at least equivalent to other imaging methods in visualizing such diverse conditions as urethral diverticula, rectal intussusception, mesh dislodgment, and avulsion of the puborectalis muscle. Ultrasound is the only imaging method able to visualize modern mesh slings and implants and may predict who actually needs such implants. Delivery-related levator trauma is the most important known etiologic factor for pelvic organ prolapse and not difficult to diagnose on 3-/4-dimensional and even on 2-dimensional pelvic floor ultrasound. It is likely that this will be an important driver behind the universal use of this technology. This review gives an overview of the method and its main current uses in clinical assessment and research. PMID:20350640

  16. Contrast-Enhanced Endoscopic Ultrasound

    PubMed Central

    Dietrich, Christoph F.; Sharma, M.; Hocke, M.

    2012-01-01

    The European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) introduced guidelines on the use of contrast-enhanced ultrasound (CEUS) in 2004. This EFSUMB-document focused mainly on liver applications. However, new applications extending beyond the liver were developed thereafter. Increased interest in recent years in CEUS technique and in the application of CEUS in novel fields like endoscopic ultrasound (EUS) has revolutionized indications and applications. As a result, the EFSUMB initiated a new update of the guidelines in 2011 to include this additional knowledge. Some of the contrast-enhanced EUS (CE-EUS) indications are established, whereas others are preliminary; these latter indications are categorized as emergent CEUS applications since the available evidence is insufficient for general recommendation. This article focuses on the use of CE-EUS in various clinical settings. The reader will get an overview of current indications and possible applications of CE-EUS. This involves the introduction of different contrast studies including color Doppler techniques (known as contrast-enhanced high mechanical index endosonography or CEHMI-EUS) as well as more modern high-resolution contrast-enhanced techniques (known as contrast-enhanced low mechanical index endosonography or CELMI EUS). PMID:24949350

  17. Ultrasound findings in cutaneous sarcoidosis

    PubMed Central

    Dybiec, Ewa; Pietrzak, Aldona; Kieszko, Robert; Kanitakis, Jean

    2015-01-01

    The diagnosis of cutaneous sarcoidosis relies mainly on the patient's history, presence of characteristic skin lesions and histological examination that shows a granulomatous, non-necrotizing dermal infiltration. The aim of the study was to assess the ultrasonographic features of cutaneous lesions of sarcoidosis before and after treatment. A 38-year-old woman with systemic sarcoidosis and specific cutaneous lesions was treated with systemic steroids followed by hydroxychloroquine. Ultrasonographic examination of the cutaneous sarcoidosis lesions was performed with a Philips iU 22 and Siemens Acuson S 2000 device, with the use of linear 15 MHz and 17 MHz transducers. Histological examination of skin lesions showed characteristic, naked, non-necrotizing granulomas in the upper dermis. Ultrasound examination revealed well-demarcated, hypoechogenic changes. Power-Doppler scan revealed increased vascularity within the lesions and the surrounding tissue. Clinical improvement of the skin lesions was confirmed by ultrasound examination, which showed a decrease in their size and normalization of dermal echogenicity and vascularity. Ultrasound examination can show cutaneous sarcoidosis lesions and their regression after appropriate treatment. PMID:25821428

  18. Venous catheterization with ultrasound navigation

    SciTech Connect

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

    2015-11-17

    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.

  19. The evolution of ultrasound in rheumatology

    PubMed Central

    Kang, Taeyoung; Lanni, Stefano; Nam, Jackie; Emery, Paul

    2012-01-01

    Musculoskeletal ultrasound is a powerful tool not only for evaluating joint and related structures but also for assessing disease activity. Ultrasound in rheumatology has rapidly evolved and been incorporated into routine clinical practice over the past decade. Moreover, technological development of equipment has made it more accessible for rheumatologists. We present a review of advances in ultrasound in rheumatology, focusing on major chronological developments. PMID:23227117

  20. [Periostal interposition in epiphysiolysis, diagnosed by ultrasound].

    PubMed

    Ostergård, L L; Gaster, P; Hjarbaek, J

    2000-06-01

    Musculoskeletal ultrasound is a rapidly expanding diagnostic field. High frequency transducers with high spacial resolution make it possible to demonstrate superficial soft tissue structures such as tendons, muscles, ligaments and even, under certain circumstances, fractures and periosteum. A case is presented where ultrasound clearly visualised periostal interposition in a distal tibial epiphysiolysis in an eight year-old boy, and some aspects of ultrasound in musculo-skeletal imaging are discussed. PMID:10895603

  1. Ultrasound assessment of transverse carpal ligament thickness: a validity and reliability study.

    PubMed

    Shen, Zhilei Liu; Li, Zong-Ming

    2012-06-01

    The transverse carpal ligament (TCL) forms the palmar boundary of the carpal tunnel and plays an important role in carpal tunnel mechanics. TCL hypertrophy has been observed for individuals with carpal tunnel syndrome (CTS) and postulated as a potential etiologic factor. Ultrasound is particularly advantageous for TCL imaging because of its capability of detecting the interfaces between the TCL and other tissues. The purposes of this study were to develop an ultrasound based method to measure the TCL thickness and to test the validity and reliability of this method. Three operators conducted two sessions of ultrasound examination on eight cadaveric specimens and eight healthy volunteers. A custom script was used to calculate TCL thickness along the TCL length from the ultrasound images. The ultrasound based TCL thickness of the cadaveric specimens was compared with the dissection based TCL thickness for validation. The results showed Pearson's correlation coefficients of 0.867-0.928, intraclass correlation coefficient (ICC) values of 0.726-0.865, a standard error of measurement of 0.02-0.07 mm and a minimal detectable difference of 0.05-0.15 mm. The high correlation coefficients and small errors indicate that the ultrasound based method is valid for measuring TCL thickness. Furthermore, ultrasound measurements showed excellent intraoperator and interoperator reliability with ICC values as 0.826-0.933 and 0.840-0.882, respectively. The ultrasound based TCL thickness was in the range of 0.93-2.34 (1.54 ± 0.33) mm and agreed well with previous studies. The ultrasound method developed in this study is a valuable tool to examine morphologic properties of healthy and pathologic TCLs. PMID:22502882

  2. Ultrasound Assessment of Transverse Carpal Ligament Thickness: A Validity and Reliability Study

    PubMed Central

    Shen, Zhilei Liu; Li, Zong-Ming

    2012-01-01

    The transverse carpal ligament (TCL) forms the palmar boundary of the carpal tunnel and plays an important role in carpal tunnel mechanics. TCL hypertrophy has been observed for individuals with carpal tunnel syndrome (CTS) and postulated as a potential etiological factor. Ultrasound is particularly advantageous for TCL imaging because of its capability of detecting the interfaces between the TCL and other tissues. The purposes of this study were to develop an ultrasound based method to measure the TCL thickness and to test the validity and reliability of this method. Three operators conducted two sessions of ultrasound examination on 8 cadaveric specimens and 8 healthy volunteers. A custom script was used to calculate TCL thickness along the TCL length from the ultrasound images. The ultrasound based TCL thickness of the cadaveric specimens was compared to the dissection based TCL thickness for validation. The results showed Pearson’s correlation coefficients of 0.867–0.928, intraclass correlation coefficient (ICC) values of 0.726–0.865, a standard error of measurement of 0.02–0.07 mm, and a minimal detectable difference of 0.05–0.15 mm. The high correlation coefficients and small errors indicate that the ultrasound based method is valid for measuring TCL thickness. Furthermore, ultrasound measurements showed excellent intra-operator and inter-operator reliability with ICC values as 0.826–0.933 and 0.840–0.882, respectively. The ultrasound based TCL thickness was in the range of 0.93–2.34 (1.54 ± 0.33) mm and agreed well with previous studies. The ultrasound method developed in this study is a valuable tool to examine morphological properties of healthy and pathological TCLs. PMID:22502882

  3. 3D Simulation of Ultrasound in the Ultra-Distal Human Radius

    NASA Astrophysics Data System (ADS)

    Kaufman, Jonathan J.; Luo, Gangming; Siffert, Robert S.

    The overall objective of this research is to develop an ultrasonic method for non-invasive assessment of the ultradistal radius (UDR). The specific objective of this study was to examine the propagation of ultrasound through the UDR and determine the relationships between bone mass and ultrasound, as well as the ability of ultrasound to discriminate between fracture and non-fracture cases. High-resolution peripheral-QCT (HR-pQCT) images were obtained from a set of 110 subjects that were part of a larger study on osteoporosis. Twenty-three of the subjects had experienced a UDR fracture within the past 2 years; the other 87 subjects served as controls. Each 3D image was used to simulate ultrasound measurements that would result from propagation through the UDR, from its anterior to its posterior surfaces. The simulation was carried out using Wave3000 (CyberLogic, Inc., New York, USA), which solves the full 3D viscoelastic wave equation using a finite difference time domain method. Bone mineral density associated with each radius was computed for each subject, and an ultrasound parameter known as net time delay (NTD) was evaluated. NTD has been shown to be highly correlated with total bone mass in both in vitro and clinical studies. Significant correlations were found between NTD and total bone mass (R2 = 0.91, p < 0.001). The data also showed a statistically significant difference in the NTD for the fracture and non-fracture cases (i.e., a decrease in mean NTD of 14% (P < 0.001), with a t-test statistic of 3.8). The study shows that ultrasound is correlated with bone mass at the UDR, as well as with fracture incidence. Therefore ultrasound may prove useful as a simple and convenient method for non-invasive assessment of osteoporosis and fracture risk. Work is ongoing to compare the simulated ultrasound data with clinical ultrasound measurements made on the same individuals.

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

    PubMed Central

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

    2015-01-01

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

  5. Ultrasound-Guided Fine Needle Aspiration Biopsy of the Thyroid

    MedlinePlus

    ... Index A-Z Ultrasound-Guided Fine Needle Aspiration Biopsy of the Thyroid An ultrasound-guided thyroid biopsy ... Thyroid? What is Ultrasound-Guided Fine Needle Aspiration Biopsy of the Thyroid? During a fine needle aspiration ...

  6. Effects of Water or Brine Immersion Thawing Combined with Ultrasound on Quality Attributes of Frozen Pork Loin

    PubMed Central

    Hong, Geun-Pyo; Chun, Ji-Yeon; Jo, Yeon-Ji

    2014-01-01

    This study explored the effects of water or brine (2% NaCl, w/v) immersion thawing combined with ultrasound treatment (40 kHz, 150 W) on the quality characteristics of pork. Ultrasound treatment of pork was conducted in two cold media (at 4℃), water and 2% (w/v) brine, respectively. Because the ultrasound treatment caused temperature increase in the media from 4℃ to 16℃, the qualities of pork thawed by ultrasound were compared with those thawed by immersion either in water or brine where the temperature was being maintained at either 4℃ (low temperature control) or 17℃ (high temperature control). The ultrasound treatment resulted in rapid thawing of pork where the thawing rate was similar to those thawed in the 17℃ media. For quality characteristics, ultrasound-treated pork in brine had an advantage of less cooking losses when comparing to the control. In particular, ultrasound treatment in brine exhibited the lowest shear force (or highest tenderness) among the freezing/thawing treatments. Although the ultrasound processing in brine caused discoloration of the pork, this thawing technique had potential to be applied as a commercial thawing technology for frozen foods. PMID:26760753

  7. Body Fat Mass Assessment: A Comparison between an Ultrasound-Based Device and a Discovery A Model of DXA

    PubMed Central

    Pineau, Jean-Claude; Lalys, Loïc; Pellegrini, Massimo; Battistini, Nino Carlo

    2013-01-01

    Objective. To examine measurement of body composition by ultrasound compared with a reference technique:dual energy X-ray absorptiometry (DXA). We evaluated the accuracy of a portable ultrasound-based device in estimating total body fat mass with those assessed by DXA in adult. Methods. Body fat mass has been estimated using a portable ultrasound-based device in comparison with a contemporary reference DXA apparatus: the Hologic Discovery A. Anthropometric data has been assessed in order to maximize the output of the software associated with the ultrasound-based device. A cross-validation between ultrasound technique (US) and DXA was developed in this study. Total body fat mass estimated by ultrasound was compared with this DXA model in a sample of 83 women and 41 men. Results. Ultrasound technique (US) of body fat (BF) was better correlated with DXA in both women (r2 = 0.97, P < 0.01) and men (r2 = 0.92, P < 0.01) with standard errors of estimates (SEE) being 2.1 kg and 2.2 kg, respectively. Conclusion. The use of a portable device based on a US produced a very accurate BF estimate in relation to DXA reference technique. As DXA absorptiometry techniques are not interchangeable, the use of our ultrasound-based device needs to be recalibrated on a more contemporary DXA. PMID:24575315

  8. Application of ultrasound in periodontics: Part I

    PubMed Central

    Bains, Vive K.; Mohan, Ranjana; Bains, Rhythm

    2008-01-01

    Ultrasonic is a branch of acoustics concerned with sound vibrations in frequency ranges above audible level. Ultrasound uses the transmission and reflection of acoustic energy. A pulse is propagated and its reflection is received, both by the transducer. For clinical purposes ultrasound is generated by transducers, which converts electrical energy into ultrasonic waves. This is usually achieved by magnetostriction or piezoelectricity. Primary effects of ultrasound are thermal, mechanical (cavitation and microstreaming), and chemical (sonochemicals). Knowledge of the basic and other secondary effects of ultrasound is essential for the development of techniques of application. PMID:20142941

  9. Ultrasound imaging in research and clinical medicine.

    PubMed

    Schellpfeffer, Michael A

    2013-06-01

    The use of ultrasound imaging in clinical obstetrics continues to grow at an almost exponential rate. Ultrasound imaging in developmental biology has only begun to be used to enhance the traditional methodologies to study the developing embryo/fetus. The various modalities of ultrasound imaging are reviewed as they apply to current uses in clinical obstetrics and developmental biologic research. New modalities are also discussed in both clinical obstetrics and developmental biologic research as well as the current limitations of ultrasound imaging faced in both of these fields. PMID:23897593

  10. Numerical simulations of clinical focused ultrasound functional neurosurgery

    PubMed Central

    Pulkkinen, Aki; Werner, Beat; Martin, Ernst; Hynynen, Kullervo

    2014-01-01

    A computational model utilizing grid and finite difference methods was developed to simulate focused ultrasound functional neurosurgery interventions. The model couples the propagation of ultrasound in fluids (soft tissues) and solids (skull) with acoustic and visco-elastic wave equations. The computational model was applied to simulate clinical focused ultrasound functional neurosurgery treatments performed in patients suffering from therapy resistant chronic neuropathic pain. Datasets of five patients were used to derive the treatment geometry. Eight sonications performed in the treatments were then simulated with the developed model. Computations were performed by driving the simulated phased array ultrasound transducer with the acoustic parameters used in the treatments. Resulting focal temperatures and size of the thermal foci were compared quantitatively, in addition to qualitative inspection of the simulated pressure and temperature fields. This study found that the computational model and the simulation parameters predicted an average of 24 ± 13 % lower focal temperature elevations than observed in the treatments. The size of the simulated thermal focus was found to be 40 ± 13 % smaller in the anterior–posterior direction and 22 ± 14% smaller in the inferior–superior direction than in the treatments. The location of the simulated thermal focus was off from the prescribed target by 0.3 ± 0.1 mm, while the peak focal temperature elevation observed in the measurements was off by 1.6 ± 0.6 mm. Although the results of the simulations suggest that there could be some inaccuracies in either the tissue parameters used, or in the simulation methods, the simulations were able to predict the focal spot locations and temperature elevations adequately for initial treatment planning performed to assess, for example, the feasibility of sonication. The accuracy of the simulations could be improved if more precise ultrasound tissue properties (especially of the

  11. Numerical simulations of clinical focused ultrasound functional neurosurgery.

    PubMed

    Pulkkinen, Aki; Werner, Beat; Martin, Ernst; Hynynen, Kullervo

    2014-04-01

    A computational model utilizing grid and finite difference methods were developed to simulate focused ultrasound functional neurosurgery interventions. The model couples the propagation of ultrasound in fluids (soft tissues) and solids (skull) with acoustic and visco-elastic wave equations. The computational model was applied to simulate clinical focused ultrasound functional neurosurgery treatments performed in patients suffering from therapy resistant chronic neuropathic pain. Datasets of five patients were used to derive the treatment geometry. Eight sonications performed in the treatments were then simulated with the developed model. Computations were performed by driving the simulated phased array ultrasound transducer with the acoustic parameters used in the treatments. Resulting focal temperatures and size of the thermal foci were compared quantitatively, in addition to qualitative inspection of the simulated pressure and temperature fields. This study found that the computational model and the simulation parameters predicted an average of 24 ± 13% lower focal temperature elevations than observed in the treatments. The size of the simulated thermal focus was found to be 40 ± 13% smaller in the anterior-posterior direction and 22 ± 14% smaller in the inferior-superior direction than in the treatments. The location of the simulated thermal focus was off from the prescribed target by 0.3 ± 0.1 mm, while the peak focal temperature elevation observed in the measurements was off by 1.6 ± 0.6 mm. Although the results of the simulations suggest that there could be some inaccuracies in either the tissue parameters used, or in the simulation methods, the simulations were able to predict the focal spot locations and temperature elevations adequately for initial treatment planning performed to assess, for example, the feasibility of sonication. The accuracy of the simulations could be improved if more precise ultrasound tissue properties (especially of the

  12. The feasibility of non-contact ultrasound for medical imaging.

    PubMed

    Clement, G T; Nomura, H; Adachi, H; Kamakura, T

    2013-09-21

    High intensity focused ultrasound in air may provide a means for medical and biological imaging without direct coupling of an ultrasound probe. In this study, an approach based on highly focused ultrasound in air is described and the feasibility of the technique is assessed. The overall method is based on the observations that (1) ultrasound in air has superior focusing ability and stronger nonlinear harmonic generation as compared to tissue propagation and (2) a tightly focused field directed into tissue causes point-like spreading that may be regarded as a source for generalized diffraction tomography. Simulations of a spherically-curved transducer are performed, where the transducer's radiation pattern is directed from air into tissue. It is predicted that a focal pressure of 162 dB (2.5 kPa) is sufficient to direct ultrasound through the body, and provide a small but measurable signal (∼1 mPa) upon exit. Based on the simulations, a 20 cm diameter array consisting of 298 transducers is constructed. For this feasibility study, a 40 kHz resonance frequency is selected based on the commercial availability of such transducers. The array is used to focus through water and acrylic phantoms, and the time history of the exiting signal is evaluated. Sufficient data are acquired to demonstrate a low-resolution tomographic reconstruction. Finally, to demonstrate the feasibility to record a signal in vivo, a 75 mm × 55 mm section of a human hand is imaged in a C-mode configuration. PMID:23965825

  13. Numerical simulations of clinical focused ultrasound functional neurosurgery

    NASA Astrophysics Data System (ADS)

    Pulkkinen, Aki; Werner, Beat; Martin, Ernst; Hynynen, Kullervo

    2014-04-01

    A computational model utilizing grid and finite difference methods were developed to simulate focused ultrasound functional neurosurgery interventions. The model couples the propagation of ultrasound in fluids (soft tissues) and solids (skull) with acoustic and visco-elastic wave equations. The computational model was applied to simulate clinical focused ultrasound functional neurosurgery treatments performed in patients suffering from therapy resistant chronic neuropathic pain. Datasets of five patients were used to derive the treatment geometry. Eight sonications performed in the treatments were then simulated with the developed model. Computations were performed by driving the simulated phased array ultrasound transducer with the acoustic parameters used in the treatments. Resulting focal temperatures and size of the thermal foci were compared quantitatively, in addition to qualitative inspection of the simulated pressure and temperature fields. This study found that the computational model and the simulation parameters predicted an average of 24 ± 13% lower focal temperature elevations than observed in the treatments. The size of the simulated thermal focus was found to be 40 ± 13% smaller in the anterior-posterior direction and 22 ± 14% smaller in the inferior-superior direction than in the treatments. The location of the simulated thermal focus was off from the prescribed target by 0.3 ± 0.1 mm, while the peak focal temperature elevation observed in the measurements was off by 1.6 ± 0.6 mm. Although the results of the simulations suggest that there could be some inaccuracies in either the tissue parameters used, or in the simulation methods, the simulations were able to predict the focal spot locations and temperature elevations adequately for initial treatment planning performed to assess, for example, the feasibility of sonication. The accuracy of the simulations could be improved if more precise ultrasound tissue properties (especially of the

  14. Prehospital stroke diagnostics based on neurological examination and transcranial ultrasound

    PubMed Central

    2014-01-01

    Background Transcranial color-coded sonography (TCCS) has proved to be a fast and reliable tool for the detection of middle cerebral artery (MCA) occlusions in a hospital setting. In this feasibility study on prehospital sonography, our aim was to investigate the accuracy of TCCS for neurovascular emergency diagnostics when performed in a prehospital setting using mobile ultrasound equipment as part of a neurological examination. Methods Following a ‘911 stroke code’ call, stroke neurologists experienced in TCCS rendezvoused with the paramedic team. In patients with suspected stroke, TCCS examination including ultrasound contrast agents was performed. Results were compared with neurovascular imaging (CTA, MRA) and the final discharge diagnosis from standard patient-centered stroke care. Results We enrolled ‘232 stroke code’ patients with follow-up data available in 102 patients with complete TCCS examination. A diagnosis of ischemic stroke was made in 73 cases; 29 patients were identified as ‘stroke mimics’. MCA occlusion was diagnosed in ten patients, while internal carotid artery (ICA) occlusion/high-grade stenosis leading to reversal of anterior cerebral artery flow was diagnosed in four patients. The initial working diagnosis ‘any stroke’ showed a sensitivity of 94% and a specificity of 48%. ‘Major MCA or ICA stroke’ diagnosed by mobile ultrasound showed an overall sensitivity of 78% and specificity of 98%. Conclusions The study demonstrates the feasibility and high diagnostic accuracy of emergency transcranial ultrasound assessment combined with neurological examinations for major ischemic stroke. Future combination with telemedical support, point-of-care analysis of blood serum markers, and probability algorithms of prehospital stroke diagnosis including ultrasound may help to speed up stroke treatment. PMID:24572006

  15. 3D ultrasound imaging for prosthesis fabrication and diagnostic imaging

    SciTech Connect

    Morimoto, A.K.; Bow, W.J.; Strong, D.S.

    1995-06-01

    The fabrication of a prosthetic socket for a below-the-knee amputee requires knowledge of the underlying bone structure in order to provide pressure relief for sensitive areas and support for load bearing areas. The goal is to enable the residual limb to bear pressure with greater ease and utility. Conventional methods of prosthesis fabrication are based on limited knowledge about the patient`s underlying bone structure. A 3D ultrasound imaging system was developed at Sandia National Laboratories. The imaging system provides information about the location of the bones in the residual limb along with the shape of the skin surface. Computer assisted design (CAD) software can use this data to design prosthetic sockets for amputees. Ultrasound was selected as the imaging modality. A computer model was developed to analyze the effect of the various scanning parameters and to assist in the design of the overall system. The 3D ultrasound imaging system combines off-the-shelf technology for image capturing, custom hardware, and control and image processing software to generate two types of image data -- volumetric and planar. Both volumetric and planar images reveal definition of skin and bone geometry with planar images providing details on muscle fascial planes, muscle/fat interfaces, and blood vessel definition. The 3D ultrasound imaging system was tested on 9 unilateral below-the- knee amputees. Image data was acquired from both the sound limb and the residual limb. The imaging system was operated in both volumetric and planar formats. An x-ray CT (Computed Tomography) scan was performed on each amputee for comparison. Results of the test indicate beneficial use of ultrasound to generate databases for fabrication of prostheses at a lower cost and with better initial fit as compared to manually fabricated prostheses.

  16. Torsional ultrasound modality for hard nucleus phacoemulsification cataract extraction

    PubMed Central

    Zeng, M; Liu, X; Liu, Y; Xia, Y; Luo, L; Yuan, Z; Zeng, Y; Liu, Y

    2008-01-01

    Aim: To evaluate the efficacy and safety of phacoemulsification using torsional modality with different parameter settings for hard nucleus cataract extraction. Design: A prospective, randomised clinical study. Methods: A clinical practice study conducted at the Cataract Service, Zhongshan Ophthalmic Center, Sun-Yat-Sen University, and Guangzhou. One eye each from 198 consecutive patients with cataract density grade IV according to the Emery–Little system classification system, requiring phacoemulsification and intraocular lens implantation, was included. Eyes were randomly assigned to the Linear Torsional combined with Ultrasound power group (Linear Tor+US group, n = 66), 100% Fixed Torsional group (Fixed Tor group, n = 65) and conventional Ultrasound burst group (US group, n = 67). All surgeries were performed by a single experienced surgeon and outcomes evaluated by another surgeon masked to treatment. Intraoperative parameters were Ultrasound Time (UST), Cumulative Dissipated Energy (CDE) and surgical complications. Patients were examined on post-op days 1, 7 and 30. Postoperative outcomes were final best corrected visual acuity (BCVA), average central and incisional corneal thickness and central endothelial cell counts. Results: The mean UST was lower in the Fixed Tor group than in the US group and in the Lin US+Tor group (p⩽0.0001). The mean CDE was lower in the Lin Tor+US group and in the Fixed Tor group than in the US group (p⩽0.0001). Comparing with the two Tor group, the US group had a lower average BCVA on post-op 1, 7 (p⩽0.0001) and 30 (p>0.01), greater average central corneal and incisional thickness on days 1, 7 (p⩽0.0001) and 30 (p>0.01), and higher average corneal endothelial cell losses on day 7 and 30 days (p⩽0.0001). Conclusions: Torsional combined with ultrasound power or high fixed torsional amplitude can yield more effective hard nucleus phacoemulsification than conventional ultrasound modality. PMID:18567650

  17. Fetal and umbilical Doppler ultrasound in high-risk pregnancies

    PubMed Central

    Alfirevic, Zarko; Stampalija, Tamara; Gyte, Gillian ML

    2014-01-01

    Background Abnormal blood flow patterns in fetal circulation detected by Doppler ultrasound may indicate poor fetal prognosis. It is also possible false positive Doppler ultrasound findings could encourage inappropriate early delivery. Objectives The objective of this review was to assess the effects of Doppler ultrasound used to assess fetal well-being in high-risk pregnancies on obstetric care and fetal outcomes. Search methods We searched the Cochrane Pregnancy and Childbirth Group’s Trials Register (September 2009) and the reference lists of identified studies. Selection criteria Randomised and quasi-randomised controlled trials of Doppler ultrasound for the investigation of umbilical and fetal vessels waveforms in high-risk pregnancies compared to no Doppler ultrasound. Data collection and analysis Two authors independently assessed the studies for inclusion, assessed risk of bias and carried out data extraction. Data entry was checked. Main results Eighteen completed studies involving just over 10,000 women were included. The trials were generally of unclear quality with some evidence of possible publication bias. The use of Doppler ultrasound in high-risk pregnancy was associated a reduction in perinatal deaths (risk ratio (RR) 0.71, 95% confidence interval (CI) 0.52 to 0.98, 16 studies, 10,225 babies, 1.2% versus 1.7 %, numbers needed to treat = 203; 95%CI 103 to 4352). There were also fewer inductions of labour (average RR 0.89, 95% CI 0.80 to 0.99, 10 studies, 5633 women, random effects) and fewer caesarean sections (RR 0.90, 95% CI 0.84 to 0.97, 14 studies, 7918 women). No difference was found in operative vaginal births (RR 0.95, 95% CI 0.80 to 1.14, four studies, 2813 women) nor in Apgar scores less than seven at five minutes (RR 0.92, 95% CI 0.69 to 1.24, seven studies, 6321 babies). Authors’ conclusions Current evidence suggests that the use of Doppler ultrasound in high-risk pregnancies reduced the risk of perinatal deaths and resulted in less

  18. Endoscopic ultrasound-guided drainage of pancreatic pseudocysts

    PubMed Central

    Săftoiu, Adrian; Vilmann, Andreas; Vilmann, Peter

    2015-01-01

    Pancreatic pseudocysts are fluid collections in the peripancreatic tissues associated with acute or chronic pancreatitis. Endoscopic ultrasound (EUS)-guided drainage has become an established indication, having better results as compared to percutaneous drainage, nonguided endoscopic drainage, or surgical drainage. The aim of this review is to assess critically the current literature concerning EUS-guided pseudocyst drainage and to review the place of the procedure in the clinical decision management algorithms of these patients. PMID:26643700

  19. Endoscopic ultrasound-guided drainage of pancreatic pseudocysts.

    PubMed

    Saftoiu, Adrian; Vilmann, Andreas; Vilmann, Peter

    2015-01-01

    Pancreatic pseudocysts are fluid collections in the peripancreatic tissues associated with acute or chronic pancreatitis. Endoscopic ultrasound (EUS)-guided drainage has become an established indication, having better results as compared to percutaneous drainage, nonguided endoscopic drainage, or surgical drainage. The aim of this review is to assess critically the current literature concerning EUS-guided pseudocyst drainage and to review the place of the procedure in the clinical decision management algorithms of these patients. PMID:26643700

  20. A Tissue-Mimicking Ultrasound Test Object Using Droplet Vaporization to Create Point Targets

    PubMed Central

    Carneal, Catherine M.; Kripfgans, Oliver D.; Krücker, Jochen; Carson, Paul L.; Fowlkes, J. Brian

    2012-01-01

    Ultrasound test objects containing reference point targets could be useful for evaluating ultrasound systems and phase aberration correction methods. Polyacrylamide gels containing albumin-stabilized droplets (3.6 µm mean diameter) of dodecafluoropentane (DDFP) are being developed for this purpose. Perturbation by ultrasound causes spontaneous vaporization of the superheated droplets to form gas bubbles, a process termed acoustic droplet vaporization (ADV). The resulting bubbles (20 to 160 µm diameter) are small compared with acoustic wavelengths in diagnostic ultrasound and are theoretically suitable for use as point targets (phase errors <20° for typical f-numbers). Bubbles distributed throughout the material are convenient for determining the point spread function in an imaging plane or volume. Cooling the gel causes condensation of the DDFP droplets, which may be useful for storage. Studying ADV in such viscoelastic media could provide insight into potential bioeffects from rapid bubble formation. PMID:21937339

  1. Minimum anesthetic volume in regional anesthesia by using ultrasound-guidance.

    PubMed

    Di Filippo, Alessandro; Falsini, Silvia; Adembri, Chiara

    2016-01-01

    The ultrasound guidance in regional anesthesia ensures the visualization of needle placement and the spread of Local Anesthetics. Over the past few years there was a substantial interest in determining the Minimum Effective Anesthetic Volume necessary to accomplish surgical anesthesia. The precise and real-time visualization of Local Anesthetics spread under ultrasound guidance block may represent the best requisite for reducing Local Anesthetics dose and Local Anesthetics-related effects. We will report a series of studies that have demonstrated the efficacy of ultrasound guidance blocks to reduce Local Anesthetics and obtain surgical anesthesia as compared to block performed under blind or electrical nerve stimulation technique. Unfortunately, the results of studies are widely divergent and not seem to indicate a dose considered effective, for each block, in a definitive way; but it is true that, through the use of ultrasound guidance, it is possible to reduce the dose of anesthetic in the performance of anesthetic blocks. PMID:27591464

  2. Tubular Enhanced Geodesic Active Contours for Continuum Robot Detection using 3D Ultrasound

    PubMed Central

    Ren, Hongliang; Dupont, Pierre E.

    2013-01-01

    Three dimensional ultrasound is a promising imaging modality for minimally invasive robotic surgery. As the robots are typically metallic, they interact strongly with the sound waves in ways that are not modeled by the ultrasound system’s signal processing algorithms. Consequently, they produce substantial imaging artifacts that can make image guidance difficult, even for experienced surgeons. This paper introduces a new approach for detecting curved continuum robots in 3D ultrasound images. The proposed approach combines geodesic active contours with a speed function that is based on enhancing the “tubularity” of the continuum robot. In particular, it takes advantage of the known robot diameter along its length. It also takes advantage of the fact that the robot surface facing the ultrasound probe provides the most accurate image. This method, termed Tubular Enhanced Geodesic Active Contours (TEGAC), is demonstrated through ex vivo intracardiac experiments to offer superior performance compared to conventional active contours. PMID:24231880

  3. In Vivo application and localization of transcranial focused ultrasound using dual-mode ultrasound arrays.

    PubMed

    Haritonova, Alyona; Liu, Dalong; Ebbini, Emad S

    2015-12-01

    Focused ultrasound (FUS) has been proposed for a variety of transcranial applications, including neuromodulation, tumor ablation, and blood-brain barrier opening. A flurry of activity in recent years has generated encouraging results demonstrating its feasibility in these and other applications. To date, monitoring of FUS beams has been primarily accomplished using MR guidance, where both MR thermography and elastography have been used. The recent introduction of real-time dual-mode ultrasound array (DMUA) systems offers a new paradigm in transcranial focusing. In this paper, we present first experimental results of ultrasound-guided transcranial FUS (tFUS) application in a rodent brain, both ex vivo and in vivo. DMUA imaging is used for visualization of the treatment region for placement of the focal spot within the brain. This includes the detection and localization of pulsating blood vessels at or near the target point(s). In addition, DMUA imaging is used to monitor and localize the FUS-tissue interactions in real time. In particular, a concave (40 mm radius of curvature), 32-element, 3.5-MHz DMUA prototype was used for imaging and tFUS application in ex vivo and in vivo rat models. The ex vivo experiments were used to evaluate the point spread function of the transcranial DMUA imaging at various points within the brain. In addition, DMUA-based transcranial ultrasound thermography measurements were compared with thermocouple measurements of subtherapeutic tFUS heating in rat brain ex vivo. The ex vivo setting was also used to demonstrate the capability of DMUA to produce localized thermal lesions. The in vivo experiments were designed to demonstrate the ability of the DMUA to apply, monitor, and localize subtherapeutic tFUS patterns that could be beneficial in transient blood-brain barrier opening. The results show that although the DMUA focus is degraded due to the propagation through the skull, it still produces localized heating effects within a sub

  4. Comb-push ultrasound shear elastography (CUSE) with various ultrasound push beams.

    PubMed

    Song, Pengfei; Urban, Matthew W; Manduca, Armando; Zhao, Heng; Greenleaf, James F; Chen, Shigao

    2013-08-01

    Comb-push ultrasound shear elastography (CUSE) has recently been shown to be a fast and accurate 2-D elasticity imaging technique that can provide a full field-of-view (FOV) shear wave speed map with only one rapid data acquisition. The initial version of CUSE was termed U-CUSE because unfocused ultrasound push beams were used. In this paper, we present two new versions of CUSE-focused CUSE (F-CUSE) and marching CUSE (M-CUSE), which use focused ultrasound push beams to improve acoustic radiation force penetration and produce stronger shear waves in deep tissues (e.g., kidney and liver). F-CUSE divides transducer elements into several subgroups which transmit multiple focused ultrasound beams simultaneously. M-CUSE uses more elements for each focused push beam and laterally marches the push beams. Both F-CUSE and M-CUSE can generate comb-shaped shear wave fields that have shear wave motion at each imaging pixel location so that a full FOV 2-D shear wave speed map can be reconstructed with only one data acquisition. Homogeneous phantom experiments showed that U-CUSE, F-CUSE, and M-CUSE can all produce smooth shear wave speed maps with accurate shear wave speed estimates. An inclusion phantom experiment showed that all CUSE methods could provide good contrast between the inclusion and background with sharp boundaries while F-CUSE and M-CUSE require shorter push durations to achieve shear wave speed maps with comparable SNR to U-CUSE. A more challenging inclusion phantom experiment with a very stiff and deep inclusion shows that better shear wave penetration could be gained by using F-CUSE and M-CUSE. Finally, a shallow inclusion experiment showed that good preservations of inclusion shapes could be achieved by both U-CUSE and F-CUSE in the near field. Safety measurements showed that all safety parameters are below FDA regulatory limits for all CUSE methods. These promising results suggest that, using various push beams, CUSE is capable of reconstructing a 2-D full FOV

  5. In Vivo Application and Localization of Transcranial Focused Ultrasound Using Dual-Mode Ultrasound Arrays

    PubMed Central

    Haritonova, Alyona; Liu, Dalong; Ebbini, Emad S.

    2015-01-01

    Focused ultrasound (FUS) has been proposed for a variety of transcranial applications, including neuromodulation, tumor ablation, and blood brain barrier opening. A flurry of activity in recent years has generated encouraging results demonstrating its feasibility in these and other applications. To date, monitoring of FUS beams have been primarily accomplished using MR guidance, where both MR thermography and elastography have been used. The recent introduction of real-time dual-mode ultrasound array (DMUA) systems offers a new paradigm in transcranial focusing. In this paper, we present first experimental results of ultrasound-guided transcranial FUS (tFUS) application in a rodent brain, both ex vivo and in vivo. DMUA imaging is used for visualization of the treatment region for placement of the focal spot within the brain. This includes the detection and localization of pulsating blood vessels at or near the target point(s). In addition, DMUA imaging is used to monitor and localize the FUS-tissue interactions in real-time. In particular, a concave (40-mm radius of curvature), 32-element, 3.5 MHz DMUA prototype was used for imaging and tFUS application in ex vivo and in vivo rat model. The ex vivo experiments were used to evaluate the point spread function (psf) of the transcranial DMUA imaging at various points within the brain. In addition, DMUA-based transcranial ultrasound thermography measurements were compared with thermocouple measurements of subtherapeutic tFUS heating in rat brain ex vivo. The ex vivo setting was also used to demonstrate the DMUA capability to produce localized thermal lesions. The in vivo experiments were designed to demonstrate the ability of the DMUA to apply, monitor, and localize subtherapeutic tFUS patterns that could be beneficial in transient blood brain barrier opening. The results show that, while the DMUA focus is degraded due to the propagation through the skull, it still produces localized heating effects within sub

  6. The Speckle Noise Reduction and the Boundary Enhancement on Medical Ultrasound Images using the Cellular Neural Networks

    NASA Astrophysics Data System (ADS)

    Park, Hyunkyung; Miyazaki, Ryota; Nishimura, Toshihiro; Tamaki, Yasuhiro

    The purpose is to remove the speckle noise and to emphasize the boundary of a tumor by filtering based on the intensity difference in the medical ultrasound images. The proposed method is evaluated using numerical phantom simulating ultrasound B-mode images, and the effect is confirmed by applying to medical ultrasound images. Therefore, some important features such as tissue boundaries and small tumors may be overlooked. A CNN (cellular neural networks) for the speckle reduction and the edge enhancement are proposed in this paper. A CNN which is a kind of recurrent neural network can deal with images by the weight of neurons called a cell. It could be obtained more detail images recognition compared with the previous studies. A determination template parameters of the CNN for ultrasound image processing is discussed. The experimental results show effectiveness of applying the proposed method to boundary enhancement and the speckle reduction of medical ultrasound image.

  7. Twofold processing for denoising ultrasound medical images.

    PubMed

    Kishore, P V V; Kumar, K V V; Kumar, D Anil; Prasad, M V D; Goutham, E N D; Rahul, R; Krishna, C B S Vamsi; Sandeep, Y

    2015-01-01

    Ultrasound medical (US) imaging non-invasively pictures inside of a human body for disease diagnostics. Speckle noise attacks ultrasound images degrading their visual quality. A twofold processing algorithm is proposed in this work to reduce this multiplicative speckle noise. First fold used block based thresholding, both hard (BHT) and soft (BST), on pixels in wavelet domain with 8, 16, 32 and 64 non-overlapping block sizes. This first fold process is a better denoising method for reducing speckle and also inducing object of interest blurring. The second fold process initiates to restore object boundaries and texture with adaptive wavelet fusion. The degraded object restoration in block thresholded US image is carried through wavelet coefficient fusion of object in original US mage and block thresholded US image. Fusion rules and wavelet decomposition levels are made adaptive for each block using gradient histograms with normalized differential mean (NDF) to introduce highest level of contrast between the denoised pixels and the object pixels in the resultant image. Thus the proposed twofold methods are named as adaptive NDF block fusion with hard and soft thresholding (ANBF-HT and ANBF-ST). The results indicate visual quality improvement to an interesting level with the proposed twofold processing, where the first fold removes noise and second fold restores object properties. Peak signal to noise ratio (PSNR), normalized cross correlation coefficient (NCC), edge strength (ES), image quality Index (IQI) and structural similarity index (SSIM), measure the quantitative quality of the twofold processing technique. Validation of the proposed method is done by comparing with anisotropic diffusion (AD), total variational filtering (TVF) and empirical mode decomposition (EMD) for enhancement of US images. The US images are provided by AMMA hospital radiology labs at Vijayawada, India. PMID:26697285

  8. Feasibility of Swept Synthetic Aperture Ultrasound Imaging.

    PubMed

    Bottenus, Nick; Long, Will; Zhang, Haichong K; Jakovljevic, Marko; Bradway, David P; Boctor, Emad M; Trahey, Gregg E

    2016-07-01

    Ultrasound image quality is often inherently limited by the physical dimensions of the imaging transducer. We hypothesize that, by collecting synthetic aperture data sets over a range of aperture positions while precisely tracking the position and orientation of the transducer, we can synthesize large effective apertures to produce images with improved resolution and target detectability. We analyze the two largest limiting factors for coherent signal summation: aberration and mechanical uncertainty. Using an excised canine abdominal wall as a model phase screen, we experimentally observed an effective arrival time error ranging from 18.3 ns to 58 ns (root-mean-square error) across the swept positions. Through this clutter-generating tissue, we observed a 72.9% improvement in resolution with only a 3.75 dB increase in side lobe amplitude compared to the control case. We present a simulation model to study the effect of calibration and mechanical jitter errors on the synthesized point spread function. The relative effects of these errors in each imaging dimension are explored, showing the importance of orientation relative to the point spread function. We present a prototype device for performing swept synthetic aperture imaging using a conventional 1-D array transducer and ultrasound research scanner. Point target reconstruction error for a 44.2 degree sweep shows a reconstruction precision of 82.8 μm and 17.8 μm in the lateral and axial dimensions respectively, within the acceptable performance bounds of the simulation model. Improvements in resolution, contrast and contrast-to-noise ratio are demonstrated in vivo and in a fetal phantom. PMID:26863653

  9. Hot topics in biomedical ultrasound: ultrasound therapy and its integration with ultrasonic imaging

    NASA Astrophysics Data System (ADS)

    Everbach, E. Carr

    2005-09-01

    Since the development of biomedical ultrasound imaging from sonar after WWII, there has been a clear divide between ultrasonic imaging and ultrasound therapy. While imaging techniques are designed to cause as little change as possible in the tissues through which ultrasound propagates, ultrasound therapy typically relies upon heating or acoustic cavitation to produce a desirable therapeutic effect. Concerns over the increasingly high acoustic outputs of diagnostic ultrasound scanners prompted the adoption of the Mechanical Index (MI) and Thermal Index (TI) in the early 1990s. Therapeutic applications of ultrasound, meanwhile, have evolved from deep tissue heating in sports medicine to include targeted drug delivery, tumor and plaque ablation, cauterization via high intensity focused ultrasound (HIFU), and accelerated dissolution of blood clots. The integration of ultrasonic imaging and therapy in one device is just beginning, but the promise of improved patient outcomes is balanced by regulatory and practical impediments.

  10. Thermal Field Imaging Using Ultrasound

    NASA Technical Reports Server (NTRS)

    Andereck, D.; Rahal, S.; Fife, S.

    2000-01-01

    It is often desirable to be able to determine the temperature field in the interiors of opaque fluids forced into convection by externally imposed temperature gradients. To measure the temperature at a point in an opaque fluid in the usual fashion requires insertion of a probe, and to determine the full field therefore requires either the ability to move this probe or the introduction of multiple probes. Neither of these solutions is particularly satisfactory, although they can lead to quite accurate measurements. As an alternative we have investigated the use of ultrasound as a relatively non-intrusive probe of the temperature field in convecting opaque fluids. The temperature dependence of the sound velocity can be sufficiently great to permit a determination of the temperature from timing the traversal of an ultrasound pulse across a chamber. In this paper we will present our results on convecting flows of transparent and opaque fluids. Our experimental cells consist of relatively narrow rectangular cavities made of thermally insulating materials on the sides, and metal top and bottom plates. The ultrasound transducer is powered by a pulser/receiver, the signal output of which goes to a very high speed signal averager. The average of several hundred to several thousand signals is then sent to a computer for storage and analysis. The experimental procedure is to establish a convective flow by imposing a vertical temperature gradient on the chamber, and then to measure, at several regularly spaced locations, the transit time for an ultrasound pulse to traverse the chamber horizontally (parallel to the convecting rolls) and return to the transducer. The transit time is related to the temperature of the fluid through which the sound pulse travels. Knowing the relationship between transit time and temperature (determined in a separate experiment), we can extract the average temperature across the chamber at that location. By changing the location of the transducer it

  11. Gestational age assessment in malaria pregnancy cohorts: a prospective ultrasound demonstration project in Malawi

    PubMed Central

    2013-01-01

    Background Malaria during pregnancy is associated with an increased risk for low birth weight (<2500 grams). Distinguishing infants that are born premature (< 37 weeks) from those that are growth-restricted (less than the 10th percentile at birth) requires accurate assessment of gestational age. Where ultrasound is accessible, sonographic confirmation of gestational age is more accurate than menstrual dating. The goal was to pilot the feasibility and utility of adding ultrasound to an observational pregnancy malaria cohort. Methods In July 2009, research staff (three mid-level clinical providers, one nurse) from The Blantyre Malaria Project underwent an intensive one-week ultrasound training to perform foetal biometry. Following an additional four months of practice and remote image review, subjects from an ongoing cohort were recruited for ultrasound to determine gestational age. Gestational age at delivery established by ultrasound was compared with postnatal gestational age assessment (Ballard examination). Results One hundred and seventy-eight women were enrolled. The majority of images were of good quality (94.3%, 509/540) although a learning curve was apparent with 17.5% (24/135) images of unacceptable quality in the first 25% of scans. Ultrasound was used to date 13% of the pregnancies when menstrual dates were unknown and changed the estimated gestational age for an additional 25%. There was poor agreement between the gestational age at delivery as established by the ultrasound protocol compared to that determined by the Ballard examination (bias 0.8 weeks, limits of agreement -3.5 weeks to 5.1 weeks). The distribution of gestational ages by Ballard suggested a clustering of gestational age around the mean with 87% of the values falling between 39 and 41 weeks. The distribution of gestational age by ultrasound confirmed menstrual dates was more typical. Using ultrasound confirmed dates as the gold standard, 78.5% of preterm infants were misclassified as

  12. Automatic Contour Tracking in Ultrasound Images

    ERIC Educational Resources Information Center

    Li, Min; Kambhamettu, Chandra; Stone, Maureen

    2005-01-01

    In this paper, a new automatic contour tracking system, EdgeTrak, for the ultrasound image sequences of human tongue is presented. The images are produced by a head and transducer support system (HATS). The noise and unrelated high-contrast edges in ultrasound images make it very difficult to automatically detect the correct tongue surfaces. In…

  13. [Ultrasound in the management of inflammatory dermatosis].

    PubMed

    Habicheyn Hiar, S; Segura Palacios, J M; Bernal Ruiz, A I

    2015-11-01

    Cutaneous ultrasound is a dermatological diagnostic imaging technique based on the interaction of high-frequency ultrasounds with the skin. Because it is non-invasive, rapid and accessible, it has increasingly wide clinical applications. This article reviews its use in the management of inflammatory dermatological diseases. PMID:26895938

  14. Editorial review: pediatric 3D ultrasound

    PubMed Central

    2014-01-01

    Three-dimensional ultrasound is an established diagnostic imaging technique in many specialties. However, in neonates, infants and children three-dimensional ultrasound still is underutilized, partially due to time constraints for post-processing and restricted availability, of devices as well as dedicated pediatric transducers. Also reimbursement issues still need to be addressed. This editorial review presents more or less established pediatric three-dimensional ultrasound applications with proven diagnostic benefit as well as potential future applications of three-dimensional/four-dimensional ultrasound in infants and children, aiming at enhancing research and promoting practical use of three-dimensional ultrasound in relevant pediatric conditions. Particularly, applications in neonatal neurosonography, ultrasound of the urogenital tract as well as some other small part and miscellaneous queries are highlighted. Additional other potential and future indications are discussed briefly, also mentioning restrictions and potential future developments. In summary, three-dimensional ultrasound holds some potential to widen sonographic diagnostic capabilities throughout childhood and hopefully will be increasingly investigated and introduced into clinical practice provided respective equipment and pediatric three-dimensional/four-dimensional ultrasound transducers become available. PMID:26676068

  15. Enhancement of fibrinolysis in vitro by ultrasound.

    PubMed Central

    Francis, C W; Onundarson, P T; Carstensen, E L; Blinc, A; Meltzer, R S; Schwarz, K; Marder, V J

    1992-01-01

    The effect of ultrasound on the rate of fibrinolysis has been investigated using an in vitro system. Plasma or blood clots containing a trace label of 125I fibrin were suspended in plasma containing plasminogen activator and intermittently exposed to continuous wave 1-MHz ultrasound at intensities up to 8 W/cm2. Plasma clot lysis at 1 h with 1 microgram/ml recombinant tissue plasminogen activator (rt-PA) was 12.8 +/- 1.2% without ultrasound and was significantly (P = 0.0001) increased by exposure to ultrasound with greater lysis at 1 W/cm2 (18.0 +/- 1.4%), 2 W/cm2 (19.3 +/- 0.7%), 4 W/cm2 (22.8 +/- 1.8%), and 8 W/cm2 (58.7 +/- 7.1%). Significant increases in lysis were also seen with urokinase at ultrasound intensities of 2 W/cm2 and above. Exposure of clots to ultrasound in the absence of plasminogen activator did not increase lysis. Ultrasound exposure resulted in a marked reduction in the rt-PA concentration required to achieve an equivalent degree of lysis to that seen without ultrasound. For example, 15% lysis occurred in 1 h at 1 microgram/ml rt-PA without ultrasound or with 0.2 microgram/ml with ultrasound, a five-fold reduction in concentration. Ultrasound at 1 W/cm2 and above also potentiated lysis of retracted whole blood clots mediated by rt-PA or urokinase. The maximum temperature increase of plasma clots exposed to 4 W/cm2 ultrasound was only 1.7 degrees C, which could not explain the enhancement of fibrinolysis. Ultrasound exposure did not cause mechanical fragmentation of the clot into sedimentable fragments, nor did it alter the sizes of plasmic derivatives as demonstrated by SDS polyacrylamide gel electrophoresis. We conclude that ultrasound at 1 MHz potentiates enzymatic fibrinolysis by a nonthermal mechanism at energies that can potentially be applied and tolerated in vivo to accelerate therapeutic fibrinolysis. Images PMID:1430229

  16. Testicular neoplasm diagnosed by ultrasound.

    PubMed

    Senay, B A; Stein, B S

    1986-06-01

    The diagnosis of testicular cancer is usually made by the findings of a testicular mass on physical examination. In rare cases a young man will present with retroperitoneal nodes and a normal testicular examination. In such cases a testicular ultrasound may localize the testis which harbors a subclinical neoplasm. In addition serum markers of B-HCG and AFP are essential. As a screening procedure a urine pregnancy test is helpful, since it can be obtained quickly while quantitative B-HCG and APF results are delayed. PMID:3523046

  17. Anaphylaxis following a transvaginal ultrasound.

    PubMed

    Jakubovic, Baruch D; Saperia, Corey; Sussman, Gordon L

    2016-01-01

    Polyethylene glycol is a ubiquitous, water-soluble, organic compound found in a wide variety of commercially available products. While generally a benign substance, in rare instances, it can induce hypersensitivity reactions. Herein, we describe a case of anaphylaxis to polyethylene glycol-containing lubricating gel used for a transvaginal ultrasound. This case highlights the importance of early recognition of a rare cause of anaphylaxis that may occur in the health-care setting. It is of particular importance given the widespread use of similar lubricating materials in multiple practice settings for the use of internal examinations and ultrasonography. PMID:26807134

  18. Use of ultrasound in osteomyelitis.

    PubMed

    Nath, A K; Sethu, A U

    1992-08-01

    The use of ultrasound in osteomyelitis has been studied in 25 patients clinically suspected of osteomyelitis. A sonographic diagnosis of osteomyelitis was made if fluid was present in direct contact with the bone, without intervening soft tissues. This was thought to represent an inflammatory exudate dissecting in a subperiosteal and/or extraperiosteal location. Ultrasonographically 15 patients were found to have osteomyelitis, proved either by surgical drainage or needle aspiration. Seven patients had soft-tissue abscesses, one had cellulitis and two patients had no abnormality. PMID:1393388

  19. Ultrasound in Acute Kidney Disease.

    PubMed

    Meola, Mario; Nalesso, Federico; Petrucci, Ilaria; Samoni, Sara; Ronco, Claudio

    2016-01-01

    Kidneys' imaging provides useful information in acute kidney injury (AKI) diagnosis and management. Today, several imaging techniques give information on kidneys anatomy, urinary obstruction, differential diagnosis between AKI and chronic kidney disease (CKD), renal blood flow and glomerular filtration rate. Ultrasound is a safe, non-invasive and repeatable imaging technique so it is widely used in the first level work-up of AKI. The utility of contrast-enhanced computed tomography and magnetic resonance imaging in AKI or in AKI during CKD is limited because of renal toxicity associated with contrast agents used. PMID:27169556

  20. New ultrasound techniques for lymph node evaluation

    PubMed Central

    Cui, Xin-Wu; Jenssen, Christian; Saftoiu, Adrian; Ignee, Andre; Dietrich, Christoph F

    2013-01-01

    Conventional ultrasound (US) is the recommended imaging method for lymph node (LN) diseases with the advantages of high resolution, real time evaluation and relative low costs. Current indications of transcutaneous ultrasound and endoscopic ultrasound include the detection and characterization of lymph nodes and the guidance for LN biopsy. Recent advances in US technology, such as contrast enhanced ultrasound (CEUS), contrast enhanced endoscopic ultrasound (CE-EUS), and real time elastography show potential to improve the accuracy of US for the differential diagnosis of benign and malignant lymph nodes. In addition, CEUS and CE-EUS have been also used for the guidance of fine needle aspiration and assessment of treatment response. Complementary to size criteria, CEUS could also be used to evaluate response of tumor angiogenesis to anti-angiogenic therapies. In this paper we review current literature regarding evaluation of lymphadenopathy by new and innovative US techniques. PMID:23946589

  1. Pulse Compression Techniques for Laser Generated Ultrasound

    NASA Technical Reports Server (NTRS)

    Anastasi, R. F.; Madaras, E. I.

    1999-01-01

    Laser generated ultrasound for nondestructive evaluation has an optical power density limit due to rapid high heating that causes material damage. This damage threshold limits the generated ultrasound amplitude, which impacts nondestructive evaluation inspection capability. To increase ultrasound signal levels and improve the ultrasound signal-to-noise ratio without exceeding laser power limitations, it is possible to use pulse compression techniques. The approach illustrated here uses a 150mW laser-diode modulated with a pseudo-random sequence and signal correlation. Results demonstrate the successful generation of ultrasonic bulk waves in aluminum and graphite-epoxy composite materials using a modulated low-power laser diode and illustrate ultrasound bandwidth control.

  2. Ultrasound microbubble contrast and current clinical applications.

    PubMed

    Dindyal, Shiva; Kyriakides, Constantinos

    2011-01-01

    Ultrasound imaging is widely used worldwide principally because it is cheap, easily available and contains no exposure to ionizing radiation. The advent of microbubble ultrasound contrast has further increased the diagnostic sensitivity and specificity of this technique thus widening its clinical applications. The third generation of ultrasound contrast agents consist of sulphur hexafluoride microbubbles encased in a phospholipid shell. This review will elaborate on the pharmacology, safety profile and method of action of these agents. We also aim to discuss the ever expanding uses for contrast enhanced ultrasound in a number of clinical specialities which include the liver, kidney, prostate, sentinel node detection, vascular tree and endovascular stent surveillance. We will also discuss some of the recent patents regarding the future uses of ultrasound microbubble contrast and recent technological advances in clinical applications. PMID:21222650

  3. Teaching prenatal ultrasound to family medicine residents.

    PubMed

    Dresang, Lee T; Rodney, William MacMillan; Dees, Jason

    2004-02-01

    Prenatal ultrasound is a powerful diagnostic tool, but there has been little research on how to teach ultrasound to family physicians. The available evidence supports teaching through didactics followed by supervised scanning. Didactic topics include physics and machine usage, indications, fetal biometry, anatomic survey, practice management, ethical issues, and resources. Supervised scanning reinforces the didactic components of training. A "hand-on-hand" supervised scanning technique is recommended for the transmission of psychomotor skills in these sessions. Curricula for teaching ultrasound should include information on which residents will be taught prenatal ultrasound, who will teach them, how to create time for learning ultrasound skills, and how to test for competency. The literature suggests that competency can be achieved within 25-50 supervised scans. Measures of competency include examination and qualitative analysis of scanning. Competency-based testing needs further development because no uniform standards have been established. PMID:14872356

  4. Width-modulated square-wave pulses for ultrasound applications.

    PubMed

    Smith, Peter R; Cowell, David M J; Freear, Steven

    2013-11-01

    A method of output pressure control for ultrasound transducers using switched excitation is described. The method generates width-modulated square-wave pulse sequences that are suitable for driving ultrasound transducers using MOSFETs or similar devices. Sequences are encoded using an optimized level-shifted, carrier-comparison, pulse-width modulation (PWM) strategy derived from existing PWM theory, and modified specifically for ultrasound applications. The modifications are: a reduction in carrier frequency so that the smallest number of pulses are generated and minimal switching is necessary; alteration of a linear carrier form to follow a trigonometric relationship in accordance with the expected fundamental output; and application of frequency modulation to the carrier when generating frequency-modulated, amplitude- tapered signals. The PWM method permits control of output pressure for arbitrary waveform sequences at diagnostic frequencies (approximately 5 MHz) when sampled at 100 MHz, and is applicable to pulse shaping and array apodization. Arbitrary waveform generation capability is demonstrated in simulation using convolution with a transducer's impulse response, and experimentally with hydrophone measurement. Benefits in coded imaging are demonstrated when compared with fixed-width square-wave (pseudo-chirp) excitation in coded imaging, including reduction in image artifacts and peak side-lobe levels for two cases, showing 10 and 8 dB reduction in peak side-lobe level experimentally, compared with 11 and 7 dB reduction in simulation. In all cases, the experimental observations correlate strongly with simulated data. PMID:24158282

  5. Cumulative phase delay imaging for contrast-enhanced ultrasound tomography.

    PubMed

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

    2015-11-01

    Standard dynamic-contrast enhanced ultrasound (DCE-US) imaging detects and estimates ultrasound-contrast-agent (UCA) concentration based on the amplitude of the nonlinear (harmonic) components generated during ultrasound (US) propagation through UCAs. However, harmonic components generation is not specific to UCAs, as it also occurs for US propagating through tissue. Moreover, nonlinear artifacts affect standard DCE-US imaging, causing contrast to tissue ratio reduction, and resulting in possible misclassification of tissue and misinterpretation of UCA concentration. Furthermore, no contrast-specific modality exists for DCE-US tomography; in particular speed-of-sound changes due to UCAs are well within those caused by different tissue types. Recently, a new marker for UCAs has been introduced. A cumulative phase delay (CPD) between the second harmonic and fundamental component is in fact observable for US propagating through UCAs, and is absent in tissue. In this paper, tomographic US images based on CPD are for the first time presented and compared to speed-of-sound US tomography. Results show the applicability of this marker for contrast specific US imaging, with cumulative phase delay imaging (CPDI) showing superior capabilities in detecting and localizing UCA, as compared to speed-of-sound US tomography. Cavities (filled with UCA) which were down to 1 mm in diameter were clearly detectable. Moreover, CPDI is free of the above mentioned nonlinear artifacts. These results open important possibilities to DCE-US tomography, with potential applications to breast imaging for cancer localization. PMID:26459771

  6. Using ultrasound to quantify tongue shape and movement characteristics.

    PubMed

    Zharkova, Natalia

    2013-01-01

    Objective : Previous experimental studies have demonstrated abnormal lingual articulatory patterns characterizing cleft palate speech. Most articulatory information to date has been collected using electropalatography, which records the location and size of tongue-palate contact but not the tongue shape. The latter type of data can be provided by ultrasound. The present paper aims to describe ultrasound tongue imaging as a potential tool for quantitative analysis of tongue function in speakers with cleft palate. A description of the ultrasound technique as applied to analyzing tongue movements is given, followed by the requirements for quantitative analysis. Several measures are described, and example calculations are provided. Measures : Two measures aim to quantify overuse of tongue dorsum in cleft palate articulations. Crucially for potential clinical applications, these measures do not require head-to-transducer stabilization because both are based on a single tongue curve. The other three measures compare sets of tongue curves, with the aim to quantify the dynamics of tongue displacement, token-to-token variability in tongue position, and the extent of separation between tongue curves for different speech sounds. Conclusions : All measures can be used to compare tongue function in speakers with cleft palate before and after therapy, as well as to assess their performance against that in typical speakers and to help in selecting more effective treatments. PMID:22117937

  7. Delimitation of the lung region with distributed ultrasound transducers

    NASA Astrophysics Data System (ADS)

    Cardona Cárdenas, Diego Armando; Furuie, Sérgio Shiguemi

    2016-04-01

    One technique used to infer and monitor patient's respiratory conditions is the electrical impedance tomography (EIT). This provides images with information about lung function. The EIT image contrast is dependent on the variation of electrical impedance, therefore, this image does not provide anatomical details in border regions of several organs. To contribute to a clinical solution, we propose a new method to delimit regions of interest such as the pulmonary region and to improve the reconstruction quality of the EIT. Using a Matlab Toolbox k-wave, the ultrasound propagation phenomenon in homogeneous medium without patient (Reference) and with thoracic models were simulated, separately via a set of several ultrasound transducers distributed around the chest. After pulse emission by a transducer (TR), all received signals were compared considering the two sets of signals. If the energy relation between parts of the signals does not exceed an empirical threshold (30% in this study), a partial mask is generated between the transmitter and the receptor. This process was repeated until all 128 transducers are considered as TR-emitters. The 128 transducers (150kHz) are uniformly distributed. The evaluation was made by visually comparing the resulting images with the respective simulated object. A simple approach was presented to delimit high contrast organs with ultrasound transducers distributed around the patient. This approach allows other lower contrast objects to become invisible by varying the threshold limit. The investigation, based on numerical simulations of ultrasonic propagation, has shown promising results in the delimitation of the pulmonary region.

  8. Cumulative phase delay imaging for contrast-enhanced ultrasound tomography

    NASA Astrophysics Data System (ADS)

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

    2015-11-01

    Standard dynamic-contrast enhanced ultrasound (DCE-US) imaging detects and estimates ultrasound-contrast-agent (UCA) concentration based on the amplitude of the nonlinear (harmonic) components generated during ultrasound (US) propagation through UCAs. However, harmonic components generation is not specific to UCAs, as it also occurs for US propagating through tissue. Moreover, nonlinear artifacts affect standard DCE-US imaging, causing contrast to tissue ratio reduction, and resulting in possible misclassification of tissue and misinterpretation of UCA concentration. Furthermore, no contrast-specific modality exists for DCE-US tomography; in particular speed-of-sound changes due to UCAs are well within those caused by different tissue types. Recently, a new marker for UCAs has been introduced. A cumulative phase delay (CPD) between the second harmonic and fundamental component is in fact observable for US propagating through UCAs, and is absent in tissue. In this paper, tomographic US images based on CPD are for the first time presented and compared to speed-of-sound US tomography. Results show the applicability of this marker for contrast specific US imaging, with cumulative phase delay imaging (CPDI) showing superior capabilities in detecting and localizing UCA, as compared to speed-of-sound US tomography. Cavities (filled with UCA) which were down to 1 mm in diameter were clearly detectable. Moreover, CPDI is free of the above mentioned nonlinear artifacts. These results open important possibilities to DCE-US tomography, with potential applications to breast imaging for cancer localization.

  9. Analysis of left ventricular impedance in comparison with ultrasound images.

    PubMed

    Choi, Seong Wook; Park, Sung Min

    2012-05-01

    Cardiac monitoring of ventricular assist devices (VADs) is important for detecting heart failure risks, such as critical arrhythmia and ventricular fibrillation, and for supplying data that are useful for hemodynamic control. Specifically, impedance cardiograms (ICGs) are especially beneficial because they have no effect on the tissue or organs and can monitor various parameters simultaneously, including the heart rate and heart contractions. In this article, we measured impedance changes in porcine left ventricles using electrodes placed around the inlet and outlet cannulae of the VAD. The measured left ventricular impedance (LVI) waveform changes are caused by heart movements, such as cardiac muscle contraction and changes in blood volume as a result of heart filling and emptying. In contrast to other impedance measurements, LVI is less affected by the movement of other organs. Using a porcine model, LVIs were measured and compared with blood flow data measured with an ultrasound blood flowmeter. The ICG showed the same frequency as the animal's heart rate, and their amplitudes were closely related to cardiac output (CO). However, the waveform differed from other vital signs, such as CO, electrocardiogram, and blood pressure. Ultrasound images were used to explain the impedance waveform. In the ultrasound images, we obtained the shape and size of the animal's heart and calculated the predicted impedance data. We then compared these to the actual measured data. These results show that the impedance signal contains detailed information on heart rate and CO; these results were unaffected by the cannulae or VAD perfusion. PMID:22188560

  10. Dynamic tracking of tendon elongation in ultrasound imaging

    NASA Astrophysics Data System (ADS)

    Karimpoor, Mahta; Screen, Hazel; Morrissey, Dylan

    2010-02-01

    The aim of this study was to evaluate the elongation of the Achilles tendon by looking at the changing position of Myo-Tendenious Junction (MTJ) using ultrasound during isometric contraction on an Isometric dynamometer. A sequence of ultrasound images in the form of movie, obtained from a unit operating at a frequency of 12MHz during isometric contraction, was analyzed offline using MATLAB to track the MTJ. This investigation has implemented important techniques for in vivo feature extraction of Achilles tendon. Prior to feature extraction, the images were filtered by anisotropic diffusion method and morphological enhancements. The cross correlation search algorithm with an adaptive mask was utilized to track MTJ by comparing adjacent segmented frames. The present method was studied on seventeen subjects, where it was able to measure the related movement accurately.

  11. Ultrasound of Biliary Cast Syndrome and Its Mimics.

    PubMed

    Hu, Bing; Horrow, Mindy M

    2016-09-01

    Biliary cast syndrome (BCS) consists of mass-like hardened collections of inspissated bile and sloughed biliary mucosa filling the intrahepatic and/or extrahepatic bile ducts, which show an alternating pattern of dilatation and stricture. It is a rare but serious complication of liver transplantation frequently necessitating repeated percutaneous, endoscopic or surgical stent placements, and cast retrieval. Although not typically considered as the modality of choice for BCS compared with magnetic resonance cholangiopancreatography and endoscopic retrograde cholangiopancreatography, ultrasound can be quite useful for this diagnosis. This article reviews the sonographic appearance of BCS in postliver transplant patients and correlates with other imaging modalities including computed tomography, MRCP, and endoscopic retrograde cholangiopancreatography. Also reviewed are other intrahepatic pathologies that mimic the appearance of BCS on ultrasound. PMID:26561220

  12. Enhancement of Sonochemical Reaction by Dual-Pulse Ultrasound

    NASA Astrophysics Data System (ADS)

    Xu, Zheng; Yasuda, Keiji

    2011-07-01

    In order to apply sonochemistry in wastewater treatment, enhancement of sonochemical reaction is necessary. Oxidation of potassium iodide and the degradation of acid orange 7 in aqueous solution using ultrasound irradiation were performed at 490 kHz. Power-modulated pulsed waves were employed and the enhancement of reaction amount was observed compared with using continuous wave. The enhancement ratio for irradiation to rigid wall was larger than that for irradiation to free surface. Moreover, the best modulated pulsed on time was experimentally determined and the effect of the superposition of pulsed waves (dual-pulse) was studied. Enhancement was also observed and calculated separately when using dual-pulse ultrasound. The enhancement upon the use of the dual-transducer was ascribed to the enlargement of sonochemical reaction field. The enhancement upon the incorporating pulsed waves was ascribed to both the reduction of reaction threshold effect and the residual acoustical pressure at the pulsed off time.

  13. Ultrasound Imaging Using Diffraction Tomography in a Cylindrical Geometry

    SciTech Connect

    Chambers, D H; Littrup, P

    2002-01-24

    Tomographic images of tissue phantoms and a sample of breast tissue have been produced from an acoustic synthetic array system for frequencies near 500 kHz. The images for sound speed and attenuation show millimeter resolution and demonstrate the feasibility of obtaining high-resolution tomographic images with frequencies that can deeply penetrate tissue. The image reconstruction method is based on the Born approximation to acoustic scattering and is a simplified version of a method previously used by Andre (Andre, et. al., Int. J. Imaging Systems and Technology, Vol 8, No. 1, 1997) for a circular acoustic array system. The images have comparable resolution to conventional ultrasound images at much higher frequencies (3-5 MHz) but with lower speckle noise. This shows the potential of low frequency, deeply penetrating, ultrasound for high-resolution quantitative imaging.

  14. Ultrasound assisted enzyme catalyzed degradation of Cetirizine dihydrochloride.

    PubMed

    Sutar, Rahul S; Rathod, Virendra K

    2015-05-01

    Cetirizine dihydrochloride, a pharmaceutical drug of the class antihistamines is frequently detected in wastewater samples. In the present work, the degradation of Cetirizine dihydrochloride is carried out using a novel technique of laccase enzyme as a catalyst under the influence of ultrasound irradiation. Effect of various process parameters such as enzyme loading, temperature, power, duty cycle, frequency and speed of agitation has been studied along with identification of the degradation intermediates. The maximum degradation of 91% is achieved at optimized experimental parameters such as 0.02% enzyme loading (w/v), 50°C temperature, power input of 100 W, 25 kHz frequency and 50% duty cycle with agitation speed of 200 rpm. It is observed that enzymatic degradation of Cetirizine dihydrochloride under the influence of ultrasound irradiation not only enhances the degradation but also reduces the time of degradation as compared to conventional enzymatic degradation technique. PMID:25515235

  15. Cadaver validation of intensity-based ultrasound to CT registration.

    PubMed

    Penney, G P; Barratt, D C; Chan, C S K; Slomczykowski, M; Carter, T J; Edwards, P J; Hawkes, D J

    2006-06-01

    A method is presented for the rigid registration of tracked B-mode ultrasound images to a CT volume of a femur and pelvis. This registration can allow tracked surgical instruments to be aligned with the CT image or an associated preoperative plan. Our method is fully automatic and requires no manual segmentation of either the ultrasound images or the CT volume. The parameter which is directly related to the speed of sound through tissue has also been included in the registration optimisation process. Experiments have been carried out on six cadaveric femurs and three cadaveric pelves. Registration results were compared with a "gold standard" registration acquired using bone implanted fiducial markers. Results show the registration method to be accurate, on average, to 1.6 mm root-mean-square target registration error. PMID:16520083

  16. Nonlocal means-based speckle filtering for ultrasound images

    PubMed Central

    Coupé, Pierrick; Hellier, Pierre; Kervrann, Charles; Barillot, Christian

    2009-01-01

    In image processing, restoration is expected to improve the qualitative inspection of the image and the performance of quantitative image analysis techniques. In this paper, an adaptation of the Non Local (NL-) means filter is proposed for speckle reduction in ultrasound (US) images. Originally developed for additive white Gaussian noise, we propose to use a Bayesian framework to derive a NL-means filter adapted to a relevant ultrasound noise model. Quantitative results on synthetic data show the performances of the proposed method compared to well-established and state-of-the-art methods. Results on real images demonstrate that the proposed method is able to preserve accurately edges and structural details of the image. PMID:19482578

  17. Ultrasound-assisted biodiesel production from Camelina sativa oil.

    PubMed

    Sáez-Bastante, J; Ortega-Román, C; Pinzi, S; Lara-Raya, F R; Leiva-Candia, D E; Dorado, M P

    2015-06-01

    The main drawbacks of biodiesel production are high reaction temperatures, stirring and time. These could be alleviated by aiding transesterification with alternative energy sources, i.e. ultrasound (US). In this study, biodiesel was obtained from Camelina sativa oil, aided with an ultrasonic probe (20kHz, 70% duty cycle, 50% amplitude). Design of experiments included the combination of sonication and agitation cycles, w/wo heating (50°C). To gain knowledge about the implications of the proposed methodology, conventional transesterification was optimized, resulting in higher needs on catalyst concentration and reaction time, compared to the proposed reaction. Although FAME content met EN 14103 standard, FAME yields were lower than those provided by US-assisted transesterification. Energy consumption measurements showed that ultrasound assisted transesterification required lower energy, temperature, catalyst and reaction time. PMID:25768413

  18. Biophysical characterization of low-frequency ultrasound interaction with dental pulp stem cells

    PubMed Central

    2013-01-01

    for cell proliferation during tooth repair. Results The results demonstrate that odontoblast MDPC-23 cell numbers were significantly increased following three consecutive ultrasound treatments over a 7-day culture period as compared with sham controls underscoring the anabolic effects of ultrasound on these cells. Data show a distinct increase in cell number compared to the sham data after ultrasound treatment for intensities of 10 and 25 mW/cm2 (p < 0.05 and p < 0.01, respectively). Using finite element analysis, we demonstrated that ultrasound does indeed propagate through the mineralized layers of the teeth and into the pulp chamber where it forms a ‘therapeutic’ force field to interact with the living dental pulp cells. This allowed us to observe the pressure/intensity of the wave as it propagates throughout the tooth. A selection of time-dependent snapshots of the pressure/intensity reveal that the lower frequency waves propagate to the pulp and remain within the chamber for a while, which is ideal for cell excitation. Input frequencies and pressures of 30 kHz (70 Pa) and 45 kHz (31 kPa), respectively, with an average SPTA of up to 120 mW/cm2 in the pulp seem to be optimal and agree with the SATA intensities reported experimentally. Conclusions Our data suggest that ultrasound can be harnessed to propagate to the dental pulp region where it can interact with the living cells to promote dentine repair. Further research is required to analyze the precise physical and biological interactions of low-frequency ultrasound with the dental pulp to develop a novel non-invasive tool for dental tissue regeneration. PMID:25516801

  19. 3D ultrasound image segmentation using wavelet support vector machines

    PubMed Central

    Akbari, Hamed; Fei, Baowei

    2012-01-01

    Purpose: Transrectal ultrasound (TRUS) imaging is clinically used in prostate biopsy and therapy. Segmentation of the prostate on TRUS images has many applications. In this study, a three-dimensional (3D) segmentation method for TRUS images of the prostate is presented for 3D ultrasound-guided biopsy. Methods: This segmentation method utilizes a statistical shape, texture information, and intensity profiles. A set of wavelet support vector machines (W-SVMs) is applied to the images at various subregions of the prostate. The W-SVMs are trained to adaptively capture the features of the ultrasound images in order to differentiate the prostate and nonprostate tissue. This method consists of a set of wavelet transforms for extraction of prostate texture features and a kernel-based support vector machine to classify the textures. The voxels around the surface of the prostate are labeled in sagittal, coronal, and transverse planes. The weight functions are defined for each labeled voxel on each plane and on the model at each region. In the 3D segmentation procedure, the intensity profiles around the boundary between the tentatively labeled prostate and nonprostate tissue are compared to the prostate model. Consequently, the surfaces are modified based on the model intensity profiles. The segmented prostate is updated and compared to the shape model. These two steps are repeated until they converge. Manual segmentation of the prostate serves as the gold standard and a variety of methods are used to evaluate the performance of the segmentation method. Results: The results from 40 TRUS image volumes of 20 patients show that the Dice overlap ratio is 90.3% ± 2.3% and that the sensitivity is 87.7% ± 4.9%. Conclusions: The proposed method provides a useful tool in our 3D ultrasound image-guided prostate biopsy and can also be applied to other applications in the prostate. PMID:22755682

  20. Superiority of chlorhexidine 2%/alcohol 70% wipes in decontaminating ultrasound equipment

    PubMed Central

    Shukla, Bhavin; Howell, Victoria; Griffiths, Alicia; Thoppil, Anita; Liu, Monica; Young, Peter

    2014-01-01

    Ultrasound equipment is known to act as a reservoir for potentially pathogenic organisms. The aims of these studies were to establish current cleaning practices, to review the extent of bacterial contamination of ultrasound equipment in our hospital, to establish an effective cleaning regimen and to ensure that cleaning does not cause damage. A questionnaire was sent to all acute NHS hospitals in England to establish current cleaning practices. A review of our current practice was performed to establish the extent of bacterial contamination of ultrasound equipment currently in use. Laboratory studies compared cleaning the probes with soap and water with decontaminating with a chlorhexidine 2% and alcohol 70% wipe, including quantifying the residual effect. Accelerated aging was performed on the probe and staff surveyed to establish potential problems with using the wipes on the probe. The survey revealed that a variety of cleaning methods were used to decontaminate ultrasound probes; 57% of our ultrasound machines were contaminated with bacteria. The laboratory studies showed superiority of the chlorhexidine and alcohol wipes over soap and water due to a residual effect, both immediately after cleaning and after 24 hours. The staff survey demonstrated no apparent change in function of the probe after cleaning with the chlorhexidine wipes. Cleaning ultrasound probes with chlorhexidine and alcohol wipes is effective and provides additional protection against bacterial contamination due to its residual effect, and appears in the short term to have no detrimental effect on the probe.

  1. Contrast-enhanced molecular ultrasound differentiates endoglin genotypes in mouse embryos.

    PubMed

    Denbeigh, J M; Nixon, B A; Lee, J J Y; Jerkic, M; Marsden, P A; Letarte, M; Puri, M C; Foster, F S

    2015-01-01

    Targeted ultrasound contrast imaging has the potential to become a reliable molecular imaging tool. A better understanding of the quantitative aspects of molecular ultrasound technology could facilitate the translation of this technique to the clinic for the purposes of assessing vascular pathology and detecting individual response to treatment. The objective of this study was to evaluate whether targeted ultrasound contrast-enhanced imaging can provide a quantitative measure of endogenous biomarkers. Endoglin, an endothelial biomarker involved in the processes of development, vascular homeostasis, and altered in diseases, including hereditary hemorrhagic telangiectasia type 1 and tumor angiogenesis, was the selected target. We used a parallel plate perfusion chamber in which endoglin-targeted (MBE), rat isotype IgG2 control and untargeted microbubbles were perfused across endoglin wild-type (Eng+/+), heterozygous (Eng+/-) and null (Eng-/-) embryonic mouse endothelial cells and their adhesion quantified. Microbubble binding was also assessed in late-gestation, isolated living transgenic Eng+/- and Eng+/+ embryos. Nonlinear contrast-specific ultrasound imaging performed at 21 MHz was used to collect contrast mean power ratios for all bubble types. Statistically significant differences in microbubble binding were found across genotypes for both in vitro (p<0.05) and embryonic studies (p<0.001); MBE binding was approximately twofold higher in Eng+/+ cells and embryos compared with their Eng+/- counterparts. These results suggest that molecular ultrasound is capable of reliably differentiating between molecular genotypes and relating receptor densities to quantifiable molecular ultrasound levels. PMID:25298070

  2. Quantitative ultrasound images generated by a PE-CMOS sensor array: scatter modeling and image restoration

    NASA Astrophysics Data System (ADS)

    Liu, Chu-Chuan; Lo, Shih-Chung Ben; Freedman, Matthew T.; Lasser, Marvin E.; Lasser, Bob; Kula, John; Wang, Yue Joseph

    2007-03-01

    In the projection geometry, the detected ultrasound energy through a soft-tissue is mainly attributed to the attenuated primary intensity and the scatter intensity. In order to extract ultrasound image of attenuated primary beam out of the detected raw data, the scatter component must be carefully quantified for restoring the original image. In this study, we have designed a set of apparatus to modeling the ultrasound scattering in soft-tissue. The employed ultrasound imaging device was a C-Scan (projection) prototype using a 4th generation PE-CMOS sensor array (model I400, by Imperium Inc., Silver Spring, MD) as the detector. Right after the plane wave ultrasound transmitting through a soft-tissue mimicking material (Zerdine, by CIRS Inc., Norfolk, VA), a ring aperture is used to collimate the signal before reaching the acoustic lens and the PE-CMOS sensor. Three sets of collimated ring images were acquired and analyzed to obtain the scattering components as a function of the off-center distance. Several pathological specimens and breast phantoms consisting of simulated breast tissue with masses, cysts and microcalcifications were imaged by the same C-Scan imaging prototype. The restoration of these ultrasound images were performed by using a standard deconvolution computation. Our study indicated that the resultant images show shaper edges and detailed features as compared to their unprocessed counterparts.

  3. Superiority of chlorhexidine 2%/alcohol 70% wipes in decontaminating ultrasound equipment.

    PubMed

    Shukla, Bhavin; Howell, Victoria; Griffiths, Alicia; Thoppil, Anita; Liu, Monica; Carter, Joseph; Young, Peter

    2014-08-01

    Ultrasound equipment is known to act as a reservoir for potentially pathogenic organisms. The aims of these studies were to establish current cleaning practices, to review the extent of bacterial contamination of ultrasound equipment in our hospital, to establish an effective cleaning regimen and to ensure that cleaning does not cause damage. A questionnaire was sent to all acute NHS hospitals in England to establish current cleaning practices. A review of our current practice was performed to establish the extent of bacterial contamination of ultrasound equipment currently in use. Laboratory studies compared cleaning the probes with soap and water with decontaminating with a chlorhexidine 2% and alcohol 70% wipe, including quantifying the residual effect. Accelerated aging was performed on the probe and staff surveyed to establish potential problems with using the wipes on the probe. The survey revealed that a variety of cleaning methods were used to decontaminate ultrasound probes; 57% of our ultrasound machines were contaminated with bacteria. The laboratory studies showed superiority of the chlorhexidine and alcohol wipes over soap and water due to a residual effect, both immediately after cleaning and after 24 hours. The staff survey demonstrated no apparent change in function of the probe after cleaning with the chlorhexidine wipes. Cleaning ultrasound probes with chlorhexidine and alcohol wipes is effective and provides additional protection against bacterial contamination due to its residual effect, and appears in the short term to have no detrimental effect on the probe. PMID:27433210

  4. Segmentation of tumor ultrasound image in HIFU therapy based on texture and boundary encoding

    NASA Astrophysics Data System (ADS)

    Zhang, Dong; Xu, Menglong; Quan, Long; Yang, Yan; Qin, Qianqing; Zhu, Wenbin

    2015-02-01

    It is crucial in high intensity focused ultrasound (HIFU) therapy to detect the tumor precisely with less manual intervention for enhancing the therapy efficiency. Ultrasound image segmentation becomes a difficult task due to signal attenuation, speckle effect and shadows. This paper presents an unsupervised approach based on texture and boundary encoding customized for ultrasound image segmentation in HIFU therapy. The approach oversegments the ultrasound image into some small regions, which are merged by using the principle of minimum description length (MDL) afterwards. Small regions belonging to the same tumor are clustered as they preserve similar texture features. The mergence is completed by obtaining the shortest coding length from encoding textures and boundaries of these regions in the clustering process. The tumor region is finally selected from merged regions by a proposed algorithm without manual interaction. The performance of the method is tested on 50 uterine fibroid ultrasound images from HIFU guiding transducers. The segmentations are compared with manual delineations to verify its feasibility. The quantitative evaluation with HIFU images shows that the mean true positive of the approach is 93.53%, the mean false positive is 4.06%, the mean similarity is 89.92%, the mean norm Hausdorff distance is 3.62% and the mean norm maximum average distance is 0.57%. The experiments validate that the proposed method can achieve favorable segmentation without manual initialization and effectively handle the poor quality of the ultrasound guidance image in HIFU therapy, which indicates that the approach is applicable in HIFU therapy.

  5. Solid volume fraction estimation of bone:marrow replica models using ultrasound transit time spectroscopy.

    PubMed

    Wille, Marie-Luise; Langton, Christian M

    2016-02-01

    The acceptance of broadband ultrasound attenuation (BUA) for the assessment of osteoporosis suffers from a limited understanding of both ultrasound wave propagation through cancellous bone and its exact dependence upon the material and structural properties. It has recently been proposed that ultrasound wave propagation in cancellous bone may be described by a concept of parallel sonic rays; the transit time of each ray defined by the proportion of bone and marrow propagated. A Transit Time Spectrum (TTS) describes the proportion of sonic rays having a particular transit time, effectively describing the lateral inhomogeneity of transit times over the surface aperture of the receive ultrasound transducer. The aim of this study was to test the hypothesis that the solid volume fraction (SVF) of simplified bone:marrow replica models may be reliably estimated from the corresponding ultrasound transit time spectrum. Transit time spectra were derived via digital deconvolution of the experimentally measured input and output ultrasonic signals, and compared to predicted TTS based on the parallel sonic ray concept, demonstrating agreement in both position and amplitude of spectral peaks. Solid volume fraction was calculated from the TTS; agreement between true (geometric calculation) with predicted (computer simulation) and experimentally-derived values were R(2)=99.9% and R(2)=97.3% respectively. It is therefore envisaged that ultrasound transit time spectroscopy (UTTS) offers the potential to reliably estimate bone mineral density and hence the established T-score parameter for clinical osteoporosis assessment. PMID:26455950

  6. Washing of Petroleum and Arsenic Contaminated Soil with Ultrasound and Alkali Phosphate Solution

    NASA Astrophysics Data System (ADS)

    Lee, Jung Hwa; Kim, Jae Gon; Cho, Yong-chan; Chon, Chul-Min; Nam, In-Hyun; Keum, Mi Jung

    2015-04-01

    Soil washing of fine textured soil has been a challenging remedial strategy due to its low remediation efficiency. We adapted ultrasound and dispersion solution to increase the remediation efficiency of the soil washing. The ultrasound and dispersion agent may enhance the dispersion of the aggregate into individual particles and may enhance release of contaminants from the aggregate. We collected the arsenic (As) contaminated silt loam soil from a smelting site, spiked with 1% of diesel and incubated for 6 months. We tested the dispersion rate and the release of diesel with the incubated soil at various pH and concentrations of orthophosphate, pyrophosphate and hexametaphosphate with or without the ultrasound of 28 kHz and 400 W. The As concentrations of coarse (> medium silt) and fine (ultrasound sharply increased the dispersion rate and diesel release comparing with no ultrasound. The optimum condition of the soil washing was turned out to be pH 11_10 mM Na-hexametaphosphate with the ultrasound. The concentration of total petroleum hydrocarbon of the incubated soil reduced from 3101.3 mg kg-1 to 14.0 mg kg-1 after 10 minute washing at the optimum condition. The fine fraction had much higher As concentration than the coarse fraction: 44.4 mg kg-1 for the fine fraction and 14.4 mg kg-1 for the coarse fraction. The results of this study indicate that the ultrasound and alkali phosphate solution increase the soil washing efficiency and can be a promising technology for the remediation of fine textured contaminated soils. Key Words : Ultrasound, Phosphate solution, Soil washing, Mixed contaminants

  7. Cardiac Gene Expression Knockdown Using Small Inhibitory RNA-Loaded Microbubbles and Ultrasound.

    PubMed

    Kopechek, Jonathan A; Carson, Andrew R; McTiernan, Charles F; Chen, Xucai; Klein, Edwin C; Villanueva, Flordeliza S

    2016-01-01

    RNA interference has potential therapeutic value for cardiac disease, but targeted delivery of interfering RNA is a challenge. Custom designed microbubbles, in conjunction with ultrasound, can deliver small inhibitory RNA to target tissues in vivo. The efficacy of cardiac RNA interference using a microbubble-ultrasound theranostic platform has not been demonstrated in vivo. Therefore, our objective was to test the hypothesis that custom designed microbubbles and ultrasound can mediate effective delivery of small inhibitory RNA to the heart. Microbubble and ultrasound mediated cardiac RNA interference was tested in transgenic mice displaying cardiac-restricted luciferase expression. Luciferase expression was assayed in select tissues of untreated mice (n = 14). Mice received intravenous infusion of cationic microbubbles bearing small inhibitory RNA directed against luciferase (n = 9) or control RNA (n = 8) during intermittent cardiac-directed ultrasound at mechanical index of 1.6. Simultaneous echocardiography in a separate group of mice (n = 3) confirmed microbubble destruction and replenishment during treatment. Three days post treatment, cardiac luciferase messenger RNA and protein levels were significantly lower in ultrasound-treated mice receiving microbubbles loaded with small inhibitory RNA directed against luciferase compared to mice receiving microbubbles bearing control RNA (23±7% and 33±7% of control mice, p<0.01 and p = 0.03, respectively). Passive cavitation detection focused on the heart confirmed that insonification resulted in inertial cavitation. In conclusion, small inhibitory RNA-loaded microbubbles and ultrasound directed at the heart significantly reduced the expression of a reporter gene. Ultrasound-targeted destruction of RNA-loaded microbubbles may be an effective image-guided strategy for therapeutic RNA interference in cardiac disease. PMID:27471848

  8. Cardiac Gene Expression Knockdown Using Small Inhibitory RNA-Loaded Microbubbles and Ultrasound

    PubMed Central

    McTiernan, Charles F.; Chen, Xucai; Klein, Edwin C.; Villanueva, Flordeliza S.

    2016-01-01

    RNA interference has potential therapeutic value for cardiac disease, but targeted delivery of interfering RNA is a challenge. Custom designed microbubbles, in conjunction with ultrasound, can deliver small inhibitory RNA to target tissues in vivo. The efficacy of cardiac RNA interference using a microbubble-ultrasound theranostic platform has not been demonstrated in vivo. Therefore, our objective was to test the hypothesis that custom designed microbubbles and ultrasound can mediate effective delivery of small inhibitory RNA to the heart. Microbubble and ultrasound mediated cardiac RNA interference was tested in transgenic mice displaying cardiac-restricted luciferase expression. Luciferase expression was assayed in select tissues of untreated mice (n = 14). Mice received intravenous infusion of cationic microbubbles bearing small inhibitory RNA directed against luciferase (n = 9) or control RNA (n = 8) during intermittent cardiac-directed ultrasound at mechanical index of 1.6. Simultaneous echocardiography in a separate group of mice (n = 3) confirmed microbubble destruction and replenishment during treatment. Three days post treatment, cardiac luciferase messenger RNA and protein levels were significantly lower in ultrasound-treated mice receiving microbubbles loaded with small inhibitory RNA directed against luciferase compared to mice receiving microbubbles bearing control RNA (23±7% and 33±7% of control mice, p<0.01 and p = 0.03, respectively). Passive cavitation detection focused on the heart confirmed that insonification resulted in inertial cavitation. In conclusion, small inhibitory RNA-loaded microbubbles and ultrasound directed at the heart significantly reduced the expression of a reporter gene. Ultrasound-targeted destruction of RNA-loaded microbubbles may be an effective image-guided strategy for therapeutic RNA interference in cardiac disease. PMID:27471848

  9. Randomized study of effectiveness of computerized ultrasound simulators for an introductory course for residents in Brazil

    PubMed Central

    2016-01-01

    Purpose: This study aimed to assess the impact of ultrasound simulation (SonoSim) on educational outcomes of an introductory point-of-care ultrasound course compared to hands-on training with live models alone. Methods: Fifty-three internal medicine residents without ultrasound experience were randomly assigned to control or experimental groups. They participated in an introductory point-of-care ultrasound course covering eight topics in eight sessions from June 23, 2014 until July 18, 2014. Both participated in lecture and hands-on training, but experimental group received an hour of computerized simulator training instead of a second hour of hands-on training. We assessed clinical knowledge and image acquisition with written multiple-choice and practical exams, respectively. Of the 53 enrolled, 40 participants (75.5%) completed the course and all testing. Results: For the 30-item written exam, mean score of the experimental group was 23.1±3.4 (n=21) vs. 21.8±4.8 (n=19), (P>0 .05). For the practical exam, mean score for both groups was 8.7 out of 16 (P>0 .05). Conclusion: The substitution of eight hours of ultrasound simulation training for live model scanning in a 24 hour training course did not enhance performance on written and image acquisition tests in an introductory ultrasound course for residents. This result suggests that ultrasound simulation technology used as a substitute for live model training on an hour-for-hour basis, did not improve learning outcomes. Further investigation into simulation as a total replacement for live model training will provide a clearer picture of the efficacy of ultrasound simulators in medical education. PMID:27044782

  10. DOES ENDOSCOPIC ULTRASOUND IMPROVE DETECTION OF LOCALLY RECURRENT ANAL SQUAMOUS CELL CANCER?

    PubMed Central

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

    2015-01-01

    Background Evaluating patients for recurrent anal cancer after primary treatment can be difficult due to distorted anatomy and scarring. Many institutions incorporate endoscopic ultrasound to improve detection, but the effectiveness is unknown. Objective To compare the effectiveness of digital rectal exam and endoscopic ultrasound during routine follow-up of anal cancer patients in detecting locally recurrent disease. Design Retrospective, single-institution review Settings Oncologic tertiary referral center Patients 175 patients with nonmetastatic anal squamous cell cancer without persistent disease after primary chemoradiotherapy who had at least one post-treatment ultrasound and examination by a colorectal surgeon. Main Outcome Measures First modality to detect local recurrence, concordance, crude cancer detection rate, sensitivity, specificity, and predictive value. Results 855 endoscopic ultrasounds and 873 digital rectal exams were performed during 35 months median follow-up. Overall, ultrasound detected 7 (0.8%) mesorectal and 32 (3.7%) anal canal abnormalities; digital exam detected 69 (7.9%) anal canal abnormalities. Locally recurrent disease was found on biopsy in 8 patients, all detected first or only with digital exam. Four patients did not have an ultrasound at the time of diagnosis of recurrence. The concordance of ultrasound and digital exam in detecting recurrent disease was fair at 0.37 (SE 0.08, 95% CI 0.21-0.54) and there was no difference in crude cancer detection rate, sensitivity, specificity, and negative or positive predictive values. Limitations The heterogeneity of follow-up timing and exams is not standardized in this study but is reflective of general practice. Conclusions Endoscopic ultrasound did not provide any advantage over digital rectal examination in identifying locally recurrent anal cancer, and should not be recommended for routine surveillance. PMID:25585077

  11. Therapeutic aspects of endoscopic ultrasound

    NASA Astrophysics Data System (ADS)

    Woodward, Timothy A.

    1999-06-01

    Endoscopic ultrasound (EUS) is a technology that had been used primarily as a passive imaging modality. Recent advances have enabled us to move beyond the use of EUS solely as a staging tool to an interventional device. Current studies suggest that interventional applications of EUS will allow for minimally invasive assessment and therapies in a cost-effective manner. Endoscopic ultrasound with fine needle aspiration (EUS-FNA) has been demonstrated to be a technically feasible, relatively safe method of obtaining cytologic specimens. The clinical utility of EUS- FNA appears to be greatest in the diagnosis and staging of pancreatic cancer and in the nodal staging of gastrointestinal and pulmonary malignancies. In addition, EUS-FNA has demonstrated utility in the sampling pleural and ascitic fluid not generally appreciated or assessable to standard interventions. Interventional applications of EUS include EUS-guided pseudocyst drainage, EUS-guided injection of botulinum toxin in the treatment of achalasia, and EUS- guided celiac plexus neurolysis in the treatment of pancreatic cancer pain. Finally, EUS-guided fine-needle installation is being evaluated, in conjunction with recent bimolecular treatment modalities, as a delivery system in the treatment of certain gastrointestinal tumors.

  12. Endoscopic ultrasound guided antitumor therapy.

    PubMed

    Bhutani, M S

    2003-08-01

    This paper will review the possibilities of EUS guided anti-tumor therapy. Ablative energy may be delivered to a tumor under EUS guidance to destruct tumor cells by ultrasound itself, radiofrequency or radiation. Pilot results of endoscopic high intensity focused ultrasound in a human trial have been reported. The feasibility of performing EUS guided radiofrequency ablation has been reported in a swine model. An EUS bases radiation target simulation method has been developed for anal cancer therapy. Targeted delivery of an anti-cancer agent into a tumor under EUS guidance is possible as reported in an early clinical trial of local immunotherapy (Cytoimplant) or modified viruses delivered by EUS guided fine needle injection in patients with advanced pancreatic carcinoma. Image guided injection of alcohol is another approach used for local tumor ablation. Application of other ablation therapies such as laser, microwave and cryo is also conceptually feasible. We will have to wait and see where these initial and ongoing attempts for applying EUS against cancer take us. PMID:12929056

  13. Ultrasound enhanced thrombolysis: Clinical evidence

    NASA Astrophysics Data System (ADS)

    Alexandrov, Andrei V.

    2005-04-01

    Phase II CLOTBUST randomized clinical trial (Houston, Barcelona, Edmonton, Calgary) evaluated patients with acute ischemic stroke due to intracranial occlusion and treated with intravenous tissue plasminogen activator (TPA) within 3 h of symptom onset. Randomization: monitoring with pulsed wave 2 MHz transcranial Doppler (TCD) (Target) or placebo monitoring (Control). Safety: symptomatic bleeding to the brain (sICH). Primary end-point: complete recanalization on TCD or dramatic clinical recovery by the total NIHSS score <3, or improvement by >10 NIHSS points within 2 hours after TPA bolus. All projected 126 patients were randomized 1:1 to target (median NIHSS 16) or control (NIHSS 17). sICH: 4.8% Target, 4.8% Controls. Primary end-point was achieved by 31 (49%, Target) versus 19 (30%, Control), p<0.03. At 3 months, 22 (42% Target) and 14 (29% Control) patients achieved favorable outcomes. Continuous TCD monitoring of intracranial occlusion safely augments TPA-induced arterial recanalization, and 2 MHz diagnostic ultrasound has a positive biological activity that aids systemic thrombolytic therapy. For the first time in clinical medicine, the CLOTBUST trial provides the evidence that ultrasound enhances thrombolytic activity of a drug in humans thereby confirming intense multi-disciplinary experimental research conducted worldwide for the past 30 years.

  14. Educational ultrasound nondestructive testing laboratory.

    PubMed

    Genis, Vladimir; Zagorski, Michael

    2008-09-01

    The ultrasound nondestructive evaluation (NDE) of materials course was developed for applied engineering technology students at Drexel University's Goodwin College of Professional Studies. This three-credit, hands-on laboratory course consists of two parts: the first part with an emphasis on the foundations of NDE, and the second part during which ultrasound NDE techniques are utilized in the evaluation of parts and materials. NDE applications are presented and applied through real-life problems, including calibration and use of the latest ultrasonic testing instrumentation. The students learn engineering and physical principles of measurements of sound velocity in different materials, attenuation coefficients, material thickness, and location and dimensions of discontinuities in various materials, such as holes, cracks, and flaws. The work in the laboratory enhances the fundamentals taught during classroom sessions. This course will ultimately result in improvements in the educational process ["The greater expectations," national panel report, http://www.greaterexpectations.org (last viewed February, 2008); R. M. Felder and R. Brent "The intellectual development of Science and Engineering Students. Part 2: Teaching to promote growth," J. Eng. Educ. 93, 279-291 (2004)] since industry is becoming increasingly reliant on the effective application of NDE technology and the demand on NDE specialists is increasing. NDE curriculum was designed to fulfill levels I and II NDE in theory and training requirements, according to American Society for Nondestructive Testing, OH, Recommended Practice No. SNT-TC-1A (2006). PMID:19045633

  15. Classification of gallstones with ultrasound

    NASA Astrophysics Data System (ADS)

    Kocherscheidt, Caroline; Albert, Ulla; Albert, Franz W.; Pandit, Madhukar C.; Pfeiffer, Matthias; Racky, J.

    2000-04-01

    The in vivo determination of the composition of gallstones is of interest to physicians, as it would offer the basis for choosing the appropriate therapy: high calcium content stones would call for laparoscopy, calcium free stones are smashed with a lithotriptor and flushed out using oral solvents. In publications regarding gallstone examinations employing ultrasound, opinion is divided as to whether or not the B-mode image is correlated with the stone composition. The following work aims at resolving this controversy. B-scans were examined in vivo and in vitro. The B-scans were segmented and several texture based features were tried out. Calcification was verified by x-ray imaging. The evaluation of the texture parameters of the segmented areas do not show any calcification dependent clustering. Analysis of images obtained in vitro using a water bath do not offer any better results than those obtained in vivo. However, the features proposed in the literature do show some correlation with the surface geometry. The investigation of tissue characterization using ultrasound imaging seems to be still open.

  16. The ultrasound challenge 2.0: introducing interinstitutional competition in medical student ultrasound education.

    PubMed

    Cortez, Eric J; Boulger, Creagh T; Eastin, Travis; Adkins, Eric J; Granitto, Emily; Pollard, Katherine; Bahner, David P

    2014-12-01

    The Ultrasound Challenge was developed at The Ohio State University College of Medicine to introduce focused ultrasound to medical students. The goal was to develop experience in ultrasound through practice and competition. Initially this competition was held between Ohio State University College of Medicine students from years 1 through 4. The Ultrasound Challenge 2.0 was held in 2013. The event expanded on the previous structure by including students from the Wayne State University College of Medicine. The goal of this article is to describe our experiences with expansion of our interinstitutional ultrasound event. The challenge consisted of 6 stations: focused assessment with sonography for trauma, aortic ultrasound, cardiac ultrasound, pelvic ultrasound, musculoskeletal ultrasound, and vascular access. The participants were given a handbook outlining the expectations for each station ahead of time. Vascular access was graded in real time using the Brightness Mode Quality Ultrasound Imaging Examination Technique (B-QUIET) method. The remainder were timed, saved, and graded after the event by 3 independent faculty members using the B-QUIET method. The highest score with the fastest time was the winner. The Ultrasound Challenge 2.0 included 40 participants: 31 from The Ohio State University College of Medicine and 9 from the Wayne State University College of Medicine. The makeup of the winners in all categories consisted of 1 first-year medical student, 7 second-year medical students, 3 third-year medical students, and 10 fourth-year medical students. The Ultrasound Challenge 2.0 was a success for those who participated. It provided the first known interinstitutional medical student ultrasound competition. Students from both institutions were able to practice their image acquisition skills, demonstrate abilities in a competitive environment, and develop collegiality and teamwork. PMID:25425378

  17. Use of prehospital ultrasound in North America: a survey of emergency medical services medical directors

    PubMed Central

    2014-01-01

    Background Advances in ultrasound imaging technology have made it more accessible to prehospital providers. Little is known about how ultrasound is being used in the prehospital environment and we suspect that it is not widely used in North America at this time. We believe that EMS system characteristics such as provider training, system size, population served, and type of transport will be associated with use or non-use of ultrasound. Our study objective was to describe the current use of prehospital ultrasound in North America. Methods This study was a cross-sectional survey distributed to EMS directors on the National Association of EMS Physicians (NAEMSP) mailing list. Respondents had the option to complete a paper or electronic survey. Results Of the 755 deliverable surveys we received 255 responses from across Canada and the United states for an overall response rate of 30%. Of respondents, 4.1% of EMS systems (95% CI 1.9, 6.3) reported currently using ultrasound and an additional 21.7% (95% CI 17, 26.4) are considering implementing ultrasound. EMS services using ultrasound have a higher proportion of physicians (p < 0.001) as their highest trained prehospital providers when compared to the survey group as a whole. The most commonly cited current and projected applications are Focused Abdominal Sonography for Trauma (FAST) and assessment of pulseless electrical activity (PEA) arrest. The cost of equipment and training are the most significant barriers to implementation of ultrasound. Most medical directors want evidence that prehospital ultrasound improves patient outcomes prior to implementation. Conclusions Prehospital ultrasound is infrequently used in North America and there are a number of barriers to its implementation, including costs of equipment and training and limited evidence demonstrating improved outcomes. A research agenda for prehospital ultrasound should focus on patient-important outcomes such as morbidity and mortality. Two commonly

  18. 21 CFR 890.5860 - Ultrasound and muscle stimulator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Ultrasound and muscle stimulator. 890.5860 Section... Ultrasound and muscle stimulator. (a) Ultrasound and muscle stimulator for use in applying therapeutic deep heat for selected medical conditions—(1) Identification. An ultrasound and muscle stimulator for use...

  19. 21 CFR 890.5860 - Ultrasound and muscle stimulator.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Ultrasound and muscle stimulator. 890.5860 Section... Ultrasound and muscle stimulator. (a) Ultrasound and muscle stimulator for use in applying therapeutic deep heat for selected medical conditions—(1) Identification. An ultrasound and muscle stimulator for use...

  20. 21 CFR 890.5860 - Ultrasound and muscle stimulator.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Ultrasound and muscle stimulator. 890.5860 Section... Ultrasound and muscle stimulator. (a) Ultrasound and muscle stimulator for use in applying therapeutic deep heat for selected medical conditions—(1) Identification. An ultrasound and muscle stimulator for use...