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Ultrasound in Medicine & Biology

Katherine W Pulsipher, Daniel A Hammer, Daeyeon Lee, Chandra M Sehgal
Microbubbles interact with ultrasound in various ways to enable their applications in ultrasound imaging and diagnosis. To generate high contrast and maximize therapeutic efficacy, microbubbles of high uniformity are required. Microfluidic technology, which enables precise control of small volumes of fluid at the sub-millimeter scale, has provided a versatile platform on which to produce highly uniform microbubbles for potential applications in ultrasound imaging and diagnosis. Here, we describe fundamental microfluidic principles and the most common types of microfluidic devices used to produce sub-10 μm microbubbles, appropriate for biomedical ultrasound...
September 18, 2018: Ultrasound in Medicine & Biology
Theresa Bucsics, Benjamin Grasl, Arnulf Ferlitsch, Philipp Schwabl, Mattias Mandorfer, Kerstin Zinober, Rafael Stern, David Chromy, Bernhard Scheiner, Wolfgang Sieghart, Markus Peck-Radosavljevic, Michael Trauner, Thomas Reiberger
Elastography point quantification (ElastPQ) is a new ultrasound-based shear wave elastography method for non-invasive assessment of liver fibrosis. We evaluated the diagnostic accuracy of ElastPQ in patients with chronic viral hepatitis. Fibrosis stage (F) was determined by transient elastography (F0/F1: <7.1 kPa, F2: 7.1-9.4 kPa, F3: 9.5-12.4 kPa, F4: ≥12.5 kPa). Area under the receiver operator characteristics curve (AUROC) analysis was performed to assess ElastPQ cutoffs for significant fibrosis (≥F2) and cirrhosis (F4)...
September 18, 2018: Ultrasound in Medicine & Biology
Wei-Ning Lee, Enoch Jing-Han Chang, Yuexin Guo, Yahua Wang
Guided wave imaging for the artery remains in its infancy in clinical practice mainly because of complex arterial microstructure, hemodynamics and boundary conditions. Despite the theoretically known potential effect of the surrounding medium on guided wave propagation in thin media in non-destructive testing, experimental evidence pertaining to thin soft materials, such as the artery, is relatively scarce in the relevant literature. Therefore, this study first evaluated the propagating guided wave generated by acoustic radiation force in polyvinyl alcohol-based hydrogel plates differing in thickness and stiffness under various material coupling conditions (water and polyvinyl alcohol bulk)...
September 18, 2018: Ultrasound in Medicine & Biology
Benjamin V Sandholt, Henrik H Sillesen
No abstract text is available yet for this article.
September 18, 2018: Ultrasound in Medicine & Biology
Arinc Ozturk, Joseph R Grajo, Michael S Gee, Alex Benjamin, Rebecca E Zubajlo, Kai E Thomenius, Brian W Anthony, Anthony E Samir, Manish Dhyani
Non-alcoholic fatty liver disease is a condition that is characterized by the presence of >5% fat in the liver and affects more than one billion people worldwide. If adequate and early precautions are not taken, non-alcoholic fatty liver disease can progress to cirrhosis and death. The current reference standard for detecting hepatic steatosis is a liver biopsy. However, because of the potential morbidity associated with liver biopsies, non-invasive imaging biomarkers have been extensively investigated. Magnetic resonance imaging-based methods have proven accuracy in quantifying liver steatosis; however, these techniques are costly and have limited availability...
September 16, 2018: Ultrasound in Medicine & Biology
Kyle P Hadinger, Joseph P Marshalek, Paul S Sheeran, Paul A Dayton, Terry O Matsunaga
Breast cancer remains a leading cause of death for women throughout the world. Recent advances in medical imaging technologies and tumor targeting agents signify vast potential for progress toward improved management of this global problem. Phase-change contrast agents (PCCAs) are dynamic imaging agents with practical applications in both the research and clinical settings. PCCAs possess characteristics that allow for cellular uptake where they can be converted from liquid-phase PCCAs to gaseous microbubbles via ultrasound energy...
September 15, 2018: Ultrasound in Medicine & Biology
Alex Benjamin, Rebecca E Zubajlo, Manish Dhyani, Anthony E Samir, Kai E Thomenius, Joseph R Grajo, Brian W Anthony
Described here is a method to determine the longitudinal speed of sound in speckle-dominated ultrasound images. The method is based on the concept that the quality of an ultrasound image is maximized when the beamformer's speed of sound matches the speed in the medium. The method captures the quality of the ultrasound image using two quantitative image-quality metrics: image brightness and sharpness around the intended focal zone. The proposed method requires no calibration, is computationally efficient and is deployable on commercial ultrasound systems without hardware or software modifications...
September 15, 2018: Ultrasound in Medicine & Biology
Ki Joo Pahk, Pierre Gélat, Hyungmin Kim, Nader Saffari
Boiling histotripsy is a non-invasive, cavitation-based ultrasonic technique which uses a number of millisecond pulses to mechanically fractionate tissue. Though a number of studies have demonstrated the efficacy of boiling histotripsy for fractionation of solid tumours, treatment monitoring by cavitation measurement is not well studied because of the limited understanding of the dynamics of bubbles induced by boiling histotripsy. The main objectives of this work are to (a) extract qualitative and quantitative features of bubbles excited by shockwaves and (b) distinguish between the different types of cavitation activity for either a thermally or a mechanically induced lesion in the liver...
September 15, 2018: Ultrasound in Medicine & Biology
Isabelle Durot, Alireza Akhbardeh, Jarrett Rosenberg, Jürgen K Willmann
The aim of this study was to assess whether the number of liver point shear wave elastography (pSWE) measurements could be reduced compared with the currently recommended 10 valid measurements. Three thousand four hundred one pSWE examinations in patients with liver disease were performed with 10 consecutive valid measurements in liver segment 8. Liver fibrosis grading using published cutoff values were compared retrospectively using the median of 10 versus the first 1-9 measurements with Kendall's τ coefficient...
September 14, 2018: Ultrasound in Medicine & Biology
Georg Riegler, Peter C Brugger, Gerlinde M Gruber, Christopher Pivec, Suren Jengojan, Gerd Bodner
The aim of this study was to evaluate the possibility of visualizing Pacinian corpuscles in the palm of the hand with high-resolution ultrasound (HRUS). In this prospective study, HRUS with a high-frequency probe (22 MHz) was used. The palms of two fresh cadaveric hands were screened for potential Pacinian corpuscles. Still ultrasound images and dynamic video sequences were obtained. In five regions with large amounts of suspected Pacinian corpuscles, tissue blocks were excised and histologically processed, and corresponding slices were compared with ultrasound images...
September 14, 2018: Ultrasound in Medicine & Biology
Barry Belmont, Ross Kessler, Nikhil Theyyunni, Christopher Fung, Robert Huang, Michael Cover, Kevin R Ward, Albert J Shih, Mohamad Tiba
Ultrasound assessment of the respiratory-induced change in size of the inferior vena cava is a useful technique in the evaluation and management of critically ill patients. We have developed an automated technique based on the Kanade-Lucas-Tomasi feature tracker and pyramidal segmentation to continuously track the diameter of the inferior vena cava during ultrasound. To test the accuracy of this automated process, the inferior vena cava of 47 spontaneously breathing patients were measured by trained ultrasound physicians and compared against the results obtained via the automated tracking...
September 10, 2018: Ultrasound in Medicine & Biology
Giovanna Ferraioli, Vincent Wai-Sun Wong, Laurent Castera, Annalisa Berzigotti, Ioan Sporea, Christoph F Dietrich, Byung Ihn Choi, Stephanie R Wilson, Masatoshi Kudo, Richard G Barr
The World Federation for Ultrasound in Medicine and Biology has produced these guidelines for the use of elastography techniques in liver diseases. For each available technique, the reproducibility, results and limitations are analyzed, and recommendations are given. This set of guidelines updates the first version, published in 2015. Since the prior guidelines, there have been several advances in technology. The recommendations are based on the international published literature, and the strength of each recommendation is judged according to the Oxford Centre for Evidence-Based Medicine...
September 9, 2018: Ultrasound in Medicine & Biology
Paul Greillier, Bénédicte Ankou, Pierre Bour, Ali Zorgani, Emma Abell, Romain Lacoste, Francis Bessière, Mathieu Pernot, Stefan Catheline, Bruno Quesson, Philippe Chevalier, Cyril Lafon
Described here is a study of transesophageal thermal ablation of isolated and perfused beating hearts and non-human primates. An endoscope integrating a transesophageal echocardiography probe and a high-intensity focused ultrasound transducer was built and tested on five Langendorff-isolated hearts and three 30-kg baboons. B-Mode ultrasound, passive elastography and magnetic resonance imaging were performed to monitor thermal lesions. In isolated hearts, continuous and gated sonication parameters were evaluated with acoustic intensities of 9-12 W/cm2 ...
September 9, 2018: Ultrasound in Medicine & Biology
Tania Pereira, Jose Muguruza, Virtu Mária, Ester Vilaprinyo, Albert Sorribas, Elvira Fernandez, Jose Manuel Fernandez-Armenteros, Juan Antonio Baena, Ferran Rius, Angels Betriu, Francesc Solsona, Rui Alves
Adventitial vasa vasorum are physiologic microvessels that nourish artery walls. In the presence of cardiovascular risk factors, these microvessels proliferate abnormally. Studies have reported that they are the first stage of atheromatous disease. Contrast-enhanced ultrasound (CEUS) of the carotid allows direct, quantitative and non-invasive visualization of the adventitial vasa vasorum. Hence, the development of computer-assisted methods that speed image analysis and eliminate user subjectivity is important...
September 8, 2018: Ultrasound in Medicine & Biology
Xi-Ming Xu, Tian-Ming Xu, Yi-Bo Wei, Xiao-Xiang Gao, Jing-Chuan Sun, Yuan Wang, Qing-Jie Kong, Jian-Gang Shi
As a non-invasive method, low-intensity pulsed ultrasound (LIPUS) can accelerate fracture healing. The mechanisms responsible for the enhanced fracture healing need to be studied further. Activation of YAP/TAZ, key mediators of the Hippo signaling pathway, could promote angiogenesis and vascular remodeling. The purpose of this study was to determine whether LIPUS treatment can activate YAP/TAZ. Human umbilical vein endothelial cells (HUVEC) were used. After LIPUS treatment, Western blot and immunofluorescence staining were used for YAP/TAZ activation...
September 8, 2018: Ultrasound in Medicine & Biology
Calum Crake, Iason T Papademetriou, Yongzhi Zhang, Natalia Vykhodtseva, Nathan J McDannold, Tyrone M Porter
Thermal ablation of solid tumors via focused ultrasound (FUS) is a non-invasive image-guided alternative to conventional surgical resection. However, the usefulness of the technique is limited in vascularized organs because of convection of heat, resulting in long sonication times and unpredictable thermal lesion formation. Acoustic cavitation has been found to enhance heating but requires use of exogenous nuclei and sufficient acoustic monitoring. In this study, we employed phase-shift nanoemulsions (PSNEs) to promote cavitation and incorporated passive acoustic mapping (PAM) alongside conventional magnetic resonance imaging (MRI) thermometry within the bore of a clinical MRI scanner...
September 8, 2018: Ultrasound in Medicine & Biology
Mehdi Naderi, Siamak Sabour
No abstract text is available yet for this article.
September 5, 2018: Ultrasound in Medicine & Biology
Minoru Kikuchi, Naoki Hirokawa, Seiya Hagiwara, Hidetaka Nakayama, Shinji Taneda, Naoki Manda, Kouichi Sakata
No abstract text is available yet for this article.
September 3, 2018: Ultrasound in Medicine & Biology
Hui Zhang, Xuexue Xing, Zheng Wang, Min He
Renal dynamic imaging and radionuclide renography use radioactivity to evaluate split renal function. We aimed to investigate the use of renal vascular color Doppler ultrasonography for evaluation of split renal function in children. Thirty-five children with unilateral kidney diseases were enrolled. For patients with unilateral renal tumor, peak systolic velocity (Vmax  = 113.04 ± 13.59 cm/s) and resistance index (RI = 0.73 ± 0.02) were higher on abnormal compared with normal sides (Vmax  = 86...
September 2, 2018: Ultrasound in Medicine & Biology
Martino V Franchi, Brent J Raiteri, Stefano Longo, Shantanu Sinha, Marco V Narici, Robert Csapo
Skeletal muscle structural assembly (and its remodeling in response to loading-unloading states) can be investigated macroscopically by assessing muscle architecture, described as fascicle geometric disposition within the muscle. Over recent decades, various medical imaging techniques have been developed to facilitate the in vivo assessment of muscle architecture. However, the main advantages and limitations of these methodologies have been fragmentally discussed. In the present article, the main techniques used for the evaluation of muscle architecture are presented: conventional B-mode ultrasonography, extended-field-of-view ultrasound, 3-D ultrasound and magnetic resonance imaging-based diffusion tensor imaging...
September 2, 2018: Ultrasound in Medicine & Biology
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