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Ultrasound in Medicine & Biology

Rei Asami, Tomohiko Tanaka, Motochika Shimizu, Yoshinori Seki, Tomohide Nishiyama, Hajime Sakashita, Takashi Okada
A vascular vector flow mapping (VFM) method visualizes 2-D cardiac flow dynamics by estimating the radial component of flow from the Doppler velocities and wall motion velocities using the mass conservation equation. Although VFM provides 2-D flow, the algorithm is applicable only to bounded regions. Here, a modified VFM algorithm, vascular VFM, is proposed so that the velocities are estimated regardless of the flow geometry. To validate the algorithm, a phantom mimicking a carotid artery was fabricated and VFM velocities were compared with optical particle image velocimetry (PIV) data acquired in the same imaged plane...
April 16, 2019: Ultrasound in Medicine & Biology
Samantha M Fix, Bhanu P Koppolu, Anthony Novell, Jared Hopkins, Thomas M Kierski, David A Zaharoff, Paul A Dayton, Virginie Papadopoulou
The gastrointestinal (GI) tract presents a notoriously difficult barrier for macromolecular drug delivery, especially for biologics. Herein, we demonstrate that ultrasound-stimulated phase change contrast agents (PCCAs) can transiently disrupt confluent colorectal adenocarcinoma monolayers and improve the transepithelial transport of a macromolecular model drug. With ultrasound treatment in the presence of PCCAs, we achieved a maximum of 44 ± 15% transepithelial delivery of 70-kDa fluorescein isothiocyanate-dextran, compared with negligible delivery through sham control monolayers...
April 16, 2019: Ultrasound in Medicine & Biology
Satomi Omotehara, Mutsumi Nishida, Kenji Kinoshita, Reizo Onishi, Aki Onodera, Mitsuhisa Suya, Toru Hasegawa, Daiki Mitsumori, Takehiko Katsurada, Takanori Teshima
This study was aimed at validating the inter-rater grading agreement for assessing disease activity in patients with established ulcerative colitis (UC) using transabdominal ultrasonography (US) versus colonoscopy (CS). Fifty-seven patients underwent US and CS at four facilities. UC disease activity was assessed using the original US grading system and CS Matts classification. Initially, the US and CS grades were assessed at each examining facility, and still images and movie clips were re-assessed at the central facility...
April 12, 2019: Ultrasound in Medicine & Biology
Sofoklis Katakis, Nikolaos Barotsis, Dimitrios Kastaniotis, Christos Theoharatos, Panagiotis Tsiganos, George Economou, Elias Panagiotopoulos, Spiros Fotopoulos, George Panayiotakis
Human assistive technology and computer-aided diagnosis is an emerging field in the area of medical imaging. Following the recent advances in this domain, a study for integrating machine learning techniques in musculoskeletal ultrasonography images was conducted. The goal of this attempt was to investigate how feature extraction techniques, that capture higher-level information, perform in identifying human characteristics. The potential success of these techniques could lead to significant improvement of the current assessment methods-as the gray-scale image analysis-for distinguishing healthy and pathologic conditions, that are heavily dependent on the image-acquisition system...
April 12, 2019: Ultrasound in Medicine & Biology
Ramkumar Anand, Arun K Thittai
Recently, compressed sensing (CS) has been applied to ultrasound imaging for either data reduction or frame rate improvement. However, there are no detailed reports yet on strategies for lateral undersampling of channel data in conventional focused beamforming (CFB) and its recovery exploiting the CS approach. We propose a strategic lateral undersampling approach for channel data using the Gaussian sampling scheme and compare it with a direct extension of the often-used uniform undersampling reported for axial undersampling to the lateral direction and 2-D random sampling reported in the literature...
April 12, 2019: Ultrasound in Medicine & Biology
Michal Byra, Lidi Wan, Jonathan H Wong, Jiang Du, Sameer B Shah, Michael P Andre, Eric Y Chang
We investigate the usefulness of quantitative ultrasound and B-mode texture features for characterization of ulnar nerve fascicles. Ultrasound data were acquired from cadaveric specimens using a nominal 30-MHz probe. Next, the nerves were extracted to prepare histology sections. Eighty-five fascicles were matched between the B-mode images and the histology sections. For each fascicle image, we selected an intra-fascicular region of interest. We used histology sections to determine features related to the concentration of collagen and myelin and ultrasound data to calculate the backscatter coefficient (-24...
April 12, 2019: Ultrasound in Medicine & Biology
Aswin Gnanaskandan, Chao-Tsung Hsiao, Georges Chahine
Heat enhancement at the target in a high intensity focused ultrasound (HIFU) field is investigated by considering the effects of the injection of microbubbles in the vicinity of the tumor to be ablated. The interaction between the bubble cloud and the HIFU field is investigated using a 3-D numerical model. The propagation of non-linear ultrasonic waves in the tissue or in a phantom medium is modeled using the compressible Navier-Stokes equations on a fixed Eulerian grid, while the microbubbles dynamics and motion are modeled as discrete singularities, which are tracked in a Lagrangian framework...
April 11, 2019: Ultrasound in Medicine & Biology
Christoph F Dietrich, Beatrice Hoffmann, Vito Cantisani, Yi Dong, Roman Hari, Harvey Nisenbaum, Delwyn Nicholls, Christian Pállson Nolsøe, Maija Radzina, Florian Recker, Andreas Serra, Linda Sweet, Sue Westerway, Michael Blaivas
No abstract text is available yet for this article.
April 11, 2019: Ultrasound in Medicine & Biology
Aysha Hanif Ingar, Iqra Abdul-Khaliq, Vardah Alam
No abstract text is available yet for this article.
April 10, 2019: Ultrasound in Medicine & Biology
Marco Chiappetta, Andrea Smargiassi, Elisa Meacci, Alfredo Cesario, Riccardo Inchingolo, Leonardo Petracca Ciavarella, Stefania Lopatriello, Andrea Contegiacomo, Maria Teresa Congedo, Stefano Margaritora
No abstract text is available yet for this article.
April 10, 2019: Ultrasound in Medicine & Biology
Quinton W Guerrero, Helen Feltovich, Ivan M Rosado-Mendez, Andrew P Santoso, Lindsey C Carlson, Ryan Zea, Timothy J Hall
Clinical prediction and especially prevention of abnormal birth timing, particularly pre-term, is poor. The cervix plays a key role in birth timing; it first serves as a rigid barrier to protect the developing fetus, then becomes the pathway to delivery of that fetus. Imaging biomarkers to define this remodeling process could provide insights to improve prediction of birth timing and elucidate novel targets for preventive therapies. Quantitative ultrasound (QUS) approaches that appear promising for this purpose include shear wave speed (SWS) estimation to quantify softness, as well as parameters based on backscattered power, such as the mean backscattered power difference (mBSPD) and specific attenuation coefficient (SAC), to quantify the organization of tissue microstructure...
April 9, 2019: Ultrasound in Medicine & Biology
Yu Wang, Liqun Jia, Xiaoman Wang, Libing Fu, Jibin Liu, Linxue Qian
The aim of the present study was to prospectively evaluate the clinical efficiency of 2-D shear wave elastography (2-D-SWE) for differentiating hepatoblastoma and hepatic hemangioma in children under 3 y of age. 2-D-SWE was performed in 109 consecutive patients with confirmed hepatic neoplasms by pathologic analysis or contrast-enhanced computed tomography plus follow-up observation, in which 71 patients were defined as the test group, and the remaining 38 patients were defined as the validation group. An elasticity value was obtained from each lesion...
April 9, 2019: Ultrasound in Medicine & Biology
Steven K Yarmoska, Heechul Yoon, Stanislav Y Emelianov
Perfluorocarbon nanodroplets (PFCnDs) are phase-change contrast agents that have the potential to enable extravascular contrast-enhanced ultrasound and photoacoustic (US/PA) imaging. Producing consistently small, monodisperse PFCnDs remains a challenge without resorting to technically challenging methods. We investigated the impact of variable shell composition on PFCnD size and US/PA image properties. Our results suggest that increasing the molar percentage of PEGylated lipid reduces the size and size variance of PFCnDs...
April 8, 2019: Ultrasound in Medicine & Biology
Xiao-Xia Qu, Yu Song, Yu-Hong Zhang, Hua-Min Qing
The purpose of this study was to evaluate the diagnostic value of ultrasonic elastography (UE) and conventional ultrasonography (CUS) in the differential diagnosis of non-mass-like (NML) breast lesions. Static sonograms of 39 pathologically diagnosed NML breast lesions were reviewed. Lesions were evaluated by CUS and UE using CUS subjective ratings (benign, malignant or indeterminate), a 5-point subjective elasticity scoring system and the quantitative strain ratio (SR). Receiver operating characteristic curves and diagnostic tests were used to assess the diagnostic value of CUS and UE...
April 8, 2019: Ultrasound in Medicine & Biology
Andrew R Walker, Tokuhisa Uejima, Christian Prinz, Jens-Uwe Voigt, Alan G Fraser
To evaluate the accuracy of measurements of the velocities and timing of blood flow and of tissue motion, we tested four commercially available ultrasound systems. Pulsed wave, continuous wave and tissue Doppler recordings acquired across a range of angles of insonation were compared against a calibrated Doppler string phantom. Temporal delays were measured from the onset of the simulated electrocardiogram to the start of each Doppler signal. Across all modalities and angles, the mean errors of measurements of velocity using the four systems were 0...
April 8, 2019: Ultrasound in Medicine & Biology
Sun Kyung Jeon, Jeong Min Lee, Ijin Joo, Jeong Hee Yoon, Dong Ho Lee, Jae Young Lee, Joon Koo Han
The purpose of our study was to investigate the diagnostic performance of 2-D ultrasound attenuation imaging (ATI) for the assessment of hepatic steatosis in patients with chronic liver disease using magnetic resonance imaging proton density fat fraction (MRI-PDFF) as the reference standard. We prospectively analyzed 87 patients with chronic liver disease who had reliable measurements at both ATI and MRI-PDFF. For the detection of hepatic steatosis of MRI-PDFF ≥5% and MRI-PDFF ≥10%, ATI measurements yielded areas under the receiver operating characteristic curve of 0...
April 8, 2019: Ultrasound in Medicine & Biology
Edward Peake, Shaun Warrington, Nicholas J Dudley, Paul S Morgan, Nicholas M Gibson
Urethane-based test objects are routinely used for ultrasound quality assurance because of their durability and robustness. The acoustic properties of these phantoms including speed of sound and attenuation, however, have a strong dependence on temperature. Reliable measurement of low-contrast penetration, which is widely used for ultrasound system quality assurance testing, with these phantoms is therefore problematic. To alleviate this, a correction method was proposed using speed of sound estimated by measuring filament target separation...
April 6, 2019: Ultrasound in Medicine & Biology
Sook Sam Leong, Jeannie Hsiu Ding Wong, Mohammad Nazri Md Shah, Anushya Vijayananthan, Maisarah Jalalonmuhali, Kwan Hoong Ng
The purpose of this study was to assess the potential of shear wave elastography (SWE) as an indicator of abnormal kidney function defined by radiolabeled glomerular filtration rate (GFR). Fifty-seven patients referred for 51 Cr-ethylenediaminetetraacetic acid GFR and 99m Tc-dimercaptosuccinic acid renal scintigraphy were included. Young's modulus (YM) measured with SWE and kidney length, volume, cortical thickness and parenchymal echogenicity measured with conventional ultrasound were correlated with patients' GFR and renal scintigraphy results...
April 5, 2019: Ultrasound in Medicine & Biology
Spyridon Bakas, Matthaios Doulgerakis-Kontoudis, Gordon J A Hunter, Paul S Sidhu, Dimitrios Makris, Katerina Chatzimichail
This study investigates the application and evaluation of existing indirect methods, namely point-based registration techniques, for the estimation and compensation of observed motion included in the 2-D image plane of contrast-enhanced ultrasound (CEUS) cine-loops recorded for the characterization and diagnosis of focal liver lesions (FLLs). The value of applying motion compensation in the challenging modality of CEUS is to assist in the quantification of the perfusion dynamics of an FLL in relation to its parenchyma, allowing for a potentially accurate diagnostic suggestion...
April 2, 2019: Ultrasound in Medicine & Biology
Danilo Cardim, Chiara Robba, Eric Schmidt, Bernhard Schmidt, Joseph Donnelly, John Klinck, Marek Czosnyka
Transcranial Doppler (TCD) ultrasonography allows continuous non-invasive monitoring of cerebral blood flow velocity in a variety of clinical conditions. Recently, signal processing of TCD signals has provided several comprehensive parameters for the assessment of cerebral haemodynamics. In this work, we applied a TCD multimodal approach in patients with acute liver failure undergoing orthotopic liver transplant (OLT) to assess the clinical feasibility of using TCD for cerebral haemodynamics assessment in this setting...
April 2, 2019: Ultrasound in Medicine & Biology
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