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Ultrasound contrast

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https://www.readbyqxmd.com/read/28432914/adaptive-optimization-of-ultrasound-beamforming-sound-velocity-using-sub-aperture-differential-phase-gradient
#1
Che-Chou Shen, Hsiao-Chi Yang
Ultrasound array imaging systems rely on a presumed beamforming sound velocity to calculate the time compensation of each element for receive focusing. The mismatch between the tissue sound velocity and the beamforming sound velocity can degrade the focusing quality due to loss of phase coherence. Since the tissue sound velocity cannot be known in prior, an adaptive optimization of beamforming sound velocity is required to improve the image quality. Differential phase gradient of channel data is proposed to estimate the optimal sound velocity for beamforming...
April 12, 2017: Ultrasonics
https://www.readbyqxmd.com/read/28432447/twofold-minimum-variance-beamforming-for-enhanced-ultrasound-imaging
#2
Sayed Mahmoud Sakhaei, Seyede Elham Shamsian
PURPOSE: To calculate the optimal weights of a minimum variance (MV) beamformer, the covariance matrix of the received data should be estimated. In ultrasound imaging, it is done through spatial smoothing. However, this technique reduces the effective aperture and consequently limits the attainable resolution. To mitigate this effect, we propose a new configuration for applying an adaptive beamforming method. METHODS: The method is based on applying MV in a twofold configuration such that the outputs of the subarrays are combined through an adaptive MV-like beamformer, instead of simply summing them...
April 21, 2017: Journal of Medical Ultrasonics
https://www.readbyqxmd.com/read/28429490/contrast-enhanced-ultrasound-classification-of-previously-indeterminate-renal-lesions
#3
Jessica G Zarzour, Mark E Lockhart, Janelle West, Eric Turner, Bradford E Jackson, John V Thomas, Michelle L Robbin
OBJECTIVES: To determine the utility of contrast-enhanced ultrasound (US) for characterizing renal lesions that were indeterminate on prior imaging. METHODS: This Institutional Review Board-approved retrospective diagnostic accuracy study evaluated all patients who underwent renal contrast-enhanced US examinations from 2006 to 2015 at our tertiary care hospital. We compared the number of lesions definitively characterized by contrast-enhanced US with the indeterminate lesions by prior imaging...
April 21, 2017: Journal of Ultrasound in Medicine: Official Journal of the American Institute of Ultrasound in Medicine
https://www.readbyqxmd.com/read/28427743/microbubble-detection-and-ultrasound-guided-vacuum-assisted-biopsy-of-axillary-lymph-nodes-in-patients-with-breast-cancer
#4
P Britton, P Willsher, K Taylor, F Kilburn-Toppin, E Provenzano, P Forouhi, J Benson, A Agrawal, J R Forman, M G Wallis
AIMS: To assess the feasibility of undertaking microbubble-guided vacuum-assisted biopsy (VAB) of the sentinel lymph node (SLN) and determine its sensitivity in detecting metastases. Patient experience and the impact of VAB on subsequent axillary surgery were also evaluated. MATERIALS AND METHODS: Patients with a normal axillary ultrasound or benign core biopsy planned for surgical SLN biopsy were recruited. Part 1 of the study was used to establish the technique of ultrasound microbubble contrast to detect the SLN...
April 17, 2017: Clinical Radiology
https://www.readbyqxmd.com/read/28427670/estimation-of-the-distribution-of-low-intensity-ultrasound-mechanical-index-as-a-parameter-affecting-the-proliferation-of-spermatogonia-stem-cells-in-vitro
#5
Zeinab Hormozi Moghaddam, Manijhe Mokhtari-Dizaji, Mansoureh Movahedin, Mohammad Ehsan Ravari
Considering the use of physical and mechanical stimulation, such as low-intensity ultrasound for proliferation and differentiation of stem cells, it is essential to understand the physical and acoustical mechanisms of acoustic waves in vitro. Mechanical index is used for quantifying acoustic cavitation and the relationship between acoustic pressure and the frequency. In this study, modeling of the mechanical index was applied to provide treatment protocol and to understand the effective physical processes on reproducibility of stem cells...
July 2017: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/28427645/ultrasound-assisted-extraction-of-achyrocline-satureioides-prevents-contrast-induced-nephropathy-in-mice
#6
Ketheley L Guss, Stefano Pavanni, Bruno Prati, Lucas Dazzi, Jairo P de Oliveira, Breno V Nogueira, Thiago M C Pereira, Marcio Fronza, Denise C Endringer, Rodrigo Scherer
Achyrocline satureioides or Macela, has been largely used in traditional folk medicine in Brazil as an anti-inflammatory agent and to treat various digestive disorders. The aim of the present study was to evaluate the preventive action of the extracts of A. satureioides obtained by maceration and ultrasound-assisted extraction, quercetin and N-acetylcysteine against contrast-induced nephropathy in mice. The antioxidant activity, cytotoxicity and inhibition of nitric oxide (NO) production in macrophages were evaluated...
July 2017: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/28427629/development-of-a-novel-folate-modified-nanobubbles-with-improved-targeting-ability-to-tumor-cells
#7
Sujuan Duan, Lu Guo, Dandan Shi, Mengmeng Shang, Dong Meng, Jie Li
Conjugation of folate (FOL) to nanobubbles could enhance the selective targeting to tumors expressing high levels of folate receptor (FR). To further improve the selective targeting ability of FOL-modified nanobubbles, a novel FOL-targeted nanobubble ((FOL)2-NB) with increasing FOL content (accomplished by linking two FOL molecules per DSPE-PEG2000 chain) was synthesized, through the methods of mechanical shaking and low-speed centrifugation based on lipid-stabilized perfluoropropane. The bubble size and distribution range were measured by dynamic light scattering (DLS)...
July 2017: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/28427128/-the-application-value-of-contrast-enhanced-ultrasound-in-the-surgery-of-renal-masses
#8
M H Liu, J H Shi, Q M H Wangqi, Y Q Lin, Z X Sun
Objective: To investigate the clinical value of contrast-enhanced ultrasound in the diagnosis of renal masses. Methods: A total of 50 patients with renal masses who underwent partial nephrectomy were analyzed from January 2014 to October 2016 in the Department of Urology of China-Japan Union Hospital of Jilin University.In the intraoperative contrast-enhanced ultrasound, the characteristics of ultrasound imaging were recorded including location, size, boundary, echo, real-time internal and peripheral blood and renal pelvis distance, artery, guidance on the selection of surgical methods, intraoperative real-time estimation of the extent of tumor resection...
April 18, 2017: Zhonghua Yi Xue za Zhi [Chinese medical journal]
https://www.readbyqxmd.com/read/28426815/using-controlled-attenuation-parameter-combined-with-ultrasound-to-survey-non-alcoholic-fatty-liver-disease-in-hemodialysis-patients-a-prospective-cohort-study
#9
Yi-Hao Yen, Jin-Bor Chen, Ben-Chung Cheng, Jung-Fu Chen, Kuo-Chin Chang, Po-Lin Tseng, Cheng-Kun Wu, Ming-Chao Tsai, Ming-Tsung Lin, Tsung-Hui Hu
BACKGROUND AND AIMS: Controlled attenuation parameter (CAP) is a non-invasive method for measuring hepatic steatosis (HS). Non-alcoholic fatty liver disease (NAFLD) is closely related to cardiovascular diseases (CVDs). CVDs are the leading cause of morbidity and mortality in hemodialysis patients. The aim of this study was to investigate the prevalence of NAFLD in hemodialysis patients. METHOD: We prospectively enrolled patients undergoing chronic hemodialysis, as well as patients with normal renal function who served as controls...
2017: PloS One
https://www.readbyqxmd.com/read/28425493/characterization-of-different-microbubbles-in-assisting-focused-ultrasound-induced-blood-brain-barrier-opening
#10
Sheng-Kai Wu, Po-Chun Chu, Wen-Yen Chai, Shih-Tsung Kang, Chih-Hung Tsai, Ching-Hsiang Fan, Chih-Kuang Yeh, Hao-Li Liu
Microbubbles (MBs) serve as a critical catalyst to amplify local cavitation in CNS capillary lumen to facilitate focused ultrasound (FUS) to transiently open the blood-brain barrier (BBB). However, limited understanding is available regarding the effect of different microbubbles to induce BBB opening. The aim of this study is to characterize different MBs on their effect in FUS-induced BBB opening. Three MBs, SonoVue, Definity, and USphere, were tested, with 0.4-MHz FUS exposure at 0.62-1.38 of mechanical index (MI) on rats...
April 20, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28421350/preoperative-imaging-evaluation-of-pancreatic-pathologies-for-the-objective-prediction-of-pancreatic-fistula-after-pancreaticoduodenectomy
#11
REVIEW
Yoshitsugu Tajima, Yasunari Kawabata, Noriyuki Hirahara
In performing pancreaticoduodenectomy (PD) or when conducting clinical trials involving PD procedure, a universal platform for predicting the risk of postoperative pancreatic fistula (POPF) is indispensable. In this article, the most significant imaging studies that focused on the objective preoperative assessment of pancreatic pathologies in association with the occurrence of POPF after PD were reviewed. Several recently developed imaging modalities can objectively predict the occurrence of POPF after PD by assessing the elasticity, fibrosis, and fatty infiltration of the pancreas...
April 18, 2017: Surgery Today
https://www.readbyqxmd.com/read/28420871/interactive-outlining-of-pancreatic-cancer-liver-metastases-in-ultrasound-images
#12
Jan Egger, Dieter Schmalstieg, Xiaojun Chen, Wolfram G Zoller, Alexander Hann
Ultrasound (US) is the most commonly used liver imaging modality worldwide. Due to its low cost, it is increasingly used in the follow-up of cancer patients with metastases localized in the liver. In this contribution, we present the results of an interactive segmentation approach for liver metastases in US acquisitions. A (semi-) automatic segmentation is still very challenging because of the low image quality and the low contrast between the metastasis and the surrounding liver tissue. Thus, the state of the art in clinical practice is still manual measurement and outlining of the metastases in the US images...
April 18, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28420236/human-hepatocarcinoma-cell-targeting-by-glypican-3-ligand-peptide-functionalized-silica-nanoparticles-implications-for-ultrasound-molecular-imaging
#13
Marco Di Paola, Alessandra Quarta, Francesco Conversano, Enzo Antonio Sbenaglia, Simona Bettini, Ludovico Valli, Giuseppe Gigli, Sergio Casciaro
Silica nanoparticles (SiNPs) are widely studied nanomaterials for their potential employment in advanced biomedical applications, like selective molecular imaging and targeted drug delivery. SiNPs are generally low cost and high biocompatible, can be easily functionalized with a wide variety of functional ligands and have been demonstrated to be effective in enhancing ultrasound contrast at clinical diagnostic frequencies. Therefore, SiNPs might be used as contrast agents in echographic imaging. In this work, we have developed a SiNPs-based system for the in vitro molecular imaging of hepatocellular carcinoma cells that express high levels of Glypican-3 protein (GPC-3) on their surface...
April 18, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28419634/contrast-enhanced-ultrasound-and-elastography-imaging-of-the-neonatal-brain-a-review
#14
REVIEW
Christopher Bailey, Thierry A G M Huisman, Robert M de Jong, Misun Hwang
Neonates presenting with neurologic symptoms require rapid, noninvasive imaging with high spatial resolution and tissue contrast. Magnetic resonance imaging (MRI) is currently the most sensitive and specific imaging modality for evaluation of neurological pathology. This modality does come with several challenges in the neonatal population, namely, the need to transport a possibly critically sick neonate to the MRI suite and the necessity of the neonate to remain still for a significant length of time, occasionally requiring sedation...
April 17, 2017: Journal of Neuroimaging: Official Journal of the American Society of Neuroimaging
https://www.readbyqxmd.com/read/28417646/cerebral-hemodynamic-assessment-and-neuroimaging-across-the-lifespan-in-sickle-cell-disease
#15
Lori C Jordan, Michael R DeBaun
Children and adults with sickle cell anemia (SCA) have a higher risk of strokes compared to age- and race-matched peers. Velocity in the middle cerebral or distal internal carotid artery as measured by transcranial Doppler ultrasound is a recognized method to identify children but not adults with SCA at high-risk for first stroke. For both children and adults with SCA that have had a stroke, no methods clearly identify individuals at highest risk of recurrent strokes or an initial silent stroke, the most common neurological injury...
January 1, 2017: Journal of Cerebral Blood Flow and Metabolism
https://www.readbyqxmd.com/read/28414927/integration-of-free-hand-3d-ultrasound-and-mobile-c-arm-cone-beam-ct-feasibility-and-characterization-for-real-time-guidance-of-needle-insertion
#16
E Marinetto, A Uneri, T De Silva, S Reaungamornrat, W Zbijewski, A Sisniega, S Vogt, G Kleinszig, J Pascau, J H Siewerdsen
This work presents development of an integrated ultrasound (US)-cone-beam CT (CBCT) system for image-guided needle interventions, combining a low-cost ultrasound system (Interson VC 7.5MHz, Pleasanton, CA) with a mobile C-arm for fluoroscopy and CBCT via use of a surgical tracker. Imaging performance of the ultrasound system was characterized in terms of depth-dependent contrast-to-noise ratio (CNR) and spatial resolution. US-CBCT system was evaluated in phantom studies simulating three needle-based procedures: drug delivery, tumor ablation, and lumbar puncture...
April 3, 2017: Computerized Medical Imaging and Graphics: the Official Journal of the Computerized Medical Imaging Society
https://www.readbyqxmd.com/read/28414680/a-rare-cause-of-abdominal-pain
#17
E M Dauchy, M Modica, N Masri
CASE: A 54 year old woman with hypothyroidism presented with right flank pain that began acutely one week prior to presentation. She was told initially she had a urinary tract infection and treatment resulted in mild symptomatic improvement. The pain returned and she presented to another Emergency Department (ED); and was told the pain was due to constipation. She returned to the ED the next day when her pain worsened and her labs were notable for WBC of 19,000/uL, BUN/Cr of 28/0.75 mg/dL, AST of 31 U/L, ALT of 92 U/L and total bilirubin of 0...
March 2017: Journal of the Louisiana State Medical Society: Official Organ of the Louisiana State Medical Society
https://www.readbyqxmd.com/read/28413557/c2-primary-leiomyoma-in-an-immunocompetent-woman-a-case-report-and-review-of-literature
#18
Mohana Rao Patibandla, Madhukar T Nayak, A K Purohit, Megha Uppin, Sundaram Challa, Gokul Chowdary Addagada, Manisha Nukavarapu
Clinical case report and review of the literature. This is the first case of primary leiomyoma in an immunocompetent woman without previous history of uterine leiomyoma being reported in the literature to the best of our knowledge. Leiomyoma, a type of smooth muscle cell tumor, involving the vertebra is extremely rare. There were very few primary leiomyoma in patients with AIDS or in the immune-suppressed patients. This 48-year-old female came with H/o neck pain, weakness and bladder retention. On examination, tone increased in all four limbs, power on the right side of the limbs 4/5, power on the left upper limb 0/5, lower limb 3/5, left plantar was up going, decreased sensation over the left second cervical vertebra (C2) dermatome and all modalities decreased below C2...
January 2017: Asian Journal of Neurosurgery
https://www.readbyqxmd.com/read/28412956/management-of-suspected-common-bile-duct-stones-on-cholangiogram-during-same-stay-cholecystectomy-for-acute-gallstone-related-disease
#19
Sandra de Sousa, Olivier Tobler, Pouya Iranmanesh, Jean-Louis Frossard, Philippe Morel, Christian Toso
BACKGROUND: Recent data have suggested that upfront cholecystectomy should be performed even in the presence of moderately abnormal liver function tests (LFTs). As a consequence, more common bile duct (CBD) stones are discovered on intra-operative cholangiogram. We assessed the presentation and management of such patients to refine their management plan. METHODS: Adult patients (>16 years) with an acute gallstone-related disease who had undergone same-stay cholecystectomy from January 2013 to January 2015 were retrospectively assessed...
April 17, 2017: BMC Surgery
https://www.readbyqxmd.com/read/28408372/effects-of-sugar-sweetened-beverage-consumption-on-microvascular-and-macrovascular-function-in-a-healthy-population
#20
Jordan Loader, Cindy Meziat, Rani Watts, Christian Lorenzen, Dominique Sigaudo-Roussel, Simon Stewart, Cyril Reboul, Gregory Meyer, Guillaume Walther
OBJECTIVE: To assess vascular function during acute hyperglycemia induced by commercial sugar-sweetened beverage (SSB) consumption and its effect on underlying mechanisms of the nitric oxide pathway. APPROACH AND RESULTS: In a randomized, single-blind, crossover trial, 12 healthy male participants consumed 600 mL (20 oz.) of water or a commercial SSB across 2 visits. Endothelial and vascular smooth muscle functions were assessed in the microcirculation using laser speckle contrast imaging coupled with iontophoresis and in the macrocirculation using brachial artery ultrasound with flow- and nitrate-mediated dilation...
April 13, 2017: Arteriosclerosis, Thrombosis, and Vascular Biology
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