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Contrast ultrasound

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https://www.readbyqxmd.com/read/27924340/exosome-like-silica-nanoparticles-a-novel-ultrasound-contrast-agent-for-stem-cell-imaging
#1
Fang Chen, Ming Ma, Junxin Wang, Fang Wang, Shi-Xiong Chern, Eric Ruike Zhao, Anamik Jhunjhunwala, Sean Darmadi, Hangrong Chen, Jesse V Jokerst
Ultrasound is critical in many areas of medicine including obstetrics, oncology, and cardiology with emerging applications in regenerative medicine. However, one critical limitation of ultrasound is the low contrast of target tissue over background. Here, we describe a novel cup-shaped silica nanoparticle that is reminiscent of exosomes and that has significant ultrasound impedance mismatch for labelling stem cells for regenerative medicine imaging. These exosome-like silica nanoparticles (ELS) were created through emulsion templating and the silica precursors bis(triethoxysilyl)ethane (BTSE) and bis(3-trimethoxysilyl-propyl)amine (TSPA)...
December 7, 2016: Nanoscale
https://www.readbyqxmd.com/read/27922869/long-distance-endovascular-growth-of-jugulotympanic-paraganglioma-evident-in-68ga-dotatate-pet-but-concealed-on-ct
#2
Nemanja Avramovic, Matthias Weckesser, Aglaé Velasco, Markus Stenner, Benjamin Noto
A 60-year-old woman was referred to contrast-enhanced CT for evaluation of jugular vein thrombosis incidentally detected by ultrasound. Contrast-enhanced CT showed an enhanced tumor of the right skull base highly suspicious of jugulotympanic paraganglioma. However, the jugular veins showed a nearly symmetric contrast enhancement without clear evidence of thrombosis. Consecutive Ga-DOTATATE PET/CT depicted high tumor uptake, which comprised the entire internal jugular vein. Endovascular growth of paraganglioma might be missed on contrast-enhanced CT because of high vascularization of the lesion...
December 3, 2016: Clinical Nuclear Medicine
https://www.readbyqxmd.com/read/27922808/vascular-assessment-for-transcatheter-aortic-valve-replacement-intravascular-ultrasound-compared-with-computed-tomography
#3
Essa Essa, Nader Makki, Peter Bittenbender, Quinn Capers, Barry George, Gregory Rushing, Juan Crestanello, Konstantinos Dean Boudoulas, Scott M Lilly
BACKGROUND: Assessment of the femoral and iliac arteries is essential prior to transcatheter aortic valve replacement (TAVR). It is critical for establishing candidacy for a femoral approach, and can help predict vascular complications. Although computed tomography angiography (CTA) is the standard imaging modality, it has limitations. OBJECTIVE: This study compared CTA with intravascular ultrasound (IVUS) in patients undergoing TAVR evaluation. METHODS: Fifteen patients undergoing pre-TAVR coronary angiography and hemodynamic assessment were recruited...
December 2016: Journal of Invasive Cardiology
https://www.readbyqxmd.com/read/27920469/role-of-ultrasound-in-colorectal-diseases
#4
REVIEW
Renáta Bor, Anna Fábián, Zoltán Szepes
Ultrasound is an undervalued non-invasive examination in the diagnosis of colonic diseases. It has been replaced by the considerably more expensive magnetic resonance imaging and computed tomography, despite the fact that, as first examination, it can usefully supplement the diagnostic process. Transabdominal ultrasound can provide quick information about bowel status and help in the choice of adequate further examinations and treatment. Ultrasonography, as a screening imaging modality in asymptomatic patients can identify several colonic diseases such as diverticulosis, inflammatory bowel disease or cancer...
November 21, 2016: World Journal of Gastroenterology: WJG
https://www.readbyqxmd.com/read/27916971/diagnostic-accuracy-of-contrast-enhanced-ultrasound-enhancement-patterns-for-thyroid-nodules
#5
Yan Zhang, Yu-Kun Luo, Ming-Bo Zhang, Jie Li, Junlai Li, Jie Tang
BACKGROUND The aim of this study was to investigate the accuracy of contrast-enhanced ultrasound (CEUS) enhancement patterns in the assessment of thyroid nodules. MATERIAL AND METHODS A total of 158 patients with suspected thyroid cancer underwent conventional ultrasound (US) and CEUS examinations. The contrast enhancement patterns of the lesions, including the peripheries of the lesions, were assessed by CEUS scans. The relationship between the size of the lesions and the degree of enhancement was also studied...
December 5, 2016: Medical Science Monitor: International Medical Journal of Experimental and Clinical Research
https://www.readbyqxmd.com/read/27914983/neuropeptide-y-y1-receptor-mediated-biodegradable-photoluminescent-nanobubbles-as-ultrasound-contrast-agents-for-targeted-breast-cancer-imaging
#6
Juan Li, Yuchen Tian, Dingying Shan, An Gong, Leyong Zeng, Wenzhi Ren, Lingchao Xiang, Ethan Gerhard, Jinshun Zhao, Jian Yang, Aiguo Wu
Targeted molecular imaging has attracted great attention in cancer diagnosis and treatment. However, most clinically used ultrasound contrast agents (UCAs) are non-targeted microbubbles seldom used for cancer imaging. Here, we fabricated fluorescent nanobubbles (NBs) by encapsulation of liquid tetradecafluorohexane (C6F14) within biodegradable photoluminescent polymers (BPLPs) through an emulsion-evaporation process and conjugation of PNBL-NPY ligand for specific targeting of Y1 receptors overexpressed in breast tumors...
November 22, 2016: Biomaterials
https://www.readbyqxmd.com/read/27914373/sparsity-constrained-contrast-source-inversion
#7
Ana B Ramirez, Koen W A van Dongen
Ultrasound imaging is used for detecting and characterizing breast lesions. A state of the art imaging method is the contrast source inversion (CSI), which solves the full wave nonlinear inverse problem. However, when the measurements are acquired in noisy environments, CSI can diverge from the correct solution after several iterations. Problems associated with noisy data were originally solved by including total variation (TV) regularization. Unfortunately, for very noisy data, TV regularization alone is not sufficient...
September 2016: Journal of the Acoustical Society of America
https://www.readbyqxmd.com/read/27914180/burned-out-testis-tumors-in-asymptomatic-infertile-men-multiparametric-sonography-and-mri-findings
#8
Laurence Rocher, Ludivine Glas, Marie France Bellin, Sophie Ferlicot, Vincent Izard, Gerard Benoit, Laurence Albiges, Karim Fizazi, Jean-Michel Correas
Multiparametric testicular ultrasound and magnetic resonance imaging (MRI) findings were analyzed in a series of 10 infertile asymptomatic men presenting with pathologically confirmed burned-out testicular tumors. Color/power Doppler ultrasound (CDUS), shear wave elastography (SWE), contrast-enhanced ultrasonography (CEUS), and MRI were performed on 10, 5, 6, and 7 patients, respectively. All lesions appeared as a hypoechoic and hypovascular nodular area at CDUS, SWE, CEUS CDUS, and CEUS (if performed). Shear wave elastography showed a stiffer nodular area compared with the surrounding/contralateral tissues (13 versus 2 kPa); MRI revealed a well-delineated nodular area in hypointense signal on T2, a high apparent diffusion coefficient value, and a lack of enhancement...
December 3, 2016: Journal of Ultrasound in Medicine: Official Journal of the American Institute of Ultrasound in Medicine
https://www.readbyqxmd.com/read/27913340/efficient-3d-reconstruction-in-ultrasound-elastography-via-a-sparse-iteration-based-on-markov-random-fields
#9
Atul Ingle, Tomy Varghese, William Sethares
Percutaneous needle-based liver ablation procedures are becoming increasingly common for treatment of small isolated tumors in hepatocellular carcinoma patients who are not candidates for surgery. Rapid three dimensional visualization of liver ablations has potential clinical value because it can enable interventional radiologists to plan and execute needle-based ablation procedures with real time feedback. Ensuring the right volume of tissue is ablated is desirable to avoid recurrence of tumors from residual untreated cancerous cells...
November 29, 2016: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/27913328/subharmonic-response-of-polymer-contrast-agents-based-on-the-empirical-mode-decomposition
#10
Rintaro Hayashi, John S Allen, Parag V Chitnis, Jonathan Mamou, Jeffrey A Ketterling
The subharmonic threshold for ultrasound contrast agents has been defined as a 20-25 dB difference between the fundamental and subharmonic (2/1) spectral components of the backscatter signal. However, this Fourier-based criterion assumes a linear time-invariant signal. A more appropriate criterion for short cycle and frequency-modulated waveforms is proposed with an adaptive signal-processing approach based on the empirical mode decomposition (EMD) method. The signal is decomposed into an orthogonal basis known as intrinsic mode functions (IMFs) and a subharmonic threshold is defined with respect to the energy ratio of the subharmonic IMF component to that of the incident signal...
December 2016: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/27913326/delay-and-standard-deviation-beamforming-to-enhance-specular-reflections-in-ultrasound-imaging
#11
Raja Sekhar Bandaru, Anders Rasmus Sornes, Jeroen Hermans, Eigil Samset, Jan D'hooge
Although interventional devices, such as needles, guide wires, and catheters, are best visualized by X-ray, real-time volumetric echography could offer an attractive alternative as it avoids ionizing radiation; it provides good soft tissue contrast, and it is mobile and relatively cheap. Unfortunately, as echography is traditionally used to image soft tissue and blood flow, the appearance of interventional devices in conventional ultrasound images remains relatively poor, which is a major obstacle toward ultrasound-guided interventions...
December 2016: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/27913324/beamforming-through-regularized-inverse-problems-in-ultrasound-medical-imaging
#12
Teodora Szasz, Adrian Basarab, Denis Kouame
Beamforming (BF) in ultrasound (US) imaging has significant impact on the quality of the final image, controlling its resolution and contrast. Despite its low spatial resolution and contrast, delay-and-sum (DAS) is still extensively used nowadays in clinical applications, due to its real-time capabilities. The most common alternatives are minimum variance (MV) method and its variants, which overcome the drawbacks of DAS, at the cost of higher computational complexity that limits its utilization in real-time applications...
December 2016: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/27911452/rationally-encapsulated-gold-nanorods-improving-both-linear-and-nonlinear-photoacoustic-imaging-contrast-in-vivo
#13
Fei Gao, Linyi Bai, Siyu Liu, Ruochong Zhang, Jingtao Zhang, Xiaohua Feng, Yuanjin Zheng, Yanli Zhao
Photoacoustic tomography has emerged as a promising non-invasive imaging technique that integrates the merits of high optical contrast with high ultrasound resolution in deep scattering medium. Unfortunately, the blood background in vivo seriously impedes the quality of imaging due to its comparable optical absorption with contrast agents, especially in conventional linear photoacoustic imaging modality. In this study, we demonstrated that two hybrids consisting of gold nanorods (Au NRs) and zinc tetra(4-pyridyl)porphyrin (ZnTPP) exhibited a synergetic effect in improving optical absorption, conversion efficiency from light to heat, and thermoelastic expansion, leading to a notable enhancement in both linear (four times greater) and nonlinear (more than six times) photoacoustic signals as compared with conventional Au NRs...
December 2, 2016: Nanoscale
https://www.readbyqxmd.com/read/27909829/contrast-enhanced-ultrasound-in-diagnosis-of-primary-hepatic-angiosarcoma
#14
Wenwu Ling, Tingting Qiu, Lin Ma, Chuanfen Lei, Yan Luo
Primary hepatic angiosarcoma (PHA) is a rare malignant tumor that occurs mainly in the elderly, with almost no specific symptoms or tumor markers. Information on the imaging characteristics of this tumor is limited due to its rarity. Therefore, it is difficult to diagnose PHA. So far, its definite diagnosis depends on histopathologic examination combined with immunohistochemical results. Patients with PHA have a poor prognosis in spite of surgical resection of this tumor. In this case report, we present a 72-year-old woman with PHA, focusing on the imaging features of this tumor, especially its enhancement pattern on contrast-enhanced ultrasound images...
December 1, 2016: Journal of Medical Ultrasonics
https://www.readbyqxmd.com/read/27908189/thermoacoustic-imaging-of-rabbit-knee-joints
#15
Zihui Chi, Yuan Zhao, Lin Huang, Zhu Zheng, Huabei Jiang
PURPOSE: Knee joint is one of the largest and most complex joints of the body. Knee joint diseases are common, and current clinical imaging technologies such as x-ray computed tomography, magnetic resonance imaging, and ultrasound imaging have limitations in the diagnosis of knee joint diseases. Emerging imaging technologies such as diffuse optical tomography and photoacoustic imaging (PAI) have been applied to the detection of osteoarthritis (OA). However, they are limited to small joints such as the finger and difficult to be used for large joints such as the knee...
December 2016: Medical Physics
https://www.readbyqxmd.com/read/27906105/pancreatic-metastases-from-ocular-malignant-melanoma-the-use-of-endoscopic-ultrasound-guided-fine-needle-aspiration-to-establish-a-definitive-cytologic-diagnosis-a-case-report
#16
Diogo Turiani Hourneaux De Moura, Danielle Azevedo Chacon, Ryan Tanigawa, Martin Coronel, Spencer Cheng, Éverson L A Artifon, José Jukemura, Eduardo Guimarães Hourneaux De Moura
BACKGROUND: When encountering solid pancreatic lesions, nonpancreatic primary metastases are rare and differentiating a metastasis from a primary neoplastic lesion is challenging. The clinical presentation and radiologic features can be similar and the possibility of a pancreatic metastasis should be considered when the patient refers to a history of a different primary cancer. Endoscopic ultrasound offers a key anatomical advantage in accessing the pancreas and endoscopic ultrasound-guided fine-needle aspiration has become the gold standard method for diagnosing pancreatic lesions...
December 1, 2016: Journal of Medical Case Reports
https://www.readbyqxmd.com/read/27905968/monitoring-the-prevalence-of-thyroid-disorders-in-the-adult-population-of-northeast-germany
#17
Rehman Mehmood Khattak, Till Ittermann, Matthias Nauck, Harald Below, Henry Völzke
BACKGROUND: Only a few studies like ours have investigated the effect of long-term stable iodine supply on thyroid disorders in a historically iodine-deficient population, but not with a long follow-up time of 10 years. METHODS: Data were derived from two independent population-based cohorts of the Study of Health in Pomerania (SHIP-0 [1997-2001] and SHIP-TREND [2008-2012]) comprising 4308 and 4420 subjects, respectively. Diagnosed thyroid disorders were assessed...
November 8, 2016: Population Health Metrics
https://www.readbyqxmd.com/read/27904441/dynamic-contrast-enhanced-ultrasound-of-the-bowel-wall-with-quantitative-assessment-of-crohn-s-disease-activity-in-childhood
#18
Damjana Kljucevsek, Dubravka Vidmar, Darja Urlep, Rok Dezman
BACKGROUND: Contrast-enhanced ultrasound (CEUS) has become an established non-invasive, patient-friendly imaging technique which improves the characterization of lesions. In addition, dynamic contrast-enhanced ultrasound (DCE-US) provides valuable information concerning perfusion of examined organs. This review addresses current applications of CEUS in children, focused on DCE-US of the bowel wall in patients with Crohn disease, which enables realtime assessment of the bowel wall vascularity with semi-quantitative and quantitative assessment of disease activity and response to medical treatment...
December 1, 2016: Radiology and Oncology
https://www.readbyqxmd.com/read/27904249/benign-biliary-strictures
#19
REVIEW
Ashley Altman, Steven M Zangan
Differentiating benign and malignant biliary strictures is a challenging and important clinical scenario. The typical presentation is indolent and involves elevation of liver enzymes, constitutional symptoms, and obstructive jaundice with or without superimposed or recurrent cholangitis. While overall the most common causes of biliary strictures are malignant, including cholangiocarcinoma and pancreatic adenocarcinoma, benign strictures encompass a wide spectrum of etiologies including iatrogenic, autoimmune, infectious, inflammatory, and congenital...
December 2016: Seminars in Interventional Radiology
https://www.readbyqxmd.com/read/27904246/noninvasive-imaging-of-the-biliary-system-relevant-to-percutaneous-interventions
#20
REVIEW
Stephen Thomas, Kayleen Jahangir
Clinical data such as history, physical examination, and laboratory tests are useful in identifying patients with biliary obstruction and biliary sources of infection. However, if intervention is planned, noninvasive imaging is needed to confirm the presence, location, and extent of the disease process. Currently, the most commonly available and used noninvasive modalities are ultrasound (US), computed tomography (CT), magnetic resonance (MR), and nuclear medicine hepatobiliary scintigraphy (HIDA). US is quick, portable, readily available, and is commonly the first imaging modality used when biliary pathology is suspected...
December 2016: Seminars in Interventional Radiology
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