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Intravascular Ultrasound Images (intravascular + ultrasound_image)
Selected AbstractsThe importance of gender on coronary artery size: In-vivo assessment by intravascular ultrasoundCLINICAL CARDIOLOGY, Issue 5 2004Sang-Gon Kim M.D. Abstract Background: It remains controversial whether women have smaller coronary arteries than men because of a gender-specific trait, or whether the observed differences are primarily due to a difference in body size. Intravascular ultrasound (IVUS), with its ability to provide unique coronary images that allow precise measurement of arterial size in vivo, is ideally suited to address this issue. Hypothesis: Female gender, independent of body size, is associated with smaller coronary artery size as measured by intracoronary ultrasound. Methods: Intravascular ultrasound images of normal left main arteries were identified retrospectively from a single center database. Associations between demographic and clinical characteristics (including body size) and left main coronary dimensions were assessed with univariant and multivariate regression analyses. Results: We identified 257 completely normal left main arteries. Mean left main arterial areas were smaller in women than in men (17.2 vs. 20.6 mm2, p < 0.001), as were mean luminal areas (14.0 vs. 16.7 mm2, p < 0.001). By multiple regression analysis, the independent predictors of left main lumen were body surface area (p < 0.001) and gender (p = 0.003). Conclusions: Body surface area and gender are both independent predictors of coronary artery size, although body size has a greater influence than gender. [source] Renal Artery Fibromuscular Dysplasia Is a Cause of Refractory Hypertension in the ElderlyECHOCARDIOGRAPHY, Issue 1 2009Raed Aqel M.D. Fibromuscular dysplasia (FMD) is predominantly a disease of younger women, but it can occur and cause refractory hypertension in the elderly. We present here classic angiographic and intravascular ultrasound images of FMD in a 70-year-old woman with refractory hypertension. Renal artery FMD should be included in the differential diagnosis of refractory hypertension even in older patients since recognizing and treating this condition will add favorably to the outcome of these patients. [source] Extraction of media and plaque boundaries in intravascular ultrasound images by level sets and min/max flowEXPERT SYSTEMS, Issue 2 2010Ali Iskurt Abstract: Estimation of the plaque area in intravascular ultrasound images after extraction of the media and plaque,lumen interfaces is an important application of computer-aided diagnosis in medical imaging. This paper presents a novel system for fully automatic and fast calculation of plaque quantity by capturing the surrounding ring called media. The system utilizes an algorithm that consists of an enhanced technique for noise removal and a method of detecting different iso levels by sinking the image gradually under zero level. Moreover, an important novelty with this technique is the simultaneous extraction of media and lumen,plaque interfaces at satisfactory levels. There are no higher dimensional surfaces and evolution of contours, stopping at high image gradients. Thus, the system runs really fast with curvature velocity only and has no complexity. Experiments also show that this shape-recovering curvature term not only removes the noisy behaviour of ultrasound images but also strengthens very weak boundaries and even completes the missing walls of the media. In addition, the lumen,plaque interface can be detected simultaneously. For validation, a new and very useful algorithm is developed for labelling of intravascular ultrasound images, taken from video sequences of 15 patients, and a comparison-based verification is done between manual contours by experts and the contours extracted by our system. [source] Reproducibility of coronary lumen, plaque, and vessel wall reconstruction and of endothelial shear stress measurements in vivo in humansCATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 1 2003Ahmet U. Coskun PhD Abstract The purpose of this study was to assess the reproducibility of an in vivo methodology to reconstruct the lumen, plaque, and external elastic membrane (EEM) of coronary arteries and estimate endothelial shear stress (ESS). Ten coronary arteries without significant stenoses (five native and five stented arteries) were investigated. The 3D lumen and EEM boundaries of each coronary artery were determined by fusing end-diastolic intravascular ultrasound images with biplane coronary angiograms. Coronary flow was measured. Computational fluid dynamics was used to calculate local ESS. Complete data acquisition was then repeated. Analysis was performed on each data set in a blinded manner. The intertest correlation coefficients for all arteries for the two measurements of lumen radius, EEM radius, plaque thickness, and ESS were r = 0.96, 0.96, 0.94, 0.91, respectively (all P values < 0.0001). The 3D anatomy and ESS of human coronary arteries can be reproducibly estimated in vivo. This methodology provides a tool to examine the effect of ESS on atherogenesis, remodeling, and restenosis; the contribution of arterial remodeling and plaque growth to changes in the lumen; and the impact of new therapies. Catheter Cardiovasc Interv 2003;60:67,78. © 2003 Wiley,Liss, Inc. [source] | ||||||||||