Showing papers by "Qi Zhang published in 2009"
17 Jun 2009
TL;DR: In this article, the authors investigated the relationship between geometric features and hemodynamic quantities in carotid artery atherosclerotic lesions using factor analysis and found that the combined role of all geometric variables in disturbed flow can be analyzed using Factor Analysis.
Abstract: Hemodynamics plays an important role in the development and progression of carotid artery atherosclerotic lesions. Certain aspects of vascular geometry, which mediates local hemodynamics, might be risk factors that increase a vessel’s atherosusceptibility [1]. To further evaluate this “geometric risk factor” hypothesis, the relationship between geometric features and hemodynamic quantities thought to typify “disturbed flow” was recently investigated [2]. Fourteen intercorrelated geometric features were initially extracted from MR images of 50 carotid bifurcations, and multivariate regression based on an a priori selection of a subset of four of these geometric features was used to identify two that were predictors of disturbed hemodynamics. Here, this work is extended to simultaneously analyze the combined role of all geometric variables using factor analysis.Copyright © 2009 by ASME
4 citations
22 Sep 2009
TL;DR: T-tests using images from two porcine coronary arteries demonstrated that four features had significant difference between regions with highest (top 25%) and lowest (bottom 25%) albumin permeability, helpful in exploring the mechanisms responsible for high permeability.
Abstract: Endothelial permeability is associated with the genesis and development of atherosclerosis. Computerized image analysis is utilized to investigate the relationship between endothelial permeability and endothelial morphology. First, microscopic images are segmented to detect endothelial cells using the speckle reduction anisotropic diffusion and marker-controlled watershed, whose optimal parameter settings are obtained from the cell detection receiver operating characteristic. Two categories of morphological features are then extracted, including cell shape features and intercellular features. Finally, Student's t-test is conducted to explore the relation of the morphology to permeability. The method correctly detected 82.3% cells in two test images, while the over-segmented and fused cells were 8.4% and 9.3%, respectively. T-tests using images from two porcine coronary arteries demonstrated that four features had significant difference (P<0.05) between regions with highest (top 25%) and lowest (bottom 25%) albumin permeability. This finding is helpful in exploring the mechanisms responsible for high permeability.