Area-preserving flattening maps of 3D ultrasound carotid arteries images
ABSTRACT Quantitative measurements of the progression (or regression) of carotid plaque burden are important in monitoring patients and evaluating new treatment options. 3D ultrasound (US) has been used to monitor the progression of carotid artery plaques in symptomatic and asymptomatic patients, and different methods of measuring various ultrasound phenotypes of atherosclerosis have been developed. We have developed a quantitative metric used to analyze changes in carotid plaque morphology from 3D US. This method matched the vertices on the carotid arterial wall surface with those on the luminal surface. Vessel-wall-plus-plaque thickness (VWT) was obtained by computing the distance between each corresponding pair, which was then superimposed on the arterial wall to produce the VWT map. Since the progression of plaque thickness is important in monitoring patients who are at risk for stroke, we also computed the change of VWT by comparing the VWT maps obtained for a patient at two different time points. In this paper, we propose a technique to flatten the 3D VWT and VWT-Change maps in an area-preserving manner, in order to facilitate the visualization and interpretation of these maps.
SourceAvailable from: Huijun Chen[Show abstract] [Hide abstract]
ABSTRACT: Local hemodynamic forces, such as wall shear stress (WSS), are thought to trigger cellular and molecular mechanisms that determine atherosclerotic plaque vulnerability to rupture. Magnetic resonance imaging has emerged as a powerful tool to characterize human carotid atherosclerotic plaque composition and morphology, and to identify plaque features shown to be key determinants of plaque vulnerability. Image-based computational fluid dynamics has allowed researchers to obtain time-resolved WSS information of atherosclerotic carotid arteries. A deeper understanding of the mechanisms of initiation and progression of atherosclerosis can be obtained through the comparison of WSS and plaque composition and morphology. To date, however, advance in knowledge has been limited greatly due to the lack of a reliable infrastructure to perform such analysis. The aim of this study is to establish a framework that will allow for the co-registration and analysis of the three-dimensional distribution of WSS and plaque components and morphology. The use of this framework will lead to future studies targeted to determining the role of WSS in atherosclerotic plaque progression and vulnerability.Physiological Measurement 08/2013; 34(9):977-990. DOI:10.1088/0967-3334/34/9/977 · 1.62 Impact Factor
[Show abstract] [Hide abstract]
ABSTRACT: Imaging equipment is experiencing advances in speed, sensitivity, safety, and workflow. There is an increasing trend toward physiologic imaging and quantitation, requiring greater consistency across manufacturers and clinics. The Human Connectome Project is symbolic of the drive toward combining multimodality anatomic and functional imaging with quantitation and sophisticated atlases. Advanced visualization methods have become essential in the evaluation of large multidimensional data sets. Hybrid imaging blends advantages from multiple modalities to provide a comprehensive anatomic, functional, physiologic, and metabolic data set. Breakthrough clinical neuroimaging applications are derived from an alignment of scientific, engineering, clinical, and business conditions.Neurologic Clinics 02/2014; 32(1):1-29. DOI:10.1016/j.ncl.2013.07.007 · 1.61 Impact Factor
[Show abstract] [Hide abstract]
ABSTRACT: Automatic segmentation of the carotid plaques from ultrasound images has been shown to be an important task for monitoring progression and regression of carotid atherosclerosis. Considering the complex structure and heterogeneity of plaques, a fully automatic segmentation method based on media-adventitia and lumen-intima boundary priors is proposed. This method combines image intensity with structure information in both initialization and a level-set evolution process. Algorithm accuracy was examined on the common carotid artery part of 26 3-D carotid ultrasound images (34 plaques ranging in volume from 2.5 to 456 mm(3)) by comparing the results of our algorithm with manual segmentations of two experts. Evaluation results indicated that the algorithm yielded total plaque volume (TPV) differences of -5.3 ± 12.7 and -8.5 ± 13.8 mm(3) and absolute TPV differences of 9.9 ± 9.5 and 11.8 ± 11.1 mm(3). Moreover, high correlation coefficients in generating TPV (0.993 and 0.992) between algorithm results and both sets of manual results were obtained. The automatic method provides a reliable way to segment carotid plaque in 3-D ultrasound images and can be used in clinical practice to estimate plaque measurements for management of carotid atherosclerosis.Ultrasound in medicine & biology 09/2013; DOI:10.1016/j.ultrasmedbio.2013.07.007 · 2.10 Impact Factor