title: Automated quantification of carotid artery stenosis on contrast-enhanced MRA data using a deformable vascular tube model.
abstract: The purpose of this study was to develop and validate a method for automated segmentation of the carotid artery lumen from volumetric MR Angiographic (MRA) images using a deformable tubular 3D Non-Uniform Rational B-Splines (NURBS) model. A flexible 3D tubular NURBS model was designed to delineate the carotid arterial lumen. User interaction was allowed to guide the model by placement of forbidden areas. Contrast-enhanced MRA (CE-MRA) from 21 patients with carotid atherosclerotic disease were included in this study. The validation was performed against expert drawn contours on multi-planar reformatted image slices perpendicular to the artery. Excellent linear correlations were found on cross-sectional area measurement (r = 0.98, P < 0.05) and on luminal diameter (r = 0.98, P < 0.05). Strong match in terms of the Dice similarity indices were achieved: 0.95 ± 0.02 (common carotid artery), 0.90 ± 0.07 (internal carotid artery), 0.87 ± 0.07 (external carotid artery), 0.88 ± 0.09 (carotid bifurcation) and 0.75 ± 0.20 (stenosed segments). Slight overestimation of stenosis grading by the automated method was observed. The mean differences was 7.20% (SD = 21.00%) and 5.2% (SD = 21.96%) when validated against two observers. Reproducibility in stenosis grade calculation by the automated method was high; the mean difference between two repeated analyses was 1.9 ± 7.3%. In conclusion, the automated method shows high potential for clinical application in the analysis of CE-MRA of carotid arteries.
authors.affiliation: Division of Image Processing, Department of Radiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands.
authors.forename: Avan
authors.initials: A
authors.lastname: Suinesiaputra
authors.forename: Patrick J H
authors.initials: PJ
authors.lastname: de Koning
authors.forename: Elena
authors.initials: E
authors.lastname: Zudilova-Seinstra
authors.forename: Johan H C
authors.initials: JH
authors.lastname: Reiber
authors.forename: Rob J
authors.initials: RJ
authors.lastname: van der Geest
mesh_terms: D057205:Automation, Laboratory; D002339:Carotid Arteries / Q000473:pathology*; D016893:Carotid Stenosis / Q000175:diagnosis* / Q000473:pathology; D003196:Computer Graphics; D003198:Computer Simulation; D003287:Contrast Media; D019786:Gadolinium DTPA; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D016014:Linear Models; D018810:Magnetic Resonance Angiography; D008953:Models, Anatomic; D008955:Models, Cardiovascular; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D014584:User-Computer Interface
chemical_list: D003287:Contrast Media; C064925:gadodiamide; D019786:Gadolinium DTPA