title: 4-D cardiac MR image analysis: left and right ventricular morphology and function.
abstract: In this study, a combination of active shape model (ASM) and active appearance model (AAM) was used to segment the left and right ventricles of normal and Tetralogy of Fallot (TOF) hearts on 4-D (3-D+time) MR images. For each ventricle, a 4-D model was first used to achieve robust preliminary segmentation on all cardiac phases simultaneously and a 3-D model was then applied to each phase to improve local accuracy while maintaining the overall robustness of the 4-D segmentation. On 25 normal and 25 TOF hearts, in comparison to the expert traced independent standard, our comprehensive performance assessment showed subvoxel segmentation accuracy, high overlap ratios, good ventricular volume correlations, and small percent volume differences. Following 4-D segmentation, novel quantitative shape and motion features were extracted using shape information, volume-time and dV/dt curves, analyzed and used for disease status classification. Automated discrimination between normal/TOF subjects achieved 90%-100% sensitivity and specificity. The features obtained from TOF hearts show higher variability compared to normal subjects, suggesting their potential use as disease progression indicators. The abnormal shape and motion variations of the TOF hearts were accurately captured by both the segmentation and feature characterization.
authors.affiliation: Department of Electrical and Computer Engineering, The University of Iowa, Iowa City, IA 52242 USA . honghai-zhang@uiowa.edu
authors.forename: Honghai
authors.initials: H
authors.lastname: Zhang
authors.forename: Andreas
authors.initials: A
authors.lastname: Wahle
authors.forename: Ryan K
authors.initials: RK
authors.lastname: Johnson
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Scholz
authors.forename: Milan
authors.initials: M
authors.lastname: Sonka
mesh_terms: D000293:Adolescent; D000328:Adult; D000465:Algorithms; D005260:Female; D006321:Heart / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D009068:Movement / Q000502:physiology; D012680:Sensitivity and Specificity; D013771:Tetralogy of Fallot / Q000503:physiopathology; D016276:Ventricular Function / Q000502:physiology*