title: Topomorphologic separation of fused isointensity objects via multiscale opening: separating arteries and veins in 3-D pulmonary CT.
abstract: A novel multiscale topomorphologic approach for opening of two isointensity objects fused at different locations and scales is presented and applied to separating arterial and venous trees in 3-D pulmonary multidetector X-ray computed tomography (CT) images. Initialized with seeds, the two isointensity objects (arteries and veins) grow iteratively while maintaining their spatial exclusiveness and eventually form two mutually disjoint objects at convergence. The method is intended to solve the following two fundamental challenges: how to find local size of morphological operators and how to trace continuity of locally separated regions. These challenges are met by combining fuzzy distance transform (FDT), a morphologic feature with a topologic fuzzy connectivity, and a new morphological reconstruction step to iteratively open finer and finer details starting at large scales and progressing toward smaller scales. The method employs efficient user intervention at locations where local morphological separability assumption does not hold due to imaging ambiguities or any other reason. The approach has been validated on mathematically generated tubular objects and applied to clinical pulmonary noncontrast CT data for separating arteries and veins. The tradeoff between accuracy and the required user intervention for the method has been quantitatively examined by comparing with manual outlining. The experimental study, based on a blind seed selection strategy, has demonstrated that above 95% accuracy may be achieved using 25-40 seeds for each of arteries and veins. Our method is very promising for semiautomated separation of arteries and veins in pulmonary CT images even when there is no object-specific intensity variation at conjoining locations.
authors.affiliation: Department of Electrical and Computer Engineering, The University of Iowa, Iowa City, IA 52242, USA. punam-saha@uiowa.edu
authors.forename: Punam K
authors.initials: PK
authors.lastname: Saha
authors.forename: Zhiyun
authors.initials: Z
authors.lastname: Gao
authors.forename: Sara K
authors.initials: SK
authors.lastname: Alford
authors.forename: Milan
authors.initials: M
authors.lastname: Sonka
authors.forename: Eric A
authors.initials: EA
authors.lastname: Hoffman
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D003287:Contrast Media; D005260:Female; D005583:Fourier Analysis; D017143:Fuzzy Logic; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008168:Lung / Q000033:anatomy & histology / Q000098:blood supply*; D008955:Models, Cardiovascular; D019047:Phantoms, Imaging; D011651:Pulmonary Artery / Q000033:anatomy & histology*; D011667:Pulmonary Veins / Q000033:anatomy & histology*; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult
chemical_list: D003287:Contrast Media