title: Modeling shear modulus distribution in magnetic resonance elastography with piecewise constant level sets.
abstract: Magnetic resonance elastography (MRE) is designed for imaging the mechanical properties of soft tissues. However, the interpretation of shear modulus distribution is often confusing and cumbersome. For reliable evaluation, a common practice is to specify the regions of interest and consider regional elasticity. Such an experience-dependent protocol is susceptible to intrapersonal and interpersonal variability. In this study we propose to remodel shear modulus distribution with piecewise constant level sets by referring to the corresponding magnitude image. Optimal segmentation and registration are achieved by a new hybrid level set model comprised of alternating global and local region competitions. Experimental results on the simulated MRE data sets show that the mean error of elasticity reconstruction is 11.33% for local frequency estimation and 18.87% for algebraic inversion of differential equation. Piecewise constant level set modeling is effective to improve the quality of shear modulus distribution, and facilitates MRE analysis and interpretation.
authors.affiliation: NUS Graduate School for Integrative Sciences & Engineering, National University of Singapore, Singapore. bingoon@ieee.org
authors.forename: Bing Nan
authors.initials: BN
authors.lastname: Li
authors.forename: Chee Kong
authors.initials: CK
authors.lastname: Chui
authors.forename: Sim Heng
authors.initials: SH
authors.lastname: Ong
authors.forename: Tomokazu
authors.initials: T
authors.lastname: Numano
authors.forename: Toshikatsu
authors.initials: T
authors.lastname: Washio
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Homma
authors.forename: Stephen
authors.initials: S
authors.lastname: Chang
authors.forename: Sudhakar
authors.initials: S
authors.lastname: Venkatesh
authors.forename: Etsuko
authors.initials: E
authors.lastname: Kobayashi
mesh_terms: D000465:Algorithms; D004548:Elasticity; D054459:Elasticity Imaging Techniques / Q000295:instrumentation / Q000379:methods*; D004867:Equipment Design; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008103:Liver Cirrhosis / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D008962:Models, Theoretical; D019047:Phantoms, Imaging; D016012:Poisson Distribution; D033081:Shear Strength