title: Hierarchical IDEAL: fast, robust, and multiresolution separation of multiple chemical species from multiple echo times.
abstract: We describe a generalized version of hierarchical IDEAL that can flexibly handle arbitrary chemical species at arbitrary echo times. The proposed work is fast and robust, and it has three key features: (1) multiresolution approach, which allows the method to handle images with disjoint regions, makes it less susceptible to local optima, and reduces the ambiguity of the separation; (2) direct phase estimation, which bypasses the phase wrapping issue, and (3) efficient algebraic formulation, which enables fast calculation and insensitivity to spatially varying phase across the image, from sources such as partial echo acquisition, receiver coils, motion, and flow. Representative results at 1.5 T and 3 T are presented from human ankle, wrist, and a water/oil/silicone phantom.
authors.affiliation: Global Imaging Group, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts 02139, USA. jtsao2@hotmail.com
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Tsao
authors.forename: Yun
authors.initials: Y
authors.lastname: Jiang
mesh_terms: D000465:Algorithms; D001704:Biopolymers / Q000032:analysis*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D001704:Biopolymers