title: 3D isotropic high-resolution diffusion-weighted MRI of the whole brain with a motion-corrected steady-state free precession sequence.
abstract: The main obstacle to high-resolution (<1.5 mm isotropic) 3D diffusion-weighted MRI is the differential motion-induced phase error from shot-to-shot. In this work, the phase error is addressed with a hybrid 3D navigator approach that corrects motion-induced phase in two ways. In the first, rigid-body motion is corrected for every shot. In the second, repeatable nonrigid-body pulsation is corrected for each portion of the cardiac cycle. These phase error corrections were implemented with a 3D diffusion-weighted steady- state free precession pulse sequence and were shown to mitigate signal dropouts caused by shot-to-shot phase inconsistencies compared to a standard gridding reconstruction in healthy volunteers. The proposed approach resulted in diffusion contrast more similar to the contrast observed in the reference echo-planer imaging scans than reconstruction of the same data without correction. Fractional anisotropy and Color fractional anisotropy maps generated with phase-corrected data were also shown to be more similar to echo-planer imaging reference scans than those generated without phase correction.
authors.affiliation: Department of Radiology, Stanford University, Stanford, California, USA. rafaelo@stanford.edu
authors.forename: R L
authors.initials: RL
authors.lastname: O'Halloran
authors.forename: M
authors.initials: M
authors.lastname: Aksoy
authors.forename: A T
authors.initials: AT
authors.lastname: Van
authors.forename: R
authors.initials: R
authors.lastname: Bammer
mesh_terms: D000328:Adult; D000465:Algorithms; D016880:Anisotropy; D016477:Artifacts; D001921:Brain / Q000033:anatomy & histology*; D055424:Cardiac-Gated Imaging Techniques / Q000379:methods*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D009038:Motion; D009068:Movement; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity