title: Quantitative analysis of spatial distortions of diffusion techniques at 3T.
abstract: Diffusion has been widely adopted in the clinical setting to study the microstructural tissue changes in conjunction with anatomic imaging and metabolic imaging to offer insights on the status of the tissue injury or lesion. However, geometric distortions caused by magnetic susceptibility effects, eddy currents and gradient imperfections greatly affect the clinical utility of the diffusion images. Several diffusion methods have been proposed in the recent years to obtain diffusion parameters with increased accuracy. In most cases, the comparisons to the clinical standard echo-planar imaging (EPI) diffusion are done visually without quantitative measurements. In this study, we present three simple, complementary quantitative methods of nonrigid image registration and shape analyses for evaluating spatial distortions on magnetic resonance images with application in comparing single-shot fast spin-echo (SSFSE) and EPI based diffusion measurements. These methods have confirmed the SSFSE based diffusion method is less distorted than the EPI based one, which is generally accepted through visual inspection.
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California - San Francisco, CA, USA. duan.xu@radiology.ucsf.edu
authors.forename: Duan
authors.initials: D
authors.lastname: Xu
authors.forename: Michael C
authors.initials: MC
authors.lastname: Lee
authors.forename: Julio
authors.initials: J
authors.lastname: Carballido-Gamio
authors.forename: Matthew
authors.initials: M
authors.lastname: Barkovich
authors.forename: Sharmila
authors.initials: S
authors.lastname: Majumdar
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Vigneron
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Nelson
mesh_terms: D000465:Algorithms; D016477:Artifacts; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D017352:Echo-Planar Imaging / Q000379:methods*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity