title: Motion and distortion correction of skeletal muscle echo planar images.
abstract: This paper examines two artifacts facing researchers who use gradient echo (GRE) echo planar imaging (EPI) for time series studies of skeletal muscles in limbs. The first is through-plane blood flow during the acquisition, causing a vessel motion artifact that inhibits proper motion correction of the data. The second is distortion of EPI images caused by B0 field inhomogeneities. Though software tools are available for correcting these artifacts in brain EPI images, the tools do not perform well on muscle images. The severity of the two artifacts was described using image similarity measures, and the data was processed with both a conventional motion correction program and custom written tools. The conventional program did not perform well on the limb images, in fact significantly degrading image quality in some trials. Data is presented which proves that arterial pulsatile signal caused the impairment in motion correction. The new tools were shown to perform much better, achieving substantial motion correction and distortion correction of the muscle EPI images.
authors.affiliation: Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario, Canada; Imaging Research Centre, St. Joseph's Healthcare, Hamilton, Ontario, Canada. Electronic address: addavis@gmail.com.
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Davis
authors.affiliation: Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario, Canada; Imaging Research Centre, St. Joseph's Healthcare, Hamilton, Ontario, Canada; School of Biomedical Engineering, McMaster University, Hamilton, Ontario, Canada; Department of Electrical and Computer Engineering, McMaster University, Hamilton, Ontario, Canada. Electronic address: nosewor@mcmaster.ca.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Noseworthy
mesh_terms: D000328:Adult; D016477:Artifacts; D017352:Echo-Planar Imaging / Q000379:methods*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D009038:Motion; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging*
keywords: Distortion correction; Echo planar magnetic resonance imaging; Image pre-processing; Magnetic resonance imaging; Motion correction; Skeletal muscle