title: Diffusion imaging in humans at 7T using readout-segmented EPI and GRAPPA.
abstract: Anatomical MRI studies at 7T have demonstrated the ability to provide high-quality images of human tissue in vivo. However, diffusion-weighted imaging at 7T is limited by the increased level of artifact associated with standard, single-shot, echo-planar imaging, even when parallel imaging techniques such as generalized autocalibrating partially parallel acquisitions (GRAPPA) are used to reduce the effective echo spacing. Readout-segmented echo-planar imaging in conjunction with parallel imaging has the potential to reduce these artifacts by allowing a further reduction in effective echo spacing during the echo-planar imaging readout. This study demonstrates that this approach does indeed provide a substantial improvement in image quality by reducing image blurring and susceptibility-based distortions, as well as by allowing the acquisition of diffusion-weighted images with a high spatial resolution. A preliminary application of the technique to high-resolution diffusion tensor imaging provided a high level of neuroanatomical detail, which should prove valuable in a wide range of applications.
authors.affiliation: Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany. heidemann@cbs.mpg.de
authors.forename: Robin M
authors.initials: RM
authors.lastname: Heidemann
authors.forename: David A
authors.initials: DA
authors.lastname: Porter
authors.forename: Alfred
authors.initials: A
authors.lastname: Anwander
authors.forename: Thorsten
authors.initials: T
authors.lastname: Feiweier
authors.forename: Keith
authors.initials: K
authors.lastname: Heberlein
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Knösche
authors.forename: Robert
authors.initials: R
authors.lastname: Turner
mesh_terms: D016477:Artifacts; D001921:Brain / Q000000981:diagnostic imaging*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D017352:Echo-Planar Imaging / Q000379:methods*; D006801:Humans; D011859:Radiography