title: Functional magnetic resonance imaging using PROPELLER-EPI.
abstract: Periodically rotated overlapping parallel lines with enhanced reconstruction-echo-planar imaging (PROPELLER-EPI) is a multishot technique that samples k-space by acquisition of narrow blades, which are subsequently rotated until the entire k-space is filled. It has the unique advantage that the center of k-space, and thus the area containing the majority of functional MRI signal changes, is sampled with each shot. This continuous refreshing of the k-space center by each acquired blade enables not only sliding-window but also keyhole reconstruction. Combining PROPELLER-EPI with a fast gradient-echo readout scheme allows for high spatial resolutions to be achieved while maintaining a temporal resolution, which is suitable for functional MRI experiments. Functional data acquired with a novel interlaced sequence that samples both single-shot EPI and blades in an alternating fashion suggest that PROPELLER-EPI can achieve comparable functional MRI results. PROPELLER-EPI, however, features different spatiotemporal characteristics than single-shot EPI, which not only enables keyhole reconstruction but also makes it an interesting alternative for many functional MRI applications.
authors.affiliation: Medical Physics Group, Department of Diagnostic and Interventional Radiology I, Jena University Hospital, Philosophenweg 3, D-07743 Jena, Germany. martinkraemer@gmx.net
authors.forename: Martin
authors.initials: M
authors.lastname: Krämer
authors.forename: Thies H
authors.initials: TH
authors.lastname: Jochimsen
authors.forename: Jürgen R
authors.initials: JR
authors.lastname: Reichenbach
mesh_terms: D000465:Algorithms; D001931:Brain Mapping / Q000379:methods*; D002540:Cerebral Cortex / Q000502:physiology*; D005071:Evoked Potentials / Q000502:physiology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D010363:Pattern Recognition, Automated / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity