title: Rapid time-resolved magnetic resonance angiography via a multiecho radial trajectory and GraDeS reconstruction.
abstract: Contrast-enhanced magnetic resonance angiography is challenging due to the need for both high spatial and temporal resolution. A multishot trajectory composed of pseudo-random rotations of a single multiecho radial readout was developed. The trajectory is designed to give incoherent aliasing artifacts and a relatively uniform distribution of projections over all time scales. A field map (computed from the same data set) is used to avoid signal dropout in regions of substantial field inhomogeneity. A compressed sensing reconstruction using the GraDeS algorithm was used. Whole brain angiograms were reconstructed at 1-mm isotropic resolution and a 1.1-s frame rate (corresponding to an acceleration factor > 100). The only parameter which must be chosen is the number of iterations of the GraDeS algorithm. A larger number of iterations improves the temporal behavior at cost of decreased image signal-to-noise ratio. The resulting images provide a good depiction of the cerebral vasculature and have excellent arterial/venous separation.
authors.affiliation: Department of Radiology, School of Medicine, Case Western Reserve University / University Hospitals of Cleveland, Cleveland, Ohio 44106, USA. gregory.r.lee@case.edu
authors.forename: Gregory R
authors.initials: GR
authors.lastname: Lee
authors.forename: Nicole
authors.initials: N
authors.lastname: Seiberlich
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Sunshine
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Carroll
authors.forename: Mark A
authors.initials: MA
authors.lastname: Griswold
mesh_terms: D000465:Algorithms; D001783:Blood Flow Velocity; D001921:Brain / Q000473:pathology / Q000503:physiopathology*; D002560:Cerebrovascular Circulation; D002561:Cerebrovascular Disorders / Q000473:pathology / Q000503:physiopathology*; D003199:Computer Systems; D003287:Contrast Media; D005682:Gadolinium; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D005682:Gadolinium