title: Noncontrast-enhanced renal angiography using multiple inversion recovery and alternating TR balanced steady-state free precession.
abstract: Noncontrast-enhanced renal angiography techniques based on balanced steady-state free precession avoid external contrast agents, take advantage of high inherent blood signal from the T 2 / T 1 contrast mechanism, and have short steady-state free precession acquisition times. However, background suppression is limited; inflow times are inflexible; labeling region is difficult to define when tagging arterial flow; and scan times are long. To overcome these limitations, we propose the use of multiple inversion recovery preparatory pulses combined with alternating pulse repetition time balanced steady-state free precession to produce renal angiograms. Multiple inversion recovery uses selective spatial saturation followed by four nonselective inversion recovery pulses to concurrently null a wide range of background T 1 species while allowing for adjustable inflow times; alternating pulse repetition time steady-state free precession maintains vessel contrast and provides added fat suppression. The high level of suppression enables imaging in three-dimensional as well as projective two-dimensional formats, the latter of which has a scan time as short as one heartbeat. In vivo studies at 1.5 T demonstrate the superior vessel contrast of this technique.
authors.affiliation: Department of Electrical Engineering, Magnetic Resonance Systems Research Laboratory, Stanford University, Stanford, California, USA. dongh@stanford.edu
authors.forename: Hattie Z
authors.initials: HZ
authors.lastname: Dong
authors.forename: Pauline W
authors.initials: PW
authors.lastname: Worters
authors.forename: Holden H
authors.initials: HH
authors.lastname: Wu
authors.forename: R Reeve
authors.initials: RR
authors.lastname: Ingle
authors.forename: Shreyas S
authors.initials: SS
authors.lastname: Vasanawala
authors.forename: Dwight G
authors.initials: DG
authors.lastname: Nishimura
mesh_terms: D000328:Adult; D000465:Algorithms; D001783:Blood Flow Velocity / Q000502:physiology; D003287:Contrast Media; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D012077:Renal Artery / Q000033:anatomy & histology* / Q000502:physiology*; D012079:Renal Circulation / Q000502:physiology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D003287:Contrast Media