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Ungated radial quiescent‐inflow single‐shot (UnQISS) magnetic resonance angiography using optimized azimuthal equidistant projections
Author(s) -
Edelman Robert R.,
Giri Shivraman,
Murphy Ian G.,
Flanagan Oisin,
Speier Peter,
Koktzoglou Ioannis
Publication year - 2014
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.25477
Subject(s) - steady state free precession imaging , cardiac cycle , physics , flip angle , nuclear medicine , single shot , azimuth , nuclear magnetic resonance , electromagnetic coil , medicine , magnetic resonance imaging , radiology , optics , quantum mechanics
Purpose We hypothesized that non–contrast‐enhanced MR angiography (NEMRA) could be performed without cardiac gating by using a variant of the quiescent‐inflow single‐shot (QISS) technique. Methods Ungated QISS (UnQISS) MRA was evaluated in eight patients with peripheral arterial disease at 1.5T. The radial acquisition used optimized azimuthal equidistant projections, a long quiescent inflow time (1200 ms) to ensure replenishment of saturated in‐plane spins irrespective of the cardiac phase, and a lengthy readout (1200 ms) so that a complete cardiac cycle was sampled for each slice. Venous and background tissue suppression was obtained using frequency‐offset–corrected inversion radiofrequency pulses. Results Scan time for UnQISS was 15.4 min for an eight‐station whole‐leg acquisition. The appearance of UnQISS MRA acquired using the body coil was comparable to electrocardiographic‐gated QISS MRA using phased array coils. A small radial view angle increment minimized eddy current–related artifacts, whereas image quality was inferior with a golden view angle radial increment or Cartesian trajectory. In patient studies, ≥50% stenoses were consistently detected. Conclusion Using UnQISS, peripheral NEMRA can be performed without the need for cardiac gating. The use of fixed imaging parameters and body coil for signal reception further simplifies the scan procedure. Magn Reson Med 72:1522–1529, 2014. © 2014 Wiley Periodicals, Inc.