Noncontrast‐enhanced renal angiography using multiple inversion recovery and alternating TR balanced steady‐state free precession

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 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 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. Magn Reson Med 70:527–536, 2013. © 2012 Wiley Periodicals, Inc.