Free-breathing renal magnetic resonance angiography with steady-state free-precession and slab-selective spin inversion combined with radial k-space sampling and water-selective excitation

The impact of radial k‐space sampling and water‐selective excitation on a novel navigator‐gated cardiac‐triggered slab‐selective inversion prepared 3D steady‐state free‐precession (SSFP) renal MR angiography (MRA) sequence was investigated. Renal MRA was performed on a 1.5‐T MR system using three inversion prepared SSFP approaches: Cartesian (TR/TE: 5.7/2.8 ms, FA: 85°), radial (TR/TE: 5.5/2.7 ms, FA: 85°) SSFP, and radial SSFP combined with water‐selective excitation (TR/TE: 9.9/4.9 ms, FA: 85°). Radial data acquisition lead to significantly reduced motion artifacts (P < 0.05). SNR and CNR were best using Cartesian SSFP (P < 0.05). Vessel sharpness and vessel length were comparable in all sequences. The addition of a water‐selective excitation could not improve image quality. In conclusion, radial k‐space sampling reduces motion artifacts significantly in slab‐selective inversion prepared renal MRA, while SNR and CNR are decreased. The addition of water‐selective excitation could not improve the lower CNR in radial scanning. Magn Reson Med 53:1228–1233, 2005. © 2005 Wiley‐Liss, Inc.