High-resolution peripheral vein bypass graft wall studies using high sampling efficiency inner volume 3D FSE

A 3D inner‐volume fast spin echo (3D IV‐FSE) sequence was developed for ECG‐gated, black‐blood, T1‐ and T2‐weighted vessel wall imaging of peripheral vein bypass grafts (PVBG). The sequence utilizes nonselective refocusing excitations to minimize echo spacings and a highly selective IV excitation scheme to minimize the need for oversampling of z‐encode slice selections. The method was tested in eight PVBG patients who also underwent 2D FSE graft imaging. High‐quality 3D imaging was achieved in all subjects, with significant spatial resolution and volume coverage gains compared to the more conventional 2D FSE sequences normalized for signal‐to‐noise ratios (SNRs) and scan times. Compared to previously proposed 3D IV‐FSE methods, nonselective refocusing resulted in a more than 20% FSE echo train sampling efficiency increase while the use of highly selective IV excitation resulted in a 30% improvement in slice oversampling efficiency. Magn Reson Med, 2008. © 2008 Wiley‐Liss, Inc.