Segmented turboFLASH: method for breath-hold MR imaging of the liver with flexible contrast.

Abstract

A method called segmented turboFLASH imaging allows high-resolution, multisection, short-inversion-time (TI) inversion-recovery (STIR), T1- or T2-weighted magnetic resonance (MR) studies of the liver to be completed within a breath-hold interval. The method was applied in a phantom and in 19 patients with hepatic lesions. Sequence comparisons were performed among segmented turboFLASH, single-shot turboFLASH, T1-weighted gradient-echo with ultrashort echo time, and T2-weighted spin-echo (SE) techniques. Signal from fat and liver could be nulled with the segmented turboFLASH method, with TIs of 10 and 300 msec, respectively; signal from these tissues could not be eliminated with the single-shot approach. Signal-difference-to-noise ratios and contrast for the best segmented sequences were comparable with those of the best T2-weighted SE and T1-weighted gradient-echo techniques. It is concluded that it is feasible to obtain breath-hold images with arbitrary tissue contrast by means of segmented turboFLASH imaging. The method may prove helpful for the detection and characterization of hepatic lesions and will likely have applications to other anatomic regions such as the chest and pelvis.