Hepatic neoplasia: breath-hold MR imaging

Twenty-seven patients with hepatic neoplasms were prospectively examined at 0.35 T with multisection magnetic resonance (MR) imaging during a single breath hold. The procedures included a spin-echo (SE) sequence with a repetition time (TR) of 250 or 125 msec and an echo time (TE) of 15 msec (TR/TE = 250 or 125/15) and gradient-echo (GRE) partial-flip sequences at 250 or 125/20 in phase and 250 or 125/12 out of phase (flip angle of 70 degrees). These procedures were compared with conventional multiacquisition sequences at SE 250/15 (n = 8) in the same patients. GRE partial-flip sequences with a large flip angle provided the optimum combination of contrast and signal-to-noise ratio for imaging hepatic neoplasms, with a signal-difference-to-noise ratio that for in-phase images was 93% greater and for out-of-phase images was 53% greater than that of the SE images. The use of in-phase TEs was preferable to maintain tissue contrast, and presaturation pulses were employed to eliminate vascular pulsation artifacts. All breath-hold procedures provided suppression of motion artifacts superior to that of the short TR, short TE multiacquisition SE imaging. Such sequences should become indispensable for MR imaging of the upper abdomen.