MR imaging of the liver: Standard spin-echo versus ''fast'' imaging techniques at 1 T

Thirty-six patients with known hepatic lesions underwent MR imaging at 1 T. The following spin-echo (SE) sequences were utilized: repetition time (TR)/echo time (TE) = 3,000/35, 70; 1,500/17; 375/17 msec. Additional single-section images with breath-holding (acquisition time <20 sec) were obtained using SE technique with TR/TE = 70/17 msec and gradient refocusing technique with TR/TE = 40/12 msec. The results show that MR imaging consistently detected a greater number of mass lesions than CT. The fast images were limited in contrast sensitivity and low signal-to-noise ratio and were more sensitive to aortic pulsation and metallic artifacts. However, these techniques afforded flow sensitivity and decreased respiratory motion artifact. The use of intravenous paramagnetic contrast agents (Gd-DTPA) resulted in increased contrast sensitivity and provided capability for dynamic scanning