[Turbo-Spin-Echo sequences in focal liver diseases].

Turbo Spin-Echo (Turbo SE) pulse sequences represent a new type of fast sequences characterized by a dramatic reduction in acquisition time with similar intrinsic contrast to that of conventional Spin-Echo (SE) pulse sequences. For a preliminary clinical comparison of turbo SE and SE sequences, a consecutive series of 25 patients with focal liver lesions was investigated by means of MRI at 1.0 T. The patients were selected on the basis of US or CT positive liver scans for focal lesions. All patients underwent MRI following the same protocol: axial T1-weighted (T1W) gradient echo (GE) sequences (TR/TE = 110/6 ms) with the "breath-hold" technique, T2-weighted (T2W) SE sequences (TR/TE = 1730/90 ms; FL = 60, M = 128 x 256, 2 AC, TA = 7 min 26 sec) and turbo SE sequences (TR/TE = 5100/112 ms, M = 240 x 256, 2 AC, TA = 2 min 48 sec). Slice thickness was 10 mm with a 1-mm gap in all cases. Qualitative (number, size and definition of the lesions) and quantitative (contrast-to-noise ratio (CNR) and relative CNR) variables were considered. SE and turbo SE sequences demonstrated the same number of lesions; the smallest lesion (3 mm) was identified by turbo SE sequences. Turbo SE sequences better depicted lesion margins than SE sequences. In all cystic conditions, CNR was higher in turbo SE than in SE sequences, while it was lower in all the extant conditions. This preliminary experience proves turbo SE pulse sequences to be a valuable tool in liver MRI, which calls for further clinical trials.