Comparison of inversion-recovery gradient- and spin-echo and fast spin-echo techniques in the detection and characterization of liver lesions

PURPOSE: To compare respiratory-triggered inversion-recovery (IR) gradient- and spin-echo (GRASE) magnetic resonance (MR) imaging with respiratory-triggered T2-weighted fast spin-echo (SE) imaging in the diagnosis of liver metastases. MATERIALS AND METHODS: In this prospective study, two radiologists independently identified focal hepatic lesions on respiratory-triggered IR GRASE and respiratory-triggered fast SE MR images in 28 consecutive patients with 186 (135 malignant and 51 benign) proved lesions. A combination of findings at surgery, intraoperative ultrasonography (US), and histologic examination served as the standard of reference, Contrast-to-noise ratios (CNRs) were obtained from 86 lesions larger than 10 mm. RESULTS: The sensitivity in the detection of liver metastases was, independent of lesion size and observer, higher for IR CRASE imaging (55%) than for fast SE imaging (44%-50%) (observer 1, P = .014; observer 2, P = .21). Confidence levels with IR GRASE imaging were higher, but not significantly so, than those with fast SE imaging (P < .098). Both observers characterized liver lesions better with IR GRASE than with fast SE imaging (observer, P = .04; observer 2, P = .48). The metastasis-liver CNR was significantly higher (P = .012)with IR GRASE imaging. CONCLUSION: The respiratory-triggered IR CRASE sequence is a fast alternative to the respiratory-triggered fast SE sequence in the evaluation of suspected liver metastases.