PURPOSE: The purpose of this study was to evaluate the usefulness of the single-shot fast spin-echo (SS-FSE)sequence in comparison with the T2-weighted fast spin-echo (T2-FSE) sequence in brain MR imaging. MATERIALS AND METHODS: In 41 patients aged 15-75 years with intracranial lesion, both SS-FSE and T2-FSE images were obtainedusing a 1.5-T MR system. Lesions included cerebral ischemia or infarcts (n=23), tumors (n=10), hemorrhages (n=3),inflammatory diseases (n=2), arachnoid cysts (n=2), and vascular disease (n=1), and the MR images wereretrospectively evaluated. To calculate contrast-to-noise ratio (CNR), percentage contrast, and signal-to-noiseratio (SNR)-and thus make a quantitative comparison-the mean signal intensities of lesions, normal brain tissue,and noise outside the patient were measured. For qualitative comparison, the visbility, margin, and extent of thelesions were rated using a five-grade system, and the degree of MR artifacts was also evaluated. Wilcoxon's signedranks test was used for statistical analysis. RESULTS: The mean CNR of lesions was significantly higher on SS-FSE(31.3) than on T2-FSE images (27.5) (p= 0.0131). Mean percentage contrast was also higher on SS-FSE (159.0) thanon T2-FSE images (108.5) (p=0.0222), but mean SNR was higher on T2-FSE (80.3) than on SS-FSE images (53.5)(p=0.0000). No significant differences in lesion visibility were observed between the two imaging sequences,though margin and extent of the lesion were worse on SS-FSE images. For MR artifacts, no significant differenceswere demonstrated. CONCLUSION: For the evaluation of most intracranial lesions, MR imaging using the SS-FSEsequence appears to be slightly inferior to the T2-FSE sequence, but may be useful where patients are ill oruncooperative, or where children require sedation.