HEPATIC HEMANGIOMAS AND MALIGNANT-TUMORS - IMPROVED DIFFERENTIATION WITH HEAVILY T2-WEIGHTED CONVENTIONAL SPIN-ECHO MR-IMAGING

PURPOSE: To determine whether hemangiomas and malignant tumors can be better differentiated at 1.5-T magnetic resonance imaging with use of more heavily T2-weighted conventional spin-echo sequences. MATERIALS A ND METHODS: Eighty-three patients with focal liver lesions (50 maligna nt tumors, 24 hemangiomas, nine cysts) larger than 1 cm were studied w ith a 3,000/80,160 sequence (repetition time msec/echo time [TE] msec) . T2 relaxation times and lesion/liver signal intensity ratios at TEs of 80 and 160 msec were measured. Receiver operating characteristic (R OC) analyses of expert readers and quantitative measures were performe d. RESULTS: T2 relaxation times demonstrated the best performance in d istinguishing hemangiomas from malignant tumors (area under ROC curve = .99 +/- .01). Mean T2 times were 76 msec +/- 11 for malignant tumors , 142 msec +/- 40 for hemangiomas, and 341 msec +/- 38 for cysts. A cu toff T2 value of 112 msec allowed discrimination between hemangiomas a nd malignant tumors with a 97% accuracy, 100% sensitivity, and 92% spe cificity. CONCLUSION: Hemangiomas and malignant tumors are better diff erentiated with use of T2 relaxation times obtained with a more heavil y T2-weighted sequence.