PURPOSE: To evaluate the accuracy of T2-weighted imaging and MR cholangiopancreatography using the single shot fast spin-echo technique for evaluating pancreaticobiliary disease. MATERIALS AND METHODS: B e t ween March and July 1997, axial and coronal T2-weighted images ( T E : 8 0 -2 00 msec) and MR cholangiopancreatograms(TE:800 -1 2 00 msec) were obtained in two ways [single slab (thickness:30 -50 mm) and multislice acquisition under chemical fat saturation] using SSFSE pulse sequencing in 131 cases of suspected pancreati-cobiliary disease. The accuracy of SSFSE MR imaging was assessed in 89 lesions of 74 patients [male,48; female,26; age range, 3 0 -86 (mean,59)years] confirmed surgicopathologically(50 lesions in 39 patients) and clinically (39 lesions in 35 patients). Two radiologists reviewed the MR images and diagnosis was determined by consensus. RESULTS: Correct diagnosis was confirmed in 84 of 89 lesions (94 %). Seven lesions were falsely interpreted, false positive and false negative results accounting for two and five cases, respective l y. Two pancreatic cancers were misdiagnosed as pancreatitis and a cancer of the proximal common bile duct(CBD) was interpreted as a distal CBD cancer. The sensitivity of SSFSE MR imaging for malignancy was 93 %. One CBD stone revealed by endoscopic retrograde cholangiopancreatography (ERCP) was not detected on MR images. In contrast, a stone in the CBD seen on MR images was not apparent on subsequent ERC P. Sensitivity and specificity for calculous disease were 96 % and 99.7 %, respective l y. A benign stricture of the ampulla of Vater was falsely interpreted as normal, and correct diagnosis was possible in two falsely diagnosed cases when MR images were rev i ewed retrospectively. CONCLUSION: The combination of T2-weighted and cholangiographic images using SSFSE is an accurate method for diagnosing pancreaticobiliary diseases.