Sphincter of Oddi manometry (SOM) is the standard method of diagnosing SOD. SOM is invasive, can be technically difficult and associated with complications. MRCP with CCK stimulation may provide useful information relating to sphincter of Oddi function. AIM: Evaluate the sensitivity/specificity of CCK-MRCP in predicting the results of SOM in patients with clinically suspected SOD (type III). METHOD: Data from consecutive patients referred for SOM who had CCK-MRCP prior to SOM were analyzed. All MRCP studies were reported by one radiologist who was blinded to the findings of SOM. Patients with prior therapy to the papilla or known pancreaticobiliary malignancy or stricture were excluded. Equivocal/failed MRCP or SOM were excluded from analysis. SOM was performed using a standard 5 F perfused, aspirating catheter (Wilson-Cook, Winston-Salem, NC); SOD was diagnosed if the mean pressure from two leads was greater or equal to 40 mmHg. MRCP was performed with oblique coronal singleshot breath-hold, 5cm slabs (8000/150//135), FOV-24 cm. Scans were performed before and 20 mins after initiation of the CCK infusion (0.02mcg/Kg, in 6ml saline, 0.1ml/sec). CCK-MRCP was abnormal if the common bile duct increased in diameter post-CCK. RESULTS: Of 25 patients (mean age 38yrs., range7-74yrs, M/F=5/20), 18 biliary and 18 pancreatic SOM studies were analyzed; CCK-MRCP was inadequate in 2 patients. Of all 12 patients, CCK MRCP was abnormal in 4 of 6 patients with abnormal biliary SOM (sensitivity 67%) and was normal in 7 of 12 patients with normal biliary SOM (specificity 58%). Of the 5 patients with an intact gallbladder, CCK-MRCP was normal in all 3 patients with normal biliary SOM and abnormal in both patients with abnormal biliary SOM. The sensitivity and specificity of CCK-MRCP in predicting abnormal biliary SOM in post- cholecystectomy patients was 50% and 44 % respectively. There was no association between pancreatic SOM and CCK-MRCP. CONCLUSION: 1] The overall sensitivity and specificity of CCK-MRCP in predicting abnormal biliary SOM was 67% and 58% respectively. 2] The sensitivity and specificity were 100% in the small sub-group of 5 patients with the gallbladder in situ. This study is on-going to further evaluate these novel findings.