Assessment value of secretin-enhanced magnetic resonance cholangiopancreatography in the pancreatic duct of 88 patients with chronic pancreatitis

Abstract

Objective To investigate effect of secretin-enhanced magnetic resonance cholangiopancreatography (S-MRCP) on visualization improvement of main and branch pancreatic duct and its diagnostic value of grading chronic pancreatitis (CP). Methods The 3.0 T magnetic resonance (MR) imaging data of 88 subjects (23 health volunteers and 65 CP patients) were prospectively analyzed. All the subjects received coronal T2-weighted sequences scan, thick slab 2-dimensional MRCP sequences scan, routine pancreas plain scan and enhanced scan before and after 0.1 mL/kg secretin intravenous injection. Sixty-five CP patients were grouped according to Cambridge classification and also according to normal and abnormal of duodenal filling (DF). The images of main pancreatic duct (MPD), branch pancreatic duct (BPD) and DF were compared before and after secretin injection. The result was compared with that of endoscopic retrograde cholangio pancreatography (ERCP) which was the gold standard. One-way analysis of variance test was performed for comparison between healthy control group and CP group. Chi-square test was used for comparison between normal DF group and abnormal DF group. The consistence between the diagnostic results of MRCP, S-MRCP and the results of ERCP were analyzed by Kappa test. Results Compare with MRCP, after secretin injection the indexes of MPD, the sensitivity, specificity, positive predictive value and negative predictive value of BPD were all improved, and the rates of misdiagnosis and missed diagnosis all decreased. Using ERCP as gold standard of CP grade diagnosis, the consistence of S-MRCP in CP grade diagnosis increased more significantly (Kappa=0.77, P=0.000 1) compared with that of MRCP (Kappa=0.55, P=0.000 1). Among 43 normal DF cases, the number of MPD dilatation, filling defect and branch duct in pancreatic head was 28, 23 and 30, respectively; among 22 abnormal DF cases which was 20, 19 and 21, respectively, and the differences were statistically significant (χ2=5.01, 3.91, 6.88 and 4.26, all P<0.05). Taking 4 min as the cutoff value of peak time, the sensitivity and specificity of which in CP diagnosis were 86.0% and 100.0%, respectively. Conclusion S-MRCP improves the visualization of MPD and BPD, and also increases the accuracy of CP grade diagnosis. Key words: Cholangiopancreatography, magnetic resonance; Cholangiopancreatography, endoscopic retrograde; Pancreatitis, chronic