Secretin Improves Visualization of Nondilated Pancreatic Ducts in Children Undergoing MRCP

OBJECTIVE. The objective of our study was to assess whether secretin improves visualization of a nondilated pancreatic duct and whether it increases identification of variant duct anatomy on MRCP in pediatric patients. MATERIALS AND METHODS. This study is a delayed retrospective review of MRCP images that were prospectively obtained of 50 volunteers without a history of pancreatic disease who ranged in age from 6 to 15 years old. MRCP images (coronal 3D fast recovery fast spin-echo [FSE] and coronal single-shot FSE fat-saturated sequences) obtained before and after secretin administration were separated for review by three radiologists (reviewers 1-3). The reviewers were blinded to the purpose of the study and to secretin administration. Reviewers ranked subjective image quality (Likert scale, 1-5 points) and reported pancreaticobiliary duct anatomy and duct visibility (yes or no). Paired t tests were used for comparison of means, and the chi-square test or Fisher exact test was used for comparison of frequencies. Sensitivity and specificity of MRCP images obtained before secretin administration were judged against MRCP images obtained after secretin administration as the reference standard. RESULTS. The frequency of image quality scores of 4 or greater assigned to 3D MRCP images was statistically significantly greater after secretin administration for reviewer 2 (p < 0.0001) and reviewer 3 (p = 0.005) and approached statistical significance for reviewer 1 (p = 0.052). Mean number of visible pancreatic duct segments (head and uncinate, body, tail) was significantly greater on the MRCP images obtained after secretin administration than on those obtained before secretin administration for all reviewers (reviewer 1, 1.9 vs 1.3; reviewer 2, 1.9 vs 1.2; reviewer 3, 1.4 vs 0.8; all, p < 0.01). For all three reviewers, the sensitivity of MRCP images obtained before secretin administration was poor for variant pancreatic ductal anatomy (reviewer 1, 37.5%; reviewer 2, 50.0%; reviewer 3, 40.0%). CONCLUSION. Secretin administration improved subjective MRCP image quality, improved subjective visualization of the pancreatic duct, and provided greater sensitivity for anatomic variants such as pancreas divisum in a cohort of children with nondilated pancreatic ducts.