Interobserver Agreement for CT and MRI Findings of Chronic Pancreatitis in Children: A Multicenter Ancillary Study Under the INSPPIRE Consortium

Abstract

Background: Imaging findings represent key criteria for diagnosing chronic pancreatitis in children. Understanding radiologists’ agreement for imaging findings is critical to standardizing and optimizing diagnostic criteria. Objective: To evaluate the interobserver agreement among experienced pediatric radiologists for subjective, quantitative, and semi-quantitative imaging findings of chronic pancreatitis in children. Methods: In this retrospective study, CT or MRI examinations performed in children with chronic pancreatitis were submitted by six sites participating in the INSPPIRE consortium. One pediatric radiologist from each of the six sites reviewed examinations; three of the radiologists independently reviewed all CT examinations, and the other three radiologists independently reviewed all MRI examinations. Reviewers recorded 13 categorical imaging findings of chronic pancreatitis and measured pancreas thickness and duct diameter. Agreement was assessed using kappa coefficients for the categorical variables and intraclass correlation coefficients (ICC) for the continuous measures. Results: A total of 76 CT and 80 MRI examinations performed in 110 children (mean age, 11.3±4.6 years; 65 girls, 45 boys) were reviewed. For CT, kappa coefficients for categorical findings ranged from −0.01 to 0.81, with relatively high kappa coefficients for parenchymal calcification (κ=0.81), main pancreatic duct dilation (κ=0.63), and atrophy (κ=0.52). ICCs for parenchymal thickness measurements ranged from 0.57 in the pancreas head to 0.80 in the body and tail. ICC for duct diameter was 0.85. For MRI, kappa coefficients for categorical findings ranged from −0.01 to 0.74, with relatively high kappa coefficients for main duct irregularity (κ=0.74), side branch dilation (κ=0.70), number of dilated side branches (κ=0.65), and main duct dilation (κ=0.64); kappa coefficient for atrophy was 0.52. ICCs for parenchymal thickness measurements ranged from 0.59 in the pancreas head to 0.68 in the tail. ICC for duct diameter was 0.77. Conclusion: Interobserver agreement was fair to moderate for most CT and MRI findings of chronic pancreatitis in children. Clinical Impact: This study highlights challenges for the imaging diagnosis of pediatric chronic pancreatitis. Standardized and/or objective criteria are needed given the importance of imaging in diagnosis.