Purpose: Secretin-stimulated magnetic resonance imaging (s-MRI) and pancreatic diffusion weighted imaging (DWI) are novel non-invasive imaging techniques for assessment of exocrine pancreatic insufficiency (EPI). The aim was to validate s-MRI assessed pancreatic secreted volume using novel semi-automatic quantification software, and to assess the ability of s-MRI with DWI to diagnose EPI in patients with cystic fibrosis (CF).
Methods: s-MRI and DWI was performed in 19 patients with CF (median age 21 years; range 16-56; eight men) and in 10 healthy controls (HC) (median age 46 years; range 20-65; four men). Sequential coronal T2-weighted images covering the duodenum and small bowel and axial DWI were acquired before and 1, 5, 9, and 13 min after secretin stimulation. A short endoscopic secretin test was used as reference method for EPI.
Results: CF patients with EPI had lower apparent diffusion coefficient before secretin in the pancreatic head (P < 0.001) and lower secreted bowel fluid volumes (P = 0.035) compared to HC and CF patients without EPI. ROC curve analyses identified that secreted fluid volume after 13 min yielded the highest diagnostic accuracy for diagnosing EPI (AUC 0.93; 95% CI [0.80-1.00]).
Conclusion: Pancreatic s-MRI is useful for the assessment of exocrine pancreatic function with high diagnostic accuracy for the diagnosis of EPI in CF.
Keywords: Cystic fibrosis; DWI; Exocrine pancreatic insufficiency; Short endoscopic secretin test; s-MRI.