Pancreatic cysts on MRI: prevalence and factors associated with reporting

To assess the prevalence of pancreatic cysts on abdominal MRI and identify factors at the examination, patient, and cyst levels associated with prospective reporting.

In this retrospective single-center study, high-risk individuals (HRIs, per NCCN criteria) and matched average-risk individuals (ARIs) who underwent abdominal MRI from 2018 to 2023 were identified. Pancreatic cysts prospectively documented on original radiology reports were extracted using a validated large language model. MRI examinations without prospectively reported cysts underwent manual image review by three radiology residents to identify additional visible cysts. A composite reference standard combining prospectively reported and retrospectively identified cysts was used to assess overall cyst prevalence. Patient-, cyst-, and examination-level factors associated with prospective reporting were evaluated using univariable and multivariable logistic regression.

The final cohort included 942 patients (314 HRIs, 579 female, mean age 61 ± 10.4 years). Using the composite reference standard, cyst prevalence was 47.9% (451/942), compared with 32.4% (305/942) based on original radiology reports alone. Among the cyst-positive patients identified by the composite reference standard, nearly one-third (32.3%, 146/451) had cysts that were not prospectively reported. Cyst reporting was associated with older age, pancreas-related indication, and larger cyst size: 44.3% of cysts < 5 mm, 77.8% of cysts 5-10 mm, and 95.5% of cysts ≥ 10 mm were reported. HRI status was associated with higher prevalence on unadjusted analysis (OR 1.57 [1.20-2.07], p = 0.001) but not after adjustment for diagnostic-quality MRCP availability (aOR 1.10 [0.82-1.49], p = 0.515).

Pancreatic cysts are common but frequently unreported, particularly when < 5 mm. Reporting is associated with indication, cyst size, and age.