Pancreatic cysts on MRI: prevalence and factors associated with reporting.

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

METHODS

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.

RESULTS

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).

CONCLUSION

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