Pancreas divisum (PD) is the most common developmental anatomic variant of pancreatic duct. The published data on the accuracy of the detection of PD by means of linear-array endoscopic ultrasound (L-EUS) are limited. This study aimed to assess the diagnostic accuracy of L-EUS compared with magnetic resonance cholangiopancreatography (MRCP) for identifying PD.

Patients who underwent L-EUS for pancreaticobiliary indications and subsequently received endoscopic retrograde pancreatograghy (ERP) treatment were retrospectively evaluated from January 2019 to July 2023.

A total of 1378 patients from 3 tertiary centers were included, of which 120 were diagnosed with PD, as confirmed with the use of ERP, yielding an endoscopic detection rate of 8.7%. L-EUS exhibited a high sensitivity of 90.8% (95% confidence interval [CI], 85.7%-96.0%) and an overall accuracy of 99% (95% CI, 98.5%-99.5%) for the diagnosis of PD. These figures were significantly superior to those of MRCP, which showed a sensitivity of 48.4% (95% CI, 38.1%-58.6%) and an accuracy of 95.4% (95% CI, 93.5%-96.3%) (P < .001). Furthermore, the area under the receiver operating characteristic curve (AUC) for PD diagnosis was notably higher for L-EUS (95.7%) compared with MRCP (74.1%) (P < .001). Consistency testing revealed that L-EUS had an excellent kappa value of 0.934, compared with the reference standard of 0.621. Univariate logistic regression analysis identified the presence of pancreatic duct stones, chronic pancreatitis, and severe pancreatitis as potential factors leading to diagnostic failure in detecting PD with the use of L-EUS. Subsequent multivariate logistic regression analysis confirmed that the presence of pancreatic duct stones (odds ratio [OR], 5.627; 95% CI, 1.391-22.765) and severe pancreatitis (OR, 12.818; 95% CI, 2.280-72.061) were significantly associated with increased odds of L-EUS diagnostic failure for PD.

Our study conclusively demonstrates that L-EUS significantly outperforms MRCP in diagnosing PD. L-EUS exhibits markedly higher sensitivity and AUC values. However, its diagnostic reliability decreases in the presence of pancreatic duct stones or severe pancreatitis.