Role of volumetric multiparametric MRI in distinguishing between intraductal papillary mucinous neoplasms and serous cystadenoma

Purpose: To evaluate the use of volumetric multiparametric MRI in differentiating pancreatic intraductal papillary mucinous neoplasms (IPMNs) from serous cystadenomas (SCAs) Methods: Included patients (123 patients with pancreatic cystic neoplasms (PCNs) measuring ≥ 10 mm) were stratified into two groups based on cyst type. Axial cyst size, region of interest (ROI)-based apparent diffusion coefficient (ADC) and volumetric data, including cyst volume, volumetric apparent diffusion coefficient (vADC), and volumetric venous enhancement (vVE) were extracted and compared between the two groups. Univariate and multiple logistic regression was used to develop models for distinguishing between IPMNs and SCAs. Results: Volume and size of the cysts, vVE and vADC and ROI-ADC were significantly different between the two groups. Cyst volume was significantly larger in SCAs (median = 14.1cm³, IQR 3.5–42.5) than in IPMNs (median = 2.5 cm³, IQR 1.1–6) (p < 0.001). IPMNs had a higher volumetric ADC value in comparison to SCAs (2925 ± 294 × 10^–6 mm²/s vs 2521 ± 202 × 10^–6 mm²/s, p < 0.001). However, IPMNs had lower vVE values compared to SCAs (37 signal intensity (SI) vs 86 SI, p < 0.001). Area under the ROC Curve (AUC) of the model that included vADC and cyst volume had 95% accuracy in distinguishing between the two groups. In comparison, the AUC of the model that included ROI-ADC and axial cyst size had 84% accuracy in distinguishing between the two groups. A threshold of 2615 × 10⁻⁶ mm²/s for volumetric ADC resulted in the identification of IPMNs from SCAs with sensitivity and specificity of 90.8% and 73.5%, respectively. Conclusion: IPMNs had smaller cyst volume, higher volumetric ADC and lower volumetric VE values compared to SCAs. Volumetric multiparametric MRI could be useful in differentiating between the IPMN and SCA groups.