Fig. 4

Radiomics nomogram a to predict high-grade BD-IPMNs. The radiomic nomogram was constructed using the rad-score, the CA19–9 level, and the size of the MPD in the data from the training cohort. Calibration for high-grade BD-IPMNs in b the training cohort, c external validation cohort 1, and d external validation cohort 2. The optimal nomogram is indicated by the dotted line reference line. The performance of the radiomics nomogram in high-grade prediction is indicated by the dashed line, and bias in the nomogram is corrected using the solid line