Integrating Contrast-Enhanced Dark-Light-Dark Sign and MRI Features for Rectal Cancer Lymph Node Diagnosis

< .001). The enhanced model outperformed ESGAR features in subgroups with lymph node short-axis diameters of less than 5 mm (training set: AUC, 0.88 95% CI: 0.85, 0.92; external test set: AUC, 0.90 95% CI: 0.80, 0.96) and pathologic T2 stage (training set: AUC, 0.89 95% CI: 0.84, 0.93; external test set: AUC, 0.91 95% CI: 0.80, 1.00). Conclusion Integrating tumor characteristics-especially the dark-light-dark sign-with ESGAR status improved preoperative LNM diagnosis, particularly in patients with lymph nodes smaller than 5 mm or who had stage T2 tumors. © The Author(s). Published by the Radiological Society of North America under a CC BY 4.0 license.