In our development dataset, the inclusion of participants who underwent direct surgery and the establishment of 3D node maps based on localization on MRI ensured the direct and precise node-by-node matching between MRI and pathology, thus providing a more reliable reference for the nodal radiological evaluation.

    The broken-ring and tail sign were derived from the CSE [8, 9], which was proposed to identify carcinoma within the node previously, and the “flare” sign, which was an important diagnostic indicator for ENE in the neck [13, 14], respectively. Both newly-proposed signs showed promising performance in detecting ENE.

    In the validation cohort, where all patients underwent TME after neoadjuvant therapy, patients with MRI-detected ENE-positive nodes before treatment still experienced worse prognoses than those without, indicating that MRI-detected ENE status could be considered as an indicator for more aggressive treatment.

    To detect ENE earlier, a process comprised of multiparametric characteristics was established, yielded an excellent diagnostic performance and showed important prognostic value. Nevertheless, it should be validated on the nodal level externally and its ability to guide treatment needs to be verified in the future.