ACR Neck Imaging Reporting and Data System for MRI Version 2025.

Posttreatment surveillance imaging of head and neck cancers poses substantial interpretation challenges because of the anatomic complexities of the region and because of changes from surgical resection, reconstruction, radiation therapy, and chemotherapy. As a result, there is frequent variability in how individual radiologists report the same imaging findings and in the levels of suspicion for recurrence with which different radiologists view identical imaging findings. In response, the ACR formed the Neck Imaging Reporting and Data System (NI-RADS) Committee in 2016, and an ACR-endorsed NI-RADS reporting paradigm was released in 2018 specific to CT and ¹⁸F-fluorodeoxyglucose PET/CT. More recently, the ACR NI-RADS Committee developed category descriptors, imaging findings, and management guidance specific to MRI to directly address surveillance imaging of those head and neck cancer types best served by this imaging modality. In this article, the authors explain ACR NI-RADS MRI version 2025 by discussing the project rationale and consensus process, illustrating the component features, and summarizing the relevant literature and underlying evidence base.