Contemporary Imaging and Reporting Strategies for Head-and-Neck Cancer: MRI, FDG PET/MRI, NI-RADS, and Carcinoma of Unknown Primary- AJR Expert Panel Narrative Review.

CT, MRI, and FDG PET/CT play major roles in the diagnosis, staging, treatment planning, and surveillance of head-and-neck cancers. Nonetheless, evolving understanding of head-and-neck cancer pathogenesis, advances in imaging techniques, changing treatment regimens, and lack of standardized guidelines have led to areas of uncertainty in the imaging of head-and-neck cancer. This narrative review aims to address four issues in the contemporary imaging of head-and-neck cancer. The first issue relates to the standard and advanced sequences that should be included in MRI protocols for head-and-neck cancer imaging. The second issue relates to approaches to surveillance imaging after treatment for head-and-neck cancer, including choice of imaging modality, frequency of surveillance imaging, and the role of standardized reporting through the Neck Imaging Reporting and Data System (NI-RADS). The third issue relates to the role of imaging in the setting of neck carcinoma of unknown primary (NCUP). The fourth issue relates to the role of simultaneous PET/MRI in head-and-neck cancer evaluation. The authors of this review provide consensus opinions for each issue.