Neck Imaging Reporting and Data System (NI-RADS) Introduction

In this video, Dr. Katie Bailey walks us through an overview of the Neck Imaging Reporting and Data System (NI-RADS) system, including why it was created and a basic overview of the principles and categorization. You can learn more about the American College of Radiology (ACR) NI-RADS system from the ACR website. In this talk, we will walk through some NI-RADS categories, show examples of each, and go through a practice case.


NI-RADS was designed to standardize surveillance and follow-up recommendations for tumors of the head/neck and aerodigestive track, including the oral cavity, nasal cavidy, nasopharynx, oropharynx, hypopharynx, and larynx. Most of these are squamous cell cancers but some, such as salivary gland, orbital, and sinonasal tumors are also included.

NI-RADS categories

NI-RADS categories include the primary tumor site and neck to look for recurrence. There are categories from 0-4 depending on the level of suspicion. Each category has a recommended management decision associated with it. Some of the categories are split into subcategories.


Category 1 includes includes expected post-surgical changes and nothing concerning or masslike. Sometimes you can have linear enhancement or mucosal edema, but you definitely don’t have nodular or masslike disease. If you have PET, there will be minimal or no uptake. These patients can have expected follow-up.


In category 2a, there can be come focal mucosal enhancement, but it would be unlikely to be masslike. If there is FDG-PET, it would be mild to moderate uptake only. These patients may need direct inspection by scope.


Category 2b may have some ill-defined enhancement in the deep soft tissues. This distinction is important because any abnormal soft tissue may not be visible along the mucosa, so scoping will not be useful. These patients likely need a short-term follow-up.


NI-RADS 3 has a new or enlarging primary mass or lymph node. These tend to be nodular or masslike and probably have intense focal uptake on PET. These patients probably need a biopsy.


Category 4 is for pathologically proven or definite radiologic and/or clinical progression. Because this is definitive progression, these patients need new clinical management or treatment. On follow-up imaging, you may find new disease in a new or distant location. This would be described separately.

Practice case

This practice case is a maxillary sinus squamous cell carcinoma. The initial tumor is very extensive. The first posttreatment scan shows postsurgical changes, with a very small area of focal FDG uptake posterior to the flap. The MRI is very reassuring with no masslike or suspicious enhancement. However, because of the deep PET uptake, we’ll call this a 2b so that it gets short term follow-up.

On the short-term follow-up, the area of nodular enhancement seen previously has worsened considerably, and there is a great deal more involvement of the skull base and adjacent structures. The FDG-PET is very highly avid. We will call this a category 4.


In summary, we show a flow-chart with the NI-RADS categories so you can quickly review. Hopefully this helps your review of post-treatment head and neck cases go more smoothly.

Be sure to check out the other videos on other head and neck topics or the head and neck YouTube Playlist

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