NI-RADS Calculator

ACR's Neck Imaging Reporting and Data System NI-RADS ™ categories are designed for use after definitive/curative treatment for head and neck cancer, and are not to be used during treatment
Please note:

  • This calculator will generate two different NI-RADS scores for neck lymph nodes and the primary site. If the scores don't match, consider the higher one for the final recommendation.

  • This calculator does not include the "X- modifier":

    • If the primary tumor is unknown, then the authors suggest designating “P-unknown primary”; if the primary cannot be assessed (dental artifact, motion, other technical reasons, or outside FOV), then the authors suggest “P-x

    • Head and neck cancer surveillance MR examinations are often tailored to a specific area of concern (e.g. skull base for perineural tumor spread), in which case the entire neck may not be imaged. If the neck cannot be assessed, then the authors suggest "N-x." 

NI-RADS Main
Which imaging modality do you want to use for scoring?

NI-RADS scoring based on CT ± PET:

Are there prior studies available for comparison?

NI-RADS 0 = Incomplete

Recommendation: Assign score in addendum after prior imaging examinations become available

Primary Site

Which of the following are identified? (select all that apply)
How is the FDG* uptake in the soft tissue?
*FDG= fluorine-18-2-fluoro-2-deoxy-D-glucose
How is the border of the mass (or mass like tissue)?
How is enhancement of the deep tissue?
What kind of mucosal abnormality is there?

NI-RADS Primary 1 = No evidence of recurrence

Recommendation: Routine surveillance

NI-RADS Primary 2a = Low suspicion

Recommendation: Direct clinical inspection

NI-RADS Primary 2b = Low suspicion

Recommendation: Short-interval follow-up (3 months)

NI-RADS Primary 2b = Low suspicion

Recommendation: Perform PET or Short-interval follow-up (3 months)

NI-RADS Primary 3 = High suspicion

Recommendation: Image guided or clinical biopsy if clinically indicated

NI-RADS Primary 4 = Definitive primary site recurrence

Recommendation: Clinical management (treatment of disease with or without biopsy)

Neck nodes

How is the FDG* uptake in the neck lymph nodes?
*FDG= fluorine-18-2-fluoro-2-deoxy-D-glucose
Are there any growing lymph nodes?

NI-RADS Neck 1 = No evidence of recurrence

Recommendation: Routine surveillance

NI-RADS Neck 2 = Low suspicion

Recommendation: Short-interval follow-up (3 months)

NI-RADS Neck 2 = Low suspicion

Recommendation: Perform PET or Short-interval follow-up (3 months)

NI-RADS Neck 3 = High suspicion

Recommendation: Image guided or clinical biopsy if clinically indicated

NI-RADS Neck 4 = Definitive nodal recurrence

Recommendation: Clinical management (treatment of disease with or without biopsy)

NI-RADS scoring based on MRI:

Are there prior studies available for comparison?

NI-RADS 0 = Incomplete

Recommendation: Assign score in addendum after prior imaging examinations become available
Is there pathologically proven or definite radiologic and clinical evidence of progression?

NI-RADS 4 = Definitive recurrence

Recommendation: Clinical management (treatment of disease with or without biopsy)

Primary Site

Which of the following changes are identified? (select all that apply)
Potential pitfall: Be familiar with the appearance of flaps, which often have different enhancement and signal characteristics than the original tumor.
Are there any mucosal abnormalities? (select all that apply)
Is there a mass?
How is the FDG* uptake in the soft tissue?
*FDG= fluorine-18-2-fluoro-2-deoxy-D-glucose

Primary Site

Which of the following are identified? (select all that apply)
Potential pitfall: Be familiar with the appearance of flaps, which often have different enhancement and signal characteristics than the original tumor.
On the first post-treatment MRI, skull base foramina and perineural findings are indeterminate (in the absence of features suspicious for residual or progressive tumor described under NI-RADS 2 and 3) and can be presumed to be post- treatment related and assigned NI-RADS 1, until further assessment on the next MRI
Are there any mucosal abnormalities? (select all that apply)
Is there a mass?
How is the FDG* uptake in the soft tissue?
*FDG= fluorine-18-2-fluoro-2-deoxy-D-glucose

NI-RADS Primary 1 = No evidence of recurrence

Recommendation: Routine surveillance

NI-RADS Primary 1f = No evidence of recurrence

Recommendation: Routine surveillance

NI-RADS Primary 2a = Low suspicion

Recommendation: Direct clinical (visual) inspection

NI-RADS Primary 2b = Low suspicion

Recommendation: Short-interval follow-up (3 months) MRI or PET to assess deep submucosal abnormality or questionable nodes.
Note: PET is not as helpful for evaluation of perineural disease at the skull base. As such, for a Primary 2b or 2f related to perineural soft tissue, short interval follow-up MRI would be preferable over PET.

NI-RADS Primary 2f = Low suspicion

Recommendation: Short-interval follow-up (3 months) MRI or PET to assess deep submucosal abnormality or questionable nodes.
Note: PET is not as helpful for evaluation of perineural disease at the skull base. As such, for a Primary 2b or 2f related to perineural soft tissue, short interval follow-up MRI would be preferable over PET.

NI-RADS Primary 3 = High suspicion

Recommendation: Image guided or clinical biopsy if clinically indicated

Neck nodes

How is the FDG* uptake in the neck lymph nodes?
*FDG= fluorine-18-2-fluoro-2-deoxy-D-glucose
If the primary tumor was FDG avid, is any of the following true about this scan?
Are there any new or enlarging* lymph nodes?
*New or enlarging node = Node that newly develops or grows during the course of surveillance (node not present or smaller on pre-treatment scan.
† This is in contradistinction to irregular borders or necrosis in nodes unchanged or decreasing in size following radiation treatment, which are considered expected post-treatment findings in radiated nodes.
How are the residual lymph nodes lymph nodes?
*New or enlarging node = Node that newly develops or grows during the course of surveillance (node not present or smaller on pre-treatment scan.
† This is in contradistinction to irregular borders or necrosis in nodes unchanged or decreasing in size following radiation treatment, which are considered expected post-treatment findings in radiated nodes.

NI-RADS Neck 1 = No evidence of recurrence

Recommendation: Routine surveillance

NI-RADS Neck 2 = Low suspicion

Recommendation: Short interval follow-up MRI or PET to assess deep
submucosal abnormality or questionable nodes.

NI-RADS Neck 3 = High suspicion

Recommendation: Image guided or clinical biopsy if clinically indicated

NI-RADS Neck 4 = Definitive nodal recurrence

Recommendation: Clinical management (treatment of disease with or without biopsy)

References:
  1. Aiken, A. H., Rath, T. J., Anzai, Y., Branstetter, B. F., Hoang, J. K., Wiggins, R. H., Juliano, A. F., Glastonbury, C., Phillips, C. D., Brown, R., & Hudgins, P. A. (2018). ACR Neck Imaging Reporting and Data Systems (NI-RADS): A White Paper of the ACR NI-RADS Committee. Journal of the American College of Radiology : JACR, 15(8), 1097–1108. https://doi.org/10.1016/j.jacr.2018.05.006
  2. Aiken AH, Hudgins PA. Neck Imaging Reporting and Data System. Magn Reson Imaging Clin N Am. 2018;26(1):51-62. doi:10.1016/j.mric.2017.08.004

Click here to visit ACR's page for NI-RADS.

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More about the NI-RADS™ Calculator:

The Neck Imaging Reporting and Data System (NI-RADS™) is a standardized reporting framework developed by the American College of Radiology (ACR) to improve the post-treatment surveillance of head and neck cancers. Introduced in 2017, NI-RADS™ provides a structured approach for interpreting imaging studies, facilitating clear communication between radiologists and clinicians, and guiding management decisions based on the likelihood of disease recurrence.

NI-RADS™ is primarily utilized in the evaluation of patients who have undergone definitive treatment for head and neck malignancies, including squamous cell carcinomas of the aerodigestive tract, salivary gland tumors, sinonasal tumors, orbital tumors, and thyroid cancers. The system is applicable across various imaging modalities, including contrast-enhanced computed tomography (CECT), magnetic resonance imaging (MRI), and positron emission tomography (PET), allowing for consistent assessment regardless of the imaging technique employed.

NI-RADS™ Categories and Management Recommendations

NI-RADS™ categorizes imaging findings into five distinct categories, each associated with specific imaging characteristics and corresponding management strategies:

  • NI-RADS 0 (Incomplete): Indicates that prior imaging is unavailable but is expected to become available for comparison. A definitive category will be assigned once prior imaging is reviewed.
  • NI-RADS 1 (No Evidence of Recurrence): Reflects expected post-treatment changes without any suspicious findings. Routine surveillance is recommended.
  • NI-RADS 2 (Low Suspicion for Recurrence): Suggests findings that are likely benign but warrant closer follow-up. This category is subdivided into:
    • 2a: Superficial mucosal abnormalities or focal mucosal FDG uptake; recommend direct visual inspection.
    • 2b: Deep, ill-defined abnormalities with mild to moderate FDG uptake; suggest short-interval follow-up imaging or immediate PET.
  • NI-RADS 3 (High Suspicion for Recurrence): Denotes new or enlarging masses with imaging features suggestive of recurrence, such as intense focal FDG uptake. Biopsy is typically recommended.
  • NI-RADS 4 (Definitive Recurrence): Indicates pathologically proven recurrence or definitive radiologic and clinical progression. Appropriate clinical management should be initiated.
Clinical Utility and Benefits

The implementation of NI-RADS™ in clinical practice offers several advantages:

  • Standardization: Provides a consistent framework for interpreting and reporting imaging findings, reducing variability among radiologists.
  • Enhanced Communication: Facilitates clear and concise communication between radiologists and the multidisciplinary care team, aiding in timely and appropriate decision-making.
  • Guided Management: Links imaging findings to specific management recommendations, streamlining patient care pathways.
  • Research and Quality Improvement: Encourages data collection and analysis for research purposes and continuous quality improvement initiatives.

By integrating NI-RADS™ into routine imaging interpretation, healthcare providers can improve the accuracy of post-treatment surveillance, ensure early detection of recurrences, and enhance overall patient outcomes in head and neck cancer care.

For more detailed information and resources on NI-RADS™, please visit the American College of Radiology NI-RADS™ page.

Table of contents

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  1. NI-RADS Calculator
    1. References:
  3. Related Calculators:
    1. More about the NI-RADS™ Calculator:
      1. NI-RADS™ Categories and Management Recommendations
      2. Clinical Utility and Benefits