NI-RADS ™ Calculator

NI-RADS Calculator

ACR's Neck Imaging Reporting and Data System NI-RADS ™ categories are designed for use after definitive/curative treatment for H&N 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? *

CT (± PET)

MRI

NI-RADS scoring based on CT ± PET:

Are there prior studies available for comparison? *

Yes

No, but prior imaging exists and will become available later

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) *

Expected posttreatment changes

Non-mass-like soft tissue distortion

Deep tissue mass/mass-like

Superficial mucosal abnormality

Pathologically proven or definite radiologic and clinical progression

How is the FDG* uptake in the soft tissue? *

No abnormal FDG uptake

Mild or moderate FDG uptake

Intense focal FDG uptake

No PET is available

*FDG= fluorine-18-2-fluoro-2-deoxy-D-glucose

How is the border of the mass (or mass like tissue)? *

Ill-defined

Discrete

How is enhancement of the deep tissue? *

Little to no enhancement

Intense (differential) enhancement

What kind of mucosal abnormality is there? *

Post-radiation edema = Low-density submucosal (mucoid) edema

Benign radiation mucositis = Diffuse linear/curvilinear mucosal enhancement

Focal mucosal enhancement (but not mass-like)

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? *

No abnormal FDG uptake

Mild or moderate FDG uptake

Intense focal FDG uptake

No PET is available

*FDG= fluorine-18-2-fluoro-2-deoxy-D-glucose

Are there any growing lymph nodes? *

No, all are residual nodes

Yes, WITHOUT new necrosis or gross extranodal extension

Yes, WITH new necrosis or gross extranodal extension

There is definite pathology/radiology evidence of nodal recurrence

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? *

Yes, there are prior post-treatment studies available for comparison

Yes, but this is the first post-treatment study (i.e post-treatment baseline)

No, but prior imaging exists and will become available later

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? *

Yes

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) *

Unchanged or decreased effacement of fat planes on pre-contrast T1w imaging

Unchanged or decreased enhancement at skull base foramina and in perineural locations

Increased soft tissue and/or enhancement in skull base foramina and perineural regions

Increased effacement of fat planes and skull base foramina on pre-contrast T1WI

Increased enhancement and nodular soft tissue along major nerves supplying the site of primary disease

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) *

Expected post-treatment changes

Diffuse thin linear mucosal enhancement or submucosal edema

Low T1 and T2 signal intensity suggesting scar/fibrosis

Deep, ill-defined non-nodular soft tissue

Focal mucosal enhancement (but not mass-like)

Focal reduced diffusion

Non-mass-like distortion of soft tissues with T2-HYPERINTENSE signal, suggesting edema / inflammation

Non-mass-like distortion of soft tissues with INTERMEDIATE T2 signal and INTERMEDIATE rather than intense enhancement

Is there a mass? *

No new focal nodular or mass-like soft tissue

Discrete nodule or mass at the primary site in which MRI features are different from the original tumor: different DWI, enhancement, or T1 and T2 signal characteristics

Discrete nodule or mass at the primary site AND signal characteristics and enhancement match the original tumor

How is the FDG* uptake in the soft tissue? *

No or mild FDG uptake

Intense focal FDG uptake

No PET is available

*FDG= fluorine-18-2-fluoro-2-deoxy-D-glucose

Primary Site

Which of the following are identified? (select all that apply) *

Decreased soft tissue and/or enhancement in skull base foramina and perineural regions, decreased effacement of fat planes on precontrast T1w imaging

No change in soft tissue in skull base foramina and perineural regions which is of same signal and enhancement characteristics

New thin smooth enhancement in skull base foramina and perineural regions within radiation field

Increased soft tissue and/or enhancement in skull base foramina and perineural regions

Increased effacement of fat planes and skull base foramina on pre-contrast T1WI

Increased enhancement and nodular soft tissue along major nerves supplying the site of primary disease

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) *

Expected post-treatment changes

Diffuse thin linear mucosal enhancement or submucosal edema

Low T1 and T2 signal intensity suggesting scar/fibrosis

Focal mucosal enhancement (but not mass-like)

Focal reduced diffusion

Non-mass-like distortion of soft tissues with T2-HYPERINTENSE signal, suggesting edema / inflammation

Is there a mass? *

Resolution of tumor, with no focal nodular or mass-like soft tissue

Partial resolution of tumor

Discrete nodule or mass at the primary site AND signal characteristics and enhancement match the original tumor

How is the FDG* uptake in the soft tissue? *

No or mild FDG uptake

Intense focal FDG uptake

No PET is available

*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? *

No abnormal FDG uptake

Mild or moderate FDG uptake

Intense focal FDG uptake

No PET is available

*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? *

Enlarging lymph node or discrete neck mass but little to no FDG uptake

Focal FDG uptake with no MRI correlate

Not applicable (primary tumor was not FDG avid)

No, there is no discordance between PET and MRI

Are there any new or enlarging* lymph nodes? *

Yes, WITHOUT irregular borders, new necrosis, or gross extranodal extension†

Yes, WITH irregular borders, new necrosis, or gross extranodal extension†

*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? *

Hypoenhancing nodes (with or without irregular borders) in the region of original node

Persistent areas of heterogeneous enhancement (with or without irregular borders)

Definite enlargement or increased enhancement

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:

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
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.