# NI-RADS — ACR Neck Imaging Reporting and Data System

> Post-definitive-treatment surveillance framework assigning primary-site and neck categories separately: 0 incomplete, 1 no evidence, 2 low suspicion with primary 2a/2b branches, 3 high suspicion and 4 proven or definite progression. P-x/N-x and unknown-primary states are qualifiers, not ordinal scores. The category supports standardized next-step communication but does not diagnose recurrence, collapse P and N, or supply a universal patient-level recurrence probability.

**Situação:** vigente · **Órgão:** Cabeça e pescoço · **Órgão emissor:** American College of Radiology · **Versão:** 2018 CT/PET framework; MRI v2025 current release · **Ano:** 2025

## Procedência e vigência
- Família: léxico
- Tipo de lógica: flat
- Modalidade: CT, MRI, PET/CT
- Fonte primária: Aiken AH, et al.. Neck Imaging Reporting and Data System MRI: A Standardized Template for Posttreatment Head and Neck Cancer Surveillance (2025) — https://edge.sitecorecloud.io/americancoldf5f-acrorgf92a-productioncb02-3650/media/ACR/Files/RADS/NI-RADS/NIRADS-MRI-2025-Assessment-Categories.pdf
- Última verificação: 2026-07-24
- Última checagem: 2026-08-12

## Lógica de decisão
Return separate P and N assessments, preserve modality/release, and never turn suspicion into pathology, a universal recurrence probability or an autonomous treatment order.

## Categorias

| Código | Rótulo | Critérios | Conduta | Risco | Localizador | Verificado |
| --- | --- | --- | --- | --- | --- | --- |
| 0 | Incomplete comparison | Incomplete comparison for a new posttreatment baseline when a required prior examination is known or expected to become available. This is distinct from P-x or N-x technical nonassessability. | Obtain the required prior study and issue an addendum after comparison. Do not treat category 0 as a negative surveillance result, low suspicion or a reason to restart the surveillance interval. | Category 0 carries no recurrence-risk meaning because the comparison needed for classification is incomplete. It must not be converted into a numerical probability or combined with the other axis. | ACR NI-RADS MRI v2025 Assessment Categories table, category 0 row and x-qualifier footnotes; official current-release index. | ✓ |
| 1 | No evidence of recurrence | No evidence of recurrence at the assessed primary site or neck: normal or expected posttreatment anatomy and change without a suspicious focal mucosal, deep or nodal abnormality. | Continue routine surveillance according to tumor type, treatment, elapsed time and the institutional care pathway. Return primary-site and neck assessments separately even when both are category 1. | Category 1 communicates no current imaging suspicion, not zero lifetime or microscopic recurrence risk. No universal negative predictive value can be transferred across sites, modalities, timepoints and populations. | ACR NI-RADS MRI v2025 Assessment Categories table, primary-site and neck category 1 rows; Aiken et al. 2018 CT/PET framework. | ✓ |
| 2 | Low suspicion | Low suspicion. At the primary site, 2a is a focal non-mass-like mucosal enhancement or focal reduced-diffusion abnormality suitable for direct inspection, whereas 2b is a deep ill-defined nonnodular abnormality. In the neck, category 2 includes equivocal residual enhancement or uptake, a new or enlarging node without definitively malignant morphology, or meaningful modality discordance. | For primary 2a, recommend direct visual or endoscopic inspection. For primary 2b, recommend short-interval imaging, with MRI favored when perineural or skull-base disease is the concern. For neck 2, recommend short-interval imaging integrating morphology, diffusion, FDG activity and trajectory. Do not collapse these branches into one generic action. | Category 2 is a qualitative low-suspicion state spanning distinct mucosal, deep and nodal patterns; it has no single portable recurrence percentage. The branch, modality, timing and treated cancer determine the useful context. | ACR NI-RADS MRI v2025 Assessment Categories table, primary-site 2a and 2b rows and neck category 2 row; Aiken et al. 2018 for CT/PET-linked management. | ✓ |
| 3 | High suspicion | High suspicion based on a discrete enhancing mass matching the tumor bed, intense focal FDG uptake compatible with tumor, progressive perineural abnormality, or a highly suspicious and concordantly progressive nodal finding. | Recommend image-guided or clinical biopsy when clinically indicated and technically feasible, with multidisciplinary review when the site is inaccessible, biopsy is contraindicated or radiologic and clinical evidence is otherwise decisive. Category 3 remains suspicion rather than proof. | Category 3 has high imaging suspicion but does not equal pathology and cannot provide an individual recurrence probability. Inflammation, treatment effect, second malignancy and technical discordance remain possible explanations. | ACR NI-RADS MRI v2025 Assessment Categories table, primary-site and neck category 3 rows; 2018 ACR white paper for linked biopsy recommendation. | ✓ |
| 4 | Pathologically proven or definite progression | Pathologically proven residual or recurrent tumor, or definite radiologic progression supported by concordant clinical evidence when the multidisciplinary team determines that tissue confirmation is unnecessary or infeasible. | Route to multidisciplinary clinical management while separately reporting exact site, extent, proof basis and complications. Category 4 does not select a systemic regimen, operation, radiation plan or prognosis. | Category 4 records known or definite disease rather than a probabilistic suspicion band, but disease extent, treatment options and patient outcome still cannot be inferred from the numeral alone. | ACR NI-RADS MRI v2025 Assessment Categories table, category 4 rows; Aiken et al. 2018 for known-recurrence management context. | ✓ |

### Citações por categoria
- **0**: Aiken AH, et al.. Neck Imaging Reporting and Data System MRI: A Standardized Template for Posttreatment Head and Neck Cancer Surveillance (2025) — https://edge.sitecorecloud.io/americancoldf5f-acrorgf92a-productioncb02-3650/media/ACR/Files/RADS/NI-RADS/NIRADS-MRI-2025-Assessment-Categories.pdf · ACR NI-RADS MRI v2025 Assessment Categories table, category 0 row and x-qualifier footnotes; official current-release index.
- **1**: Aiken AH, et al.. Neck Imaging Reporting and Data System MRI: A Standardized Template for Posttreatment Head and Neck Cancer Surveillance (2025) — https://edge.sitecorecloud.io/americancoldf5f-acrorgf92a-productioncb02-3650/media/ACR/Files/RADS/NI-RADS/NIRADS-MRI-2025-Assessment-Categories.pdf · ACR NI-RADS MRI v2025 Assessment Categories table, primary-site and neck category 1 rows; Aiken et al. 2018 CT/PET framework.
- **2**: Aiken AH, et al.. Neck Imaging Reporting and Data System MRI: A Standardized Template for Posttreatment Head and Neck Cancer Surveillance (2025) — https://edge.sitecorecloud.io/americancoldf5f-acrorgf92a-productioncb02-3650/media/ACR/Files/RADS/NI-RADS/NIRADS-MRI-2025-Assessment-Categories.pdf · ACR NI-RADS MRI v2025 Assessment Categories table, primary-site 2a and 2b rows and neck category 2 row; Aiken et al. 2018 for CT/PET-linked management.
- **3**: Aiken AH, et al.. Neck Imaging Reporting and Data System MRI: A Standardized Template for Posttreatment Head and Neck Cancer Surveillance (2025) — https://edge.sitecorecloud.io/americancoldf5f-acrorgf92a-productioncb02-3650/media/ACR/Files/RADS/NI-RADS/NIRADS-MRI-2025-Assessment-Categories.pdf · ACR NI-RADS MRI v2025 Assessment Categories table, primary-site and neck category 3 rows; 2018 ACR white paper for linked biopsy recommendation.
- **4**: Aiken AH, et al.. Neck Imaging Reporting and Data System MRI: A Standardized Template for Posttreatment Head and Neck Cancer Surveillance (2025) — https://edge.sitecorecloud.io/americancoldf5f-acrorgf92a-productioncb02-3650/media/ACR/Files/RADS/NI-RADS/NIRADS-MRI-2025-Assessment-Categories.pdf · ACR NI-RADS MRI v2025 Assessment Categories table, category 4 rows; Aiken et al. 2018 for known-recurrence management context.

## Histórico de versões

| Data | Evento | Detalhe | Situação |
| --- | --- | --- | --- |
| 2026-07-24 | revised | Monitored source changed (content_hash). Detected automatically; awaiting reviewer confirmation. | dismissed |
| 2026-07-23 | revised | Monitored source changed (content_hash). Detected automatically; awaiting reviewer confirmation. | dismissed |
| 2026-07-21 | revised | Monitored source changed (content_hash). Detected automatically; awaiting reviewer confirmation. | dismissed |
| 2026-07-20 | revised | Monitored source changed (content_hash). Detected automatically; awaiting reviewer confirmation. | dismissed |
| 2026-07-19 | revised | Monitored source changed (content_hash). Detected automatically; awaiting reviewer confirmation. | dismissed |
| 2026-07-18 | revised | Monitored source changed (content_hash). Detected automatically; awaiting reviewer confirmation. | dismissed |
| 2026-07-17 | revised | Monitored source changed (content_hash). Detected automatically; awaiting reviewer confirmation. | dismissed |
| 2026-07-16 | revised | Monitored source changed (content_hash). Detected automatically; awaiting reviewer confirmation. | dismissed |
| 2026-07-15 | revised | Monitored source changed (content_hash). Detected automatically; awaiting reviewer confirmation. | dismissed |
| 2026-07-10 | revised | Monitored source changed (content_hash). Detected automatically; awaiting reviewer confirmation. | dismissed |
| 2026-07-08 | revised | Monitored source changed (content_hash). Detected automatically; awaiting reviewer confirmation. | dismissed |
| 2026-07-07 | revised | Monitored source changed (content_hash). Detected automatically; awaiting reviewer confirmation. | dismissed |
| 2026-07-05 | revised | Monitored source changed (content_hash). Detected automatically; awaiting reviewer confirmation. | dismissed |
| 2026-06-30 | revised | Monitored source changed (content_hash). Detected automatically; awaiting reviewer confirmation. | dismissed |
| 2026-06-29 | revised | Monitored source changed (content_hash). Detected automatically; awaiting reviewer confirmation. | dismissed |
| 2026-06-25 | revised | Monitored source changed (content_hash). Detected automatically; awaiting reviewer confirmation. | dismissed |
| 2026-06-24 | revised | Monitored source changed (content_hash). Detected automatically; awaiting reviewer confirmation. | dismissed |
| 2025-07-01 | revised | ACR published the current MRI v2025 template and assessment-category table, including category 0, separate primary and neck axes, primary 2a/2b branches and x qualifiers. | confirmed |
| 2018-08-01 | published | The ACR NI-RADS Committee published the CT and PET/CT posttreatment surveillance white paper with linked primary-site and neck categories and management recommendations. | confirmed |


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> Conteúdo de referência reescrito. Confira a publicação primária vigente. Não é dispositivo médico nem substitui o julgamento clínico. O radiologista responsável pelo laudo permanece o autor e o responsável.

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