Lung-RADS v2022
Lung Cancer Screening CT assessment and management
1 Scan Information
2 Nodule Characteristics
Nodule Type
Average of long and short axis
Nodules with benign calcification patterns are classified as Category 2 regardless of size.
3 Suspicious Features (4X Modifier)
About Lung-RADS v2022
Lung-RADS (Lung Imaging Reporting and Data System) is a quality assurance tool developed by the American College of Radiology (ACR) to standardize lung cancer screening CT reporting and management recommendations.
Screening Eligibility (USPSTF 2021)
- Age 50-80 years
- ≥20 pack-year smoking history
- Current smoker OR quit within past 15 years
- No symptoms of lung cancer
Lung-RADS Categories
| Category | Description | Malignancy Risk | Management |
|---|---|---|---|
| 1 | Negative (no nodules) | <1% | Continue annual LDCT |
| 2 | Benign appearance/behavior | <1% | Continue annual LDCT |
| 3 | Probably benign | 1-2% | 6-month LDCT |
| 4A | Suspicious | 5-15% | 3-month LDCT |
| 4B | Very suspicious | >15% | Chest CT, PET-CT, tissue sampling |
| 4X | Suspicious + additional features | Variable | As per 4A/4B + clinical correlation |
Size Thresholds - Solid Nodules
Baseline Screening
| Size | Category |
|---|---|
| <6 mm | 2 |
| 6-8 mm | 3 |
| 8-15 mm | 4A |
| ≥15 mm | 4B |
New Nodule on Follow-up
| Size | Category |
|---|---|
| <4 mm | 2 |
| 4-6 mm | 3 |
| 6-8 mm | 4A |
| ≥8 mm | 4B |
Size Thresholds - Part-Solid Nodules
| Total Size | Solid Component | Category |
|---|---|---|
| <6 mm | Any | 2 |
| ≥6 mm | <6 mm | 3 |
| ≥6 mm | 6-8 mm | 4A |
| ≥6 mm | ≥8 mm | 4B |
Size Thresholds - Ground-Glass Nodules
| Scan Type | Category 2 | Category 3 |
|---|---|---|
| Baseline | <30 mm | ≥30 mm |
| New nodule | <20 mm | ≥20 mm |
4X Modifier
The "X" modifier is added to category 3, 4A, or 4B when additional suspicious features are present:
- Spiculation: Irregular margins with radiating linear strands
- Lymphadenopathy: Enlarged or morphologically suspicious nodes
- Growing nodule: Increase in size compared to prior imaging
- Known malignancy: History of primary cancer (risk of metastasis)
- Part-solid with growing solid component
Benign Calcification Patterns
Nodules with the following calcification patterns are classified as Category 2 regardless of size:
- Complete (diffuse) calcification
- Central calcification
- Laminated (concentric) calcification
- Popcorn calcification (hamartoma)
- Fat-containing nodule (hamartoma)
Key Changes in Lung-RADS v2022
- Adjusted size thresholds based on nodule volume
- Clarified management for atypical adenomatous hyperplasia-like GGNs
- Enhanced guidance for part-solid nodule assessment
- Updated S modifier for incidental findings
References
- American College of Radiology. Lung-RADS v2022 Assessment Categories. ACR; 2022. ACR Lung-RADS
- Kazerooni EA, Armstrong MR, Amorosa JK, et al. ACR CT Accreditation Program and the Lung Cancer Screening Program Designation. J Am Coll Radiol. 2015;12(1):38-42. doi:10.1016/j.jacr.2014.08.016
- McKee BJ, Regis SM, McKee AB, et al. Performance of ACR Lung-RADS in a Clinical CT Lung Screening Program. J Am Coll Radiol. 2016;13(2):R25-R29. doi:10.1016/j.jacr.2015.09.035
- Pinsky PF, Gierada DS, Black W, et al. Performance of Lung-RADS in the National Lung Screening Trial. Ann Intern Med. 2015;162(7):485-491. doi:10.7326/M14-2086
- US Preventive Services Task Force. Screening for Lung Cancer: US Preventive Services Task Force Recommendation Statement. JAMA. 2021;325(10):962-970. doi:10.1001/jama.2021.1117