Lung-RADS v2022 calculator
Lung-RADS applies to low-dose CT done within a screening programme. For an incidental nodule on a diagnostic CT you want Fleischner instead — the thresholds differ because the populations do.
Scope. Lung-RADS applies ONLY to low-dose CT performed within a lung cancer screening programme. An incidentally detected nodule on a diagnostic CT is a Fleischner problem, not a Lung-RADS one — the populations, and therefore the size thresholds, are different.
Categories, risk and management
| Category | Meaning | Malignancy | Management |
|---|---|---|---|
| 0 | Incomplete | n/a | Additional imaging and/or prior chest CT needed before the study can be categorised. |
| 1 | Negative | <1% | Continue annual screening LDCT in 12 months. |
| 2 | Benign | <1% | Continue annual screening LDCT in 12 months. |
| 3 | Probably benign | 1-2% | 6-month follow-up LDCT. |
| 4A | Suspicious | 5-15% | 3-month LDCT. PET/CT may be used when there is a solid component of 8 mm or more. |
| 4B | Very suspicious | >15% | Diagnostic chest CT with or without contrast, PET/CT and/or tissue sampling depending on the probability of malignancy and comorbidity. |
| 4X | Very suspicious with additional features | >15% | Category 3 or 4 nodule with additional imaging findings that increase suspicion — manage as 4B. |
Modifiers
- S — Significant or potentially significant non-lung-cancer finding. Added to any category; does not change the lung-cancer management.
- C — Prior diagnosis of lung cancer returning to screening.
Size thresholds at a glance
| Type | Baseline | New or growing |
|---|---|---|
| Solid | <6 mm = 2 · 6–<8 = 3 · 8–<15 = 4A · ≥15 = 4B | <4 mm = 2 · 4–<6 = 3 · 6–<8 = 4A · ≥8 = 4B |
| Part-solid | total <6 mm = 2 · solid <6 = 3 · solid 6–<8 = 4A · solid ≥8 = 4B | total <6 mm = 3 · solid <4 = 4A · solid ≥4 = 4B |
| Ground-glass | <30 mm = 2 · ≥30 mm = 3 | same |
Related
- Lung-RADS or Fleischner? Picking the right pathway
- Fleischner calculator — for incidental nodules
- All radiology calculators
Source. American College of Radiology, Lung-RADS v2022. View the ACR document
This is a reference implementation of a published guideline, for use by qualified clinicians. It does not account for patient-specific factors and is not a substitute for clinical judgment or a formal radiology consultation. See our full disclaimer.