What this calculator does
Supports standardized assessment of findings encountered on low-dose lung cancer screening CT.
Choose the relevant finding pathway, morphology, size, and interval behavior to derive the applicable category.
Before you calculate
- Confirm that the examination belongs to a lung cancer screening program, then identify baseline versus follow-up status.
- Record the correct finding pathway, nodule type, mean diameter or volume, and interval behavior from comparable examinations.
Clinical scope
Use Lung-RADS only for low-dose CT performed in a lung cancer screening program. It standardizes screening findings and management across nodule, airway nodule, atypical pulmonary cyst, and follow-up pathways.
Applicability and exclusions
- Do not use Lung-RADS for a diagnostic CT obtained because of symptoms.
- Incidentally detected nodules outside a screening program require a separate incidental-nodule framework, such as applicable Fleischner guidance.
Method and calculation logic
Choose the finding pathway, nodule composition, mean diameter or volume, and interval behavior. Category 4X can be added when features increase suspicion beyond the base category; the S modifier identifies significant non-lung-cancer findings.
Interpretation table
| Category | General interpretation |
|---|---|
| 0 | Incomplete; comparison or additional evaluation needed |
| 1-2 | Negative or benign-appearing screening result |
| 3 | Probably benign; short-term surveillance pathway |
| 4A-4B | Suspicious to very suspicious |
| 4X | Additional features increase suspicion |
Common failure modes
- Using Lung-RADS for an incidental nodule or a diagnostic CT performed for symptoms.
- Ignoring infectious or inflammatory findings, atypical pulmonary cyst rules, or the separate 4X and S modifiers.
Lung-RADS is a screening assessment and management category, not a diagnosis of lung cancer.
Worked example
Case: Fictional example: a solid pulmonary nodule is identified on a baseline lung cancer screening LDCT.
Calculation: Select baseline examination, solid-nodule pathway, enter the measured size, and record any suspicious features or S modifier.
Interpretation: Confirm the generated category and management interval against the v2022 table, including the exact measurement method.
How to use this calculator
- Complete the visible imaging and measurement fields. Required inputs are marked in the workbench.
- Review the calculated category, score, measurements, and any recommendation or warning.
- Copy the report-ready text only after checking the result against the complete examination and source guideline.
Calculator-specific questions
Can Lung-RADS be used for incidental nodules?
No. It is designed for lung cancer screening CT, not incidental nodules on unrelated examinations.
What does the S modifier mean?
It flags a clinically significant finding unrelated to lung cancer; it does not replace describing that finding and its management in the report.
Are patient measurements sent to RadPhrases?
No. Calculator inputs and results are processed in the browser and are not submitted by this page.