The short answer
Lung-RADS is the scoring system radiologists use on lung cancer screening CT scans. Each scan gets a category based on the most concerning finding. A higher category means more checking is needed. NCI reports that most positive screening CTs do not turn out to be lung cancer.
Lung-RADS gives a screening CT a category based on the findings seen on the scan.
NCI reports that Lung-RADS criteria are stricter than the criteria used in the National Lung Screening Trial to call a scan positive.
NCI reports that most positive screening CTs do not turn out to be lung cancer. Ask your care team what your category means for you.
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This page is for anyone whose lung cancer screening CT report gives a Lung-RADS category. It explains what the term means, what a positive screen does and does not tell you, and what to ask your care team.
What Lung-RADS is
Lung-RADS is a set of criteria used to assess findings on low-dose CT (LDCT) scans done to screen for lung cancer. NCI notes these criteria are in wide use in the United States. The radiologist uses them to place your scan in a category.
Your report will name the category. This page does not list what each category means or how soon each follow-up scan is due, because we could not confirm those details in an NCI, CDC or other approved source. Your radiologist or care team can tell you what your category means and what comes next.
Positive screens are often not cancer
A positive screen means more checking is needed. It does not mean you have cancer.
NCI reports that in the National Lung Screening Trial (NLST), 3.6% of people whose LDCT was positive were found to have lung cancer. NCI also states that the Lung-RADS criteria are stricter than the NLST criteria for calling a screen positive, and may lower the false-positive rate seen in that trial.
Why the next scan matters
A finding is often judged by comparing it with earlier scans. If you change screening centers, ask that your earlier scans be sent. Keep your follow-up appointments, and ask who books the next scan and when it is due.
When to call sooner
If you have new or worsening symptoms before your next scan, such as coughing up blood, call your care team right away rather than waiting. For severe trouble breathing or heavy bleeding, call 911.
Ask these before you leave
- What category did I get, and which finding set it?
- When is my next scan, and who books it?
- Is there an older CT to compare with?
- What would make you want to see me sooner?
Related pages
See Lung Nodules Found During Screening, What Does Pulmonary Nodule Mean?, and Lung Cancer Screening.
Sources
Common questions
What is Lung-RADS?
It is a system for describing what a low-dose CT lung screening scan shows. NCI notes the criteria are widely used in the United States.
Does a positive screen mean I have lung cancer?
No. NCI reports that in the National Lung Screening Trial, 3.6% of people with a positive low-dose CT had lung cancer. Lung-RADS criteria may lower the false-positive rate seen in that trial.
What happens after my Lung-RADS result?
The next step depends on your category and your scan. It may be a routine screening scan, a repeat scan sooner, or more tests. Ask your care team which applies to you and when.
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Sources last checked: 2026-10-02 what this meansLast updated: 2026-09-27Next planned review: 2027-09-27
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Cancer Explained does not originate medical claims. Every page restates guidance already published by the National Cancer Institute, the CDC, the USPSTF and the FDA, in plain language, with the source cited so you can check the original yourself. AI does the translating and organizing; automated checks test claims, citations, clarity and safety before anything publishes, and this is translation and navigation, not clinical judgment. Nothing here is personal medical advice, and no page can account for your particular situation.
Editorial status: Source checked — This page was written with AI assistance and then compared with the sources listed on it, looking for statements those sources do not back up. That check is not a sentence-by-sentence record and can miss errors. It is not a medical review, and it does not confirm the page is complete or right for your situation.
Human medical review: not completed. Pages here are not signed off by a clinician before they publish. That is not an oversight we are quietly working around: we restate published guidance and cite it, so the authority belongs to the source rather than to us, and every page names where its claims come from — you can verify us instead of trusting us. Where a volunteer clinician has reviewed a page, their name and credentials appear on it; where no name appears, no clinician has checked it. We are glad to have reviewers and are recruiting them, and we do not hold pages back waiting for one. Use this site to understand your situation and to ask better questions of the people treating you.
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