Lung-RADS
Read Your Scan Editorial Team·Last updated
Written from published radiology references and reviewed for plain language. Not written or signed by a physician, and not a diagnosis. How we write these pages →
In plain language
The scoring scale used for CT lung cancer screening, which converts what a nodule looks like into how soon the next scan should be. Most people screened land in the lowest categories and simply continue annual screening.
Upload your MRI, CT, X-ray or ultrasound — de-identified in your browser — and every finding is mapped onto your images and explained without jargon.
Where you'll see this
The impression of a low-dose screening chest CT.
Your report may word it “LungRADS” or “Lung Imaging Reporting and Data System”. These mean the same thing.
Questions worth asking your doctor
- What category did I get, and what does that category normally lead to?
- What is the recommended next step for this category — waiting, another scan, or a biopsy?
- Who decides the timing, and what should I do if my symptoms change before then?
How often does this turn up?
Lung-RADS is used in organised lung cancer screening programmes for people at higher risk, usually because of a smoking history, and it appears on every low-dose CT done within one. It is not used for a chest CT ordered because someone has symptoms — those are reported differently, and confusing the two contexts is the most common misreading of the category.
Does it mean something is wrong?
The categories describe what a nodule looks like and, above all, when to look again. Category 1 means nothing found, 2 means findings that are benign in appearance, 3 means probably benign, and 4 is subdivided into 4A, 4B and 4X with rising suspicion. Category 0 means the study was incomplete or previous images are needed. Category 2 is worth understanding properly, because it is the most common positive result and it explicitly includes nodules — small ones with benign features. Being told a nodule was seen and categorised 2 is a normal screening outcome, not a near miss.
What to do with it
The category maps directly to an interval. Categories 1 and 2 return you to annual screening. Category 3 usually means a repeat CT in about six months, because stability over time is what resolves most nodules. Category 4 leads to shorter-interval imaging, a PET scan, or a tissue sample depending on the subcategory. Most nodules found in screening never turn out to be cancer, which is why the system is built around watching rather than acting immediately.
Frequently asked questions
- What does Lung-RADS 2 mean?
- A negative screening result with benign-appearing findings, which commonly includes small nodules. It returns you to routine annual screening. Finding a nodule in this category is an ordinary outcome rather than a cause for concern.
- Does a lung nodule mean cancer?
- Usually not. Nodules are very common, particularly in people who have had chest infections, and the large majority found in screening are benign. Size, appearance and above all whether it changes over time are what separate them, which is why follow-up intervals rather than immediate action are the norm.
- Is Lung-RADS the same as the Fleischner criteria?
- No, and they apply in different situations. Lung-RADS is for organised screening in high-risk people. The Fleischner criteria are for a nodule found by chance on a scan done for another reason. The same nodule can be handled differently depending on which context it appeared in.
Standard scoring systems
Still worried about what your report says?
Upload your scan (de-identified in your browser) and your radiologist's report, and every finding is mapped onto the images, explained in plain language and scored. Informational only — not a diagnosis.
Read Your Scan is informational only — not a medical diagnosis, and not a substitute for a licensed radiologist or your doctor. If you have urgent symptoms, seek care.