What it means
When tissue heals, the body often patches it with tough, fibrous scar tissue, much like a scar on the skin. In the lungs, scars can look like thin lines or bands on CT, sometimes pulling nearby lung slightly out of shape. Fibrosis also affects other organs. In the liver, for example, years of damage can cause scarring, which over time can become cirrhosis.
When it matters
A small, unchanged scar after an old chest infection is common and usually harmless. Widespread fibrosis is a different matter. Scarring through both lungs, especially in the lower and outer parts, can point to an interstitial lung disease, a group of conditions that scar the lungs. This often leads to breathing tests and a visit to a lung specialist. In the liver, scarring can be measured with elastography, a scan of tissue stiffness.
Questions to ask your doctor
- Is this a small old scar, or a more widespread change?
- Has it changed compared with my older scans?
- Should I have breathing tests or see a specialist about it?
