- Micronodule = nodules of less than 3 mm
- Small nodules = nodules of less than 2 cm
Steps for Decision Making
- Decide whether there are multiple micronodules or small nodules
- Where are the nodules? Are they subpleural?
- If they are subpleural, are they uniformly distributed throughout the lungs or secondary pulmonary lobules?
- If they are not subpleural, they are likely centrilobular. The next question is whether there is tree-in-bud pattern or not.
- Look for associated findings as a clue to limit differential diagnoses