Evaluation of Solitary pulmonary nodule
What is the general approach to the evaluation of SPN?
The initial step is to determine whether a “nodule” identified on chest radiography is truly a pulmonary nodule or a pseudolesion that mimics a nodule.
If a “nodule” is actually a pseudolesion caused by a skeletal finding, such as a rib fracture, it exhibits the same anatomic relationship to its apparent bone of origin on multiple radiographic projections.
A true pulmonary nodule that overlaps with skeletal structures on one radiographic projection would appear to move away from its apparent bone of origin on other radiographic projections. Radiopaque nipple markers are sometimes helpful in distinguishing nipples from true pulmonary nodules. When a true lung nodule has been confirmed, a more detailed investigation begins.