Things to consider when the course of a CVL is unusual on a CXR:

1. Is it in a large vessel or a tributary that you can identify? (like the ones we just reviewed)

2. Is it in an anomalous vessel? (more on this in a minute)

3. Is it in an artery instead of a vein? (more on this, but it is fortunately very rare, except in the setting of a code)

4. Is it not in a vessel at all, but extravascular (particularly if there are other secondary signs of trauma, like pleural fluid, PTX, apical cap, mediastinal hematoma)