Correct!
3. Contrast-enhanced thoracic CT
Contrast-enhanced CT would be most appropriate to further evaluate the metallic fragment to more precisely localize the fragment and determine its possible etiology and effects on regional anatomy. While a pericardial location for the metallic fragment is possible, and untoward effects on the pericardium due to the fragment cannot be excluded at this point, no chest radiographic features to suggest pericardial effusion are noted. MR examination would not be as efficacious as CT because most metallic fragments are likely be ferromagnetic, and thus will cause a dephasing artifact in the region of the fragment that will obscure both the fragment itself and the anatomy in the immediate vicinity of the fragment. Anterior mediastinotomy would provide visualization of the anterior mediastinum and subaortic space, but there is a significant chance this metallic fragment resides within the heart itself, not the inferior portion of the anterior mediastinum, and thus this procedure would not be appropriate unless further non-invasive localization methods show that the focus resides in a location amenable to visualization at anterior mediastinotomy. 18FDG-PET scanning would not play any role in the localization of a metallic fragment.
The patient underwent enhanced thoracic CT (Figure 3) to further characterize the finding at chest radiography.
Figure 3. Left: Representative static images from the contrast-enhanced axial thoracic CT.Right: video of the thoracic CT.
Which of the following is correct regarding the description of the thoracic CT findings? (Click on the correct answer to proceed to the fifth of eight panels)