CT and MR imaging evaluation of chest wall disorders.

Computed tomography (CT) and magnetic resonance (MR) imaging have complementary roles in the evaluation of chest wall disorders, which include mesenchymal tumors, primary and secondary malignancies, and inflammatory and infectious diseases. Important anatomic regions of the chest wall to evaluate on axial images include the supraclavicular fossa, axilla, and parasternal-internal mammary zone. For diagnosis of a suspected lipoma, CT is faster and less expensive; however, MR imaging may better delineate the extent of more invasive tumors if surgery is planned. MR imaging best depicts intramuscular neurofibromas and soft-tissue, intraspinal, and marrow involvement of neurogenic tumors, although CT more readily shows small calcifications and bone destruction. For diagnosis of lymphangioma, particularly when intravenous contrast material cannot be given for CT, MR imaging is preferred. CT more accurately demonstrates cortical bone destruction from masses arising in the ribs, but MR imaging is better for depicting infiltration of bone marrow and the extent of soft-tissue involvement. MR imaging displays Pancoast tumors and chest wall invasion from lung cancer better than CT because of its multiplanar capability and depiction of subtle differences in soft-tissue contrast. Both CT and MR imaging are helpful in evaluating infections, with CT being used to reveal bone destruction and to guide aspiration and drainage and MR imaging demonstrating soft-tissue involvement. The choice of technique, CT versus MR imaging, often depends on the specific clinical question to be addressed.