Sonographic features of mediastinal tumors.

Although mediastinal sonography, thus far, is used rarely in the United States, it might play a role in the diagnostic workup of mediastinal pathology as an adjunctive examination technique to other imaging studies (chest radiography, CT, and MR imaging). Mediastinal sonography is an effective and inexpensive imaging method, with a higher sensitivity than conventional radiographs, for the detection of mediastinal tumors [1-3]. The diagnostic advantage of mediastinal sonography over chest radiography results from its capability to demonstrate deep central mediastinal lymph nodes sonographically long before a displacement of pleuromediastinal lines occurs [3]. Mediastinal sonography is inferior only marginally to CT in the detection of supraaortic, pericardial, and prevascular lesions (sensitivity, 98-100%), but certain compartments (e.g., the posterior mediastinum and the paravertebral region) can be evaluated only with CT or MR imaging [3]. In addition to the assessment of size and topographic characteristics of mediastinal masses, sonography precisely visualizes the internal structure of the tumor, which may suggest a specific diagnosis when considered along with the clinical presentation and the location of the tumor [4]. This article illustrates the sonographic appearance of various mediastinal tumors.