Pulmonary artery sarcoma mimicking chronic thromboembolic disease: computed tomography and magnetic resonance imaging findings.

<bold>Purpose: </bold>The diagnosis of the rare primary malignant tumors of the pulmonary arteries is often delayed as symptoms are nonspecific.<bold>Methods: </bold>Computed tomography (CT) and magnetic resonance imaging (MRI) of three patients with occlusion of the right pulmonary artery, two with sarcoma and one with chronic thromboembolic disease were analyzed for discriminating diagnostic criteria.<bold>Results: </bold>Criteria suggesting pulmonary artery sarcoma are inhomogeneous high or low attenuation (hemorrhage, necrosis), soft-tissue density in pulmonary arteries, vascular distension, enhancement after administration of gadopentetate dimeglumine. Criteria for chronic thromboembolic disease are homogeneous soft-tissue lesions, abrupt vascular narrowings and cut-offs, as well as regional parenchymal hyperdensities.<bold>Conclusion: </bold>CT and MRI provide complementary findings suggesting advanced pulmonary artery sarcoma instead of chronic thromboembolism. [ABSTRACT FROM AUTHOR]