Imaging of Chronic Thromboembolic Pulmonary Hypertension.

Chronic thromboembolic pulmonary hypertension (CTEPH) is pulmonary hypertension secondary to chronic obstruction of pulmonary arteries by organized thromboemboli. Echocardiography and Echocardiography and ventilation/perfusion (V/Q) scan are the initial screening examinations for CTEPH; the diagnosis is often missed on computed tomography (CT). Imaging findings of chronic thromboembolic pulmonary disease overlap with those of acute pulmonary embolism, and radiologists should evaluate for the presence of concurrent chronic disease in all cases of acute pulmonary embolism detected on CT pulmonary angiography. Conditions that can mimic CTEPH include in situ thrombus, vasculitis, pulmonary artery sarcoma, and fibrosing mediastinitis.