CT Diagnosis of Chronic Pulmonary Thromboembolism

Chronic pulmonary thromboembolism is mainly a consequence of incomplete resolution of pulmonary thromboembolism. Increased vascular resistance due to obstruction of the vascular bed leads to pulmonary hypertension. Chronic thromboembolic pulmonary hypertension is clearly more common than previously was thought, and misdiagnosis is common because patients often present with nonspecific symptoms related to pulmonary hypertension. Computed tomography (CT) is a useful alternative to conventional angiography not only for diagnosing chronic pulmonary thromboembolism but also for determining which cases are treatable with surgery and confirming technical success postoperatively. The vascular CT signs include direct pulmonary artery signs (complete obstruction, partial obstruction, eccentric thrombus, calcified thrombus, bands, webs, poststenotic dilatation), signs related to pulmonary hypertension (enlargement of main pulmonary arteries, atherosclerotic calcification, tortuous vessels, right ventricular enlargem...