CT Diagnosis of Chronic Pulmonary Thromboembolism1

• Published in: Radiographics Vol. 29; no. 1; p. 31
• Main Authors: Eva Castañer, Xavier Gallardo, Eva Ballesteros, Marta Andreu, Yolanda PallardÃ, Josep Maria Mata, Lluis Riera
• Format: Journal Article
• Language: English
• Published: Radiological Society of North America 01-01-2009
• ISSN: 0271-5333; 1527-1323
• DOI: 10.1148/rg.291085061

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 enlargement, hypertrophy), and signs of systemic collateral supply (enlargement of bronchial and nonbronchial
systemic arteries). The parenchymal signs include scars, a mosaic perfusion pattern, focal ground-glass opacities, and bronchial
anomalies. The presence of one or more of these radiologic signs arouses suspicion and allows diagnosis of this entity. Early
recognition of chronic pulmonary thromboembolism may help improve the outcome, since the condition is potentially curable
with pulmonary thromboendarterectomy.
© RSNA, 2009