[Spiral computerized tomography of the pulmonary arteries: diagnosis of acute and chronic lung embolism].

The use of tailored acquisition spiral CT protocols together with standardized contrast medium injections result in a detailed visualization of the pulmonary arteries. Since spiral CT is a quick and noninvasive imaging modality, it is especially suited for severely ill patients suspected to be suffering from acute pulmonary embolism. In contrast to perfusion scintigraphy, spiral CT will directly visualize the emboli, and should be performed if scintigraphy is not conclusive before the patient is referred to angiography. In cases of chronic pulmonary embolism spiral CT will directly visualize thromboemboli, consecutive wall thickening, pulmonary infarctions, and relative hyperperfusion as well as signs of pulmonary arterial hypertension and right heart failure. Acquisition protocols, diagnostic criteria, and clinical value of spiral CT are presented.