[Systematic evaluation of the pulmonary circulation with computerized tomography: normal and post-embolic pathologic features].

Pulmonary circulation was evaluated in normal subjects and in post-embolic patients. Eight normal subjects, 3 patients with acute pulmonary embolism and 8 patients with chronic thromboembolic pulmonary hypertension underwent CT of the chest. High-resolution CT and angio-CT were performed to study pulmonary parenchyma and pulmonary arteries, respectively. CT showed thrombi in the main or interlobar pulmonary arteries in all 3 cases of acute pulmonary embolism and in 4 of 8 patients affected with chronic thromboembolic pulmonary hypertension. The diameters of the main pulmonary and right interlobar arteries correlated with systolic pulmonary artery pressure (p < 0.001), as measured by right heart catheterization. In the patients affected with chronic thromboembolic pulmonary hypertension, the ratio of the calibers of the segmental arteries to the corresponding bronchi was markedly higher, which was observed also in the patients with acute pulmonary embolism. The bronchial arteries were dilated in 4 of 8 cases of chronic thromboembolic pulmonary hypertension. Lung density was significantly high in the perihilar compartment in the patients with acute thromboembolic hypertension, but not in normal controls and in the cases of acute pulmonary embolism. In conclusion, CT can help to diagnose pathological pulmonary circulation. Particularly, the ratio of the diameters of the segmental arteries to the corresponding bronchi can be useful to evaluate blood circulation.