Comparison of Computed Tomography and Cineangiography in the Demonstration of Central Pulmonary Arteries in Cyanotic Congenital Heart Disease

Purpose: To assess the diagnostic accuracy of contrast-enhanced computed tomography (CT) for central pulmonary artery pathology in patients with cyanotic congenital heart disease (CCHD) and right ventricular outflow obstruction. Methods: We compared contrast-enhanced CT and cine pulmonary arteriography in 24 patients with CCHD to assess central pulmonary arteries including the confluence. Both investigations were interpreted by a cardiac radiologist in a double-blinded manner at an interval of 3 weeks. Angiography was used as the gold standard for comparison. Results: The sensitivity for visualization of main pulmonary artery (MPA), right pulmonary artery (RPA), left pulmonary artery (LPA), and confluence on CT was 94%, 100%, 92.8%, and 92.8%, respectively. Diagnostic specificity for the same entities was 28.5%, 100%, 80%, and 50%, respectively. The positive predictive value for each was 76.2%, 100%, 94.1%, and 72.2%, respectively. The low specificity of CT in the evaluation of the MPA and the confluence is perhaps due to distorted right ventricular outflow anatomy in CCHD. Large aortopulmonary collaterals in this region were mistaken for the MPA in some patients with pulmonary atresia. Conclusion: CT is a useful, relatively noninvasive, imaging technique for the central pulmonary arteries in selected patients. It can supplement diagnostic information from angiography but cannot replace it. LPA demonstration on axial images alone is inadequate