Role of 64-slice multidetector computed tomography in the diagnosis of abnormal vascular connections in congenital heart disease

Abstract

The aim of this study was to evaluate the role of 64-slice multidetector computed tomography in the diagnosis of abnormal systemic and pulmonary vascular connections and the associated congenital anomalies in comparison to echocardiography. The study enrolled 100 consecutive patients with the provisional diagnosis of congenital heart disease referred for further evaluation by MDCT. Low dose protocol was used for imaging. ECG-gating was used only when coronary anatomy needed to be defined. Ninety-one abnormal vascular connections were found in 73 cases. Abnormal venous connections were further classified into 19 anomalous pulmonary venous connections and 13 anomalous systemic venous connections. Abnormal arterial connections include systemic-systemic connections: 8 coronary artery fistulas, 7 cases of systemic collaterals in aortic coarctation and 2 vascular rings, as well as systemic-pulmonary connections: 38 patent ductus arteriosus (PDA), 4 major aortopulmonary collateral arteries (MAPCAs) and one coronary artery to pulmonary artery fistula. There was significant agreement between echocardiography and MDCT in the diagnosis of partial anomalous pulmonary venous connections (PAPVC) and total anomalous pulmonary venous connections (TAPVC) but not in determining the site drainage, in which MDCT was more accurate. In comparison to MDCT, echocardiography had a sensitivity and specificity of 90.9–95.5% respectively in the diagnosis of PAPVC and 100% and 98.9% in the diagnosis of TAPVC, while only a sensitivity of 45.5% in determining the site of drainage in PAPVC and 75% in TAPVC. However, echocardiography showed all intracardiac defects including that missed by MDCT. The majority of PAPVC were right-sided anomalous veins. Most TAPVC were supracardiac and half were isolated TAPVC. All anomalous systemic venous connections were incidentally discovered by MDCT and were not detected by echocardiography. The left superior vena cava was a component of a duplicated SVC in all cases. The majority of persistent azygos venous system cases were associated with complex CHD. MDCT clearly showed the origin, course and termination of coronary artery fistulas. Echocardiography showed the intracardiac defects in all cases, including that missed by MDCT. Three fistulas originated from the right coronary artery, five from the left coronary artery and one fistula originated from both the right coronary artery and the left circumflex. All coronary-cameral fistulas drained into right cardiac chambers. Less than half were associated with other CHD. Systemic collaterals in coarctation were clearly demonstrated by MDCT, none of which could be visualized by echocardiography. MDCT was not indicated for the diagnosis of PDA but for the associated CHD. Furthermore, MDCT clearly showed MAPCAs with echocardiography being able to detect one case. MDCT provides complete and accurate visualization of extracardiac vasculature but is less reliable for intracardiac defects. It can be used safely in neonates with complex congenital heart disease. It has advantages of non-invasiveness, fast acquisition, high spatial and temporal resolution and three-dimensional reconstruction.