Purpose : To determine the diagnostic accuracy of three- dimensional reconstructed CT imaging with multi-detector row CT in the evaluation of the stenosis of pulmonary arteries in infants and children with pre operative or post operative congenital heart disease in comparison with Conventional Cardiac Angiography.

Materials and Methods : In our institute 483 CT angiography of congenital heart disease was done between April 2003 and September 2004. Out of them 23 patients (mean age 5.1 years, range 1month 19days-15years), who underwent both CT angiography and conventional cardiac angiography within 2 months were included in this study. We used low dose protocol for CT angiography and the radiation doses were 0.5~2.1 mSv. CT angiography was done without EKG gating. The breath-hold was not applied to uncooperative patients. Main pulmonary trunk or conduit and both pulmonary arteries were evaluated for the degree of stenosis with grading system from 1 to 5 (0% to 100%) from reformatted CT images and conventional cardiac angiography separately. We applied weighted kappa value to evaluate the agreement of two examinations.

Results : The total 65 segments were analyzed. The weighted kappa value for main pulmonary artery or conduit was 0.959, for right pulmonary artery 0.900, for left pulmonary artery 0.826. The overall weighted kappa value was 0.886. There was only 1 false positive case of CT angiography in presence of stenosis.

Conclusion : Multi-detector low helical CT angiography is equivalent to conventional cardiac angiography for the assessment of pulmonary artery stenosis in patients with congenital heart disease. Moreover, the CT angiography is non-invasive and can give satisfactory images in a short time without EKG gating and breath-holding.