Use of Angiographic CT Imaging in the Cardiac Catheterization Laboratory for Congenital Heart Disease

Abstract

This study sought to retrospectively evaluate our initial experience using angiographic computed tomography (ACT) in a pediatric cardiac catheterization laboratory. ACT provides cross-sectional CT images from a rotational angiography run using a C-arm mounted flat-panel detector in the interventional suite. A 3-dimensional (3D) angiographic image can be created from the CT volume set and used in real time during the procedure. To our knowledge, its use has never previously been described for congenital heart disease. 3D reconstructions were created and we retrospectively reviewed cases during our first year of ACT use. Images obtained were independently evaluated to determine their diagnostic utility. Radiation dose reduction protocols were defined using phantom testing and radiation dose calculation. ACT was used during 41 cardiac catheterizations in patients at a median age of 5.1 years (range: 0.4 to 58.8 years) for evaluation of: right ventricular outflow tract (RVOT)/central pulmonary arteries (PAs) in 20; cavopulmonary connection (CPC) in 11; pulmonary veins in 5; distal PAs in 4; and other locations in 5. Four subjects had 2 anatomic areas studied by ACT. The mean contrast volume for ACT was 1.2 ± 0.4 ml/kg. Diagnostic-quality imaging was obtained in 71% of cases: 13/20 RVOT/central PAs; 9/11 CPC; 4/5 pulmonary veins; 2/4 distal PAs; and 4/5 others. In 12 cases, ACT contributed to clinical outcomes beyond standard angiography. Radiation dose reduction protocols allowed ACT to be comparable in exposure to a standard biplane cineangiogram. Diagnostic-quality imaging can be obtained using ACT in 71% of cases without a significant increase in contrast or radiation exposure. In certain cases, ACT provides additional anatomic detail and may aid complex catheter manipulations. Future work is needed to continue to define applications of this new technology.