The applications of non-ECG-gated MSCT angiography in children with congenital heart disease

Background: To minimize radiation exposure during a multi-slice computed tomography (MSCT) examination in children with congenital heart disease (CHD), we assessed diagnostic value and the various applications of MSCT without electrocardiography (ECG)-gated image acquisition.

Methods: Three-dimensional (3D) images were reconstructed to include volume rendering and differential color-coding of the arteries and veins. The vessel diameter in MSCT was measured with CT attenuation profiles and compared with that of angiography. Ventricular volumetry was initially validated by phantom experiment and followed by comparison with that of cine-angiography (n=15). Simulation for surgical operation was performed to evaluate the possibility of an intraventricular conduit in patients diagnosed with a double outlet right ventricle.

Results: Differential color-coding was able to provide accurate and understandable anatomical structure in CHD. The diameter of the descending aorta measured in MSCT correlated well with the values obtained by angiography (r(2)=0.86). According to the results of the phantom experiment, ventricular volume was studied in patients whose heart rate was faster than 120 beat/min. The left and the right ventricular volume in MSCT correlated well with values obtained by cine-angiography (r(2)=0.98 for RV, r(2)=0.94 for LV). Simulative operation of intraventricular rerouting provided appropriate indication for biventricular repair in patients diagnosed with a double outlet right ventricle.

Conclusions: Non-ECG-gated MSCT angiography is applicable for precise anatomical diagnosis, ventricular volumetric study, and simulation surgery in children with CHD.