Prospective electrocardiography-triggered CT angiography of the great thoracic vessels in infants and toddlers with congenital heart disease: Feasibility and image quality

Abstract

To investigate feasibility and image quality and to calculate radiation dose estimates for computed tomography angiography (CTA) of the great thoracic vessels in infants and toddlers with congenital heart disease (CHD) using end-systolic prospective electrocardiography-triggered sequential dual-source data acquisition. This study was institutional review board approved; informed consent was obtained. Twenty children (age 1.2±1.1 years) underwent 22 prospective ECG-triggered sequential dual-source CTA examinations (Somatom Definition, Siemens) with tube current (250 mAs/rot) centered at 250 ms past the R-peak in the cardiac cycle (end-systole). Tube voltage was set to 80 kV. Image quality was evaluated by two readers independently using a four-point grading scale (4=excellent, 1=non-diagnostic). Radiation dose estimates were calculated from the dose-length-product (DLP). All CT images showed diagnostic image quality (mean score 3.67±0.67, κ=0.85). Stair-step artifacts were present in one and breathing artifacts in 4 patients, with neither impairing diagnostic image quality. Mean heart rate (bpm) was 107.6±12.1 (76-130), mean heart rate variability (bpm) was 2.5±2.0 (1-9). Mean scan length (mm) was 90.7±22.7 (50-134). Mean estimated effective dose was 0.32±0.11 mSv. Prospective ECG-triggered sequential dual source CTA is feasible in infants and toddlers with CHD, thereby allowing almost motion-free imaging of the great thoracic vessels with the benefit of a low radiation dose.