Evaluating Low-kV Dual-source CT Angiography by High-pitch Spiral Acquisition and Iterative Reconstruction in Pediatric Congenital Heart Disease Patients

We retrospectively evaluated the qualities of pediatric cardiovascular dual-source computed tomography (DSCT) images reconstructed by sinogram-affirmed iterative reconstruction (SAFIRE) and filtered back projection (FBP). We analyzed the cases of 287 congenital heart disease (CHD) patients < 5 years old, referred to our department in August 2013-March 2015. We divided them into two groups according to tube voltage (70 kVp, n=147; 80 kVp, n=140). All images were acquired by a CARE kV system and reconstructed by FBP and SAFIRE. The attenuation, noise, and signal-to-noise ratio (SNR) at each region of the heart and great vessels were measured. The volume CT dose index and dose-length product values were recorded. Compared to FBP, reconstruction by SAFIRE showed that the attenuation volume was significantly lower by 0.4% except for the ascending aorta (p<0.05), the noise value was lower by about 20% (p<0.05), and the SNR was higher by approx. 25% (p<0.05). The radiation dose in the 70 kVp group was significantly lower than that in the 80 kVp group. No significant differences in SNR were observed between the patient groups. DSCT image acquisition with SAFIRE using the CARE kV system results in low image noise and radiation dose in pediatric patients with CHD.