Evaluation of High-Pitch Ungated Pediatric Cardiovascular Computed Tomography for the Assessment of Cardiac Structures in Neonates. Issue 3 (May 2016) - Sriharan, Mona
Abstract : Purpose: We evaluated a high-pitch, non–electrocardiogram-gated cardiac computed tomographic protocol, designed to image both cardiac and extracardiac structures, including coronary arteries, in a neonatal population (less than 1 year old) that was referred for congenital heart disease assessment and compared it with an optimized standard-pitch protocol in an equivalent cohort. Materials and Methods: Twenty-nine high-pitch scans were compared with 31 age-matched, sex-matched, and weight-matched standard-pitch, dosimetrically equivalent scans. The visualization and subjective quality of both cardiac and extracardiac structures were scored by consensus between 2 trained blinded observers. Image noise, signal-to-noise and contrast-to-noise ratios, and radiation doses were also compared. Results: The high-pitch protocol better demonstrated the pulmonary veins ( P =0.03) and all coronary segments (all P <0.05), except the distal right coronary artery ( P =0.10), with no significant difference in the visualization of the remaining cardiac or extracardiac structures. Both contrast-to-noise and signal-to-noise ratios improved due to greater vessel opacity, with significantly fewer streak ( P <0.01) and motion ( P <0.01) artifacts. Image noise and computed tomographic dose index were comparable across the 2 techniques; however, the high-pitch acquisition resulted in a small, but statistically significant, increase in dose-length product [13.0 mGy.cm (9.0 to 17.3) vs. 11.0 mGy.cm (9.0 to 13.0), P =0.05] due to greater z-overscanning. Conclusions: In neonates, a high-pitch protocol improves coronary artery and pulmonary vein delineation compared with the standard-pitch protocol, allowing a more comprehensive assessment of cardiovascular anatomy while obviating the need for either patient sedation or heart rate control.