Real-world impact of high-pitch helical CT on radiation exposure and image quality in infants being evaluated for cardiothoracic pathologies.

Abstract

Background: Evaluation of cardiothoracic pathologies is a common indication for computed tomography (CT) in infants. However, CT is fraught with challenges specific to the patient population, such as increased sensitivity to radiation and inability to remain stationary during imaging.

Objective: This study investigates potential advantages of a high-pitch helical CT protocol for infants with cardiothoracic pathologies. Namely, we evaluate whether a high-pitch helical CT protocol can minimize radiation exposure without compromising image quality.

Materials and methods: This retrospective study included 98 consecutive cardiac protocol CT examinations of infants (56 males, 42 females; mean age 3.3 ± 2.8 months) performed at a tube voltage of 80 kV between 2016 and 2022. Forty-seven examinations were acquired with a non-gated conventional helical protocol on a multi-detector CT scanner (control group) and 51 were acquired with a non-gated high-pitch helical protocol on a dual-source CT scanner (high-pitch (HP) group). Patient characteristics, radiation exposure parameters, and imaging datasets were extracted from the picture archiving and communication system (PACS). Image quality was assessed subjectively by two radiologists who independently assigned ratings, and objectively through attenuation measurements.

Results: Radiation exposure was approximately 75% lower in the HP group (0.54 mSv vs. 2.46 mSv, P < .001). HP examinations demonstrated comparable, or better, image quality across all metrics in both subjective and objective analyses. In the subjective analysis, the HP group achieved superior ratings for visualization of the aorta (P = .04). In the objective analysis, the HP group achieved superior signal-to-noise ratio (SNR) in the left atrium (P < .001), left ventricle (P = .04), and aorta (P = .003), and superior contrast-to-noise ratio (CNR) in the left atrium (P = .003) and aorta (P = .009).

Conclusion: Our findings suggest that employing high-pitch helical CT protocols for evaluation of cardiothoracic pathologies in infants decreases radiation exposure while achieving similar to slightly better image quality compared to conventional helical CT protocols.