Feasibility of Ultra-low Radiation and Contrast Medium Dosage in Aortic CTA Using Deep Learning Reconstruction at 60 kVp: An Image Quality Assessment

Abstract

ObjectiveTo assess the viability of using ultra-low radiation and contrast medium (CM) dosage in aortic computed tomography angiography (CTA) through the application of low tube voltage (60kVp) and a novel deep learning image reconstruction algorithm (ClearInfinity, DLIR-CI). MethodsIodine attenuation curves obtained from a phantom study informed the administration of CM protocols. Non-obese participants undergoing aortic CTA were prospectively allocated into two groups and then obtained three reconstruction group. The conventional group (100kVp-CVgroup) underwent imaging at 100kVp and received 210 mg iodine/kg in combination with a hybrid iterative reconstruction algorithm (ClearView, HIR-CV). The experimental group was imaged at 60kVp with 105 mg iodine/kg, while images were reconstructed with HIR-CV (60 kVp-CV group) and with DLIR-CI (60 kVp-CI group). Student's t-test was used to compare differences in CM protocol and radiation dose. One-way ANOVA compared CT attenuation, image noise, SNR, and CNR among the three reconstruction groups, while the Kruskal-Wallis H test assessed subjective image quality scores. Post hoc analysis was performed with Bonferroni correction for multiple comparisons, and consistency analysis conducted in subjective image quality assessment was measured using Cohen's kappa. ResultsThe radiation dose (1.12±0.23 mSv vs. 2.03±0.82 mSv) and CM dosage (19.04±3.03 mL vs. 38.11±6.47 mL) provided the reduction of 45% and 50% in the experimental group compared to the conventional group. The CT attenuation, SNR and CNR of 60kVp-CI were superior to or equal to those of 100kVp-CV. Compared to the 60 kVp-CV group, images in 60kVp-CI showed higher SNR and CNR (all P < 0.001). There was no difference between the 60kVp-CI and 100kVp-CVgroup in terms of the subjective image quality of the aorta in various locations (all P > 0.05), with 60kVp-CI images were deemed diagnostically sufficient across all vascular segments. ConclusionsFor non-obese patients, the combined use of 60kVp and DLIR-CI algorithm can preserving image quality while enabling radiation dose and contrast medium savings for aortic CTA compared with 100kVp using HIR-CV.