Overall evaluability of low dose protocol for computed tomography angiography of thoracic aorta using 80kV and iterative reconstruction algorithm using different concentration contrast media.

Abstract

Multidetector Computed Tomography Angiography (MDCTA) is presently the imaging modality of choice for aortic disease. However, the effective radiation dose and the risk related to the use of contrast agents associated with MDCTA is an issue of concern. Aim of this study was to assess image quality of a low dose ECG-gated MDCTA of thoracic aorta using different concentration contrast media without tailored injection protocol. Two-hundred patients were randomised into four different scan protocols: Group A (Iodixanol 320 and 80 Kvp tube voltage), Group B (Iodixanol 320 and 100Kvp tube voltage), Group C (Iomeprol 400 and 80Kvp tube voltage) and Group D (Iomeprol 400 and 100Kvp tube voltage). Image quality, noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and effective dose (ED) were compared among groups. No significant differences in image noise, SNR and CNR between groups with the same tube voltage. Significant differences in SNR and CNR were found among groups with 80kV versus groups using 100kV but without differences in terms of image quality. ED was significantly lower in groups with 80kV. Multidetector Computed Tomography Angiography protocols using 80kV and low concentration contrast media are feasible without need of tailored injection protocols.