Objective: The aim of the study was to estimate the decrease in ionizing radiation exposure dose using adaptive tube voltage, tube current parameters and individualized contrast media injection protocol compared to basic retrospectively ECG-gated CCTA protocol and to compare image quality.
Methods: This retrospective study consisted of 30 consecutive patients who had body mass index (BMI) between 25 kg/m2 and 30 kg/m2 and underwent retrospectively ECG-gated CCTA. We have enrolled 15 patients which were scanned with an adaptive tube voltage, tube current and an individualized contrast media injection protocol (study group), the other 15 patients underwent basic retrospectively ECG-gated CCTA protocol (control group). Comparison of ionizing radiation effective dose, subjective and objective image quality was accomplished. Differences in ionizing radiation effective dose were deemed statistically significant if p < 0.01, for other variables we considered a p value of less than 0.05 to be statistically significant.
Results: he difference of a mean effective dose between study and control groups was statistically significant (6.39 ± 0.88 mSv and 17.44 ± 2.45 mSv, p < 0.01). Despite significantly higher image noise, significantly lower contrast-to-noise ratio and signal-to-noise ratio in a study group, both groups showed comparable average image quality (62.03±16.85 and 39.98±8.79, p < 0.01; 5.16±2.03 and 7.71±1.28, p < 0.01; 3 (2.5-3) and 2.75 (2.75-3), p = 0.95).
Conclusions: Despite higher image noise compared to basic retrospectively ECG-gated CCTA protocol, adaptive tube voltage, tube current parameters and individualized contrast media injection protocol allows substantial reduction in ionizing radiation exposure dose to a patient (up to 63%) with an adequate image quality for the evaluation of coronary arteries.
