Abstract：Objective To investigate the effect of 320-row wide-detector CT with low tube-voltages technology (80 kV) on the image
quality and radiation dose of coronary CT angiography (CCTA) of overweight patients. Methods A total of 60 overweight patients
(25 kg/m2≤BMI<30 kg/m2) requiring CCTA were prospectively enrolled in the study and randomly divided into two groups. In
group A, 30 patients were scanned with tube voltage of 80 kV protocol丨 30 patients in group B were scanned with tube voltage of
100 kV protocol as a control group. All CCTA scans were acquired using prospective electrocardiogram (ECG) gating technology
and automated tube current control technology. The image was reconstructed by adaptive iterative dose reduction three-dimensional
algorithm. The CT values and noise of aortic root, left anterior descending artery, circumflex artery and right coronary artery were
measured丨 the signal to noise ratio (SNR) and contrast to noise ratio (CNR) were calculated. Two experienced radiologists used the
4-point scoring method to evaluate the quality of scanned images subjectively. Effective radiation dose was calculated. Results
There was no significant difference in BMI between group A and group B (P>0.05)丨 The effective radiation dose in group A was
significantly reduced by 42.8%, compared with group B (1.70±0.77) mSv and (2.98±1.87) mSv, respectively. Although the
image noise was higher under the condition of 80 kV, the difference was statistically significant (P<0.01)丨 However, there was no
significant difference in SNR and CNR between two groups (P>0.05). There was no significant difference in the scores of subjective
image quality of each coronary segment (P>0.05). Conclusion 320-row wide-detector CT can perform low-kV (80 kV) CCTA for
overweighs patients, efficiently reduce radiation dose and ensure the quality of images.
