Clinical application of dual-source CT in coronary angiography with contrast medium injection based on automatic tube voltage technique / 中华放射学杂志

ABSTRACT

Objective:To explore the clinical value of auto-tube voltage controlled contrast medium injection based on 3rd generation dual source CT coronary angiography.Methods:Patients with suspected coronary heart disease were prospectively enrolled from March to December, 2019 at Shandong Provincial Hospital and coronary CT angiography (CCTA) images were acquired from 220 patients, including 107 male, 113 female, aged from 34 to 82 years. Patients were divided into experimental and control groups with the random number table. In experimental group (113 patients), automatic tube voltage selection technology was used, the contrast agent dosage was set according to tube voltage. The injection time was 10 s; In control group (107 patients), tube voltage and contrast agent dosage were set according to weights. The injection time was 12 s. Images were acquired by ECG gating using the 3rd generation dual source CT (DSCT) with intravenous injection of 350 mg/L contrast medium, followed up with saline of the same dose. Interclass correlation coefficient (ICC) was used to evaluate the individual bias of raters. The rank sum test was used to evaluate the group-level differences of subjective image quality and contrast agent dosage. The t-test was used to evaluate the group-level differences of objective image quality and effective radiation dose (ED). Results:The noise of aortic root in the two groups were (27±4), (26±5) HU, respectively, with no statistical difference ( t=1.017, P=0.284). All ICC values were more than 0.5 indicating good correlation batween 2 raters. The objective image quality score was no significant differences( P>0.05). The subjective image quality scores of the two groups were 1.15±0.10 and 1.18±0.12, respectively, with no statistical difference (Z=-0.231, P=0.818). The ED value (2.2±0.6) mSv of experimental group was statistically lower than that of control group (4.6±1.8) mSv ( t=-13.107, P<0.001); the contrast dosage (35±7) ml of experimental group was statistically lower than that of control group（46±6）ml ( t=-8.699, P<0.001). Conclusions:The novel scanning protocol with auto-tube voltage based contrast agent setting is more convenient and practical with reduced radiation dose and contrast dose, while maintaining image quality.