320-Detector Row CT Narrow Acquisition Window in Single Cardiac Cycle for CTCA:Clinical Evaluation

XING Gui-rong; BAO Li-li; LIU Ai-shi

doi:10.15953/j.1004-4140.2016.25.04.08

Abstract：Objective: To evaluate the value of narrow acquisition acquisition CTCA by single cardiac cycle using 320-detector row CT. Methods: 80 patients (HR ≤ 65 bpm, HRv ≤ 5 bpm) were enrolled from september 2015 to January 2016 in this study. All of patients were divided into two groups. Group A included 40 patients with acquisition phase 70%~80% in R-R interval and Group B with acquisition phase 30%~80% in R-R interval. Both two groups with tube voltage 100 kV and tube current tailored to BMI (300~580 mA). Two groups were evaluated by radiation dose and image quality (all coronary artery segments scaleand percentage of assessable, aorta attenuation). A P value below 0.05 was considered to be statistically significant. Results: All patients include group A and B successfully underwent single cardiac cycle CTCA. The mean effective dose for group A was 2.02 mSv ±0.78 mSv; this represents a 46% reduction as compared with that group B (4.35 mSv ±0.85 mSv, t = -12.474,P = 0.000). The mean image quality score was 3.61 ±0.53 obtained with Group A versus 3.71 ±0.48 obtained with Group B (Z = -3.074,P = 0.002). The difference of the percentage of assessable coronary artery segments in both groups was not statistically significant (χ2 = 0.215,P = 0.643). The difference of aorta attenuation in both groups was not statistically significant (t = -1.132,P = 0.261). Conclusions: narrow acquisition acquisition CTCA may reduce the radiation dose keeping image quality assessable in patients with low HR (≤ 65 bpm) and HRv (≤ 5 bpm).