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Biophysics - Radiology and Medical Imaging

Preliminary Study of Prospective ECG-Gated 320-Detector CT Coronary Angiography in Patients with Ventricular Premature Beats
Published: Wednesday, June 06, 2012
Author: Tong Zhang et al.

by Tong Zhang, Jinquan Bai, Wei Wang, Dan Wang, Baozhong Shen


To study the applicability of prospective ECG-gated 320-detector CT coronary angiography (CTCA) in patients with ventricular premature beats(VPB), and determine the scanning mode that best maximizes image quality and reduces radiation dose. Methods: 110 patients were divided into a VPB group (60 cases) and a control group (50 cases) using CTCA.All the patients then underwent coronary angiography (CAG) within one month. CAG served as a reference standard through which the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of CTCA in diagnosing significant coronary artery stenosis (luminal stenosis =50%) could be analyzed. The two radiologists with more than 3 years’ experience in cardiac CT each finished the image analysis after consultation. A personalized scanning mode was adopted to compare image quality and radiation dose between the two groups.

Methodology/Principal Findings

At the coronary artery segment level, sensitivity, specificity, PPV, and NPV in the premature beat group were 92.55%, 98.21%, 88.51%, and 98.72% respectively. In the control group these values were found to be 95.79%, 98.42%, 90.11%, and 99.28% respectively. Between the two groups, specificity, sensitivity PPV, NPV was no significant difference. The two groups had no significant difference in image quality score (P>0.05). Heart rate (77.20±12.07 bpm) and radiation dose (14.62±1.37 mSv) in the premature beat group were higher than heart rate (58.72±4.73 bpm) and radiation dose (3.08±2.35 mSv) in the control group. In theVPB group, the radiation dose (34.55±7.12 mSv) for S-field scanning was significantly higher than the radiation dose (15.10±1.12 mSv) for M-field scanning.


With prospective ECG-gated scanning for VPB, the diagnostic accuracy of coronary artery stenosis is very high. Scanning field adjustment can reduce radiation dose while maintaining good image quality. For patients with slow heart rates and good rhythm, there was no statistically significant difference in image quality.