宽体探测器CT绝对时相单心动周期扫描在心律不齐患者CCTA中的可行性

Feasibility study of absolute phase one-beat scanning with wide-detector CT for patients with arrhythmia in coronary computed tomography angiography

目的:探讨宽体探测器CT绝对时相单心动周期扫描在心律不齐患者冠状动脉CT成像中的可行性。方法:连续选取心律不齐(6个心动周期内心率变化大于20次/分)及窦性律齐患者各100例,行冠状动脉CT成像检查。心律不齐组采用绝对时相扫描,窦性律齐组采用相对时相扫描。比较两组的主动脉根部CT值、有效辐射剂量(ED)、信噪比(SNR)、对比噪声比(CNR)及冠状动脉图像质量评分。结果:两组患者的性别、年龄、体质量指数(BMI)、扫描心率差异均无统计学意义(P值分别为0.572、0.763、0.347、0.551)。心律不齐组心率波动[(55.22±23.27)次/分]大于窦性律齐组[(2.34±1.69)次/分],差异有统计学意义(P=0.000)。两组图像的主动脉根部CT值、SNR、CNR和冠状动脉图像质量评分差异均无统计学意义(P值分别为0.458、0.350、0.203、0.813)。心律不齐组的有效辐射剂量[(3.21±1.20)mSv]高于窦性律齐组[(2.59±1.16)mSv],差异有统计学意义(P=0.000)。结论:宽体探测器CT绝对时相单心动周期扫描在心律不齐患者冠状动脉CT成像中具有可行性,但有效辐射剂量稍高于窦性律齐患者的相对时相扫描。

Objective: To investigate the feasibility of absolute phase one-beat scanning for coronary computed tomography angiography (CCTA) in patients with arrhythmia using wide-detector CT. Methods: CCTA was consecutively performed in 100 patients with arrhythmia (changed greater than 20 times/min in 6 heart beat) and 100 patients with normal sinus rhythm respectively.Absolute phase scanning was used in arrhythmia group,and relative phase scanning was used in normal sinus rhythm group.The CT value of the root of the aorta,effective radiation dose (ED),signal-to-noise ratio (SNR),contrast noise ratio (CNR) and the image quality score of coronary artery were compared between the two groups. Results: There were no statistical differences in sex,age,body mass index (BMI) and scanning heart rate between the two groups ( P =0.572,0.763,0.347,0.551,respectively).The heart rate changes were statistically different [(55.22±23.27)times/min vs (2.34±1.69)times/min, P =0.000] in the two groups,and the heart rate of patients in arrhythmia group was larger than that of in arrhythmia group.There were no statistical differences in CT value of the root of the aorta,SNR,CNR and the image quality score of coronary artery between the two groups ( P =0.458, 0.350, 0.203,0.813,respectively).The effective radiation dose in arrhythmia group and normal sinus rhythm group was statistically different [(3.21±1.20)mSv vs (2.59±1.16)mSv, P =0.000],and the arrhythmia group had a higher effective radiation dose than the arrhythmia group. Conclusion: It is feasible to perform CCTA with absolute phase one-beat scanning in patients with arrhythmia using wide-detector CT,however,the effective radiation dose is slightly higher than the relative phase scanning for patients with sinus rhythm.