摘要
目的:探讨不同心率(律)的条件下,320排容积CT冠状动脉血管成像的图像质量和辐射剂量。方法:将259例临床怀疑或确诊冠状动脉疾病的患者分为两组:窦性心律组(S组)220例;心律失常组(N组)39例。其中S组分为:A组79例,心率<65bpm;B组102例,65≤心率<80bpm;C组39例,心率≥80bpm。扫描完成后选用最佳的时相,对冠状动脉进行容积重组(VR)、多平面重组(MPR)、曲面重组(CPR)。按照4分法将图像质量分类并统计分析,比较各组冠状动脉血管段的优良率、可评价性;记录各组的辐射剂量,比较辐射剂量的差异。结果:S组与N组之间冠状动脉血管段优良率和可评价性的差异均无统计学意义。所有病例共有9段冠状动脉不可评价。所有病例平均辐射剂量为(9.49±6.54)mSv;S组和N组平均辐射剂量分别为(8.45±5.7)mSv、(15.36±7.79)mSv,两组之间辐射剂量差异具有统计学意义(t=-5.29,P=0.000)。窦性心律各组辐射剂量差异具有统计学意义(2=126.43,P=0.000)。结论:320排CT能较好适应心率(律)变化,保证诊断图像质量,对于心率<65bpm以下的窦性心律患者辐射剂量降低显著。
Objective:To evaluate the image quality and radiation dose of heart rate and heart rhythm with prospective electrocardiogram(ECG)-triggering using 320-detector CT scanner.Methods:A total of 259 patients suspected or known coronary artery disease,who underwent coronary CT angiography using 320-detector CT scanner were individed into sinurhythm goup(S group) and nonsinurhythm group(N group).S group was divided into subgroup A(79 cases) with heart rate below 65 beats per minute(bpm);subgroup B(102 cases),with heart rate from 65 to 80 bpm;subgroup C(39 cases) with heart rate beyond 80 bpm.Following data acquisition,all images with best phase were transferred to a workstation for further processing by means of VR,MPR,CPR.Based on 4-point scale,image quality was scored and categorized.Statistic analysis was made for grade of image quality.Radiation dose was recorded for statistic analysis.Results:No significant difference was found for image quality scale and score between group S and group N.The same as in the cases with sinus rhythm.A sum of nine segments of coronary artery were found not to be assessable.The effective dose of the integrated sample was on average(9.49±6.54) mSv;the effective dose of Group S was on average(8.45±5.7) mSv,whereas on average(15.36±7.79) mSv in Group N,a significant diference showed in them(t =-5.29,P=0.000).Mean effective dose of subgroup A,B and C was(3.23±1.87) mSv,(10.38±4.44) mSv,13.98±5.58 respectively.A significant difference was foud among them.Conclusion:320-detector CT scanner combined with prospectvie ECG-triggering technology can provide diagnostic images adaptive to higher heart rate and arrhythmia,radiation dose was significantly reduced for patients with sinus rhythm and heart rate below 65 bpm.
出处
《医学影像学杂志》
2011年第5期666-670,共5页
Journal of Medical Imaging
