房颤患者的64层CTCA:平均心率对图像质量和最佳重建期相的影响

目的:评价房颤患者64层螺旋CT冠状动脉成像中平均心率对最佳图像重建时相和图像质量的影响.方法:58例房颤患者行64层螺旋CT冠状动脉成像,扫描前均未服用美托洛尔.血管图像质量分为好、中等和差.分析平均心率和患者总体图像质量之间的相关性,采用判别分析法计算获得总体图像质量为好和中等的平均心率阈值和最佳重建时相在收缩末期的平均心率阈值.结果:平均心率和患者总体图像质量之间呈负相关(r=-0.43,P=0.001);患者总体图像质量为好和中等的平均心率阈值分别为80次/min和95次/min;最佳重建时相在收缩末期的平均心率阈值为85次/min.结论:控制患者平均心率在一定阈值以下并结合舒张中期蕈建.能保证房颤患者64层螺旋CT冠状动脉成像获得较高的图像质量.

64- Slice CT Coronary Angiography in Patients with Atrial Fibrillation: Effect of Average Heart Rate on Optimal Reconstruction Interval and Image Quality

Purpose: To evaluate the effect of average heart rate on optimal reconstruction interval and image quality in patients with atrial fibrillation at 64- detector row CT coronary angiography. Methods: Fifty-eight patients underwent 64-detector row CT coronary angiography. No beta-blocker was taken in all patients. Spearman correlation coefficient was used to analyze the correlation between average heart rate and average image quality. A Bayesian discriminant analysis was used to determine the difference of average heart rate threshold between poor and moderate image quality, and the difference of average heart rate threshold between moderate and good image quality. Further, Bayesian discriminant analysis was used to determine the difference of average heart rate threshold between optimal reconstruction interval at mid-diastole and end-systole. Results: Negative correlation was found between average heart rate and average image quality (r =-0.43, P = 0.001). The average heart rate threshold for achieving good and moderate image quality was 80bpm and 95bpm, for optimal reconstruction interval at end systole was 85bpm. Conclusion: Mean heart rate less than certain threshold and reconstruction at middle-diastolic phase would be fundamental for higher image quality of 64-CT coronary angiography in patients with atrial fibrillation.