摘要
目的采用前瞻性心电门控技术行低心率患者冠状动脉CT成像(CTCA),探讨重叠时间(PT)设置的临床应用价值。方法本研究共选取拟行CTCA检查的患者160例(心率≤55次/min,心率变异≤5次/min),依据患者体重指数选择管电流(270~800mA)、管电压设置为120kV。PT设置范围在0—150ms,每间隔10ms纳入10例患者。绘制受试者工作特征曲线(ROC)推断不同门设置下冠状动脉节段可评估性的切点。采用X2检验比较切点前后冠状动脉节段可评估率差异;分析心率与图像质量、辐射剂量的相关性。结果共有2257支冠状动脉节段参与评分,冠状动脉评分(4.55±0.66)分;ROC曲线显示不同胛设置下冠状动脉节段可评估性的切点为40ms,〈40ms与t〉40ms者冠状动脉节段可评估率比较:96.2%%VS99.2%(X2=23.751,P=0.000),差异具有统计学意义;PT设置与图像质量、辐射剂量呈正相关。结论在低心率及心率变异度下前瞻性心电门控技术可将PT设置修改为40ms可获得满足诊断的图像,同时降低辐射剂量。
Objective To evaluate value of padding time setting in coronary artery computed tomographic angiography with prospectively gated axial (PGA) CT technique at low heart rate ( ~〈65 beats per minute, bpm). Methods 160 pa- tients with heart rates(HR) (54.51 ± 6.66)bpm( range :42 -- 65 bpm) was evaluated in this retrospective study. All pa- tients used PGA CT technique (tube voltage was 120 kV and tube current tailored to BMI). The patient enrolled in subset by every 10 ms with the padding time(PT) setting(0 - 150 ms). The PT of ≤40 ms and 〉40 ms was compared with per- eentage of assessable coronary artery segments by Chi-Square test. To evaluate the relationship between PT and image quali- ty or radiation dose by spearman or pearson correlation analysis. Results There were 2257 coronary artery segments to be evaluated. The mean image quality score was 4.55 + 0.66. Below a PT of 40ms, as determined by receiver operator charac- teristic(ROC) curve, 3.8% of coronary segments were non-diagnostic compared with 0.8% with PT of 〉 40 ms( X2 = 23. 751 ,P = 0. 000). The relationship between PT and image quality or radiation dose was positive correlation. Conclu- sion PGA coronary CT angiography using 40ms padding time settings could offer assessable image quality at low HR and HRv.
出处
《临床放射学杂志》
CSCD
北大核心
2014年第1期117-120,共4页
Journal of Clinical Radiology
基金
内蒙古财政厅科研项目(编号:NC20080018)
内蒙古高等学校科学研究项目(编号:NJZY07091)