256层螺旋CT“双低”技术在冠状动脉血管造影中的应用价值

The Application Value of 256-Slice Spiral CT"Double-Low"Technique in Coronary CT Angiography

目的探讨256层螺旋CT“双低”(低管电压和低对比剂剂量)技术在冠状动脉CT血管成像(CCTA)中的应用价值。方法连续收集2020年4—8月于医院行CCTA检查的80例患者,按随机数字表法分成试验组和对照组,各40例。试验组行低管电压(100 kV)扫描并采用低对比剂剂量(40 ml),对照组行常规扫描(120 kV)并采用常规对比剂剂量(60 ml),比较两组的图像质量[客观评价包括左冠状动脉前降支(LAD)、左冠状动脉回旋支(LCX)、右冠状动脉(RCA)三大分支的近段、中段、远段的CT值和椎旁肌肉组织CT值,以及主动脉的CT值,并计算两组的信噪比(SNR)和对比噪声比(CNR);主观评价由两名高年资放射科诊断医师进行]和辐射剂量[采用CT剂量指数(CTDI)、CT剂量长度乘积(DLP)、有效辐射剂量(ED)评价]。结果两组均成功完成检查,且两组图像质量的客观评价指标和主观评分比较,差异均无统计学意义(P>0.05);一致性检验结果显示,两名高年资放射科诊断医师的主观评价结果的一致性较高(Kappa=0.81);两组图像均满足诊断需求;试验组的CTDI、DLP、ED均低于对照组,差异有统计学意义(P<0.05)。结论采用“双低”技术行CCTA扫描,可大幅度降低患者的辐射剂量,同时获得满足诊断需求的影像图像。

Objective The application value of 256-slice spiral CT"double-low"(low tube voltage and low dosage of contrast media)technique in coronary CT angiography(CCTA)was explored.Methods A total of 80 patients who underwent CCTA examination from April to August 2020 in the hospital were selected,and they were divided into an experiment group and a control group according to the random number method,with 40 cases in each.The experiment group underwent low tube voltage(80 kV)scanning and used low dosage(40 ml)of contrast media,while the control group underwent routine scanning(120 kV)and used routine dosage of contrast media(60 ml).The image quality[The objective evaluation included CT values of the proximal,middle,and distal lumens of the left anterior descending(LAD),left circumflex(LCX)and right coronary artery(RCA),as well as CT values of paravertebral muscle tissue and aorta,the signal to noise ratio(SNR)and contrast to noise ratio(CNR)were also calculated.The subjective evaluation was conducted by two senior diagnostic radiologists.]and radiation dose[evaluated by CT dose index(CTDI),CT dose length product(DLP)and effective dose(ED)]were compared between the two groups.Results All patients successfully completed the examination,and there was no significant difference in the objective evaluation indexes and subjective scores of image quality between the two groups(all P>0.05);The consistency test results showed that the subjective evaluation of the two senior diagnostic radiologists were consistent(Kappa=0.81);The images of the two groups could meet the diagnostic needs;The values of CTDI,DLP and ED in the experiment group were lower than those in the control group,and the differences were statistically significant(P<0.05).Conclusion The use of"double low"technique for CCTA scanning can significantly reduce the ED and obtain images meeting the requirements of diagnosis at the same time.