小剂量对比剂CT肺动脉造影诊断肺动脉栓塞的临床价值分析

Analysis on the clinical value of CTPA with small-dose contrast agent in diagnosing PE

目的:分析小剂量对比剂CT肺动脉造影(CTPA)诊断肺动脉栓塞(PE)的临床应用价值。方法:选取在医院就诊的65例高度怀疑为PE患者,根据CTPA检查时所用对比剂(非离子型碘普罗胺Ultravist 370)的不同,将其分为常规组(35例)和小剂量组(30例)。常规组行常规CTPA检查模式,注射对比剂50 ml,管电压120 k V;小剂量组对比剂为30 ml,管电压为80 k V。评价两组图像质量及辐射剂量,并对比诊断效能。结果:小剂量组肺动脉主干、左右肺动脉、肺段动脉CT值、信噪比(SNR)以及对比噪声比(CNR)均略低于常规组,但差异无统计学意义;两组图像质量主观评分均≥3分,满足诊断需要,评分分布未见统计学差异。小剂量组扫描后实际容积CT剂量指数(CTDI_(vol))、剂量长度乘积(DLP)和有效剂量(E)明显低于常规组,差异有统计学意义(t=2.051,t=2.175,t=2.106;P<0.05)。常规组和小剂量组诊断PE的特异度分别为92.31%和85.00%,灵敏度分别为77.78%和90.00%,准确度分别为88.57%和86.67%,两组比较差异均无统计学意义。结论:小剂量对比剂CTPA检查能够获得满足PE诊断基本需求的图像质量,诊断效能好,且可显著降低对比剂用量与辐射剂量,临床应用价值高。

Objective:To analyze clinical application value of computed tomography pulmonary angiography(CTPA)with small-dose contrast agent in diagnosing pulmonary embolism(PE).Methods:65 patients with high suspicion of PE were selected and they were divided into routine group(35 cases)and small-dose group(30 cases)according the different contrast agent(non-ionic iopromide Ultravist 370)in CTPA examination.The routine group underwent routine CTPA examination mode(injecting 50 mL of contrast agent,and choosing 120 kV tube voltage),while the contrast agent was 30 mL and tube voltage was 80 kV in small-dose group.The image quality and radiation dose of the two groups were evaluated,and the diagnostic efficiency of the two groups was compared.Results:The CT values,signal-to-noise ratios(SNR)and contrast-to-noise ratios(CNR)of main pulmonary artery,left and right pulmonary artery and pulmonary segmental artery in the small-dose group were slightly lower than those in the routine group,but there were no statistically significant differences between the two groups.The subjective scores of image quality of two groups were all not lower than 3 scores,which met the diagnostic requirements.There was no statistical difference in score distribution.After scan,the actual volume CT dose index(CTDIvol),dose length produce(DLP)and effective dose(E)in the small-dose group were significantly lower than those in the routine group(t=2.051,t=2.175,t=2.106,P<0.05).There were no significant differences in specificity(92.31%vs.85.00%),sensitivity(77.78%vs.90.00%)and accuracy(88.57%vs.86.67%)between the routine group and the small-dose group in diagnosing PE.Conclusion:CTPA examination with small-dose contrast agent can obtain the image quality that meets basic requirements for diagnosing PE,and it has favorable diagnostic efficiency.It can significantly decrease both the contrast agent dosage and the radiation dose,and it has high clinical application value.