128层螺旋CT低管电压联合低对比剂技术在下肢动脉疾病中的临床应用价值

The clinical value of 128-slice spiral CT with the technology of low tube voltage and low dosage of contrast in the lower extremity arterial diseases

目的探讨128层螺旋CT低管电压联合低对比剂技术在下肢动脉疾病应用的可行性及临床价值。方法选择2012年12月至2013年10月行下肢动脉CTA检查的患者60例,采用低管电压联合低对比剂技术(80kV、250mAs,对比剂:1.0ml/kg)进行扫描,其中12例进行了数字减影血管造影(DSA)。记录每次扫描的股动脉、腘动脉、胫后动脉CT值,算出均值,并统计出容积剂量指数(CTDIvoI)、剂量长度乘积(DLP),计算出有效剂量(ED)。由2名5年以上心血管影像诊断经验的放射医师以5分制对图像质量进行主观评价,并对两名医师的评分进行Kappa一致性检验。结果本组的CTDIvoI、DLP、ED分别为(4.85±0.00)mGy、(572±26.31)mGy.cm、(8.56±1.23)mSv。CT均值为(517±12.45)HU,达到诊断要求。两名医师图像主观评价得分分别为4.18±0.75、4.09±0.86,主观评价结果一致性好(Kappa=0.893,P=0.00)。12例患者CTA与DSA诊断符合率达100%。结论采用低管电压联合低对比剂技术行下肢动脉CTA检查,受检者的辐射剂量和对比剂用量明显降低,且图像质量满足诊断要求,对下肢动脉疾病的诊断和复查具有较大的临床应用价值。

Objective To explore the clinical value of 128-Slice spiral CT with the technology of low tube voltage and low dosage of contrast in the lower extremity arterial diseases .Methods Sixty patients with lower extremity arterial diseases underwent CTA examinations with the technology of low tube voltage and low dosage of contrast （80 kV ,250 mAs ,con-trast medium ：1 .0 ml/kg） ,including 12 cases performed with digital subtraction angiography （DSA） .CT values of femo-ral artery ,popliteal artery ,posterior tibial artery of every patient were recorded to calculate the mean attenuation .CT dose volume index （CTDIvoI） and dose length product （DLP） was recorded to calculate the effective dose （ED） .Two ra-diologists evaluated the image quality with 5 points methods subjectively ,and the scores were conducted consistency test with Kappa .Results The mean values of CTDIvoI ,DLP and ED were （4 .85 ± 0 .00） mGy ,（572 ± 26 .31） mGy .cm amd （8 .56 ± 1 .23） mSv .The mean attenuation was （517 ± 12 .45） HU ,which meeting the requirement of diagnosis .The mean subjective scores of the two radiologists were 4 .18 ± 0 .75 ,4 .09 ± 0 .86 respectively ,and both of them have good consistency （Kappa=0 .893 ,P=0 .00） .12 cases with CTA and DSA diagnosis coincidence rate were 100% .Conclusion The technology of low tube voltage and low dosage of contrast in the lower extremity arterial CTA examination significant-ly reduces the radiation dose and the dose of contrast medium ,with the image quality diagnosable .Therefore ,it is of great value in clinical application for the diagnosis and follow-up of the lower extremity arterial diseases .