摘要
目的：阐述 Revolution CT 低剂量扫描技术在儿童先天性心脏病（congenital heart diseas， CHD）中的应用价值。方法选择 CHD 患儿34例，随机分为两组，A 组17例，Asir— V：50％，B 组：17例，Asir—V：80％，两组扫描条件均为70 Kv，300 mAs，探测器宽度120～160 mm，扫描时间0.3 s，造影剂：碘海醇350 mgI ／mL，用量1 mL／kg，记录升主动脉、降主动脉、肺动脉主干、左心室的 CT 值及同层面背部软组织 CT 值，根据标准差 SD 计算各兴趣区信噪比（signal-to-noise ratio，SNR）及对比信噪比（contrast-to-noise ratio，CNR），记录每个病例的剂量长度乘积（dose-length product，DLP），并根据公式换算有效剂量（effective doses，ED），由两位工作10年以上的副主任医师独立读片诊断并对图像质量进行评分。结果A 组各兴趣区 SNR 及 CNR 小于 B 组，差异有统计学意义（P ＞0.01），A 组 DLP 及 ED 与 B 组比较，差异无统计学意义（P ＜0.01），两位医师读片显示病例图像质量良好，读片结果一致性良好（K ＝0.621、0.683）；结论CTA 是小儿先天性心脏病的重要诊断手段，“双低”技术保证图像质量的前提下有效减少了 CT 辐射剂量，Asir—V：80％会获得更高的图像信噪比。
Objetive To explore the value of Asir-V plus low-dose scanning technique in children with congenital heart disease （CHD）.Methods Thirty-four CHD children were randomly divided into group A （n=1 7）,Asir-V：50% and group B （n =1 7）,Asir-V：80%.The scanning conditions of two groups were 70 Kv,300 mAs,detector width 1 20 ~1 60 mm,scanning time 0.3 s,contrast agent：350 mgI /mL and dosage 1 mL/kg.The values of computed tomography （CT）were recorded for ascending aorta,descending aorta,pul-monary artery and left ventricle.Standard deviation （SD）was calculated for area of interest signal -to -noise ratio （SNR）and contrast ratio of signal-to-noise ratio （CNR）.Dose length product （product dose-length, DLP）was recorded for each case and effective dose （ED）was converted according to the formula.Medical di-agnosis was made and image quality scored independently by two experienced doctors. Results The values of CNR and SNR of group A were less than those of group B.The differences were statistically significant （P 〈0.01 ）.The inter -group differences of DLP and ED were statistically insignificant （P 〉0.05）.Two inde-pendent doctors reviewed the films to ensure the image quality of each case and the consistency was decent （K=0.621 ,0.683）. Conclusions Computed tomography angiography is an important diagnostic means for children with congenital heart disease.And “double low”technology is applied for ensuring image quality under the premise of effectively reducing CT radiation dose and improving Asir-V with a higher image SNR ratio.
出处
《临床小儿外科杂志》
CAS
2016年第5期494-496,517,共4页
Journal of Clinical Pediatric Surgery
