儿童鼻腔疾病CT扫描的剂量选择研究

Applications of different dose CT scanning in children nasal disease

目的 探讨儿童鼻腔疾病的不同剂量螺旋CT扫描技术及其临床应用价值.方法 对临床怀疑鼻腔疾病而行常规剂量（100mAs）CT检查的36例患儿,再行选定低剂量（50 mAs、30 mAs）对照CT扫描;统计各剂量组的权重CT剂量指数（CTDIw）和容积CT剂量指数（CTDIvol）,并对每幅图像进行质量评价和定性诊断.结果 30 mAs和50 mAs低剂量组的CTDIw和CTDIvol均明显低于常规剂量（100 mAs）组[分别为（3.53±1.43）、（6.34±2.2）mGy比（112.76±1.64）mGy,（4.17±0.81）、（8.51±1.26）mGy比（16.83±2.72）mGy,P＜0.05或P＜0.01];50 mAs剂量组扫描图像质量以良为主（61.11%）,且其疾病定性诊断与常规剂量组差异无统计学意义（P＞0.05）;而30 mAs剂量组扫描图像质量和定性诊断与常规剂量组比较差异均有统计学意义（P＜0.05）.结论 低剂量螺旋CT扫描儿童鼻腔疾病,完全能够代替常规剂量的螺旋CT扫描,且50 mAs低剂量即可满足临床诊断需要,并能有效降低患者的受辐射剂量.

Objective To discuss the value of different dose spiral CT scan technique in children nasal disease. Methods Thirty-six children suspected nasal cavity disease were inspected by conventional-dose（100 mAs）CT and compared with the groups scanned with low-dose（50 mAs, 30 mAs）. The weight of CT dose index（CTDIw）and volume CT dose（CTDIvol） of differ-dose group were counted. The quality of all images were evaluated. Results The CTDIw and CTDIvol of every low-dose group were lower than those of rule-dose group [（3.53 ± 1.43） mGy vs （6.34 ±2.2）mGy vs （112.76 ±1.64）mGy, （4.17 ±0.81）mGy vs （8.51 ±1.26）mGy vs （16.83 ±2.72）mGy,P 〈 0.05 or P 〈 0.01]. The imaging quality of 50 mAs dose group was good （61.11%）. There was no significant difference in disease＇s diagnosis between the 50 mA dose group and rule-dose group（P 〉0.05）. The quality of the images of 30 mas dose group had significant difference （P 〈 0.05） compared with that in the conventional-dose group. Conclusions The low-dose scanning can replace the rule-dose in children＇s nasal disease. The 50 mAs dose can reduce the radiation dose in patient＇s body.