体型特异性剂量估算在儿童肺炎支原体肺炎胸部CT中的应用  

Size-specific dose estimation for chest CT examination in pediatric patients with mycoplasma pneumoniae pneumonia

作　　者：范恒鑫 罗春海[1] 潘奇[1] 杜佳忆 邱海静 FAN Hengxin;LUO Chunhai;PAN Qi;DU Jiayi;QIU Haijing(Department of Radiology,the Second Affiliated Hospital of Xi’an Medical University,Xi’an 710038,China)

机构地区：[1]西安医学院第二附属医院影像科,陕西西安710038

出　　处：《实用放射学杂志》2024年第10期1606-1610,共5页Journal of Practical Radiology

基　　金：陕西省卫生健康科研项目(2022B009)。

摘　　要：目的采用体型特异性剂量估算(SSDE)分析儿童肺炎支原体肺炎(MPP)低剂量胸部CT辐射剂量。方法前瞻性选取行低剂量胸部CT扫描患者95例,体质量≤50 kg 65例,采用80 kV、DoseRight Z-DOM(30~50 mAs);体质量>50 kg 30例,采用100 kV、DoseRight Z-DOM(50~100 mAs);回顾性收集行常规胸部CT扫描患者65例,体质量≤50 kg 40例,体质量>50 kg 25例,均采用120 kV、DoseRight Z-DOM(50~100 mAs)及固定管电流(mAs);采用图像噪声、信噪比(SNR)及对比噪声比(CNR)进行图像质量客观评价,2名主治医师用5分制、双盲法进行图像质量主观评价;收集容积CT剂量指数(CTDI_(vol))和剂量长度乘积(DLP)指标,并计算SSDE和有效剂量(ED)。结果80 kV扫描与常规扫描的CTDI_(vol)、DLP、SSDE、ED值比较,分别降低约81.3%、80.3%、81.5%、82.4%,差异有统计学意义(Z=-8.433、-8.137、-8.146、-8.142,P<0.05),体质量≤50 kg患者80 kV扫描与常规扫描图像噪声、SNR、CNR比较差异有统计学意义(Z=-6.762、-5.075、-3.430,P<0.05);100 kV扫描与常规扫描的CTDI_(vol)、DLP、SSDE、ED值比较,分别降低约75.7%、76.3%、75.3%、75.3%,差异有统计学意义(Z=-6.301、-6.173、-6.347、-6.308,P<0.05),体质量>50 kg患者100 kV扫描与常规扫描图像噪声、SNR比较差异有统计学意义(Z=-5.367、-4.650,P<0.05);2组图像质量主观评分均≥3分,达到临床诊断要求;80 kV、100 kV扫描的SSDE比CTDI_(vol)分别高45.3%、29.9%,体质量≤50 kg、体质量>50 kg常规扫描的SSDE比CTDI_(vol)分别高45.7%、28.8%。结论低kV结合DoseRight Z-DOM有效降低了儿童MPP的辐射剂量;SSDE比CTDI_(vol)更能准确评估儿童所受辐射剂量。Objective To analyze the radiation dose in low-dose chest CT examination of pediatric patients with mycoplasma pneumoniae pneumonia(MPP)by using size-specific dose estimation(SSDE).Methods A total of 95 patients who were scanned with low-dose chest CT were prospectively selected,65 patients with weight≤50 kg,using 80 kV and DoseRight Z-DOM(30-50 mAs);30 patients with weight>50 kg,using 100 kV and DoseRight Z-DOM(50-100 mAs).A total of 65 patients who were scanned with conventional chest CT were retrospectively collected,40 patients with weight≤50 kg,25 patients with weight>50 kg,using 120 kV,DoseRight Z-DOM(50-100 mAs)and fixed mAs.Image noise,signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)were used to objectively evaluate image quality.The subjective evaluation of image quality was performed by two radiologists using a 5-score system and a double-blind method.The volume CT dose index(CTDI_(vol))and dose length product(DLP)were collected,the SSDE and effective dose(ED)were measured,respectively.Results Compared with conventional scan,CTDI_(vol),DLP,SSDE,and ED values of 80 kV scan was decreased by 81.3%,80.3%,81.5%,and 82.4%,respectively,with a statistical difference(Z=-8.433,-8.137,-8.146,-8.142,P<0.05).There were statistically significant differences in image noise,SNR,and CNR between 80 kV scan and conventional scan in patients with weight≤50 kg(Z=-6.762,-5.075,-3.430,P<0.05).In 100 kV scan,CTDI_(vol),DLP,SSDE,and ED values was decreased by 75.7%,76.3%,75.3%,and 75.3%,respectively,with a statistical difference(Z=-6.301,-6.173,-6.347,-6.308,P<0.05).There were statistically significant differences in image noise and SNR between 100 kV scan and conventional scan in patients with weight>50 kg(Z=-5.367,-4.650,P<0.05).The subjective evaluation scores of the two groups images were all greater than 3 points,all images could be used for clinical diagnosis.SSDE was 45.3%and 29.9%higher than CTDI_(vol)for 80 kV and 100 kV scans,respectively,SSDE was 45.7%and 28.8%higher than CTDI_(vol)for conventional sc

关 键 词：体型特异性剂量估算 肺炎支原体肺炎 计算机体层成像 辐射剂量 

分 类 号：R563.1[医药卫生—呼吸系统] R814.42[医药卫生—内科学]