CAJ | 학술논문

目的研究儿童低剂量CT尿路成像的临床实践可行性.方法对2010年12月至2012年4月30例经腹部超声(ultrasonography,USG)检查怀疑有尿路梗阻或畸形的患儿行低剂量CT尿路成像(CT Urography,CTU)检查.低剂量措施包括:取消平扫,直接行增强后实质期和分泌期扫描;降低扫描预设参数,对于体重＞25 kg的患儿参数设定为100 kV/50 mAs(低剂量CTU1),对于体重≤25 kg的患儿参数设定为80 kV/40 mAs(低剂量CTU2).以肾轮廓及三维图像整体观的清晰度高低、肾盂周围伪影影响诊断与否为分级标准,对图像质量进行优、良、差三级评价,计算评为良以上图像(合格图像)的百分率.根据术后及/或随访结果,统计低剂量CTU的临床诊断符合率.应用低剂量CTU及儿童常规剂量CTU(扫描预设参数为120 kV/85 mAs)进行儿童体部模体扫描,计算辐射剂量长度积(dose length products,DLP)并进行统计分析和比较.结果本组低剂量CTU的符合诊断标准图像的合格率,以肾盂为观察指标,合格率为98.3％,以肾轮廓及三维图像为观察指标,合格率为100％,临床诊断符合率为100％.低剂量CTU1、低剂量CTU2、64层螺旋CT儿童常规CTU、双源CT儿童常规CTU的2期扫描总体DLP分别为62、20、212和184 mGy×cm,采用低剂量CTU措施的模体扫描DLP较儿童常规CTU明显降低.其中,低剂量CTU1剂量分别比64层螺旋CT和双源CT(dual sorce CT,DSCT)常规序列减少了66.3％和90.6％,低剂量CTU2剂量比原来64层螺旋CT和DSCT的儿童常规CTU的4期剂量减少了83.2％和95.3％.结论针对儿童,通过合理简化扫描步骤和降低扫描参数,完全可以获得符合诊断要求的CTU图像,辐射剂量较常规序列大大降低,值得在临床实践中推广应用.
목적 연구인동저제량CT뇨로성상적림상실천가행성.방법 대2010년12월지2012년4월30례경복부초성(ultrasonography,USG)검사부의유뇨로경조혹기형적환인행저제량CT뇨로성상(CT Urography,CTU)검사.저제량조시포괄:취소평소,직접행증강후실질기화분비기소묘;강저소묘예설삼수,대우체중＞25 kg적환인삼수설정위100 kV/50 mAs(저제량CTU1),대우체중≤25 kg적환인삼수설정위80 kV/40 mAs(저제량CTU2).이신륜곽급삼유도상정체관적청석도고저、신우주위위영영향진단여부위분급표준,대도상질량진행우、량、차삼급평개,계산평위량이상도상(합격도상)적백분솔.근거술후급/혹수방결과,통계저제량CTU적림상진단부합솔.응용저제량CTU급인동상규제량CTU(소묘예설삼수위120 kV/85 mAs)진행인동체부모체소묘,계산복사제량장도적(dose length products,DLP)병진행통계분석화비교.결과 본조저제량CTU적부합진단표준도상적합격솔,이신우위관찰지표,합격솔위98.3％,이신륜곽급삼유도상위관찰지표,합격솔위100％,림상진단부합솔위100％.저제량CTU1、저제량CTU2、64층라선CT인동상규CTU、쌍원CT인동상규CTU적2기소묘총체DLP분별위62、20、212화184 mGy×cm,채용저제량CTU조시적모체소묘DLP교인동상규CTU명현강저.기중,저제량CTU1제량분별비64층라선CT화쌍원CT(dual sorce CT,DSCT)상규서렬감소료66.3％화90.6％,저제량CTU2제량비원래64층라선CT화DSCT적인동상규CTU적4기제량감소료83.2％화95.3％.결론 침대인동,통과합리간화소묘보취화강저소묘삼수,완전가이획득부합진단요구적CTU도상,복사제량교상규서렬대대강저,치득재림상실천중추엄응용.
Objective To evaluate the clinical feasibility of applying low-dose CT urography (CTU) in children.Methods From December 2010 to April 2012,30 children with suspected urinary malformation on screening ultrasonography (USG) undertook low-dose CTU examinations.The lowdose steps were prescribed as follows:eliminating plane scan and post-contrast parenchymal and excretory phase scanning; The preset scan procotols were modified as 100 kV/50 mAs for body weight above 25 Kg (CTU1) and 80 kV/40 mAs for body weight no more than 25 Kg (CTU2).The image quality was evaluated as good,average and poor based on the clarity of kidney outline,three-dimensional image overview and renal pelvis.The images of good or average quality were considered eligible and their rates calculated.Based on intraoperative findings and follow-ups,the diagnostic rate of lowv dose CTU was acquired.Phantom scanning dose(dose length products,DLP)with low-dose CTU and routine CTU (120 kV/85 mAs) protocols were compared.Results The image eligible rate of lowv dose CTU was 98.3％-100％ (98.3％ for renal pelvis,100％ for kidney and three-dimensional overview).The diagnostic rate of low-dose CTU was 100％.The 2 phase DLP of phantom scanning with low-dose CTU1,CTU2,64 spiral CT routine CTU,dual-source CT (DSCT) routine CTU protocols were 62,20,212 and 184 mGy cm respectively.Phantom scanning dose with low dose CTU protocols decreased 66.3％ and 90.6％ versus that of routine protocols.And it also decreased 83.2％ and 95.3％ than that of 4-phase routines.Conclusions Through expedited steps and protocol modification,low-dose CTU imaging for children is feasible and qualified for clinical diagnosis.It is recommended for clinical application.