CAJ | 학술논문

目的：探讨64层螺旋CT采用管电流自动调节技术在成人胸部CT扫描中获得稳定图像质量并降低辐射剂量的可行性。方法选择成人胸部CT扫描300例，随机分为研究组1、研究组2和对照组。研究组采用管电流自动调节扫描技术，研究组1与组2预设噪声指数（NI）分别为10、20；对照组采用固定管电流扫描技术。记录每位患者胸部扫描时的平均毫安秒(mAs)、容积CT剂量指数(CTDIvol)及剂量长度乘积(DLP)。由两位副主任医师独立对图像质量采用5分制进行评分，≥3分被认为符合临床诊断要求，并取每例患者肺尖部、主动脉弓水平、心脏水平及肺底部4幅图像，测量相应部位图像噪声并计算其平均值。结果图像质量评价，与对照组比较，NI为10时，肺窗、骨窗及纵隔窗图像接受率和主观噪声评分无明显差异（P＞0.05），NI为20时，肺窗、骨窗及纵隔窗的图像诊断接受率和主观噪声评分均降低，纵隔窗降低最明显，差异有统计学意义（P＜0.05），三组图像评分均达到了临床诊断接受标准。结论采用管电流自动调节技术行胸部CT扫描能在保证图像质量的前提下有效降低辐射剂量，应根据检查需求合理选择噪声指数。
목적：탐토64층라선CT채용관전류자동조절기술재성인흉부CT소묘중획득은정도상질량병강저복사제량적가행성。방법선택성인흉부CT소묘300례，수궤분위연구조1、연구조2화대조조。연구조채용관전류자동조절소묘기술，연구조1여조2예설조성지수（NI）분별위10、20；대조조채용고정관전류소묘기술。기록매위환자흉부소묘시적평균호안초(mAs)、용적CT제량지수(CTDIvol)급제량장도승적(DLP)。유량위부주임의사독립대도상질량채용5분제진행평분，≥3분피인위부합림상진단요구，병취매례환자폐첨부、주동맥궁수평、심장수평급폐저부4폭도상，측량상응부위도상조성병계산기평균치。결과도상질량평개，여대조조비교，NI위10시，폐창、골창급종격창도상접수솔화주관조성평분무명현차이（P＞0.05），NI위20시，폐창、골창급종격창적도상진단접수솔화주관조성평분균강저，종격창강저최명현，차이유통계학의의（P＜0.05），삼조도상평분균체도료림상진단접수표준。결론채용관전류자동조절기술행흉부CT소묘능재보증도상질량적전제하유효강저복사제량，응근거검사수구합리선택조성지수。
Objective??To?assess?the?feasibility?of?using?an?automatic?tube?current?modulation?(ATCM)?method?to?obtain?consistent?image?quality?and?reduce?radiation?dose?for?adult?undergoing?chest?scans?with?a?set?of?64-slice?spiral?CT.?Methods??300?adults?undergoing?chest?scans?on?a?GE?64-slice?VCT?were?equality?divided?into?three?groups?randomly.?The?automatic?tube?current?modulation?method?was?used?in?study?group?1?(NI=10)?and?study?group?2?(NI=20),?and?the?standard?tube?current?modulation?method?was?used?in?the?control?group.?The?average?mAs?value,volume?CT?dose?index?(CTDIvol)?and?dose?length?product?(DLP)?were?recorded?respectively.Two?deputy?chief?physicians?assessed?image?quality?on?a?5-point?scale?with?5?being?the?best.?Scores?greater?than?or?equal?to?3?were?considered?clinically?acceptable.?The?image?noise?was?measured?at?apex?of?lung,?lower?edge?of?aorta?arch,?middle?area?of?left?atrium?and?base?of?lung,?and?then?we?calculate?the?average.?Results??There?were?no?statistical?difference?in?diagnostic?acceptability?and?image?noise?scores?on?lung?window、bone window and mediastinal window among the three group when NI was 10. But there was signiifcant difference when NI was 20. All studies had?acceptable?image?quality.?Conclusion??With?reasonable?noise?index?setting,?one?may?obtain?clinically?acceptable?images?with?much?reduced?radiation?dose?using?the?automatic?tube?modulation?method.