CAJ | 학술논문

目的：探讨噪声指数指导自动管电流调制技术对肺结核患者CT复查中降低辐射剂量的应用价值。方法 CATPHAN500模体测试，采用噪声指数10~27，每次增加1进行图像采集，共采集18组，图像采集分别用肺和标准算法重建，获得噪声指数与高对比分辨率的关系。初诊患者采用常规剂量（噪声指数10）扫描，诊断为肺结核后复查时采用低剂量（噪声指数17）扫描，记录扫描中自动生成的受检者X线剂量参数，包括CT容积剂量指数（CTDIvol）、剂量长度乘积（DLP），采用5分制双盲法对图像作量化评价，测量升主动脉的SD值。结果模体测试，高对比分辨率在噪声指数<19时，7LP/cm线对数均能清晰显示。初诊和复查时的图像质量主观评价均符合临床诊断要求。初诊及复查图像升主动脉SD值分别为（8.52±1.30）Hu、（13.90±2.37）Hu，差异有统计学意义（P<0.05），复查时图像噪声大于初查睦。CTDIvol、DPL初诊时分别为（9.87±2.23）mGy、（333.79±73.24）mGy.cm，复查时分别为（4.15±1.96）mGy、（139.91±63.86）mGy.cm，二者差异均有统计学意义（P<0.05）。结论噪声指数指导自动管电流调制技术用于肺结核CT复查，图像质量符合要求，且可降低对患者的辐射剂量。
목적：탐토조성지수지도자동관전류조제기술대폐결핵환자CT복사중강저복사제량적응용개치。방법 CATPHAN500모체측시，채용조성지수10~27，매차증가1진행도상채집，공채집18조，도상채집분별용폐화표준산법중건，획득조성지수여고대비분변솔적관계。초진환자채용상규제량（조성지수10）소묘，진단위폐결핵후복사시채용저제량（조성지수17）소묘，기록소묘중자동생성적수검자X선제량삼수，포괄CT용적제량지수（CTDIvol）、제량장도승적（DLP），채용5분제쌍맹법대도상작양화평개，측량승주동맥적SD치。결과모체측시，고대비분변솔재조성지수<19시，7LP/cm선대수균능청석현시。초진화복사시적도상질량주관평개균부합림상진단요구。초진급복사도상승주동맥SD치분별위（8.52±1.30）Hu、（13.90±2.37）Hu，차이유통계학의의（P<0.05），복사시도상조성대우초사목。CTDIvol、DPL초진시분별위（9.87±2.23）mGy、（333.79±73.24）mGy.cm，복사시분별위（4.15±1.96）mGy、（139.91±63.86）mGy.cm，이자차이균유통계학의의（P<0.05）。결론조성지수지도자동관전류조제기술용우폐결핵CT복사，도상질량부합요구，차가강저대환자적복사제량。
Objective Application value and significance of noise index guiding automatic tube current modulation technique in pulmonary tuberculosis review by CT scanning. Methods CATPHAN500 model test,between the noise index of 10~27,each 1 increase in image acquisition,which were collected in 18 groups,respectively with lung and standard reconstruction algorithm,to obtain the relationship of noise figure and high contrast resolution. Patients were randomly selected in our hospital during January 2012 year to January 2013 year,and they were diagnosed if pulmonary tuberculosis with conventional dose(noise index 10)CT scan of the chest,55 cases of the patients needed to review the diagnosis,using low dose in the review(noise index 17)of chest CT scan, record CT scanning their X-ray dose parameters of automatic generation in detail,including CT volume dose index(CTDIvol)and dose length product(DLP). By 2 radiologists using 5 points double blind method for quantitative evaluation of images,measured SD value of the ascending aorta,and all the data for statistical analysis using SPSS13.0 software. Results In the model test,the high contrast resolution was used when the noise figure was less than 19,7LP/cm pairs can clearly display. Subjective assessment of image quality in newly diagnosed group and review diagnosed group were consistent with the clinical diagnostic requirements. In newly diagnosed group and review group photos ascending aortic SD values were(8.52±1.30)Hu and(13.90±2.37)Hu, both two groups had statistics significant difference(P<0.05),and review diagnosed group photos noise were more than the newly diagnosed group. The average CTDIvol,DPL in newly diagnosed group were(9.87±2.23)mGy,(333.79±73.24)mGy. cm,and the average CTDIvol,DPL in review diagnosed group were(4.15±1.96)mGy,(139.91±63.86)mGy.cm,which the two groups’ difference had statistics significance respectively(P≤0.05). Conclusion Noise index guiding automatic tube current modulation technique in pulmonary tuberculosis review by CT scanning can significantly reduce the patient radiation dose, meanwhile images quality meet the clinical diagnostic requirements.