CAJ | 학술논문

目的对比研究DR与CR双面阅读成像系统辐射剂量与成像质量的关系.方法在相同的辐射剂量下用DR和CR双面阅读成像系统对ALVIM统计学摄影模体TRG进行曝光,记录摄影条件和模体表面入射剂量,然后固定此摄影条件kV值,选用不同mAs值(分别为3.2、4.0、4.3、4.8和5.2 mAs)用CR双面阅读成像系统对模体进行曝光,记录表面入射剂量,并将所获取的影像在图像诊断工作站显示器上由3名影像医师进行视读打分,按照5分值判断法评判,绘制ROC曲线,计算每种信号的判断概率值(Pdet),对不同摄影系统及条件下3名观察者对模体影像信息的判断概率平均值采用双因素方差分析(ANOVA)进行比较.结果在辐射剂量为137.5 μGy时,DR所摄取模体影像内容物中0.5 ～ 1.0 nun直径骨代替物和0.9 ～ 2.0 mm直径肌肉代替物的Pdet值分别是0.742～0.923和0.635 ～0.900,CR双面阅读成像系统所得模体影像内容物中上述直径的骨代替物和肌肉代替物的Pdet值分别是0.526 ～0.586和0.473 ～0.560;DR和CR双面阅读成像系统对不同直径的骨替代物ROC曲线Pdet相差为0.216 ～0.337,以直径1.0mm为著,相差0.337；二者对直径0.9～2.0mm的肌肉替代物相差为0.075 ～0.342,以直径2.0mm为著,相差0.342,差异有统计学意义(F =35.30,P＜0.01).当CR双面阅读系统的摄影条件增为75 kV、4.8 mAs时,辐射剂量为180.4μGy,两种摄影系统所摄取影像ROC曲线的Pdet值基本相同,二者对直径0.5～1.0 mm骨代替物ROC曲线的Pdet相差为-0.003 ～0.009；二者对直径0.9 ～2.0 mm肌肉代替物ROC曲线的Pdet 相差为～0.005 ～0.008,差异无统计学意义(F=5.23,P＞0.05).在相同的判断概率值Pdet下,CR双面阅读成像系统所用表面入射剂量为180.4 μGy,DR所用的表面入射剂量为137.5 μGy.结论在相同曝光条件下,DR对模体内容物的检出率高于CR双面成像系统；在获得相似图像质量时,DR的辐射剂量低于CR双面阅读成像系统. 目的對比研究DR與CR雙麵閱讀成像繫統輻射劑量與成像質量的關繫.方法在相同的輻射劑量下用DR和CR雙麵閱讀成像繫統對ALVIM統計學攝影模體TRG進行曝光,記錄攝影條件和模體錶麵入射劑量,然後固定此攝影條件kV值,選用不同mAs值(分彆為3.2、4.0、4.3、4.8和5.2 mAs)用CR雙麵閱讀成像繫統對模體進行曝光,記錄錶麵入射劑量,併將所穫取的影像在圖像診斷工作站顯示器上由3名影像醫師進行視讀打分,按照5分值判斷法評判,繪製ROC麯線,計算每種信號的判斷概率值(Pdet),對不同攝影繫統及條件下3名觀察者對模體影像信息的判斷概率平均值採用雙因素方差分析(ANOVA)進行比較.結果在輻射劑量為137.5 μGy時,DR所攝取模體影像內容物中0.5 ～ 1.0 nun直徑骨代替物和0.9 ～ 2.0 mm直徑肌肉代替物的Pdet值分彆是0.742～0.923和0.635 ～0.900,CR雙麵閱讀成像繫統所得模體影像內容物中上述直徑的骨代替物和肌肉代替物的Pdet值分彆是0.526 ～0.586和0.473 ～0.560;DR和CR雙麵閱讀成像繫統對不同直徑的骨替代物ROC麯線Pdet相差為0.216 ～0.337,以直徑1.0mm為著,相差0.337；二者對直徑0.9～2.0mm的肌肉替代物相差為0.075 ～0.342,以直徑2.0mm為著,相差0.342,差異有統計學意義(F =35.30,P＜0.01).噹CR雙麵閱讀繫統的攝影條件增為75 kV、4.8 mAs時,輻射劑量為180.4μGy,兩種攝影繫統所攝取影像ROC麯線的Pdet值基本相同,二者對直徑0.5～1.0 mm骨代替物ROC麯線的Pdet相差為-0.003 ～0.009；二者對直徑0.9 ～2.0 mm肌肉代替物ROC麯線的Pdet 相差為～0.005 ～0.008,差異無統計學意義(F=5.23,P＞0.05).在相同的判斷概率值Pdet下,CR雙麵閱讀成像繫統所用錶麵入射劑量為180.4 μGy,DR所用的錶麵入射劑量為137.5 μGy.結論在相同曝光條件下,DR對模體內容物的檢齣率高于CR雙麵成像繫統；在穫得相似圖像質量時,DR的輻射劑量低于CR雙麵閱讀成像繫統.
목적 대비연구DR여CR쌍면열독성상계통복사제량여성상질량적관계.방법 재상동적복사제량하용DR화CR쌍면열독성상계통대ALVIM통계학섭영모체TRG진행폭광,기록섭영조건화모체표면입사제량,연후고정차섭영조건kV치,선용불동mAs치(분별위3.2、4.0、4.3、4.8화5.2 mAs)용CR쌍면열독성상계통대모체진행폭광,기록표면입사제량,병장소획취적영상재도상진단공작참현시기상유3명영상의사진행시독타분,안조5분치판단법평판,회제ROC곡선,계산매충신호적판단개솔치(Pdet),대불동섭영계통급조건하3명관찰자대모체영상신식적판단개솔평균치채용쌍인소방차분석(ANOVA)진행비교.결과 재복사제량위137.5 μGy시,DR소섭취모체영상내용물중0.5 ～ 1.0 nun직경골대체물화0.9 ～ 2.0 mm직경기육대체물적Pdet치분별시0.742～0.923화0.635 ～0.900,CR쌍면열독성상계통소득모체영상내용물중상술직경적골대체물화기육대체물적Pdet치분별시0.526 ～0.586화0.473 ～0.560;DR화CR쌍면열독성상계통대불동직경적골체대물ROC곡선Pdet상차위0.216 ～0.337,이직경1.0mm위저,상차0.337；이자대직경0.9～2.0mm적기육체대물상차위0.075 ～0.342,이직경2.0mm위저,상차0.342,차이유통계학의의(F =35.30,P＜0.01).당CR쌍면열독계통적섭영조건증위75 kV、4.8 mAs시,복사제량위180.4μGy,량충섭영계통소섭취영상ROC곡선적Pdet치기본상동,이자대직경0.5～1.0 mm골대체물ROC곡선적Pdet상차위-0.003 ～0.009；이자대직경0.9 ～2.0 mm기육대체물ROC곡선적Pdet 상차위～0.005 ～0.008,차이무통계학의의(F=5.23,P＞0.05).재상동적판단개솔치Pdet하,CR쌍면열독성상계통소용표면입사제량위180.4 μGy,DR소용적표면입사제량위137.5 μGy.결론 재상동폭광조건하,DR대모체내용물적검출솔고우CR쌍면성상계통；재획득상사도상질량시,DR적복사제량저우CR쌍면열독성상계통.
Objective To compare imaging quality and radiation dose on DR and dual-sided reading of CR system.Methods The TRG of ALVIM statistics phantom was exposed by DR and dual-sided reading of CR with the same radiation dose,then the exposure factor and the entrance surface dose (ESD) were recorded.After that,the phantom was exposed by dual-sided reading of CR with various mAs ( 3.2,4.0,4.3,4.8 and 5.2 mAs) and the same kV,and the ESD was recorded,too.The acquired images were read by three radiologists on the monitor of diagnosis work station with the same window width and window level,then the total points of the images were given with the method of a five-level confidence scale.ROC curves were drawn and probability Pdet was calculated.Then the data was analyzed statistically by analysis of variance (ANOVA).Results The ROC analysis of bone substitute with diameter from 0.5 to 1.0 mm and muscle substitute with diameter from 0.9 to 2.0 mm showed A (z) values of 0.742 to 0.923 and 0.635 to 0.900 for DR system when the radiation dose was 137.5 μGy.The ROC analysis of bone substitute and muscle substitute showed A(z) values of 0.526 to 0.586 and 0.473 to 0.560 for dual-sided reading of CR at the same radiation dose.The probability Pdet discrepancy of bone substitute in two systems was from 0.216 to 0.337,with the highest of 0.337 in the diameter of 1.0 mm.The probability Pdet discrepancy by muscle substitute in two systems was from 0.075 to 0.342,with the highest of 0.342 in the diameter of 2.0 mm.There was significant statistical difference between the two groups ( F =35.30,P ＜ 0.01 ).When the exposure factor of dual-sided reading of CR system was 75 kV,4.8 mAs,the ESD was 180.4 μ Gy,the ROC analysis in the bone substitute with diameter from 0.5 to 1.0 mm and muscle substitute with diameter from 0.9 to 2.0 mm showed A(z) values was the same.The probability Pdet discrepancy of bone substitute in two systems was from - 0.003 to 0.009.The probability Pdet discrepancy of muscle substitute in two systems was from -0.005 to 0.008,and there was no statistical difference between the two groups ( F =5.23,P ＞0.05).When the probability Pdet of two systems was the same,the ESD was 180.4 μGy by dual-sided reading of CR system,and the ESD was 137.5 μGy by DR system.Conclusion Detection with DR system was proved to be superior to dual-sided reading of CR system at the same radiation dose.When the image quality was similar,the radiation dose of DR system was less than the dual-sided reading of CR system.