重庆医科大学学报
重慶醫科大學學報
중경의과대학학보
UNIVERSITATIS SCIENTIAE MEDICINAE CHONGQING
2009年
11期
1517-1520
,共4页
曾勇明%吴富荣%张志伟%罗天友%欧阳羽
曾勇明%吳富榮%張誌偉%囉天友%歐暘羽
증용명%오부영%장지위%라천우%구양우
数字X线摄影%仿真体模%模拟病变%辐射剂量
數字X線攝影%倣真體模%模擬病變%輻射劑量
수자X선섭영%방진체모%모의병변%복사제량
Digital radiography%Anthropomorphic phantom%Simulated lesion%Radiation dose
目的:前瞻性研究不同X线辐射剂量与图像质量的相关性,以探索数字X线摄影(Digital radiography,DR)最适宜曝光量.方法:在仿真胸部体模中放置模拟网状、线状和结节病变结构.用125 kVp不同mAs,对体模及分辨率测试卡进行DR成像.4位放射陕师分别对所有图像进行阅片评分,同时测量入射体表剂量(Entrance surface dose,ESD)、均方根(Root mean squar,RMS)和空间分辨率.结果:ESD随着mAs的增加会增加,而RMS随着mAs的增加会降低;ESD增加至一定量时,空间分辨率达到极限值.曝光指数(Exposure index,EI)值1800以下的图像模拟微小结节显示不清,EI值2000以上的图像对模拟病变的检出高.结论:在保证DR图像质量的前提下,最优化的曝光剂量可以有效地减少辐射损伤.
目的:前瞻性研究不同X線輻射劑量與圖像質量的相關性,以探索數字X線攝影(Digital radiography,DR)最適宜曝光量.方法:在倣真胸部體模中放置模擬網狀、線狀和結節病變結構.用125 kVp不同mAs,對體模及分辨率測試卡進行DR成像.4位放射陝師分彆對所有圖像進行閱片評分,同時測量入射體錶劑量(Entrance surface dose,ESD)、均方根(Root mean squar,RMS)和空間分辨率.結果:ESD隨著mAs的增加會增加,而RMS隨著mAs的增加會降低;ESD增加至一定量時,空間分辨率達到極限值.曝光指數(Exposure index,EI)值1800以下的圖像模擬微小結節顯示不清,EI值2000以上的圖像對模擬病變的檢齣高.結論:在保證DR圖像質量的前提下,最優化的曝光劑量可以有效地減少輻射損傷.
목적:전첨성연구불동X선복사제량여도상질량적상관성,이탐색수자X선섭영(Digital radiography,DR)최괄의폭광량.방법:재방진흉부체모중방치모의망상、선상화결절병변결구.용125 kVp불동mAs,대체모급분변솔측시잡진행DR성상.4위방사협사분별대소유도상진행열편평분,동시측량입사체표제량(Entrance surface dose,ESD)、균방근(Root mean squar,RMS)화공간분변솔.결과:ESD수착mAs적증가회증가,이RMS수착mAs적증가회강저;ESD증가지일정량시,공간분변솔체도겁한치.폭광지수(Exposure index,EI)치1800이하적도상모의미소결절현시불청,EI치2000이상적도상대모의병변적검출고.결론:재보증DR도상질량적전제하,최우화적폭광제량가이유효지감소복사손상.
Objective: To prospectively research the correlation between the radiation dose and image quality in order to explore the optimization of exposure dose for digital radiography (DR). Methods:Simulated reticular, linear,and nodular structures were located in an anthropomorphic chest phantom.The phantom and resolution wedge were exposed by DR system with the same kilovoltage values (125 kVp) and different mAs sets.Four radiologists assessed all of the images.In addition,the entrance surface dose (ESD),root mean squar (RMS) and resolution were measured. Results:ESD was increasing along with mAs's enhancement,but RMS was decreasing when mAs was increasing. As long as the ESD increased to a certain degree, spatial resolution would go up to the limit. Images obtained with lower dose (EI<1800)were obscure at the tiny nodular structure.Images of 2 000 El value could show clearly the Simulated lesion. Conclusion: The optimization of exposure dose for DR imaging may effectively decrease radiation injuries under the precondition of DR image quality to be guaranteed.