CAJ | 학술논문

射线源焦点的大小与形状对射线检测图像质量有重要的影响，但在射线检测中却很少对射线源焦点进行实测，这不利于准确控制射线检测图像质量。对射线源焦点的测量方法进行对比试验分析，以获得对射线源焦点进行评估的有效便捷方法。分别应用小孔成像板、星形测试卡、双线型像质计(Image quality indicator, IQI)等测试体，对工业应用的便携式X射线机进行了焦点尺寸测量。用星形测试卡、双线型像质计所测算的焦点尺寸一致性较好，但较之小孔成像的测量结果却存在较大偏差。实际检测时射线机焦点大小可能与标称值明显不同，有必要对射线焦点特性进行及时评价；双线型像质计可一定程度上代替星形测试卡的使用，便捷地实现图像不清晰度的测量、射线源焦点尺寸的评估。
사선원초점적대소여형상대사선검측도상질량유중요적영향，단재사선검측중각흔소대사선원초점진행실측，저불리우준학공제사선검측도상질량。대사선원초점적측량방법진행대비시험분석，이획득대사선원초점진행평고적유효편첩방법。분별응용소공성상판、성형측시잡、쌍선형상질계(Image quality indicator, IQI)등측시체，대공업응용적편휴식X사선궤진행료초점척촌측량。용성형측시잡、쌍선형상질계소측산적초점척촌일치성교호，단교지소공성상적측량결과각존재교대편차。실제검측시사선궤초점대소가능여표칭치명현불동，유필요대사선초점특성진행급시평개；쌍선형상질계가일정정도상대체성형측시잡적사용，편첩지실현도상불청석도적측량、사선원초점척촌적평고。
Background:Image quality in radiographic testing is often conditioned by the size and distribution of X-ray source. However, determination of focal spot is not performed effectively in practice, thus it is difficult to accurately control the image quality in the testing.Purpose: This study aims to obtain a quick and efficient test method to evaluate the focal spot for X-ray source.Methods: Test tools such as pinhole plate, star test pattern and duplex wire image quality indicator (IQI) were used to measure the focal spot of a portable X-ray source separately. Several measurements were carried out and compared in details.Results: Results of star test pattern and duplex wire IQI were coincident, but different from the results of pinhole imaging method obviously.Conclusion: Nominal focal spot size of an X-ray source may be considerably different from that in practice use, so it is necessary to timely evaluate characteristics of the focal spot. The duplex wire IQI can usually replace star test pattern to measure un-sharpness in radiographic testing images and to evaluate focal spot size.