医用诊断X线管焦点辐射对焦点MTF的影响

EFFECT OF OFF-FOCUS RADIATION ON MODULATION TRANSFER FUNCTION MTF OF THE FOCAL SPOT

医用诊断X线管焦点的调制传递函数MTF值为评价X线管焦点成像性能的一重要参数。对具有焦点外辐射的焦点MTF计算方法以及焦点外辐射对焦点MTF的影响尚未见报道。本文结合实验研究和理论推导得到了焦点外辐射的焦点MTF计算公式,并对两X线管的四个焦点进行了测量研究。

The Modulation Transfer Function (MTF) of X-ray tube is an impertant parameter to evoluate the imaging character of diagnostic X-ray tube. The effect of magnification on MTF has beer studied, bud the effect of off-focus radiation on MTF of focal spot has not been reportes MTF calculating equation of off-focus radiation and the measures of four focuses of tow tubes are provided in this paper.