影响Radiographic Quality之三要素： Density(黑化度)-mAs Contrast(对比度)-kVp Sharpness(清晰度)-motion,Geometric Distortion(失真度)-position,angle 影响Radiographic Quality之三要素： Density （黑化度）- mAs Contrast（对比度）- kVp Sharpness（清晰度）- motion, Geometric Distortion（失真度）- position, angle