摘要
目的:基于对称性器官X线照片影像左右两侧光学密度不对称的现象,解疑X线管短轴方向的X线强度分布是否相等。方法:在与X线管短轴方向平行的各照射野面积的中线上,设计一个中心测试点及若干内、外侧缘测试点,用表面剂量仪测试3组曝光条件下,各照射野面积内、外侧缘的平均接受剂量是否相等。结果:10cm×12.5cm、12.5cm×17.5cm、20cm×25cm、25cm×30cm照射野的内侧缘平均接受剂量依次为:2.47μGy、1.40μGy、2.10μGy及2.74μGy。外侧缘平均接受剂量依次为:14.26μGy、11.46μGy、19.61μGy及4.98μGy。结论:①3组曝光条件下,照射野面积不同,短轴方向上的平均接受剂量外侧缘均大于内侧缘;②因照射野短轴方向内、外侧缘的平均接受剂量不相等。所以,在X线管短轴方向上的X线强度分布不相等。
Objective: To study density difference of symmetrical organs images between the left and right and explain consistency of X-ray intensity distribution on the short axis of X-ray tube. Methods: On a line across the short center axis of X-ray tube, three points (center point, point close to verge inside, point close to verge outside) were determined, the skin doses of three points were measured. Results: Corresponding to the exposure field of 10cm×12.5cm, 12.5cm×17.5cm, 20cm×25cm, 25cm×30cm, the doses of point close to verge inside were 2.47, 1.40, 2.10, 2.74μGy, the ones of points close to verge outside, 14.26, 11.46, 19.61, 4.98μGy respectively. Conclusion: ①The dosage outside exposure field on X-ray short axis is higher than inside; ②The X-ray intensity on X-ray short axis is not identical.
出处
《医学影像学杂志》
2006年第3期293-295,共3页
Journal of Medical Imaging
关键词
X线管短轴方向
X线强度分布
X-ray short axis, X-ray intensity distribution