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目的 :探讨西门子内置 2 9对多叶光栅的适形效果以及优化方法。方法 :随机生成 2 0例形状各异的面积界于 2 2× 2 2cm2 和 2× 2cm2 二维封闭曲线 ,采用两种方法让多叶光栅生成上述形状 :a .全自动生成 ;b .根据曲线的最长径方向调整光阑角度后再生成。然后按生成形状照射到胶片上 ,运用胶片剂量分析软件分析剂量结果。结果 :适形效果与射野大小、形状有较大关系 ,b方法的适形效果普遍强于a方法。结论 :当射野等效面积满足一定大小时 ,通过合理的优化方案 ,运用多叶光栅可以获得较好的适形效果
Objective: To discuss the conformal effect and optimization method of Siemens built-in 29 pairs of multi-lobe gratings. Methods: Twenty cases with different shapes were randomly generated in 2 2 × 2 2 cm 2 and 2 × 2 cm 2 two-dimensional closed curves. Two methods were adopted to generate the above shape for the multi-leaf grating: a. Fully automatic generation; b. The longest diameter direction of the aperture angle adjustment and then generated. The resulting shape is then irradiated onto the film and the dose result is analyzed using film dose analysis software. Results: The conformal effect has a great relationship with the size and shape of the field. The conformal effect of method b is generally stronger than that of a method. Conclusion: When the equivalent area of the radio field satisfies a certain size, a good conformal effect can be obtained by using a multi-leaf grating through a reasonable optimization scheme