【摘要】 本文对较小厚度范围内颌骨、金属铝在X片上的灰度水平与厚度变化关系进行了探讨,提出在数字减影牙片中以金属铝制成均匀楔形灰阶,代替传统金箔制成的台阶式灰阶.更多还原

【Abstract】 To improve the gray stepwedge, the gray level of bone and pure aluminum wedge were studied with thickness of wedge (0 -8mm) increasing. The results showed both of them represented good linear relations and no statistical difference existed between their linear relations, demonstrating their similar blocking ability to X -ray. Conclusion: Replacement of the gold stepwedge with a continuous wedge of aluminum will yield more precise and efficient reference for DSR.更多还原