Faculty of Dentistry, Department of Oral Diagnosis and Oral Radiology, Ege University, Bornova, Izmir, Turkey.
J Appl Oral Sci. 2010 Jul-Aug;18(4):390-6. doi: 10.1590/s1678-77572010000400012.
To produce a copper (Cu) stepwedge with aluminum (Al) equivalent mean gray values (MGV).
The thicknesses of Cu steps that were equivalent to those of the Al were formulated using the X-ray attenuation properties of the materials. The Al and fabricated Cu stepwedges were radiographed, but the MGVs of the Cu stepwedge were mismatching to those of the Al. Using a mathematical function to adjust the pixel MGV of Cu stepwedge to those of the Al, new Cu stepwedges were created. In vitro iterations were performed until best approximation to Al was reached.
The MGV of the Cu stepwedges fabricated by formularization were different than those of Al (p=0.001). Iteration method led to MGV similar to those of the Al stepwedge (p=0.207).
Construction of a Cu stepwedge according to the basic rules of radiophysic failed to result in a stepwedge with similar radiodensity values to those of Al stepwedge. Further studies may use the formularization method only for prototype Cu wedge production, but consecutive iterations shall be compassed to obtain the best approximation to Al MGV.
制作具有与铝（Al）等效平均灰度值（MGV）的铜（Cu）台阶楔块。
使用材料的 X 射线衰减特性，制定出与 Al 厚度等效的 Cu 台阶厚度。对 Al 和制作的 Cu 台阶楔块进行射线照相，但 Cu 台阶楔块的 MGV 与 Al 不匹配。使用数学函数调整 Cu 台阶楔块的像素 MGV 以匹配 Al，从而创建新的 Cu 台阶楔块。进行体外迭代，直到达到与 Al 的最佳近似值。
通过公式化制作的 Cu 台阶楔块的 MGV 与 Al 的 MGV 不同（p=0.001）。迭代方法导致与 Al 台阶楔块相似的 MGV（p=0.207）。
根据放射物理学的基本规则制作 Cu 台阶楔块，无法得到与 Al 台阶楔块相似的放射密度值的台阶楔块。进一步的研究可以仅使用公式化方法进行原型 Cu 楔块的生产，但需要进行连续迭代以获得与 Al MGV 的最佳近似值。
