Mean glandular dose coefficients (D(g)N) for x-ray spectra used in contemporary breast imaging systems.
Mean glandular dose coefficients (D(g)N) for x-ray spectra used in contemporary breast imaging systems.
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DOI：
10.1088/0031-9155/60/18/7179
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发表时间：
2015-09-21
影响因子：
3.5
通讯作者：
Boone JM
中科院分区：
文献类型：
--
作者：
Nosratieh A;Hernandez A;Shen SZ;Yaffe MJ;Seibert JA;Boone JM
为当代乳腺成像系统中使用的一系列阳极-滤光器组合和管电压，建立归一化腺体剂量系数DgN表。先前发表的单能DgN值与各种光谱一起用于数学计算DgN系数。采用TASMICS的钨阳极光谱；利用MCNPx蒙特卡罗代码生成钼和铑阳极光谱。用不同厚度的Al、Rh、Mo或Cu对光谱进行过滤。使用阳极和过滤材料进行了初步的HVL计算。通过添加小厚度的聚甲基丙烯酸甲酯（PMMA）作为乳房压缩桨的替代品，产生一系列HVL值，以在每个管电压下产生一系列HVL值。采用谱加权法，计算了乳腺密度为0%、12.5%、25%、37.5%、50%和100%时，压缩乳腺厚度为3 ~ 8 cm时生成的谱的DgN系数。分别为W + 50 μm Ag、W + 500 μm Al、W + 700 μm Al、W + 200 μm Cu、W + 300 μm Cu、W + 50 μm Rh、Mo + 400 μm Cu、Mo + 30 μm Mo、Mo + 25 μm Rh、Rh + 400 μm Cu和Rh + 25 μm Rh制备了11个标准化腺剂量（DgN）系数表。在可能的情况下，将这些结果与先前公布的DgN值进行比较，发现与先前报告的值平均差异小于2%。超过200页的DgN系数计算用于许多新的乳房成像应用的模拟x射线系统光谱。报告的值被发现是非常一致的，当比较公布的值。
To develop tables of normalized glandular dose coefficients DgN for a range of anode–filter combinations and tube voltages used in contemporary breast imaging systems. Previously published mono-energetic DgN values were used with various spectra to mathematically compute DgN coefficients. The tungsten anode spectra from TASMICS were used; Molybdenum and Rhodium anode-spectra were generated using MCNPx Monte Carlo code. The spectra were filtered with various thicknesses of Al, Rh, Mo or Cu. An initial HVL calculation was made using the anode and filter material. A range of the HVL values was produced with the addition of small thicknesses of polymethyl methacrylate (PMMA) as a surrogate for the breast compression paddle, to produce a range of HVL values at each tube voltage. Using a spectral weighting method, DgN coefficients for the generated spectra were calculated for breast glandular densities of 0%, 12.5%, 25%, 37.5%, 50% and 100% for a range of compressed breast thicknesses from 3 to 8 cm. Eleven tables of normalized glandular dose (DgN) coefficients were produced for the following anode/filter combinations: W + 50 μm Ag, W + 500 μm Al, W + 700 μm Al, W + 200 μm Cu, W + 300 μm Cu, W + 50 μm Rh, Mo + 400 μm Cu, Mo + 30 μm Mo, Mo + 25 μm Rh, Rh + 400 μm Cu and Rh + 25 μm Rh. Where possible, these results were compared to previously published DgN values and were found to be on average less than 2% different than previously reported values. Over 200-pages of DgN coefficients were computed for modeled x-ray system spectra that are used in a number of new breast imaging applications. The reported values were found to be in excellent agreement when compared to published values.