Central axis tissue--air ratios as a function of area-perimeter at depth and their applicability to irregularly shaped fields.
Central axis tissue--air ratios as a function of area-perimeter at depth and their applicability to irregularly shaped fields.
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中心轴组织-空气比率作为深度面积-周长的函数及其对不规则形状区域的适用性。
DOI：
10.1088/0031-9155/17/4/008
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发表时间：
1972
影响因子：
3.5
通讯作者：
D. Wrede
中科院分区：
文献类型：
--
作者：
D. Wrede
使用 Gupta 和 Cunningham 的方形视场原始数据，绘制了一系列中心轴组织空气比 (TAR) 曲线，作为深度面积的函数，除以周长 (A/P) 以获得固定的深度值。通过等剂量绘图仪，实验获得了地幔场深度达 30 cm 的 TAR 值，以及其他形状不规则区域达 10 cm 的 TAR 值。将这些值与表格值进行比较，以评估方场 A/P 作为常规确定中轴 TAR 值的方便参数的有效性。使用了常见的矩形、L形、五边形和特殊的地幔形状。在所有情况下，使用 A/P 作为 TAR 值的确定标准导致与表格方形字段值的差异小于 3%。
Families of central axis tissue-air ratio (TAR) curves as a function of area at depth, divided by perimeter (A/P) for fixed values of depth, were plotted and tabulated using the original data of Gupta and Cunningham for square fields. By means of an isodose plotter, values of TAR were experimentally obtained up to depths of 30 cm for mantle field, and up to 10 cm for other irregularly shaped fields. These were compared with the tabulated values in order to evaluate the validity of square fieldA/P's as a convenient parameter for the routine determination of central axis TAR values. Rectangular, L, pentagonal and special mantle shapes, which are all frequently encountered, were used. In all cases, the use of A/P as the determining criterion for values of TAR resulted in less than 3% difference from the tabulated square field values.