Experimental evaluation of fiber-interspaced antiscatter grids for large patient imaging with digital x-ray systems
Experimental evaluation of fiber-interspaced antiscatter grids for large patient imaging with digital x-ray systems
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DOI：
10.1088/0031-9155/52/16/010
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发表时间：
2007-08-21
影响因子：
3.5
通讯作者：
Schueler, Beth A.
中科院分区：
文献类型：
--
作者：
Fetterly, Kenneth A.;Schueler, Beth A.
X射线散射会影响大体型患者的放射成像。用于投影射线照相术的数字X射线成像系统的优化需要使用尽可能最好的防散射滤线栅。与数字X射线成像系统结合使用的防散射滤线栅的性能可以通过测量信噪比（SNR）改善因子（KSNR）来表征。几种线性聚焦防散射滤线栅的SNR改善因子是根据滤线栅的基本初级和散射透射分数测量值以及X射线束和散射体模的固有散射-初级比（SPR）确定的。固有的SPR和散射透射分数测量使用一个渐进的铅束停止方法。测量了8个网格的KSNR，其中线率（N）在40至80 cm（-1）的范围内，比率（r）在8：1至15：1的范围内。所有的网格都有纤维空隙材料和碳纤维覆盖物。使用的散射体模是固体水（（R）），厚度为10至50 cm，使用30 x 30 cm（2）视野。所有测量值均使用104 kVp X射线束获得。非网格成像条件的SPR范围从10 cm体模的2.55到50 cm体模的25.9。散射透射分数范围从N50 r15网格的0.083下限到N40 r8网格的0.22上限，一次透射分数范围从N80 r15网格的0.69下限到N40 r8网格的0.76下限。SNR改善因子的范围从10 cm体模和N40 r8网格的1.2到50 cm体模和性能最佳的N50 r15、N44 r15和N40 r14网格的2.09。
Radiographic imaging of large patients is compromised by x-ray scatter. Optimization of digital x-ray imaging systems used for projection radiography requires the use of the best possible antiscatter grid. The performance of antiscatter grids used in conjunction with digital x- ray imaging systems can be characterized through measurement of the signal-to-noise ratio (SNR) improvement factor (KSNR). The SNR improvement factor of several linear, focused antiscatter grids was determined from measurements of the fundamental primary and scatter transmission fraction measurements of the grids as well as the inherent scatter-to-primary ratio (SPR) of the x- ray beam and scatter phantom. The inherent SPR and scatter transmission fraction was measured using a graduated lead beam stop method. The KSNR of eight grids with line rates (N) in the range 40 to 80 cm(-1) and ratios ( r) in the range 8: 1 to 15: 1 was measured. All of the grids had fiber interspace material and carbon-fiber covers. The scatter phantom used was Solid Water ((R)) with thickness 10 to 50 cm, and a 30 x 30 cm(2) field of view was used. All measurements were acquired using a 104 kVp x- ray beam. The SPR of the non-grid imaging condition ranged from 2.55 for the 10 cm phantom to 25.9 for the 50 cm phantom. The scatter transmission fractions ranged from a low of 0.083 for the N50 r15 grid to a high of 0.22 for the N40 r8 grid and the primary transmission fractions ranged from a low of 0.69 for the N80 r15 grid to 0.76 for the N40 r8 grid. The SNR improvement factors ranged from 1.2 for the 10 cm phantom and N40 r8 grid to 2.09 for the 50 cm phantom and the best performing N50 r15, N44 r15 and N40 r14 grids.