Technical Note: On GAFChromic EBT-XD film and the lateral response artifact
Technical Note: On GAFChromic EBT-XD film and the lateral response artifact
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DOI：
10.1118/1.4939226
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发表时间：
2016-02-01
期刊：
影响因子：
3.8
通讯作者：
Chan, Maria F.
中科院分区：
文献类型：
--
作者：
Lewis, David F.;Chan, Maria F.
目的：新的辐射变色胶片GAFChromic EBT-XD含有与GAFChromic EBT 3相同的活性材料10，12-pentacosadiynoate锂，但结晶形式不同。这项工作调查的影响，这种变化对众所周知的横向响应伪影时，EBT-XD电影是数字化的平板scanner.Methods：的剂量响应的一个单一的生产批次的EBT-XD的特征在于扫描未曝光的电影加上一组电影暴露于2.5和50戈伊之间的剂量，使用6 MV光子。为了表征横向反应伪影，作者使用未曝光胶片加上暴露于20至50戈伊剂量的样本子集。这些胶片的数字图像是在三台Epson 10000 XL扫描仪上垂直于扫描方向的七个离散横向位置处获取的。使用在离散横向位置处的测量，确定作为胶片横向位置的函数的扫描仪响应。从每个扫描仪的数据，导出一组系数，由此可以校正测量的响应值以去除横向响应伪影的影响。EBT-XD的数据进行了分析，在他们以前的工作和EBT 3在该paper.Results报告的结果进行比较：对于在相同的方向扫描，并具有相等的响应的电影，作者发现，EBT-XD和EBT 3电影的横向响应伪影是非常相似的。对于这两种膜，伪影随着净响应的增加而增加。然而，由于EBT-XD的灵敏度低于EBT 3，因此需要更大的曝光剂量才能达到相同的净响应。在此基础上，较低的灵敏度EBT-XD相对于EBT 3的结果，在净响应变化较少，相等的曝光量和减少的影响的横向响应artifaction.Conclusions：的结晶活性成分的形状EBT-XD和EBT 3不影响的横向响应伪影的基本存在时，在平板扫描仪上的电影数字化。由于其较低的灵敏度，EBT-XD胶片需要更高的剂量才能达到与EBT 3相同的响应，从而导致横向响应伪影的影响较小。对于>10戈伊的剂量，EBT-XD红色和绿色通道剂量响应曲线的斜率大于EBT 3的相应斜率。由于这两个原因，作者更喜欢剂量超过约10戈伊的EBT-XD。2016年美国医学物理学家协会。
Purpose: The new radiochromic film, GAFChromic EBT-XD, contains the same active material, lithium-10,12-pentacosadiynoate, as GAFChromic EBT3, but the crystalline form is different. This work investigates the effect of this change on the well-known lateral response artifact when EBT-XD film is digitized on a flatbed scanner.Methods: The dose response of a single production lot of EBT-XD was characterized by scanning an unexposed film plus a set of films exposed to doses between 2.5 and 50 Gy using 6 MV photons. To characterize the lateral response artifact, the authors used the unexposed film plus a subset of samples exposed to doses between 20 and 50 Gy. Digital images of these films were acquired at seven discrete lateral locations perpendicular to the scan direction on three Epson 10000XL scanners. Using measurements at the discrete lateral positions, the scanner responses were determined as a function of the lateral position of the film From the data for each scanner, a set of coefficients were derived whereby measured response values could be corrected to remove the effects of the lateral response artifact. The EBT-XD data were analyzed as in their previous work and compared to results reported for EBT3 in that paper.Results: For films scanned in the same orientation and having equal responses, the authors found that the lateral response artifact for EBT-XD and EBT3 films was remarkably similar. For both films, the artifact increases with increased net response. However, as EBT-XD is less sensitive than EBT3, a greater exposure dose is required to reach the same net response. On this basis, the lower sensitivity of EBT-XD relative to EBT3 results in less net response change for equal exposure and a reduction in the impact of the lateral response artifact.Conclusions: The shape of the crystalline active component in EBT-XD and EBT3 does not affect the fundamental existence of the lateral response artifact when the films are digitized on flatbed scanners. Owing its lower sensitivity, EBT-XD film requires higher dose to reach the same response as EBT3, resulting in lesser impact of the lateral response artifact. For doses >10 Gy, the slopes of the EBT-XD red and green channel dose response curves are greater than the corresponding ones for EBT3. For these two reasons, the authors prefer EBT-XD for doses exceeding about 10 Gy. 2016 American Association of Physicists in Medicine.