A quantitative CBCT pipeline based on 2D antiscatter grid and grid-based scatter sampling for image-guided radiation therapy.
A quantitative CBCT pipeline based on 2D antiscatter grid and grid-based scatter sampling for image-guided radiation therapy.
复制标题
基于 2D 抗散射网格和基于网格的散射采样的定量 CBCT 管道，用于图像引导放射治疗。
DOI：
10.1002/mp.16681
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发表时间：
2023
期刊：
影响因子：
3.8
通讯作者：
Altunbas,Cem
中科院分区：
文献类型：
--
作者：
Bayat,Farhang;Ruan,Dan;Miften,Moyed;Altunbas,Cem
在放射治疗中，要将锥束CT （CBCT）成像的作用从目标定位扩展到定量治疗监测和计划适应，定量准确性至关重要。尽管CBCT图像质量改进方法取得了进展，但CBCT与多检测器CT （MDCT）之间的定量精度差距仍然存在。本研究研究了一种物理驱动的方法，该方法结合了鲁棒散射抑制、原始数据校正和迭代图像重建，以进一步提高CBCT图像质量和定量精度，称为定量CBCT （qCBCT）。方法sqcbct方法包括钨制二维防散射网格硬件、基于网格的散射采样残余散射校正、图像滞后和偏移探测器几何直线安装的CBCT波束硬化校正。采用迭代图像重建方法重建图像，降低图像噪声。qCBCT使用多种幻影进行评估，以研究物体大小及其组成对图像质量的影响，并以临床CBCT和用于治疗计划的金标准MDCT图像为基准对图像质量进行基准测试。结果与临床CBCT相比，qcbct在CT数准确性和图像伪影减少方面有统计学意义的提高。与金标准MDCT相比，qCBCT和临床CBCT的平均HU误差分别为17±9和38±29 HU。在MDCT和qCBCT图像之间，幻象大小相关的HU变化幅度具有可比性。通过迭代重建，与临床CBCT方案相比，对比噪声比提高了25%。结论新型散射抑制技术与其他数据校正方法相结合，qCBCT的CT数精度可与用于治疗计划的金标准MDCT相媲美。这种方法可能潜在地改善CBCT在图像引导放射治疗中完成要求高定量准确性的任务方面的前景，例如在线剂量计算和治疗反应评估。
BackgroundQuantitative accuracy is critical for expanding the role of cone beam CT (CBCT) imaging from target localization to quantitative treatment monitoring and plan adaptations in radiation therapy. Despite advances in CBCT image quality improvement methods, quantitative accuracy gap between CBCT and multi‐detector CT (MDCT) remains.PurposeIn this work, a physics‐driven approach was investigated that combined robust scatter rejection, raw data correction and iterative image reconstruction to further improve CBCT image quality and quantitative accuracy, referred to as quantitative CBCT (qCBCT).MethodsQCBCT approach includes tungsten 2D antiscatter grid hardware, residual scatter correction with grid‐based scatter sampling, image lag, and beam hardening correction for offset detector geometry linac‐mounted CBCT. Images were reconstructed with iterative image reconstruction to reduce image noise. qCBCT was evaluated using a variety of phantoms to investigate the effect of object size and its composition on image quality, and image quality was benchmarked against clinical CBCT and gold standard MDCT images used for treatment planning.ResultsQCBCT provided statistically significant improvement in CT number accuracy and reduced image artifacts when compared to clinical CBCT images. When compared to gold standard MDCT, mean HU errors in qCBCT and clinical CBCT were 17 ± 9 and 38 ± 29 HU, respectively. Magnitude of phantom size dependent HU variations were comparable between MDCT and qCBCT images. With iterative reconstruction, contrast‐to‐noise ratio improved by 25% when compared to clinical CBCT protocols.ConclusionsCombination of novel scatter suppression techniques and other data correction methods in qCBCT provided CT number accuracy comparable to gold standard MDCT used for treatment planning. This approach may potentially improve CBCT's promise in fulfilling the tasks that demand high quantitative accuracy, such as online dose calculations and treatment response assessment, in image guided radiation therapy.