Feasibility of dual-energy CBCT material decomposition in the human torso with 2D anti-scatter grids and grid-based scatter sampling.
Feasibility of dual-energy CBCT material decomposition in the human torso with 2D anti-scatter grids and grid-based scatter sampling.
复制标题
利用二维抗散射网格和基于网格的散射采样对人体躯干进行双能 CBCT 材料分解的可行性。
DOI：
10.1002/mp.16611
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发表时间：
2024
期刊：
影响因子：
3.8
通讯作者：
Altunbas,Cem
中科院分区：
文献类型：
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作者：
Altunbas,Cem
背景锥形束计算机断层扫描（CBCT）中的双能量（DE）成像技术具有潜在的临床应用，包括材料定量和改善组织可视化。然而，DE CBCT的性能受到散射辐射的影响的限制，这限制了其用于小物体imaging.PurposeThis研究探讨了DE CBCT材料分解的可行性，通过减少散射与二维抗散射网格和基于测量的散射校正方法。具体而言，调查重点是碘定量准确性和虚拟单能（VME）成像的幻影，模仿头部，胸部，腹部和骨盆anatomis.MethodsA 2D反散射网格原型与残余散射校正方法在直线加速器安装CBCT系统中使用，以研究在DE CBCT的强大的散射抑制的影响。使用模拟头部、胸部和腹部/骨盆解剖结构的体模在90和140 kVp下采集扫描。将不同浓度的碘小瓶放置在每个体模中，CBCT图像被分解为碘和水基材料图像。评价了2D抗散射滤线栅（有和无残余散射校正）对VME图像中碘浓度定量和造影剂可视化的影响。基准碘浓度定量准确性，一组类似的实验和DE处理也进行了与传统的多探测器CT scanner.ResultsIn CBCT图像，一个二维网格与或不散射校正可以区分碘和水DE处理后，在人体躯干大小的幻影图像。然而，当仅使用2D网格时，碘定量误差在骨盆体模中高达10 mg/mL。在2D网格CBCT中添加散射校正，可将骨盆体模中的碘定量误差降低至1.5 mg/mL以下，与多探测器CT中的碘定量误差相当。虽然在VME CBCT图像中没有观察到明显的对比度噪声比改善，在所有研究的体模尺寸中，与90和140 kVp CBCT图像进行视觉比较，40 keV VME图像中的对比度可视化明显更好。结论本研究表明，如果使用2D防散射网格和剩余能量来实现强大的散射抑制，则在人体躯干的DE CBCT中，准确的DE分解可能是可行的。散射校正这种方法可以在各种CBCT应用中实现更好的对比度可视化以及组织和造影剂定量。
BackgroundDual‐energy (DE) imaging techniques in cone‐beam computed tomography (CBCT) have potential clinical applications, including material quantification and improved tissue visualization. However, the performance of DE CBCT is limited by the effects of scattered radiation, which restricts its use to small object imaging.PurposeThis study investigates the feasibility of DE CBCT material decomposition by reducing scatter with a 2D anti‐scatter grid and a measurement‐based scatter correction method. Specifically, the investigation focuses on iodine quantification accuracy and virtual monoenergetic (VME) imaging in phantoms that mimic head, thorax, abdomen, and pelvis anatomies.MethodsA 2D anti‐scatter grid prototype was utilized with a residual scatter correction method in a linac‐mounted CBCT system to investigate the effects of robust scatter suppression in DE CBCT. Scans were acquired at 90 and 140 kVp using phantoms that mimic head, thorax, and abdomen/pelvis anatomies. Iodine vials with varying concentrations were placed in each phantom, and CBCT images were decomposed into iodine and water basis material images. The effect of a 2D anti‐scatter grid with and without residual scatter correction on iodine concentration quantification and contrast visualization in VME images was evaluated. To benchmark iodine concentration quantification accuracy, a similar set of experiments and DE processing were also performed with a conventional multidetector CT scanner.ResultsIn CBCT images, a 2D grid with or without scatter correction can differentiate iodine and water after DE processing in human torso‐sized phantom images. However, iodine quantification errors were up to 10 mg/mL in pelvis phantoms when only the 2D grid was used. Adding scatter correction to 2D‐grid CBCT reduced iodine quantification errors below 1.5 mg/mL in pelvis phantoms, comparable to iodine quantification errors in multidetector CT. While a noticeable contrast‐to‐noise ratio improvement was not observed in VME CBCT images, contrast visualization was substantially better in 40 keV VME images in visual comparisons with 90 and 140 kVp CBCT images across all phantom sizes investigated.ConclusionsThis study indicates that accurate DE decomposition is potentially feasible in DE CBCT of the human torso if robust scatter suppression is achieved with 2D anti‐scatter grids and residual scatter correction. This approach can potentially enable better contrast visualization and tissue and contrast agent quantification in various CBCT applications.