发表机构
Université Laval; CHU de Québec Université Laval; Elekta Instrument AB（拉瓦尔大学; 魁北克大学医院集团-拉瓦尔大学; Elekta仪器公司）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究提出伽玛刀CBCT采用线-弧-线扫描轨迹以减少锥束伪影，通过概念验证表明该轨迹能显著提升图像质量，且对现有配置改动有限。
AI 中文摘要
目的。伽玛刀锥束计算机断层扫描（CBCT）图像因锥形X射线束（其方向为使射线束在其下缘垂直于探测器相交）而对某些患者产生明显的锥束伪影。使用一种比当前弧线扫描提供更完整视场采样的特殊扫描轨迹可以减少锥束伪影。在本研究中，通过概念验证评估了伽玛刀CBCT采用线-弧-线扫描轨迹的可行性。方法。使用定制的研究用伽玛刀，对Catphan 503模体和拟人头部模体进行不同特殊扫描轨迹的成像，这些轨迹由弧线和直线的组合构成。然后使用迭代算法对每种轨迹的CBCT图像进行重建。主要结果。在所研究的轨迹中，线-弧-线轨迹提供了最大的图像质量改善，CBCT图像中没有明显的锥束伪影：Catphan模块之间的轴向界面清晰可辨，且模体在轴向轴上的上缘比当前弧线轨迹锐利92%。对于头部CBCT图像，所提出的轨迹消除了颅骨上侧的大部分锥束伪影，这是当前伽玛刀CBCT图像的特征。伪影的减少也导致两个模体在均匀性方面的视觉改善。意义。线-弧-线CBCT扫描轨迹在伽玛刀上可行，且对当前配置的改动有限，并能产生图像质量改善的图像。
英文摘要
Objective. Gamma Knife cone-beam computed tomography (CBCT) images suffer from distinct cone-beam artifacts for some patients, due to the conical X-ray beam which is oriented to intersect the detector perpendicularly at its inferior edge. The use of an exotic scan trajectory which provides more complete sampling across the field of view than the current arc can reduce cone-beam artifacts. In this study, the feasibility of a line-arc-line scan trajectory for the Gamma Knife CBCT is assessed through a proof of concept. Approach. Using a customized research Gamma Knife, a Catphan 503 and an anthropomorphic head phantom are imaged for different exotic scan trajectories, consisting of combinations of arcs and lines. The CBCT images for each trajectory are then reconstructed with an iterative algorithm. Main results. A line-arc-line trajectory provides the largest image quality improvement among the investigated trajectories, with no noticeable cone-beam artifacts in the CBCT images: the axial interfaces between modules of the Catphan are well defined, and the superior edge of the phantom on the axial axis is sharper by 92\%, compared with the current arc trajectory. For the head CBCT images, the proposed trajectory removes most of the cone-beam artifact on the superior side of the skull, characteristic of the current Gamma Knife CBCT images. The artifact reduction also leads to a visual improvement in terms of uniformity in both phantoms. Significance. A line-arc-line CBCT scan trajectory would be feasible on the Gamma Knife with limited changes to the current configuration, and could produce images with improved image quality.
CommentsThis paper is 13 pages in length, including 7 figures and 2 tables, and presents the continuation of the study presented in the Preprint arXiv:2609.28232v1 [physics.med-ph]. The contents of this paper were presented at the 2026 Joint AAPM | COMP Annual Meeting. The manuscript has been submitted to Physics in Medecine &; Biology
