Purpose: This study compares two augmented reality (AR)-guided imaging workflows, one based on ultrasound shape completion and the other on cone-beam computed tomography (CBCT), for planning and executing lumbar needle interventions. The aim is to assess how imaging modality influences user performance, usability, and trust during AR-assisted spinal procedures. Methods: Both imaging systems were integrated into an AR framework, enabling in situ visualization and trajectory guidance. The ultrasound-based workflow combined AR-guided robotic scanning, probabilistic shape completion, and AR visualization. The CBCT-based workflow used AR-assisted scan volume planning, CBCT acquisition, and AR visualization. A between-subject user study was conducted and evaluated in two phases: (1) planning and image acquisition, and (2) needle insertion. Results: Planning time was significantly shorter with the CBCT-based workflow, while SUS, SEQ, and NASA-TLX were comparable between modalities. In the needle insertion phase, the CBCT-based workflow yielded marginally faster insertion times, lower placement error, and better subjective ratings with higher Trust. The ultrasound-based workflow achieved adequate accuracy for facet joint insertion, but showed larger errors for lumbar puncture, where reconstructions depended more heavily on shape completion. Conclusion: The findings indicate that both AR-guided imaging pipelines are viable for spinal intervention support. CBCT-based AR offers advantages in efficiency, precision, usability, and user confidence during insertion, whereas ultrasound-based AR provides adaptive, radiation-free imaging but is limited by shape completion in deeper spinal regions. These complementary characteristics motivate hybrid AR guidance that uses CBCT for global anatomical context and planning, augmented by ultrasound for adaptive intraoperative updates.

翻译：目的：本研究比较两种增强现实（AR）引导的成像工作流——基于超声形状补全的工作流与基于锥形束计算机断层扫描（CBCT）的工作流——在腰椎穿刺介入的规划与执行中的应用。旨在评估成像模态如何影响AR辅助脊柱手术中的用户表现、可用性及信任度。方法：两种成像系统均集成于AR框架中，实现原位可视化与穿刺轨迹引导。基于超声的工作流结合了AR引导的机器人扫描、概率形状补全与AR可视化。基于CBCT的工作流采用AR辅助的扫描体积规划、CBCT采集与AR可视化。研究进行了组间用户实验，分两阶段评估：（1）规划与图像采集阶段；（2）穿刺针置入阶段。结果：基于CBCT的工作流规划时间显著更短，而两种模态在系统可用性量表（SUS）、情景意识问卷（SEQ）及NASA任务负荷指数（NASA-TLX）得分上相近。在穿刺针置入阶段，基于CBCT的工作流在置入时间上略快，置入误差更低，主观评分更优且信任度更高。基于超声的工作流在关节突关节穿刺中达到足够精度，但在腰椎穿刺中误差较大，因其重建更依赖于形状补全。结论：研究结果表明两种AR引导成像流程均能有效支持脊柱介入手术。基于CBCT的AR在穿刺阶段的效率、精度、可用性及用户信心方面具有优势；而基于超声的AR提供自适应、无辐射的成像，但在脊柱深部区域受形状补全限制。这些互补特性为混合AR引导提供了依据：可利用CBCT获取全局解剖结构用于规划，并辅以超声实现术中自适应更新。