Volume-of-change cone-beam CT for image-guided surgery.
Volume-of-change cone-beam CT for image-guided surgery.
复制标题
用于图像引导手术的体积变化锥束 CT。
DOI：
10.1088/0031-9155/57/15/4969
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发表时间：
2012
影响因子：
3.5
通讯作者：
Siewerdsen,JeffreyH
中科院分区：
文献类型：
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作者：
Lee,Junghoon;Stayman,JWebster;Otake,Yoshito;Schafer,Sebastian;Zbijewski,Wojciech;Khanna,AJay;Prince,JerryL;Siewerdsen,JeffreyH
c臂锥束CT （CBCT）可以为手术指导提供术中三维成像能力，但工作流程和辐射剂量是其广泛应用的主要障碍。一个主要原因是，每次3D图像采集都需要进行一次完整的扫描，每次都需要使用全辐射剂量来呈现全新的3D图像。在本文中，我们建议利用患者特异性CT或CBCT作为先验知识，仅从稀疏的x射线集准确重建因手术过程而改变的区域方面。所提出的方法包括在先前体积和术中x射线稀疏集之间进行3D-2D配准，从注册的先前体积创建数字重建x射线片（drr），通过从术中x射线中减去drr来计算差值图像，从差值图像中重建变化体积（VOC），最后将VOC重建与先前体积融合以可视化整个手术场。当手术改变是局部且相对较小时，VOC重建只需要很小的体积和少量的投影，与重建整个手术野相比，计算量更少，辐射剂量更低。我们将这种方法应用于从CBCT试验台获得的骶成形术幻象数据和从带有平板探测器的c臂CBCT系统获得的新鲜尸体的椎体成形术数据。从不同数量的图像（10-66张）中重建VOCs，并使用四种不同的度量（均方误差、相关系数、结构相似性指数和感知差异模型）与CBCT基础真值进行比较。结果表明，即使只使用15-20幅图像，重建质量也很好，与地面真值的结构相似度接近1，允许剂量减少10-20倍。
C-arm cone-beam CT (CBCT) can provide intraoperative 3D imaging capability for surgical guidance, but workflow and radiation dose are the significant barriers to broad utilization. One main reason is that each 3D image acquisition requires a complete scan with a full radiation dose to present a completely new 3D image every time. In this paper, we propose to utilize patient-specific CT or CBCT as prior knowledge to accurately reconstruct the aspects of the region that have changed by the surgical procedure from only a sparse set of x-rays. The proposed methods consist of a 3D–2D registration between the prior volume and a sparse set of intraoperative x-rays, creating digitally reconstructed radiographs (DRRs) from the registered prior volume, computing difference images by subtracting DRRs from the intraoperative x-rays, a penalized likelihood reconstruction of the volume of change (VOC) from the difference images, and finally a fusion of VOC reconstruction with the prior volume to visualize the entire surgical field. When the surgical changes are local and relatively small, the VOC reconstruction involves only a small volume size and a small number of projections, allowing less computation and lower radiation dose than is needed to reconstruct the entire surgical field. We applied this approach to sacroplasty phantom data obtained from a CBCT test bench and vertebroplasty data with a fresh cadaver acquired from a C-arm CBCT system with a flat-panel detector. The VOCs were reconstructed from a varying number of images (10–66 images) and compared to the CBCT ground truth using four different metrics (mean squared error, correlation coefficient, structural similarity index and perceptual difference model). The results show promising reconstruction quality with structural similarity to the ground truth close to 1 even when only 15–20 images were used, allowing dose reduction by the factor of 10–20.