Alignment of sources and detectors on breast surface for noncontact diffuse correlation tomography of breast tumors.
Alignment of sources and detectors on breast surface for noncontact diffuse correlation tomography of breast tumors.
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DOI：
10.1364/ao.54.008808
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发表时间：
2015-10-10
期刊：
影响因子：
1.9
通讯作者：
Yu G
中科院分区：
文献类型：
--
作者：
Huang C;Lin Y;He L;Irwin D;Szabunio MM;Yu G
非接触式扩散相关层析成像(NcDCT)是一种在不扭曲血流动力学特性的情况下对深部组织血流分布进行三维成像的新兴技术。为了使ncDCT适用于活体乳腺肿瘤的成像，我们设计了一种电动ncDCT探头来扫描乳房表面。提出了一种基于计算机辅助设计(CAD)的方法，从商用3D摄像机获得的任意乳房表面生成实体体积网格。通过射线追踪将ncDCT的源和探测器对准乳房表面，利用CAD软件模拟ncDCT扫描。所生成的乳房体积网格连同NcDCT在对准的源和探测器对上的边界数据用于基于有限元方法的血流图像重建。我们评估了人体模型和人体乳房上的源对齐的准确性；在扫描的切向和径向上，最大对准误差都小于10%。通过计算机模拟评估对准误差(分配10%)对肿瘤重建的影响。对齐误差对模拟肿瘤位置和血流对比的偏差分别为0.77 mm(小于1 mm的节点距离)和1%，对血流图像重建影响较小。最后，以人乳腺肿瘤为例，重建了肿瘤与正常血流的对比度，验证了ncDCT在临床应用的可行性。
Noncontact diffuse correlation tomography (ncDCT) is an emerging technology for 3D imaging of deep tissue blood flow distribution without distorting hemodynamic properties. To adapt the ncDCT for imaging in vivo breast tumors, we designed a motorized ncDCT probe to scan over the breast surface. A computer-aided design (CAD)-based approach was proposed to create solid volume mesh from arbitrary breast surface obtained by a commercial 3D camera. The sources and detectors of ncDCT were aligned on the breast surface through ray tracing to mimic the ncDCT scanning with CAD software. The generated breast volume mesh along with the boundary data of ncDCT at the aligned source and detector pairs were used for finite-element-method-based flow image reconstruction. We evaluated the accuracy of source alignments on mannequin and human breasts; largest alignment errors were less than 10% in both tangential and radial directions of scanning. The impact of alignment errors (assigned 10%) on the tumor reconstruction was estimated using computer simulations. The deviations of simulated tumor location and blood flow contrast resulted from the alignment errors were 0.77 mm (less than the node distance of 1 mm) and 1%, respectively, which result in minor impact on flow image reconstruction. Finally, a case study on a human breast tumor was conducted and a tumor-to-normal flow contrast was reconstructed, demonstrating the feasibility of ncDCT in clinical application.