Body Surface Tracking of Complex Motion with Obstructed Viewing in Hybrid Imaging

 描述（由申请人提供）：在医学成像过程中，患者运动几乎是不可避免的，这是图像退化和伪影的重要来源，进而可能影响许多患者接受的护理质量。用于解决患者运动的一种方法是采用视觉跟踪系统（VTS），其涉及在患者上放置少量反射标记，其可以使用立体相机在3D空间中定位和跟踪。然后，跟踪的标记可以用作感兴趣的结构（诸如心脏）的替代物。所跟踪的替代物提供了可量化的测量，其可以与目标结构的运动直接相关，然后可以用于前瞻性或回顾性运动校正。然而，标记增加了患者工作流程的复杂性，仅提供患者表面的稀疏采样，并且标记的最佳数量和放置是未知的。该项目解决了基于标记的VTS系统的缺点，提出开发和测试一种新型的低成本无标记VTS系统，用于在混合成像系统中跟踪患者运动。使用无标记VTS成功跟踪患者体表的主要障碍是衣服阻碍了患者身体的无障碍视野。候选人林赛博士建议采用一种平移方法，使用计算方法来补偿拟议的无标记VTS系统中的服装。林赛博士曾接受过计算机科学和计算机视觉方面的培训，此前曾专注于捕捉、建模和渲染物理现象（如光）的计算方面，并计划将这些知识扩展到医学成像领域。林赛博士的目标是获得必要的培训和技能，使他能够将其专业知识和现有的计算技能转化为具有医学相关性的研究领域：即，检测和跟踪患者运动，以改善混合成像的运动校正。林赛博士的长期职业目标是成为一名有成就的独立调查员，专注于通过翻译计算机科学的进步来解决医学成像中的重大问题。拟议的工作将在位于马萨诸塞州伍斯特的马萨诸塞州大学医学中心（UMass）进行，主要由核医学领域医学成像和医学物理领域的国际知名专家Michael King博士指导。Gennert博士、Sullivan博士和Licho博士分别在计算机视觉、机械工程和医学成像、放射学和核医学方面具有专长，他们也将担任共同导师。 拟议项目的具体目的是：1）开发一种新型无标记VTS，我们称之为PT- Cam，使用最先进的摄像机技术，成本低，2）模拟表面运动作为心脏内部运动的替代，3）对PT-Cam系统进行测试，以确定临床使用的可接受性和可行性，对接受临床MPI PET/CT成像的患者进行测试。因此，该研究计划的主要目标是开发一种临床上可行的方法，通过使用一种新的无标记的表面跟踪方法，可以补偿衣服，并提供从表面跟踪结构的内部运动建模的运动跟踪患者进行混合成像研究。如果成功，该项目不仅将提供一个创新的，无标记的 VTS系统用于混合成像期间的运动补偿的低成本表面跟踪，但它也将为候选人提供必要的培训，使其成为医学领域的独立调查员，并有可能成为医学成像领域的领导者。

 DESCRIPTION (provided by applicant): During medical imaging, patient motion is virtually unavoidable presenting a significant source of image degradation and artifacts, which in turn, can impact the quality of care received by many patients. One method used to address patient motion is to employ visual tracking systems (VTS), which involves placing a small number of reflective markers on the patient that can be located and tracked in 3D space using stereo cameras. The tracked markers can then be used as a surrogate to a structure of interest, such as the heart. The tracked surrogate provides a quantifiable measure that can be directly correlated with the motion of the target structure, which can then be used for prospective or retrospective motion correction. However, the markers add complexity to patient workflow, provide only a sparse sampling of the patient's surface, and the optimal number and placement of markers is unknown. This project addresses the shortcomings of marker-based VTS systems by proposing to develop and test a novel low-cost marker-less VTS system for tracking patient motion within a hybrid imaging system. The primary barrier for successfully tracking the patient's body surface using marker-less VTS is that clothing prevents an unobstructed view of the patient's body. The candidate, Dr. Lindsay, is proposing to incorporate a translational method using computational approaches to compensate for garments within the proposed marker-less VTS system. Dr. Lindsay has received training in computer science and computer vision and previously has focused on the computational aspects of capturing, modeling, and rendering of physical phenomena such as light and is proposing to extend this knowledge to the medical imaging field. Dr. Lindsay's goals for this proposal are to acquire the necessary training and skills that will allow him to translate his expertise and existing computational skills to an area f research with medical relevance: namely, detecting and tracking patient motion for the purpose of improving motion correction for hybrid- imaging. Dr. Lindsay's long-term career goal is to become an accomplished independent investigator focusing on solving significant problems in medical imaging by translating advances in Computer Science. The proposed work will take place the University of Massachusetts Medical Center (UMass) in Worcester, MA under the primary mentorship of Dr. Michael King, an internationally known expert in the area of medical imaging and medical physics in Nuclear Medicine. Drs. Gennert, Sullivan, Licho have expertise in computer vision, mechanical engineering and medical imaging, and radiology and Nuclear Medicine, respectively will also serve as co-mentors. The specific aims of the proposed project are to: 1) develop a novel marker-less VTS, which we call PT- Cam, using low-cost using state-of-the-art camera technology, 2) model surface motion as a surrogate for internal motion of the heart, and 3) conduct tests of the PT-Cam system, in order to determine the acceptability and feasibility of clinical usage, on patients undergoing clinical MPI PET/CT imaging. Thus, the main objective of this program of research is to develop a clinically viable method for motion tracking patients undergoing hybrid-imaging studies by using a novel marker-less surface-tracking method that can compensate for clothing and provide modeling of interior motion of structures from surface tracking. If successful, not only will this project provide an innovative, marker-less VTS system for low-cost surface tracking for motion compensation during hybrid imaging but it will also give the candidate the necessary training needed to become an independent investigator in the medical field and potentially a leader in the field of medical imaging.