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

 描述(申请人提供)：在医学成像过程中，患者的运动几乎是不可避免的，这是图像退化和伪影的重要来源，而这反过来又会影响许多患者接受的护理质量。一种用于处理患者运动的方法是使用视觉跟踪系统(VTS)，这涉及在患者身上放置少量的反射标记，这些标记可以使用立体摄像机在3D空间中进行定位和跟踪。然后，被跟踪的标记可以用作诸如心脏之类的感兴趣结构的替代品。被跟踪的代理提供了可与目标结构的运动直接相关的可量化测量，然后可用于前瞻性或回溯性运动校正。然而，标记物增加了患者工作流程的复杂性，仅提供患者表面的稀疏样本，并且标记物的最佳数量和位置未知。该项目解决了基于标记的VTS系统的缺点，建议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的运动。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对患者身体的畅通无阻的观察。候选人林赛博士提议在拟议的无标记VTS系统中加入一种使用计算方法来补偿服装的转换方法。林赛博士接受过计算机科学和计算机视觉方面的培训，此前专注于光等物理现象的捕捉、建模和渲染的计算方面，并建议将这方面的知识扩展到医学成像领域。林赛博士这项提议的目标是获得必要的培训和技能，使他能够将自己的专业知识和现有的计算技能转化为与医学相关的研究领域：即检测和跟踪患者的运动，以改进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，专注于通过转化计算机科学的进步来解决医学成像中的重大问题。拟议的工作将在马萨诸塞州伍斯特的马萨诸塞大学医学中心(UMassus)进行，由国际知名的核医学医学成像和医学物理专家迈克尔·金博士担任主要导师。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以及放射学和核医学方面拥有专业知识，他们也将担任共同导师。该项目的具体目标是：1)开发一种新型的无标记VTS，我们称之为PT-Cam，使用最先进的摄像技术，使用低成本；2)模拟表面运动作为心脏内部运动的替代；以及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，接受临床MPI PET/CT成像。因此，这项研究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表面跟踪方法来对接受混合成像研究的患者进行运动跟踪，该方法可以补偿衣服并提供从表面跟踪到结构内部运动的建模。如果成功，这个项目不仅将提供一个创新的，无标记的 VTS系统用于低成本的表面跟踪，用于混合成像期间的运动补偿，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研究员，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.