Combined Multi-Pinhole and Fan-Beam Brain SPECT

 描述(申请人提供)：FDA最近批准标记为DaTcan的SPECT显像剂I-123用于帕金森病(PD)的诊断和监测进展，开辟了SPECT脑成像的新纪元。与灌注成像不同的是，在PD中，整个大脑都是感兴趣的体积，而PD的感兴趣结构是位于大脑内部的壳核和尾状核(以及潜在的黑质)。然而，对于帕金森病患者，也需要枕叶成像来计算纹状体结合率(SBR)，这是一项对早期诊断帕金森病并与其他临床表现相似的疾病进行鉴别的重要参数。我们的假设是，将当前双探头SPECT系统剩余探头上的专门设计的多针孔(MPH)准直器与剩余探头上的扇形光束准直器相结合，再加上具有建模系统空间分辨率的迭代重建，将以边际成本(准直仪(S)和重建软件的价格)改进对大脑内部区域结构的检测和量化。MPH准直仪的设计将为大脑内部提供更高的空间分辨率/灵敏度。扇形光束准直器将提供更低的 这将提供一种低成本的系统，可以改善大脑内部区域结构的可视化和相对量化功能，可能小到黑质约4 mm，这是目前除了昂贵的脑专用SPECT系统之外无法实现的。随着新的SPECT显像剂的批准，这将极大地影响帕金森病的早期发现和鉴别，可能还会影响其他神经疾病。我们进一步调查我们的假设的方法是基于我们在NIH R21 EB016391提供的资金下进行的初步探索，并组织成五个具体目标。第一个具体目标是通过对使用信道化霍特林观测器(CHO)的检测任务进行基于任务的优化以及通过计算SBR来量化纹状体功能来完成MPH准直器的优化设计。第二个具体目标是完成将MPH系统的几何形状和响应纳入重建的开发。第三个具体目标是让我们在亚利桑那大学伽玛射线成像中心(CGRI)的同事建造MPH。第四个具体目标是使用模体在SPECT/CT相机上安装和测试组合的扇束和MPH系统。我们的第五个具体目标是想象五名患者使用联合系统。

 DESCRIPTION (provided by applicant): The recent FDA approval of the SPECT imaging agent I-123 labeled DaTscan for diagnosis and monitoring progression of Parkinson's Disease (PD) has open up a new era in SPECT brain imaging. Unlike with perfusion imaging where the entire brain is the volume of interest, with PD the structures of interest are the putamen and caudate (and potentially substantia nigra) which lie in the interior portion of the brain. However imaging of the occipital lobe is also required with PD for calculation of the striatal binding rati (SBR), a parameter of significance in the early diagnosis and differentiation of PD from other disorders with similar clinical presentations. Our hypothesis is that combining a specifically designed multi-pinhole (MPH) collimator on one detector head with a fan-beam collimator on the remaining head of current dual-headed SPECT systems, coupled with iterative reconstruction with modeling system spatial resolution, will result in improved detection and quantification of structures in the interior region of the brain at marginal cost (the price of collimator(s) and reconstruction software). The MPH collimator would be designed to provide enhanced spatial resolution / sensitivity for the interior of the brain. The fan-beam collimator would provide lower resolution but complete sampling of the brain addressing data sufficiency and allowing a volume-of-interest to be defined over the occipital lobe for calculation of SBR's. Clinically this would provide a low-cost system allowing improved visualization and relative quantification of function of structures in the interior region of the brain, potentially as small as the ~4 mm substantia nigra, which cannot currently be achieved by other than expensive, brain dedicated, SPECT systems. This would greatly impact the early detection and differentiation of PD, and possibly other neurological disorders as new SPECT imaging agents are approved. Our approach for further investigating our hypothesis is based on the initial exploration we have conducted under funding provided by NIH R21 EB016391 and is organized into five specific aims. The first specific aim is to complete the optimization of the MPH collimator design through task-based optimization for the tasks of detection using the Channelized Hotelling Observer (CHO) and quantification of striatal function by calculation of the SBR. The second specific aim is to finish development of inclusion of MPH system geometry and response in reconstruction. The third specific aim is to have our colleagues at the Center for Gamma Ray Imaging (CGRI) at the University of Arizona construct the MPH. The fourth specific aim is to install and test the combined fan-beam and MPH system on a SPECT/CT camera using phantoms. Our fifth specific aim is to image five patients with the combined system.