High Resolution PET Brain Imager for Detection and Management of Alzheimer^s

描述（由申请人提供）：阿尔茨海默病是一种使人衰弱的疾病，随着人口的持续老龄化，患病率将增加。预计到2050年，美国将有1600万例病例。我们需要更好的分子生物标志物和分子成像仪，以便在早期阶段发现这种可怕的疾病，并协助开发/监测新药和治疗策略的效果。分子成像以其高灵敏度和特异性为阿尔茨海默病和其他痴呆疾病的诊断、指导和监测提供了必要的工具。这些成像仪需要提供高灵敏度和高分辨率。用于正电子成像（PET）或单伽马（SPECT）的标准临床核医学成像仪并不适合在一到几毫米的高分辨率下对大脑进行成像。PET是首选的方式，因为它本身具有高分辨率和高效率的操作。尽管在专门用于脑成像的PET系统方面已经取得了进展，但由于检测器头部的体积庞大，它们不便于携带，并且限制了可以进行的研究类型。因此，我们提出了一个完全可穿戴的头盔- pet系统，使用新的，非常紧凑的硅光电倍增管技术。我们的设备将随着人的头部移动，允许人在原地（在跑步机上）坐、站、跑，甚至做一些小的侧面运动，因此它是坐、站和有限的运动的容忍度。此外，该技术与MRI兼容，可作为PET插入物用于MRI/fMRI成像。可穿戴成像仪不断地与患者头部共同注册，因此运动伪影大大减少，以实现高空间分辨率扫描。此外，由于将检测器模块放置在靠近大脑的位置，提高了系统效率，因此可以降低注射剂量。在跟踪疾病进展/消退、治疗监测等情况下，这将使患者能够进行更多的成像，而不会增加辐射剂量，此外还可以降低每次扫描的成本。此外，由于部分体积效应，作为提高分辨率的间接结果，成像仪检测1-2mm特征的灵敏度将大大提高。我们将使用sipm阵列与LYSO晶体阵列耦合，并带有紧凑型读出电子器件，以生产内径为26厘米，初始高度为5厘米，最终高度为15厘米的多环PET成像仪。这个紧凑的环将夹在内部和外部轻质外壳之间，以产生一个头盔- PET脑扫描仪。系统的重量将由一个设计合理的机械系统来支撑，该系统带有一个灵活的悬挂臂/电缆。该支撑系统将为从探测器模块到外部（移动机柜）数据采集系统的相关信号电缆提供路径。最终目标是实现接近1mm空间分辨率的实用稳健性能，其效率是标准PET扫描仪的10倍，同时具有可行的系统复杂性和可持续的成本。

DESCRIPTION (provided by applicant): Alzheimer's disease is a debilitating condition that wil increase in prevalence as the population continues to age. It is expected that the USA will see 16 million cases by 2050. There is a need for better molecular biomarkers and molecular imagers to detect this horrible disease at its earliest stages and assist with the development/monitoring of the efects of new drugs and therapeutic strategies. Molecular imaging with its high sensitivity and specificity offers the best chance to provide the necessary tools to diagnose, guide and monitor therapy of Alzheimer's and other dementia diseases. These imagers need to offer high sensitivity and high resolving power. Standard clinical nuclear medicine imagers used for positron imaging (PET) or single gamma (SPECT) are not optimized for imaging the brain at a high resolution of one to a few mm. PET is the preferred modality due to its intrinsically high resolution and high efficiency operation. Although there have been advances in specialized PET systems for brain imaging, they are not portable and limit the types of studies which can be performed due to the bulky size of the detector heads. Thus we propose a fully wearable Helmet-PET system using the new, very compact Silicon Photomultiplier technology. Our device will move with the person's head and allow the person to sit, stand, run in place (on a treadmill) and even make minor side movements, therefore it is sitting-, standing-, and limited movement- tolerant. In addition, this technology is MRI compatible and can be used as a PET insert for MRI/fMRI imaging. A wearable imager is constantly co-registered to the patient's head and thus movement artifacts are greatly minimized in order to achieve high spatial resolution scans. In addition, because of increased system efficiency with the detector modules placed close to the brain, lower injection doses are possible. This wil enable more imaging sessions for a patient without increasing the radiation dose in cases of following the progression/regression of disease, treatment monitoring, etc, in addition to lowering the cost per scan. Also, due to the Partial Volume Effect the sensitivity of the imager to detect features of 1-2mm will be increased by a substantial factor as the indirect result of the increased resolution. We will use arrays of SiPMs coupled to arrays of LYSO crystals with compact readout electronics to produce a multi-ring PET imager with a 26 cm inner diameter and initialy 5cm and ultimately 15cm in height. This compact ring will be sandwiched between inner and outer lightweight housing shells to produce a Helmet- PET brain scanner. The weight of the system will be supported by a properly designed mechanical system with a flexible suspension arm/cable. This support system will provide a path for the associated signal cables from the detector modules to the externally located (in a mobile cabinet) data acquisition system. The final goal is to achieve a practical robust performance approaching 1mm spatial resolution at 10 times the efficiency of standard PET scanners, with a viable system complexity and sustainable cost. PUBLIC HEALTH RELEVANCE: This research will help to diagnose and manage Alzheimer's disease while containing costs and lowering radiation dose to the patient. It will allow research studies which were not able to be performed in the past and assist in the development of new treatments in the search for a cure for Alzheimer's. It also may open the doors for research into other brain diseases such as Parkinson's disease.