Inveon: A Triple Modality Biomedical Imaging System

描述（由申请人提供）：本申请申请资金支持购买最先进的PET-SPECT-CT成像系统。这种三模态成像仪将积极支持美国国立卫生研究院资助的研究，解决实验药理学、肿瘤生物学、分子成像和认知神经科学领域的基本问题。麻省总医院在发展和开展涉及不同同位素技术、功能性核磁共振成像和光学成像的成像研究方面有着悠久的历史。最近，对小动物模型的高分辨率成像的需求已经升级，特别是对联合成像方式的需求。利用PET和SPECT技术进行同位素成像，可以对放射性标记配体的分布进行功能成像，以测量血流量、代谢、受体和/或酶功能等生理参数；然而，这些技术并不一定能描绘出组织或器官的解剖边界，这严重限制了对数据的解释。解剖标志是极其重要的，特别是在小鼠的全身成像。像CT这样的解剖成像方式可以提供这些地标，此外，还可以为PET和SPECT数据的衰减校正提供准确的地图。PET和SPECT的联合使用可能是非常有利的，例如，用于开发用于癌症诊断和/或治疗的探针。通过同时使用PET和SPECT成像，一个探针可以用两种同位素进行放射性标记：一种用于PET，另一种用于SPECT。用于SPECT成像的同位素通常比PET同位素具有更长的半衰期，这使得长期随访研究不可能单独使用PET成像。PET和SPECT成像的联合使用还可以在同一成像过程中对代谢（通过PET）和血流（通过SPECT）进行成像。目前我们还没有仪器可以让我们同时获取这些信息。我们现有的Concord微型PET系统P4是一个灵长类动物大小的系统；其2毫米的分辨率不足以支持对小鼠大脑的成像研究。我们已经在灵长类动物大脑的研究中广泛使用了这种PET系统。我们还将其用于小鼠模型异种移植肿瘤的成像研究，但这些研究受到无法精确定位肿瘤边界的阻碍。同时获取PET数据与SPECT和CT数据的组合系统将使我们认识到这类研究的潜力。考虑到MGH卓越的生物医学成像研究社区，Martinos中心广泛的多模态成像资源，以及现有的技术专长和基础设施，拟议的三模态PET-CT-SPECT成像仪将立即提高许多现有研究项目的效率、可及性和创新性，并为MGH的综合生物医学成像研究环境战略做出贡献。西门子提出的系统是目前唯一可用的三模态系统。

DESCRIPTION (provided by applicant): This application requests funding to support the purchase of a state-of-the-art PET-SPECT-CT imaging system. This triple modality imager will actively support NIH-funded research addressing questions of fundamental importance in fields of experimental pharmacology, tumor biology, molecular imaging, and cognitive neuroscience. Massachusetts General Hospital has long a history of developing and conducting imaging research involving different isotope-based techniques, functional MRI, and optical imaging. Recently, the need for high-resolution imaging in small animal models has escalated, especially, the need for combined imaging modalities. Isotope-based imaging with PET and SPECT techniques enables functional imaging of the distribution of radio labeled ligands to measure physiological parameters such as blood flow, metabolism, receptor and/or enzyme function; however, these techniques do not necessarily delineate anatomical borders of tissues or organs, which severely limits interpretation of the data. Anatomical landmarks are extremely important, especially in whole-body imaging of the mouse. Anatomical imaging modalities like CT can provide these landmarks and, in addition, can provide accurate maps for attenuation correction of PET and SPECT data. The combined use of PET and SPECT can be extremely advantageous, for instance, for developing probes for cancer diagnosis and/or therapy. By using PET and SPECT imaging together, one probe can be radio labeled with two isotopes: one for PET and another for SPECT. The isotopes used for SPECT imaging generally have longer half-lives than PET isotopes, enabling long-term follow up studies not possible with PET imaging alone. The combined use of PET and SPECT imaging also enables imaging of metabolism (via PET) and blood flow (via SPECT) in the same imaging session. Currently we do not have instrumentation to allow us to acquire this information simultaneously. Our existing Concord micro PET system, P4, is a primate-size system; its resolution of 2 mm is not high enough to support imaging studies in mouse brain. We have used this PET system extensively for studies in the primate brain. We have also used it for imaging studies of xeno transplanted tumors in mouse models, but these studies are hindered by the inability to precisely localize tumor boundaries. A combined system for simultaneous acquisition of PET data with SPECT and CT data would allow us to realize the potential of such studies. Given the exceptional biomedical imaging research community at the MGH, the broad multimodality imaging resources of the Martinos Center, and the existing technical expertise and infrastructure in place, the proposed triple modality PET-CT-SPECT imager would immediately increase the efficiency, accessibility, and innovation of many existing research programs, and contribute to the MGH's strategy for an integrated biomedical imaging research environment. The proposed system manufactured by Siemens is the only triple modality system presently available.