Advances in Hybrid PET/MRI Cardiac Imaging

混合 PET/MRI 心脏成像的进展

• 批准号: RGPIN-2020-04125
• 负责人: Prato, Frank
• 金额: $ 2.48万
• 依托单位: University of Western Ontario
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=760734
• 关键词: Advances; Hybrid; PET; MRI; Cardiac

Research Program Vision: Advance molecular imaging through a) the development of cardiac hybrid PET/MRI methodologies and b) participate in their application to biological discovery, healthcare and commercialization. N.B. To be clear, hybrid PET/MRI is the simultaneous acquisition of PET and MRI data/images over the same anatomy (e.g. the heart). The Needed Infrastructure: I established a leading-edge hybrid PET/MRI program and state-of-the-art medical cyclotron and radiochemistry facility including the recruitment of eight PhD scientists (three radiochemists, two PET/MRI imaging biophysicists and three molecular biologists). Hypothesis: Hybrid PET/MRI has the potential to dramatically improve current understanding of the molecular biology of the heart. However, this requires a convergent incorporation of PET and MRI. Background: We will use this convergent approach to address two limitations of cardiac PET: a) restricted to distinguish only one PET probe as all PET probes are detected by the same signal (annihilation radiation) and b) dynamic PET acquisition to measure myocardial blood flow is collected without correction for bulk, cardiac and respiratory movement. We propose how the simultaneously collected MRI data could address these cardiac PET limitations. Specifically, we will focus on dynamic blood flow measurement of the myocardium using 13N-Ammonia (13NA). N.B. In my last NSERC/DG (ends June 2020) I a) completed my discovery work on biophysical mechanisms of magnetic field transduction (4 papers published; 77 citations) and b) for the development of an MRI reporter gene; (5 papers published, 2 submitted; 53 citations) this NSERC, if funded, would continue to support a PhD student who is completing this work. Specific New Objectives: 1.I will continue to investigate the use of cardiac functional MRI BOLD (cfBOLD) as an alternative to 13NA. Proof-of-principle has been established in dogs [Sci Transl Med, May 2019]. Implementation in humans would allow a PET/MRI evaluation of inflammation, that currently takes 200 min, to be done in 50 min. 2.I will develop a method to perform two measurements of blood flow (rest and stress using two injections of 13NA) that currently takes 70min to take only 20 min. This will use a subtraction technique dependent on detection and correction of bulk cardiac motion using simultaneously acquired MRI data. 3.I will develop a method using simultaneously acquired MRI data to correct for most of the cardiac and respiratory blurring of 13NA images. I will employ a low-rank tensor (LRT) formulation to generate the three-dimensional cardiac and respiratory motion fields from MRI data. These motion fields will be used to correct 13N-ammonia PET data. Impact: a) Reduce radiation dose (cfBOLD), b) Improved cardiac spatial resolution (cfBOLD, LRT approach), c) Reduce acquisition time (cfBOLD, rapid injections of 13NA), d) Increased information per examination, e) Allow accurate tracking of PET labeled cells.

研究计划愿景：通过a）心脏混合PET/MRI方法的开发和B）参与其在生物发现、医疗保健和商业化方面的应用，推进分子成像。N.B.需要明确的是，混合PET/MRI是在同一解剖结构（例如心脏）上同时采集PET和MRI数据/图像。 所需的基础设施：我建立了一个领先的混合PET/MRI程序和最先进的医疗回旋加速器和放射化学设施，包括招聘八名博士科学家（三名放射化学家，两名PET/MRI成像生物学家和三名分子生物学家）。假设：混合PET/MRI有可能极大地改善目前对心脏分子生物学的理解。然而，这需要PET和MRI的融合结合。工作背景：我们将使用这种会聚方法来解决心脏PET的两个局限性：a）由于所有PET探头都被相同的信号（湮灭辐射）检测到，因此仅限于区分一个PET探头，以及B）收集用于测量心肌血流量的动态PET采集，而不对体积、心脏和呼吸运动进行校正。我们提出如何同时收集MRI数据可以解决这些心脏PET的限制。具体而言，我们将重点关注使用13 N-氨（13 NA）的心肌动态血流测量。N.B.在我的上一个NSERC/DG（截至2020年6月）中，我a）完成了我对磁场转导的生物物理机制的发现工作（发表了4篇论文; 77次引用）和B）开发MRI报告基因;（发表了5篇论文，提交了2篇论文; 53次引用）如果获得资助，NSERC将继续支持正在完成这项工作的博士生。 具体的新目标：1.我将继续研究使用心脏功能MRI BOLD（cfBOLD）作为13 NA的替代方法。已在犬中确立了原理证明[Sci Transl Med，2019年5月]。在人类中的实施将允许对炎症进行PET/MRI评估，目前需要200分钟，2.我将开发一种方法来进行两次血流量测量（使用两次13 NA注射的休息和应激）这将使用减影技术，该减影技术依赖于同时使用获取MRI数据。 3.我将开发一种使用同时采集的MRI数据来校正13 NA图像的大多数心脏和呼吸模糊的方法。我将采用低秩张量（LRT）制定从MRI数据生成三维心脏和呼吸运动场。这些运动场将用于校正13 N-氨PET数据。 影响力：a）减少辐射剂量（cfBOLD），B）提高心脏空间分辨率（cfBOLD，LRT方法），c）减少采集时间（cfBOLD，快速注射13 NA），d）增加每次检查的信息，e）允许准确跟踪PET标记的细胞。