CAREER: Next Generation Positron Emission Tomography Integrated with Magnetic Resonance Imaging

新兴的混合正电子发射断层扫描与磁共振成像（PET/MRI）系统集成代表了生物医学成像领域的前沿技术。虽然目前正在进行首次临床研究，以评估多模态成像的这一重大突破的前景，但在这项技术找到常规应用的方式之前，方法上的挑战和潜力仍然需要解决或利用。提出的研究探讨了PET成像中的“超校正”技术，当与MRI信息相结合时，将彻底改变最敏感的体内分子成像方式之一。该项目将是实现PET和MRI全面技术能力的重要一步，将其能力扩展到肿瘤、神经系统和心脏病的诊断和预后益处，从而改善患者护理和研究。除了科研活动外，本项目还制定计划，通过研究、教育和外展相结合的活动来实现PI的教育目标。新的生物医学工程课程预计将满足密歇根州东南部学生日益增长的需求，并为下一代生物医学成像工程师和科学家提供高质量的培训。该项目和大学预科生物医学工程项目提供的研究机会将吸引女性和历史上代表性不足的学生从事工程学科的职业。在线医学影像资源将促进公众对生物医学影像领域的了解，为其稳定发展播下种子。尽管PET和MRI的潜力令人兴奋，但这项新技术的发展比预期的临床接受要慢得多。由于缺乏PET衰减校正的传输源和未充分发掘MR信息的优势，需要解决这两个系统集成带来的一系列挑战。提出的职业发展计划是一项系统的努力，旨在推进PET/MRI混合系统，以实现更多明确的应用。在此奖项期间要完成的具体研究目标包括：a)确定核磁共振辅助关节PET活动和衰减估计技术，b)评估核磁共振辅助运动敏感PET图像重建技术，c)研究核磁共振辅助部分体积校正的PET图像重建技术，d)定量评估和验证技术，使用真实模拟的PET和MRI数据以及脑，心脏和全身成像的物理模拟实验。基于飞行时间PET数据的核磁共振辅助联合估计活度和衰减的研究有望消除基于核磁共振分割的衰减图造成的区域变化偏差。本研究提出的MR辅助运动校正和部分体积校正将充分利用高分辨率、高软组织对比度的MR图像来抑制器官运动模糊，克服PET成像分辨率的固有局限性。一旦成功完成，该项目有可能彻底改变PET和MRI混合系统，导致新的科学发现和临床应用。

The emerging hybrid Positron Emission Tomography integrated with Magnetic Resonance Imaging (PET/MRI) system represents the cutting edge technology in the field of biomedical imaging. While first clinical studies are currently underway to assess the prospect of this major breakthrough in multimodal imaging, methodological challenges and potentials still need to be addressed or exploited before this technology finds its way to routine applications. The proposed research investigates "super-correction" techniques in PET imaging to revolutionize one of the most sensitive in vivo molecular imaging modalities when integrated with MRI information. The project will be an important step toward reaching the full technological capabilities of PET and MRI, extending its capabilities to diagnostic and prognostic benefits for oncologic, neurologic, and cardiologic diseases thus improving patient care and research. Besides scientific research activities, this project also draws up plans to reach the PI's educational goals through activities to integrate research, education, and outreach. The new biomedical engineering curricula are expected to meet the growing demands of students from southeast Michigan and provide high-quality training to the next generation engineers and scientists in biomedical imaging. The research opportunities provided through this project and the pre-college biomedical engineering programs will attract female and historically under-represented students to pursue careers in the engineering discipline. The online medical imaging resource will promote public understanding of the biomedical imaging field to plant seeds for its steady growth.Despite the considerable excitement about the potential of PET and MRI, this new technology is evolving significantly slowly than expected toward its clinical acceptance. Difficulties due to lack of transmission source for PET attenuation correction and underexplored benefits of MR information demands the need to address set of challenges due to integration of these two systems. The proposed career development plan is a systematic effort to advance the hybrid PET/MRI system to enable for more defining applications. The specific research objectives to be accomplished during this award include: a) to determine MR-assisted joint PET activity and attenuation estimation techniques, b) to evaluate MR-assisted motion-sensitive PET image reconstruction techniques, c) to investigate MR-assisted PET image reconstruction techniques for partial volume correction, and d) to evaluate and validate techniques quantitatively using realistically simulated PET and MRI data and physical phantom experiments for brain, cardiac, and whole-body imaging. The proposed research on MR-assisted joint estimation of activity and attenuation from the time-of-flight PET data is expected to eliminate the regionally varying bias resulted from the MR segmentation-based attenuation map. The proposed study on MR-assisted motion correction and partial volume correction will fully take advantage of the high-resolution, high soft-tissue contrast MR images to suppress the organ motion blurring and conquer the inherent limitations of PET imaging resolution. When successfully completed, the project has the potential to revolutionize the hybrid PET and MRI system leading to new scientific discoveries and clinical applications.