Motion-Robust Pulse Design for Parallel Transmission Excitation at Ultra-High Field MRI

超高场患者运动耐受功能磁共振成像背景功能磁共振成像(FMRI)是绘制神经元活动图的最常用技术，它可以评估健康与疾病/受伤的大脑功能如何，并确定大脑的哪些区域处理运动或说话等任务。由于fMRI采集包括对相同体积的重复扫描，以对大脑各个部分信号的时间变化进行统计分析，因此患者的运动会使数据随着时间的推移而不一致，并恶化分析。最先进的超高场(UHF)扫描仪为研究神经元活动提供了独特的机会，提高了功能磁共振成像功能映射信号的准确性。不幸的是，纠正超高频核磁共振固有的人为对比度变化需要专门设计的成像方案(并行传输射频脉冲)。在目前的技术中，这些脉冲是为静止的患者设计的，当患者移动时会导致数据不一致。项目的目标和方法在这项研究中，您将开发设计脉冲的技术，使其“冻结”运动；即，在患者可以在功能磁共振扫描期间自由移动的情况下获得一致的数据。这些可容忍运动的并行传输脉冲将在扫描前只设计一次，以适应用户指定的“预期”或“最大”患者运动范围，并且在扫描期间只需要简单的调整，而不是计算昂贵的重新设计。运动对功能磁共振分析的影响将被记录下来，这些脉冲的性能将通过体内实验进行评估。研究结果将指导新的功能磁共振成像方案的开发，并使对痴呆症和帕金森患者进行超高频功能磁共振成像更加可行。这个跨学科的项目位于工程学、物理学和心理学的边界，您将受益于与物理和心理学院的教职员工合作。研究培训该项目位于多个学科的界面上，并受益于来自物理学和心理学的指导团队。您将在多学科领域培养特定且可移植的技能，包括：MRI和fMRI物理的扎实知识信号处理与患者开展研究fMRI数据采集和分析MRI扫描仪(7T)，并行传输和运动跟踪硬件计算建模和电磁模拟(Sim4Life)编程流畅(例如，MatLab，C++，Python)实验设计(心理)MRI序列开发(西门子IDEA)还将支持您参加通过博士生提供的350多个工作坊，以进一步发展研究和专业技能，心理学和物理学院为博士生提供积极的培训组合，包括教学机会、研讨会和网络活动。该项目的多学科性质和所获得的技能将使学生在研究生涯中取得成功。CUBRIC与西门子医疗保健公司有着密切的合作关系，并受益于西门子工程师的全职在场，这将使学生接触到学术界和产业界的合作。

Patient-motion tolerant functional Magnetic Resonance Imaging at the Ultra-high FieldBackgroundFunctional magnetic resonance imaging (fMRI), the most commonly used technique to map neuronal activity, makes it possible to evaluate how healthy versus diseased/injured brains function and determine which regions of the brain handle tasks like moving or speaking. Because fMRI acquisitions consist of repetitive scanning of the same volume to conduct statistical analysis on the temporal variation of the signal in every part of the brain, patient motion makes data inconsistent over time and deteriorates the analysis. Motion is specifically problematic with uncooperative patients such as patients with Parkinson's or dementia.The state-of-the-art ultra-high field (UHF) scanners provide a unique opportunity to study neuronal activity with increased accuracy of the functional mapping signals for fMRI. Unfortunately, correcting the artificial contrast variations intrinsic to UHF MRI require specifically designed imaging protocols (parallel-transmit RF pulses). With current techniques, these pulses are designed for a stationary patient, leading to inconsistent data when the patient movesProject aims and methodsIn this study, you will develop techniques to design pulses that will 'freeze' motion; ie, acquire consistent data while the patient can freely move during a functional MRI scan. These motion-tolerant parallel-transmit pulses will be designed only once before a scan to accommodate a user-specified range of 'expected' or 'maximum' patient motion, and will require only simple adjustments rather than a computationally expensive redesign during the scan.The effect of motion on fMRI analysis will be documented, and the performance of these pulses will be evaluated via in-vivo experiments. The outcomes will guide the development of novel fMRI imaging protocols and make it more feasible to conduct UHF functional MRI on patients with dementia and Parkinson's.This interdisciplinary project lies at the boundary of engineering, physics and psychology, and you will benefit from working with faculty members from the schools of Physics and Psychology.Research trainingThe project lies at the interface of multiple disciplines and benefits from a team of supervisors from Physics and Psychology. You will develop specific and transferrable skills across multi-disciplinary domains, including:robust knowledge on MRI and fMRI physicssignal processingconducting research with patientsfMRI data acquisition and analysisMRI scanner (7T), parallel-transmit and motion tracking hardwarecomputational modelling and electromagnetic simulations (Sim4Life)programming fluency (e.g. Matlab, C++, Python)experiment design (PsychoPy)MRI sequence development (Siemens IDEA).You will also be supported to attend from over 350 workshops offered through the Doctoral Academy to further develop research and professional skills, and the schools of Psychology and Physics have active portfolios of training for PhD students that include teaching opportunities, seminars and networking events. The multi-disciplinary nature of the project and acquired skills will launch the student on a successful research career.CUBRIC has strong collaborative ties with Siemens Healthcare and benefits from the full-time presence of an on-site Siemens engineer, which will expose the student to academia-industry collaborations.