Upgrade of 7T MRI Research System

描述（由申请人提供）：本申请旨在升级位于内布拉斯加大学医学中心（UNMC）生物成像核心设施中的7特斯拉小动物磁共振成像（MRI）和波谱（MRS）系统的梯度和电子设备。本系统用于16个NIH资助的项目，包括两个计划项目和一个纳米医学COBRE，并得到核心支持P30赠款的支持。目前资助的项目每台扫描仪平均每周使用20小时的MRI系统时间，占当前系统使用的80%。拟议的升级将提高各种项目的成像研究的质量和产量，包括神经成像、光谱学以及神经科学和纳米技术开发中的细胞和纳米颗粒跟踪研究。纳米技术项目包括开发抗逆转录病毒、抗炎、神经保护和抗癌药物的药物输送平台。待升级的系统是2001年安装的Bruker Biospec 7 T/21 cm系统。由于系统硬件的老化，当前和未来的操作系统软件版本不再兼容。因此，这里提议的升级将发挥三个重要作用。首先，拟议的硬件升级将改善信噪比、梯度性能和系统稳定性，这些改进对于用于神经功能障碍和疾病的MRI评估的光谱研究特别有用。其次，增强的数字化仪速度和相关的软件更新将允许短时间和零回波时间成像，这是一种为超顺磁性氧化铁（SPIO）示踪剂研究提供强大正对比的技术。零回波时间成像与T2* 加权成像相结合，将有可能通过在SPIO存在下发生的相关的正和负信号强度变化来开发用于细胞和纳米颗粒生物分布研究的自动检测算法。第三，升级将包括一个多通道接收器和线圈，以利用新软件版本中可用的“并行成像”方法。该特征将显著改善单次激发成像技术的质量和空间保真度，改善扩散张量成像，并允许弛豫和灌注映射技术迁移到基于回波平面或螺旋成像的单次激发方法。 公共卫生相关性：内布拉斯加大学医学中心正在开发基于成像的疾病检测方法和使用纳米颗粒药物递送治疗脑部疾病、类风湿性关节炎和癌症的新疗法。开发这些新药物递送方法的关键环节是能够首先在动物疾病模型中然后在人类中使用成像方法非侵入性地跟踪其分布和治疗效果。该申请提出将MRI扫描仪升级到当前标准，允许在研究疾病的小动物模型以开发药物递送纳米颗粒的同时采用有效且临床相关的成像方法。

DESCRIPTION (provided by applicant): This application proposes to upgrade the gradients and electronics of a 7 Tesla small animal magnetic resonance imaging (MRI) and spectroscopy (MRS) system located in the bioimaging core facility at the University of Nebraska Medical Center (UNMC). The present system is used for 16 NIH-funded projects including two program projects and a nanomedicine COBRE, and is supported by a Core Support P30 grant. Currently funded projects use an average of 20 hours per week of MRI system time per scanner which represents 80% of the current system use. The proposed upgrade will enhance the quality and throughput of imaging studies for a wide range of projects, including neuroimaging, spectroscopy, and cell- and nanoparticle-tracking studies in the neurosciences and in nanotechnology development. Nanotechnology projects include development of drug delivery platforms for antiretroviral, anti-inflammatory, neuroprotective, and anti-cancer medications. The system to be upgraded is a Bruker Biospec 7T/21cm system installed in 2001. Because of the age of the system's hardware, current and future operating system software releases are no longer compatible. Thus, the upgrades proposed here will serve three important functions. First, the proposed hardware upgrade will improve signal to noise, gradient performance, and system stability, improvements that will be particularly useful for spectroscopic studies used for MRI assessment of neurological dysfunction and disease. Second, enhanced digitizer speed and the associated software update will allow short and zero echo time imaging, a technique that provides robust positive contrast for super paramagnetic iron oxide (SPIO) tracer studies. Zero echo time imaging combined with T2* weighted imaging will make possible the development of automated detection algorithms for cell and nanoparticle biodistribution studies via the correlated positive and negative signal intensity changes that occur in the presence of SPIO. Third, the upgrades will include a multichannel receiver and coil to take advantage of "parallel imaging" methods available in the newer software releases. This feature will significantly improve the quality and spatial fidelity of single shot imaging techniques, improving diffusion tensor imaging and allowing the migration of relaxivity and perfusion mapping techniques to echo planar or spiral imaging based single shot methods. Public Health Relevance: Imaging-based disease detection methods and new therapies for brain diseases, rheumatoid arthritis, and cancer using nanoparticle drug delivery are being developed at the University of Nebraska Medical Center. A critical link in the development of these new drug delivery methods is the ability to track their distribution and therapeutic effectiveness non-invasively using imaging methods first in animal models of disease and then in humans. This application proposes to upgrade an MRI scanner to current standards, allowing efficient and clinically relevant imaging methods to be employed while studying small animal models of disease for development of drug delivery nanoparticles.