MR Physics Simulation Package for Pulse, Sequence, and Hardware Design

项目概述：我们拟开发软件，精确模拟MRI过程，从自旋激发到图像重建，严格执行MRI的物理定律，准确3D表示人体解剖结构、场分布、组织自旋磁化和弛豫特性。输出将是真实的图像，准确地表示所选样本、序列和场的信号、对比度和噪声分布、静态和RF场相关的伪影（以及许多其他东西）。这将有助于在MRI系统上实施新硬件、脉冲或序列之前进行中间、低成本的评估、修订和优化阶段。为了与软件一起使用，我们将提供一个真实的静态，梯度和射频磁场分布库，在1.0到9.4特斯拉的几种场强下，人体解剖，基本脉冲序列和重建方法。用户还可以输入专门设计的受试者解剖结构、不同的组织自旋磁化/弛豫特性、任何场强下的新场分布、奇异脉冲序列和/或新的重建方法。该软件还将计算所需脉冲序列的头部平均值和最大局部比能量吸收率（SAR），以便与安全法规进行比较。所有这些都是免费的，开源的，因此研究人员可以根据他们的具体需求进行修改。相关性：近年来，MRI的进步使其成为医学和研究领域的宝贵工具，通过准确的非侵入性诊断、解剖和生理信息，挽救了生命，降低了护理成本。通过使用更高的静态场强度和更高的射频场频率，不断努力改进MRI，但人体施加的场的扭曲是MRI进步的重大障碍。有了我们提供的工具，将有可能在任何场强下使用计算机对脉冲、序列和硬件进行关键的研究、开发和安全评估，以减少对磁铁时间的需求和在实际MRI系统上实施未经测试的原型的成本。它也将成为MR教育和培训的绝佳工具。这将大大降低成本，提高MRI进展的速度和可及性，并允许宝贵的MRI系统时间更多地用于重要的医学和科学研究，而不是用于技术发展的评估。

DESCRIPTION (provided by applicant): Project Summary: We propose to develop software to accurately simulate the MRI process, from spin excitation through image reconstruction, with rigorous implementation of the physical laws of MRI and accurate 3D representations of human anatomies, field distributions, and tissue spin magnetization and relaxation properties. The output will be realistic images, accurately representing signal, contrast, and noise distributions, static and RF field-related artifacts (among many other things) for the chosen sample, sequence, and fields. This will facilitate an intermediate, low-cost stage of evaluation, revision, and optimization before implementation of novel hardware, pulses, or sequences on an MRI system. For use with the software, we will provide a library of realistic static, gradient, and RF magnetic field distributions at several field strengths from 1.0 to 9.4 tesla, human anatomies, basic pulse sequences, and reconstruction methods. The user will also be able to input specially-designed subject anatomies, different tissue spin magnetization/relaxation properties, novel field distributions at any field strength, exotic pulse sequences, and/or new reconstruction methods. The software will also calculate the head-average and maximum local Specific energy Absorption Rates (SAR) for the desired pulse sequence for comparison to safety regulations. All will be freely available and open-source so researchers can make modifications for their specific needs. Relevance: Advances in MRI have made it an invaluable tool in medicine and research in recent years, saving both lives and cost of care with accurate non-invasive diagnostic, anatomic, and physiologic information. Continual effort is devoted to improving MRI by using higher static field strengths, and thus higher RF field frequencies, but distortions of the applied fields by the human body present significant obstacles to the advancement of MRI. With the tools we will provide it will be possible to perform critical research, development, and safety evaluation of pulses, sequences, and hardware at any field strength using computers to reduce the need for magnet time and the cost of implementing untested prototypes on actual MRI systems. It will also make an excellent tool for MR education and training. This should greatly reduce the cost and increase the speed and accessibility of advancement of MRI and allow for valuable MRI system time to be dedicated more to important medical and scientific studies and less to evaluation of technical developments.