Development of Enabling Technologies for Clinical Ultrahigh Field Body MRI

临床批准的7特斯拉(7T)成像技术的问世受到了很高的期望。潜力 更高的信噪比(SNR)、新的对比度和前所未有的分辨率有望扩展的优势 这曾经是一种生物医学研究工具，用于定义最先进的患者护理的成像设备。这个 获得FDA批准的好处是，它为临床医生创造了调查其真正潜力的机会 并发现它对患者护理产生独特影响的应用。然而，目前FDA的批准是 仅适用于头部和膝盖应用，即使到那时，核磁共振扫描仪也仅限于使用其 已安装的功能。并行传输(PTX)，这一功能可以解决面临的一些最大挑战 超高场磁共振(UHF)还没有得到充分的开发、集成和验证，不能安全地在 临床环境。这些挑战，如不均匀的传输场和当地供暖规模的问题 正在成像的对象的大小。虽然头部和膝盖的成像可以在没有此功能的情况下进行，但PTX 它在人体躯干上的应用是绝对必要的。而7T在成像方面显示出了巨大的潜力 在研究背景下，如何扩展这些有希望的目标是一个关键问题 结果。我们认为，在实现以下目标之前，需要进一步开发和整合几项使能技术 获得FDA批准。这些发展在三个技术目标中得到解决。一是发展 以及射频(RF)线圈的优化，以高效地将RF能量传输到 为了实现与较低场强相比在信噪比方面所承诺的收益。第二个是 建立人体模型的虚拟数据库和克服现有限制的策略 在尝试使用PTX系统时，假设安全系数过于严格。第三个问题涉及整合 扩展的多参数前列腺成像协议和运动补偿中的PTX功能 战略通过序列定制的PTX解决方案和优化。最终的翻译目标是使用前列腺 作为在比较癌症检测的患者研究中探索射频线圈和PTX使能序列的试验床 以及相同患者在3T时成像的成像指标。在成功完成这些开发工作后 和翻译目标，我们将克服障碍，使临床躯干成像在超高频和验证 它在临床环境中的有效使用。该项目的成果将是扩大FDA的关键组成部分 批准的7T适应症。一旦到达临床医生手中，就建立了超高频成像对 能够使用7T作为一线扫描方式，患者的预后将大大受益。

The advent of clinically approved imaging at 7 Tesla (7T) has been met with high expectations. The potential benefits of increased signal-to-noise ratio (SNR), new contrasts and unprecedented resolution promise to extend what once was a tool for biomedical research into an imaging device defining state of the art patient care. The benefit of obtaining FDA approval is that it creates the opportunity for clinicians to investigate its true potential and to discover the applications where it uniquely impacts patient care. The current FDA approval however is only for head and knee applications, and even then, the MRI scanner is limited to using only a fraction of its installed functionality. Parallel transmit (pTx), a functionality that can tackle some of the biggest challenges facing ultrahigh field (UHF) MRI, has not been sufficiently developed, integrated and validated to safely use in the clinical setting. These challenges such as non-uniform transmit fields and issues with local heating scale with the size of the object being imaged. While imaging the head and knee can manage without this functionality, pTx it is an absolute necessity for applications in the human torso. While 7T has shown great potential at imaging targets in the torso in the research setting, there is the critical question of how to expand upon these promising results. We believe that several enabling technologies need to be further developed and integrated prior to obtaining FDA approval. These developments are addressed in three technical aims. The first is the development and optimization of radiofrequency (RF) coils to efficiently transmit RF energy into and receive signals from the body in order to realize the promised gains in SNR compared to lower field strengths. The second is the construction of a virtual database of human body models and strategies for overcoming the current limitations of assuming overly restrictive safety factors when attempting to use the pTx system. The third involves integrating pTx functionality into an extended multi-parametric prostate imaging protocol and motion compensation strategies through sequence tailored pTx solutions and optimization. A final translational aim will use the prostate as a testbed to explore the RF coils and pTx enabled sequences in a patient study comparing cancer detection and imaging metrics with the same patients imaged at 3T. Upon successful completion of these developmental and translational aims, we will have overcome the barriers to enabling clinical torso imaging at UHF and verified its effective use in a clinical setting. The outcomes of this project will be critical component in expanding the FDA approved indications for 7T. Once in the hands of clinicians, establishing the unique impact of UHF imaging on patient outcomes will greatly benefit from being able to use 7T as a front-line scanning modality.