Development of Enabling Technologies for Clinical Ultrahigh Field Body MRI

临床批准的7特斯拉（7T）成像的出现已经达到了很高的期望。的潜在 提高信噪比（SNR）、新的对比度和前所未有的分辨率的好处， 它曾经是一种生物医学研究的工具，现在变成了一种成像设备，定义了最先进的病人护理。的 获得FDA批准的好处是，它为临床医生创造了研究其真正潜力的机会 并发现其对患者护理产生独特影响的应用。然而，目前FDA的批准是 仅用于头部和膝盖应用，即使如此，MRI扫描仪也仅限于使用其 安装功能。并行传输（pTx），这一功能可以解决面临的一些最大挑战 超高频（UHF）MRI尚未得到充分开发、集成和验证，无法安全用于 临床设置。这些挑战，例如不均匀的发射场和局部加热的问题， 被成像物体的大小。虽然头部和膝关节成像可以在没有此功能的情况下进行管理，但pTx 这对于人体躯干的应用是绝对必要的。虽然7T在成像方面显示出巨大的潜力， 在研究环境中的躯干目标，有一个关键问题，如何扩大这些有前途的 结果我们认为，在实现这一目标之前，需要进一步开发和整合几种使能技术。 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 以及优化射频（RF）线圈，以有效地将RF能量传输到微电子器件中并从微电子器件接收信号。 为了实现与较低场强相比在SNR方面的承诺增益，二是 建立人体模型虚拟数据库和克服目前 在尝试使用pTx系统时假设过度限制的安全因素。第三是整合 pTx功能纳入扩展的多参数前列腺成像协议和运动补偿 通过序列定制的pTx解决方案和优化策略。最终的平移目标将使用前列腺 作为一个试验平台，在一项比较癌症检测的患者研究中探索RF线圈和pTx启用序列 和在3T下成像的相同患者的成像度量。在成功完成这些开发后， 和翻译的目标，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。 7T的批准适应症。一旦在临床医生手中，建立UHF成像的独特影响， 能够使用7T作为一线扫描模式，患者的治疗效果将大大受益。

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.