Light Coils: MRI with Modular RF Coils Using Optical Power and Data Transmission

用于磁共振成像（MRI）的密集接收线圈阵列的设计由于导电电缆中的电磁干扰和串扰而具有挑战性，所述电磁干扰和串扰导致信号传输期间的信噪比（SNR）损失。这限制了通道的最大数量。通过结合创新的射频（RF）天线架构、低噪声低功率前端电子器件和最先进的硅光子技术，这项工作中的光线圈方法将克服传统接收线圈阵列的问题，为光供电并使用模块化广播技术的MRI线圈阵列提供强大且可扩展的解决方案。存在与当前RF线圈阵列相关联的主要缺点：1.固定和有限数量的线圈元件; 2.不能适应各种尺寸; 3.需要导电电缆来将MR信号传输到接收器并输送用于驱动放大器和有源失谐的功率。导电电缆在MRI中存在潜在的安全隐患，并且它们之间的串扰会损害成像性能。4.线圈周围密集的电缆束和电路会影响射频传输性能。具有全光信号和功率传输的模块化RF线圈技术可以克服这些问题，并实现迄今为止无法实现的通道数量的设计，以提高采集速度和SNR。模块化设计还将为不同体型的患者提供最佳的贴合度和性能，从而在人类大脑研究中获得新的发现。在这个方案中，我们将最先进的射频电子学和光学技术联合收割机结合起来，实现了光线圈技术。每个光线圈元件与用于光功率和信号传输的特定波长相关联。信号和电力传输波将使用在线光子IC分别进行复用和解复用。光线圈元件之间的光学连接器用于分配信号和功率波以及机械连接。只有主光线圈元件通过光纤连接到控制系统。所有连接的元件只有内部光纤连接和光学连接器，以连接到下一个光线圈元件。我们将使用新型放大器和有源失谐网络研究和优化RF线圈元件的功率要求，并评估在两个16通道柔性光线圈模块原型上实施光线圈技术的可行性，该模块可以连接形成32个阵列，并将其与最先进的信号传输系统和市售线圈进行比较。我们还将确保开发的解决方案和技术在项目的第二阶段可升级到更高通道数的RF线圈阵列，届时将展示具有前所未有的时间和空间分辨率的256通道光线圈的功能性MRI和MREG。

The design of dense receive coil arrays for magnetic resonance imaging (MRI) is challenging due to electromagnetic interference and crosstalk in the electrically conducting cables which lead to signal-to-noise ratio (SNR) losses during signal transmission. This limits the maximum number of channels. By combining innovative radio frequency (RF) antenna architectures, low-noise-low-power front end electronics and state-of-the-art silicon photonics technology, the Light Coil approach in this work will overcome the problems of conventional receive coil arrays offering a robust and scalable solution for MRI coil arrays that are optically powered and use modular broadcasting technologies. There are major draw-backs associated with the current RF coil arrays: 1. Fixed and limited number of coil elements; 2. cannot adapt to various sizes; 3. conducting cables are required to transfer MR signal to the receiver and to deliver power for driving the amplifiers and active detuning. Electrically conducting cables present a potential safety hazard in MRI, and crosstalk between them impairs the imaging performance. 4. The dense cable bundles and circuitry around the coil affects the RF transmission performance. A modular RF coil technology with fully optical signal and power transmission can overcome these problems and enable design of so-far-not-attainable number of channels to improve acquisition speed and SNR. The modular design will also facilitate optimal fit and performance for different patient sizes enabling new findings in human brain research. In this proposal, we combine the state-of-the-art RF electronics and optics to realize the Light Coil technology. Each Light Coil element is associated with a specific wavelength for optical power and signal transmission. Signal and power transmission waves will be multiplexed and demultiplexed separately using on-coil photonic ICs. Optical connectors between the Light Coil elements are used both for distributing the signal and power waves and for mechanical attachment. Only the main Light Coil element is connected to the control system via fibers. All the attached elements have only internal fiber connections and optical connectors to get attached to the next Light Coil element. We will investigate and optimize power requirements on an RF coil element using novel amplifier and active detuning networks, and assess feasibility of implementing Light Coil technology on two 16-channel flexible Light Coil module prototypes which can be attached to form an array of 32, and compare it to the state-of-the-art signal transmission systems and commercially available coils. We will also ensure that the developed solutions and techniques are upscalable to higher channel count RF coil arrays in the second phase of the project where functional MRI and MREG with 256-channel Light Coils with unprecedented temporal and spatial resolution will be demonstrated.