标题： MRDust：基于磁共振图像调制的无线植入数据上行与定位 显示英文标题

标题： MRDust: Wireless Implant Data Uplink & Localization via Magnetic Resonance Image Modulation

摘要： 磁共振成像（MRI）展现出丰富且具有临床价值的内源性对比机制，能够区分软组织，并对流体、扩散、磁化率、血氧水平等敏感。 然而，MRI的灵敏度最终受到核磁共振（NMR）物理学的限制，其时空分辨率受信噪比（SNR）和空间编码的制约。 另一方面，微型可植入传感器可以提供高度局部化的生理信息，但当存在多个植入物时，通信和定位可能具有挑战性。 本文介绍了MRDust，一种主动的“对比剂”，它将主动传感器植入物与MRI结合，从而可以直接将高度局部化的生理数据编码到MR图像中，以增强解剖图像。 MRDust采用微米级片上线圈来主动调制局部磁场，实现MR信号幅度和相位调制以进行数字数据传输。 由于MRI本质上捕获的是解剖组织结构，因此这种方法有可能同时实现数据通信、定位和多植入物的图像配准。 本文介绍了该方法的基本物理原理、设计权衡以及设计方法。 为了验证这一概念，使用TSMC 28 nm技术设计了一款900 $\times$ 990 $\mu$mm$^2$芯片，片上线圈直径为630 $\mu$mm。 该芯片在MR750W GE3T MRI扫描仪中使用定制硬件进行了测试。 使用自旋回波回波平面成像（SE-EPI）序列成功实现了体素幅度调制，获得了25.58的信噪比（CNR），功耗为130 $\mu$W。 显示英文摘要

摘要： Magnetic resonance imaging (MRI) exhibits rich and clinically useful endogenous contrast mechanisms, which can differentiate soft tissues and are sensitive to flow, diffusion, magnetic susceptibility, blood oxygenation level, and more. However, MRI sensitivity is ultimately constrained by Nuclear Magnetic Resonance (NMR) physics, and its spatiotemporal resolution is limited by SNR and spatial encoding. On the other hand, miniaturized implantable sensors offer highly localized physiological information, yet communication and localization can be challenging when multiple implants are present. This paper introduces the MRDust, an active ``contrast agent" that integrates active sensor implants with MRI, enabling the direct encoding of highly localized physiological data into MR images to augment the anatomical images. MRDust employs a micrometer-scale on-chip coil to actively modulate the local magnetic field, enabling MR signal amplitude and phase modulation for digital data transmission. Since MRI inherently captures the anatomical tissue structure, this method has the potential to enable simultaneous data communication, localization, and image registration with multiple implants. This paper presents the underlying physical principles, design tradeoffs, and design methodology for this approach. To validate the concept, a 900 $\times$ 990 $\mu$m$^2$ chip was designed using TSMC 28 nm technology, with an on-chip coil measuring 630 $\mu$m in diameter. The chip was tested with custom hardware in an MR750W GE3T MRI scanner. Successful voxel amplitude modulation is demonstrated with Spin-Echo Echo-Planar-Imaging (SE-EPI) sequence, achieving a contrast-to-noise ratio (CNR) of 25.58 with a power consumption of 130 $\mu$W.