A Prototype Wireless Digital MR Spectrometer on a Single Integrated Circuit

单个集成电路上的原型无线数字磁共振波谱仪

• 批准号: 8597817
• 负责人: ROLAND BAMMER
• 金额: $ 19.63万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-01 至 2015-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8597817
• 关键词: Affect; Anesthesia procedures; Architecture; Back; Brain; Calibration; Callback; Childhood; Clinic; Clinical; Clinical Protocols; Communication; Consumption; Coupling; Data; Dependence; Development; Devices; Diagnosis; Diagnostic; Dimensions; Elderly; Electronics; Feeds; Forehead; Freedom; Future; Head; Health; Health Care Costs; Healthcare; Healthcare Systems; Heating; Housing; Human Resources; Image; Individual; Lead; Left; Lesion; Link; Magnetic Resonance Imaging; Masks; Measurement; Measures; Mechanics; Morphologic artifacts; Motion; Movement; Neurologic; Optics; Pathology; Patients; Pediatrics; Performance; Phase; Philosophy; Photons; Physiologic pulse; Positioning Attribute; Positron-Emission Tomography; Printing; Process; Public Health; RF coil; Reading; Resistance; Risk; Safety; Sampling; Scanning; Sedation procedure; Signal Transduction; Silicon; Solutions; Source; Staging; Stress; Subject Headings; System; Techniques; Technology; Time; Tissues; Translations; Update; Validation; Wireless Technology; Work; analog; base; cost; design; digital; feeding; flexibility; high risk; image processing; improved; innovation; microchip; miniaturize; motor disorder; new technology; novel strategies; operation; patient population; patient safety; portability; prototype; radiologist; skills; tool development; transmission process; trend; wireless fidelity; wireless network

DESCRIPTION (provided by applicant): The final deliverable of this project is a powerful microchip, or system-on-a-chip (SOC), that contains the functionality of a complete digital MR spectrometer and wireless transmitter. The three specific aims present an iterative, three stage strategy for chipset development. With the completion of each specific aim, the deliverables will be fully functional chipsets with decreasing footprint until we reach the dimensions of the final SOC. We begin with a 50x50x20mm prototype on a printed circuit board that will eventually be reduced to a miniature 2x2x1mm complete SOC blueprint. This microchip technology will be the centerpiece of a wireless, digital RF chain that is superior in performance to the traditional wired, analog RF chain, and is a paradigm shift for the entire field of MRI. Integration of this microchip into an RF coil will enable digital processing of the MR signal to be performed directly on the coil, followed by digital wireless signal transmission, thereby improving SNR and removing all mechanical connections between the RF coil and MR scanner. Specifically, we will develop the microchip technology for integration into a miniature RF coil-based "wireless marker", whose position can be tracked inside the MR scanner bore. Motion tracking of the head is performed using three wireless markers that are easily placed on the forehead, which will provide pose information for real-time motion correction of brain MRI. This application fittingly highlights the strengths of the microchip approach (miniature, wireless device), as well as our significant in-house expertise in motion correction. Head motion is still a fundamental problem for brain MRI, which adds to healthcare costs while also reducing diagnostic confidence. A wireless marker based motion correction solution will significantly benefit healthcare by reducing prep/scan time, costs, and stress to patient that are caused by a dependence on anesthesia and repeat scans due to motion. The diagnostic quality of MRI will also be improved, particularly in patient populations who have difficulty keeping still (e.g. pediatrics, elderly). Wireless markers also possess several advantages over alternative techniques, including: (1) improved patient safety by eliminating electrically conducting wires that can cause tissue heating; (2) no additional load is placed on the existing MR receiver hardware since communication occurs within its own wireless network; (3) compatibility with a wide range of clinical scans, as only a short navigator pulse-sequence is needed for position measurement; (4) does not require any cross-calibration routines (e.g. optical camera tracking), since tracking and imaging are performed in the same MR coordinate system; and (5) importantly, a miniature, wireless-marker tracking-device will be easy to use, thereby facilitating their portability to the high-throughput clinic. Looking beyond motion correction (and the scope of this R21), the powerful chipsets are an enabling technology for wireless, digital communication between ALL RF coils and the MR scanner. The chipset digitizes the MR signal directly on the RF coil, digitally modulates, and wirelessly transmits the digital MR signal. SNR i therefore increased by avoiding resistive losses and coupling due to long coaxial cables. In the case of a multi-channel imaging RF coil, each channel would have a matching set of on-coil microchips that perform all MR spectrometer operations. By performing these operations directly on the RF coil, the MR scanner becomes channel independent, and RF channel upgrades a thing of the past. An array of microchips may be deployed in a massively multi-channel coil, thereby facilitating the trend in MRI towards parallel imaging. Finally, the elimination of cables and large oncoil electronics will result in lighter and easier to handle RF coils. Digital wireless links in MRI may also benefit from similar technology that is being rapidly advanced in the field of modern mobile telephony. In summary, the powerful chipsets developed here will not only influence motion correction, but also innovate a fully digital and fully wireless MR scanner in the future. In the current R21, we expect to produce a high-impact motion correction strategy that is, overall, the most comprehensive, robust, and patient friendly solution to date. The technology and preliminary results garnered will then be used for two future R01 proposals. The first R01 will be for clinical validation of an even more refined wireless marker. The second R01 will be to refine and validate a high-fidelity wireless spectrometer IC for imaging RF coils. Another future application would be MR-PET where a small footprint IC spectrometer would eliminate a lot of the current x-ray dense RF electronics, which interacts with 511keV photons and thus perturbs the PET imaging process.

描述(由申请人提供)：该项目的最终交付成果是一个功能强大的微芯片，或称片上系统(SOC)，它包含一个完整的数字磁共振光谱仪和无线发射器的功能。这三个具体目标代表了芯片组开发的迭代、三阶段战略。随着每个特定目标的完成，可交付的芯片组将是功能齐全的芯片组，占地面积不断减少，直到我们达到最终SOC的尺寸。我们从印刷电路板上的50x50x20 mm原型开始，最终将其缩减为微型2x2x1 mm完整的SOC蓝图。这种微芯片技术将成为无线数字射频链的核心，该链在性能上优于传统的有线模拟射频链，是整个核磁共振领域的范式转变。将这种微芯片集成到射频线圈中，可以直接在线圈上对磁共振信号进行数字处理，然后进行数字无线信号传输，从而提高信噪比并消除射频线圈和磁共振扫描仪之间的所有机械连接。具体地说，我们将开发微芯片技术，将其集成到一个基于射频线圈的微型“无线标记器”中，其位置可以在磁共振扫描仪孔内进行跟踪。头部的运动跟踪使用三个无线标记，这些标记可以方便地放置在前额上，为脑MRI的实时运动校正提供姿势信息。这一应用恰如其分地突出了微芯片方法(微型、无线设备)的优势，以及我们在运动矫正方面的重要内部专业知识。头部运动仍然是脑MRI的一个基本问题，这增加了医疗成本，同时也降低了诊断信心。基于无线标记的运动校正解决方案将通过减少准备/扫描时间、成本以及因依赖麻醉和因运动而重复扫描而给患者带来的压力，使医疗保健显著受益。MRI的诊断质量也将得到提高，特别是在难以保持静止的患者群体中(如儿科、老年人)。与替代技术相比，无线标记器还具有几个优点，包括：(1)通过消除可能引起组织加热的导线来提高患者的安全性；(2)由于通信发生在其自身的无线网络中，因此不会对现有的MR接收器硬件施加额外的负载；(3)与广泛的临床扫描兼容，因为位置测量只需要较短的导航器脉冲序列；(4)不需要任何交叉校准例程(例如，光学相机跟踪)，因为跟踪和成像是在相同的MR坐标系中执行的；以及(5)重要的是，微型无线标记跟踪设备将易于使用，从而便于 它们可移植到高吞吐量的诊所。除了运动校正(以及这款R21的范围)之外，强大的芯片组是实现所有RF线圈和MR扫描仪之间无线、数字通信的一种技术。芯片组直接将射频线圈上的MR信号数字化，进行数字调制，并无线传输数字MR信号。因此，通过避免因长同轴电缆引起的阻性损耗和耦合，SNR i增加。在多通道成像RF线圈的情况下，每个通道将有一组匹配的线圈上微芯片来执行所有的磁共振光谱仪操作。通过直接在RF线圈上执行这些操作，MR扫描仪变得独立于通道，RF通道升级成为过去。微芯片阵列可以部署在大规模多通道线圈中，从而促进了MRI向并行成像的趋势。最后，消除电缆和大型内线圈电子设备将导致更轻和更容易处理射频线圈。数字无线 磁共振成像中的链接也可能受益于现代移动电话领域迅速发展的类似技术。总而言之，这里开发的功能强大的芯片组不仅将影响运动校正，还将在 未来。在目前的R21中，我们预计将产生一种高影响的运动矫正策略，总体上是迄今为止最全面、最健壮和对患者最友好的解决方案。然后，获得的技术和初步结果将用于未来的两个R01提案。第一个R01将用于临床验证一种更精致的无线标记。第二个R01将改进和验证用于射频线圈成像的高保真无线光谱仪IC。另一个未来的应用将是MR-PET，一台占地面积较小的IC光谱仪将消除大量当前与511keV光子相互作用的高密度射频电子设备，从而扰乱PET成像过程。