Reducing the Size and Cost of MRI by Using a Zero-He Moderate-Field MRI Magnet Integrated with a Cryocooled RF Coil

摘要： 这一应用表明，更经济的无制冷剂磁体 在0.5T-1T的中等磁场下运行，并与冷冻射频线圈集成，可以产生 信噪比(SNR)可能与1.5T MRI扫描仪相当 传统的射频线圈。该项目为实现高性能、更小尺寸和 更低成本的核磁共振扫描仪，适用于新兴的介入和医疗保健应用。它 众所周知，通过冷却来降低射频线圈的电阻对任何一个都是有利的 小线圈或低磁场。因为所需的扫描时间与平方成比例地减少 在SNR方面，即使是适度的SNR改进也是非常有利的，特别是在 干预性和护理点情况。第一阶段工作的第一个目标是证明 通过射频接收线圈的传导冷却获得显著更高信噪比的可行性， 并建立场强、磁体大小(成本)和通过以下方式获得的SNR之间的权衡 射频接收线圈的低温冷却。第一阶段的第二个目标是使用此权衡的结果 一种实用型无低温磁体的设计研究 将在这项工作的第二阶段建造的冷冻冷却射频接收线圈。添加低温冷冻剂 以较小的增量成本将RF接收线圈(较高SNR)提供给磁体 磁铁系统。申请者SSI在开发高级 SBIR资助的无低温磁共振磁体，以及几种国际医疗设备 公司已经采用(获得许可)SSI的MRI无冷源磁铁技术。

Abstract: This application proposes to demonstrate that the more economic cryogen-free magnets operating at moderate fields of 0.5T-1T, and integrated with cryocooled RF coils, can produce signal to noise ratios (SNR) that are potentially comparable to those of 1.5 T MRI scanners with conventional RF coils. This project paves the way towards high-performance, smaller size, and lower cost MRI scanners suited to the emerging interventional and point-of-care applications. It is well established that reducing the RF coil resistance by cooling is advantageous for either small coils or low fields. Because the required scan time decreases in proportion to the square of SNR, even modest improvements in SNR are highly advantageous, especially in interventional and point-of-care situations. The first Aim of the Phase I effort is to demonstrate the feasibility of obtaining significantly higher SNR by conduction-cooling of RF receive coils, and establish the tradeoffs between field strength, magnet size (cost), and SNR gained by cryocooling of the RF receive coil. The second Aim of Phase I is to use results of this tradeoff study to design a practical cryogen-free magnet for head-MRI that includes an integrated cryocooled RF receive coil that will be built in Phase II of this work. The addition of cryocooled RF receive coils (higher SNR) to the magnet is provided at a small incremental cost to the magnet system. SSI, the applicant, has a proven record in the development of advanced cryogen-free MRI magnets under SBIR funding, and several international medical device companies have adopted (licensed) SSI’s MRI cryogen-free magnet technology.