Portable Low-Cost MRI System Based on Permanent Magnets/Magnet Arrays
Portable Low-Cost MRI System Based on Permanent Magnets/Magnet Arrays
复制标题
基于永磁体/磁体阵列的便携式低成本 MRI 系统
DOI：
10.13104/imri.2019.23.3.179
复制
发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Wenwei Yu
中科院分区：
文献类型：
--
作者：
S. Huang;Z. Ren;S. Obruchkov;Jia Gong;R. Dykstra;Wenwei Yu
便携式低成本核磁共振系统有可能实现医疗保健和及时的核磁共振诊断，并使这种成像方式可用于常规扫描和欠发达地区。永磁体或永磁体阵列具有结构简单、无需维护、功耗低、成本低等优点，是一种极具吸引力的磁场来源，可实现扫描仪的便携式和低成本。然而，当采用傅里叶成像方法并使用线性梯度场时，需要均匀的场，因此要么需要庞大的磁铁，要么成像体积太小，如果磁铁缩小的话就不能成像器官。近年来，随着基于非线性梯度场的图像重建技术的发展，无空间线性的场模式可以作为空间编码磁场对磁共振信号进行编码成像。因此，对磁场的均匀性的要求可以放宽，这允许尺寸更小、重量更轻的永久磁体(阵列)成像覆盖头部等器官的更大体积。它提供了构建真正便携的低成本核磁共振扫描仪的机会。对于这一令人兴奋的潜在应用，永磁体(阵列)引起了越来越多的关注。磁体(阵列)通过场型和均匀性与成像体积、重建方法、射频激励和线圈等密切相关。本文综述了各种类型的永磁体(阵列)，特别是可用于空间编码的永磁体(阵列)，以期向便携式、低成本的磁共振成像系统发展。旨在使读者熟悉MRI用永磁体的相关知识、文献和最新进展。讨论了使用永磁体提供无空间线性或高均匀度的图案化磁场以用于便携式装置重建的前景和挑战。
Portable low-cost MRI systems have the potential to enable point-of-care and timely MRI diagnosis, and to make this imaging modality available to routine scans and to underdeveloped areas. With simplicity, no maintenance, no power consumption, and low cost, permanent magnets or arrays are attractive to use as a source of magnetic field to realize portability and low cost for a scanners. However, when taking the Fourier imaging approach and using linear gradient fields, homogeneous fields are required, thus either a bulky magnet is needed, or the imaging volume is too small to image an organ if the magnet is scaled down. Recently, with the progress on image reconstruction based on non-linear gradient field, field patterns without spatial-linearity can be used as spatial encoding magnetic fields to encode MRI signals for imaging. As a result, the requirements for the homogeneity of the field can be relaxed, which allows permanent magnets(arrays) with reduced sizes, reduced weight to image bigger volumes covering organs such as a head. It offers chances to construct a truly portable low-cost MRI scanner. For this exciting potential application, permanent magnets(arrays) have attracted increased attention. A magnet(array) is strongly associated with the imaging volume, reconstruction methods, and RF excitation and coils, etc. through field patterns and homogeneity. This paper offers a review on permanent magnets(arrays) of different kinds, especially those can be used for spatial encoding towards the development of portable and low-cost MRI systems. It is aimed to familiarize the readers with relevant knowledge, literature, and the latest updates of the development on permanent magnets for MRI. Perspectives on and challenges of using permanent magnets to supply a patterned magnetic field, without spatial-linearity nor high homogeneity, for reconstruction in a portable setup are discussed.
影响因子：
2.2
作者：
Van Landeghem, Maxime;Danieli, Ernesto;Casanova, Federico
通讯作者：
Casanova, Federico