Magnetic resonance imaging with inherent local shimming

 描述（由申请人提供）：磁共振成像（MRI）可能是现代神经科学研究中最主要的成像技术，因为其具有高空间分辨率、无创性和多功能成像对比度。然而，MRI易受主磁场（B0）不均匀性的影响，因此几乎所有MRI扫描仪都配备了广泛的B0匀场功能。目前所有领先的MRI制造商使用的传统全身匀场线圈通常无法充分校正由于高阶或局部B0不均匀性造成的成像伪影。当使用快速成像技术时，这些伪影尤其明显，例如在功能性MRI（fMRI，用于成像大脑功能）和扩散张量成像（DTI，用于成像大脑连接）中。最近提出的多线圈局部匀场策略可以在高阶和局部不均匀性的存在下更好地执行，然而，它需要通常在RF线圈内的单独匀场线圈阵列才是有效的和高效的，因此在已经受限的空间内占用了相当大的空间用于对象。此外，匀场阵列将产生不期望的电磁干扰和屏蔽效应，损害RF灵敏度并且还降低局部匀场的灵活性和性能。在实践中，还需要放大RF线圈，进一步降低信噪比（SNR）。为了解决所有这些限制并在不影响任何RF性能的情况下提供大大改善的B0均匀性，我们在这里建议进一步开发一种有前途的新硬件平台，该平台能够在单个统一线圈阵列内实现固有的局部匀场和并行RF接收。具体来说，从我们成功的初步结果证明了16通道的实施，我们将1）开发和构建一个32通道头部线圈阵列与固有的局部匀场和RF接收，2）将新集成的32通道头部线圈到GE MR 750 3T MRI扫描仪，并验证了许多优势，在体内的fMRI和DTI应用。我们预计，这种新技术将RF和匀场组件固有地结合在单个统一的线圈阵列中，将大大改善磁场均匀性和高SNR，而无需单独的线圈组。此外，这一创新可以进一步扩展到全身其他器官的成像，从而完全消除对全身匀场线圈的需求，并显着扩大扫描仪孔，以提高患者的舒适度并降低制造成本。

 DESCRIPTION (provided by applicant): Magnetic resonance imaging (MRI) is perhaps the most dominant imaging technique for modern neuroscience research because of its high spatial resolution, noninvasiveness, and versatile imaging contrasts. However, MRI is susceptible to main magnetic field (B0) inhomogeneities, as such virtually all MRI scanners are equipped with extensive capabilities for B0 shimming. The traditional whole-body shimming coils, which are used by all leading MRI manufacturers today, often cannot adequately correct for imaging artifacts due to high-order or local B0 inhomogenneities. These artifacts are especially apparent when fast imaging techniques are used such as in functional MRI (fMRI, used to image brain function) and diffusion tensor imaging (DTI, used to image brain connectivity). Recently proposed multi-coil local shimming strategy can perform better in the presence of high-order and local nonuniformities, however, it requires a separate array of shim coils, typically within th RF coil, to be effective and efficient, thus taking up considerable room within the already confined space for subjects. In addition, the shim array would create undesirable electromagnetic interferences and shielding effects, compromising the RF sensitivity and also reducing the flexibility and performance of the local shimming. In practice it would also require the RF coil to be enlarged, further reducing the signal-to-noise ratio (SNR). To address all these limitations and provide greatly improved B0 homogeneity without compromising any RF performance, we propose here to further develop a promising new hardware platform that enables inherent local shimming and parallel RF reception within a single unified coil array. Specifically, extending from our successful preliminary results demonstrating a 16- channel implementation, we will 1) develop and construct a 32-channel head coil array with inherent local shimming and RF reception, and 2) incorporate the newly integrated 32-channel head coil into a GE MR750 3T MRI scanner and validate the many advantages in vivo for fMRI and DTI applications. We anticipate that this new technology, inherently combining RF and shimming components within a single unified coil array, will achieve greatly improved magnetic field homogeneity and high SNR, without the need for separate sets of coils. Moreover, this innovation could be further expanded to image other organs throughout the body, thereby removing the need for whole-body shimming coils altogether and significantly widening the scanner bore to increase patient comfort and reduce manufacturing costs.