自动高阶匀场在神经影像学研究中的应用。
Automated High-Order Shimming for Neuroimaging Studies.
机构信息
Department of Radiology, University of Iowa, Iowa City, IA 52242, USA.
GE Healthcare, Waukesha, WI 53188, USA.
出版信息
Tomography. 2023 Dec 1;9(6):2148-2157. doi: 10.3390/tomography9060168.
B inhomogeneity presents a significant challenge in MRI and MR spectroscopy, particularly at high-field strengths, leading to image distortion, signal loss, and spectral broadening. Existing high-order shimming methods can alleviate these issues but often require time-consuming and subjective manual selection of regions of interest (ROIs). To address this, we proposed an automated high-order shimming (autoHOS) method, incorporating deep-learning-based brain extraction and image-based high-order shimming. This approach performs automated real-time brain extraction to define the ROI of the field map to be used in the shimming algorithm. The shimming performance of autoHOS was assessed through in vivo echo-planar imaging (EPI) and spectroscopic studies at both 3T and 7T field strengths. AutoHOS outperforms linear shimming and manual high-order shimming, enhancing both the image and spectral quality by reducing the EPI image distortion and narrowing the MRS spectral lineshapes. Therefore, autoHOS demonstrated a significant improvement in correcting B inhomogeneity while eliminating the need for additional user interaction.
B 不均匀性在 MRI 和磁共振波谱学中是一个重大挑战,特别是在高场强下,会导致图像失真、信号丢失和谱线展宽。现有的高阶匀场方法可以缓解这些问题,但通常需要耗时且主观地选择感兴趣区域 (ROI)。为了解决这个问题,我们提出了一种自动化高阶匀场 (autoHOS) 方法,结合了基于深度学习的脑提取和基于图像的高阶匀场。该方法执行自动实时脑提取,以定义用于匀场算法的场图 ROI。通过在 3T 和 7T 场强下进行体内 echo-planar 成像 (EPI) 和波谱研究来评估 autoHOS 的匀场性能。与线性匀场和手动高阶匀场相比,autoHOS 提高了图像和光谱质量,通过减少 EPI 图像失真和缩小 MRS 谱线形状来增强图像和光谱质量。因此,autoHOS 在纠正 B 不均匀性方面表现出显著的改善,同时消除了额外的用户交互需求。