高空间分辨率、高质量白质纤维束成像：在头部专用高梯度性能3T MRI扫描仪上使用动态逐层B0匀场的DTI
High-spatial resolution, high-quality white matter tractography using DTI with dynamic slice-by-slice B0 shimming in a head-only high-gradient performance 3T MRI scanner
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- University of Iowa（爱荷华大学）
- GE HealthCare（通用电气医疗）
机构由 AI 辅助整理，请以论文原文为准。
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中文总结 AI 辅助
本研究评估动态逐层B0匀场（DySiBo）对DTI白质纤维束成像的影响，发现其能显著减少磁敏感性伪影，在脑干、颞叶和额叶等区域生成更多高质量纤维流线，且仅需10个扩散张量方向即可解析交叉纤维，改善临床白质评估。
中文摘要 AI 辅助
传统单次激发平面回波成像（SS-EPI）采集的扩散张量成像（DTI）数据受到磁场不均匀性（ΔB0）的显著影响，导致图像畸变和信号去相位。多次激发EPI可以减轻ΔB0引起的伪影，但代价是扫描时间增加。近期发展的脑组织选择性、动态逐层B0匀场技术已证明能有效减少脑内局部ΔB0。当与采用平面回波成像（EPI）读出方式的DTI结合时，图像畸变和信号去相位显著减少。本研究旨在评估动态逐层B0匀场技术（DySiBo）对白质（WM）纤维束成像的影响。我们回顾性分析了使用SS-EPI和2次激发的多次激发EPI（MS-2shot-EPI）读出、两种空间分辨率（1x1x2mm3和2x2x2mm3）、有无DySiBo的DTI数据集。生成并检查WM纤维束成像，以考察对通常受ΔB0诱导伪影影响区域的影响。我们发现，在EPI图像中通常受ΔB0诱导伪影影响的区域（包括脑干、颞叶和额叶），使用DySiBo的DTI数据集生成了更多的WM流线。DySiBo在两种平面内分辨率下均显著改善了基于DTI的纤维束成像中WM流线的生成。总之，DySiBo与需要10个扩散张量方向的DTI结合使用，足以生成具有足够高信噪比和角度分辨率的数据，以解析交叉纤维，并在通常受磁敏感性诱导伪影影响的脑区产生高质量的WM纤维束成像。这对定量WM微结构指标和患者WM束的临床评估具有重要意义。
英文摘要
Data from conventional diffusion tensor imaging (DTI) using single-shot echo planar imaging (SS-EPI) acquisition are substantially influenced by magnetic field inhomogeneities (delta B0), which result in image distortion and signal dephasing. Multi-shot EPI can mitigate the delta B0-induced artifacts but at the cost of increased scan time. Recent brain tissue-selective, dynamic slice-by-slice B0 shimming techniques have demonstrated effective reduction of local delta B0 in the brain. When combined with DTI utilizing an echo-planar imaging (EPI) read-out, image distortion and signal dephasing are significantly reduced. The purpose of our study was to assess the impact of DTI with dynamic slice-by-slice B0 shimming technique (DySiBo) on white matter (WM) tractography. We retrospectively analyzed DTI datasets using SS-EPI and Multi-shot EPI with 2 shots (MS-2shot-EPI) readout at two spatial resolutions (1x1x2mm3 and 2x2x2mm3) with and without DySiBo. WM tractography was generated and inspected to examine the impact upon regions typically affected by delta B0-induced artefacts. We found more WM streamlines were generated in the DTI datasets with DySiBo in regions conventionally impacted by delta B0-induced in EPI images, including the brainstem, temporal and frontal lobes. DySiBo substantially improved the generation of WM streamlines in DTI-based tractography at both in-plane resolutions. In conclusion, DySiBo in conjunction with DTI requiring 10 diffusion tensor directions is sufficient to generate data with high enough SNR and angular resolution to resolve crossing fibers and produce high quality WM tractography in brain regions typically affected by susceptibility-induced artefacts. This has implications for quantitative WM microstructural indices and clinical evaluation of WM tracts in patients.
