Noninvasive Quantitative Imaging of Selective Microstructure Sizes via Magnetic Resonance
Noninvasive Quantitative Imaging of Selective Microstructure Sizes via Magnetic Resonance
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DOI：
10.1103/physrevapplied.15.014045
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发表时间：
2020-06
影响因子：
4.6
通讯作者：
Milena Capiglioni;A. Zwick;Pablo Jimenez;G. Álvarez
中科院分区：
文献类型：
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作者：
Milena Capiglioni;A. Zwick;Pablo Jimenez;G. Álvarez
通过非侵入性成像提取可靠、定量的活体组织微结构信息是理解疾病机制和早期病理诊断的一个突出挑战。磁共振成像是追求这一目标的最受欢迎的技术，但仍然提供比活体研究中相关微结构细节大得多的分辨率。监测组织内的分子扩散是克服分辨率限制的一种很有前途的机制。然而，获取详细的显微结构信息需要获取数十张图像，这对体内研究来说是不现实的，测量时间和结果都很长。作为解决这一悬而未决的问题的一步，我们在这里报告一种只需要两次测量的方法及其原理验证实验，通过适当的动态控制磁场梯度的核自旋来产生选择性微结构尺寸的图像。我们用自旋回波序列设计微结构大小的滤光片，利用磁化“衰变”而不是常用的衰减率。这种方法的结果是可以用当前技术执行的定量图像，并基于定义生物组织组成的微结构参数来揭示丰富的诊断信息。
Extracting reliable and quantitative microstructure information of living tissue by non-invasive imaging is an outstanding challenge for understanding disease mechanisms and allowing early stage diagnosis of pathologies. Magnetic Resonance Imaging is the favorite technique to pursue this goal, but still provides resolution of sizes much larger than the relevant microstructure details on in-vivo studies. Monitoring molecular diffusion within tissues, is a promising mechanism to overcome the resolution limits. However, obtaining detailed microstructure information requires the acquisition of tens of images imposing long measurement times and results to be impractical for in-vivo studies. As a step towards solving this outstanding problem, we here report on a method that only requires two measurements and its proof-of-principle experiments to produce images of selective microstructure sizes by suitable dynamical control of nuclear spins with magnetic field gradients. We design microstructure-size filters with spin-echo sequences that exploit magnetization "decay-shifts" rather than the commonly used decay-rates. The outcomes of this approach are quantitative images that can be performed with current technologies, and advance towards unravelling a wealth of diagnostic information based on microstructure parameters that define the composition of biological tissues.