论文标题
生物医学成像的双扩散编码和应用
Double diffusion encoding and applications for biomedical imaging
论文作者
论文摘要
扩散磁共振成像（DMRI）是在微观尺度上探测组织结构的最重要的当代非侵入性模态之一。大多数DMRI技术采用标准的单个扩散编码（SDE）测量，涵盖不同序列参数范围取决于方法的复杂性。尽管已经为SDE数据提出了许多信号表示和生物物理模型，但由于缺乏特异性，它们在本质上受到了限制。已经提出了先进的DMRI方法，以提供超出SDE推断出的其他微观结构信息。这些增强的对比性可以在表征生物组织的表征中起重要作用，例如在疾病（例如神经退行性，癌症，中风），衰老，学习和发育中。 在这篇综述中，我们着重于双重扩散编码（DDE），该编码的多功能性，更具体的扩散相关性以及临床前和临床应用的可行性，在其他高级采集中脱颖而出。已经采用了各种DDE方法来探测区室大小（第3节），将微观扩散各向异性的影响与方向分散剂（第4节），探测位移相关性，研究交换或抑制快速扩散隔间（第6节）。 DDE测量还可以用于改善生物物理模型的鲁棒性（第5节），并通过代谢物的磁共振光谱研究细胞内扩散（第7节）。这篇综述讨论了与临床前和临床环境中的实施和对比有关的所有这些主题以及重要的实践方面（第9节），旨在为读者提供指南，以确定正确的DDE获取其特定应用。
Diffusion Magnetic Resonance Imaging (dMRI) is one of the most important contemporary non-invasive modalities for probing tissue structure at the microscopic scale. The majority of dMRI techniques employ standard single diffusion encoding (SDE) measurements, covering different sequence parameter ranges depending on the complexity of the method. Although many signal representations and biophysical models have been proposed for SDE data, they are intrinsically limited by a lack of specificity. Advanced dMRI methods have been proposed to provide additional microstructural information beyond what can be inferred from SDE. These enhanced contrasts can play important roles in characterizing biological tissues, for instance upon diseases (e.g. neurodegenerative, cancer, stroke), aging, learning, and development. In this review we focus on double diffusion encoding (DDE), which stands out among other advanced acquisitions for its versatility, ability to probe more specific diffusion correlations, and feasibility for preclinical and clinical applications. Various DDE methodologies have been employed to probe compartment sizes (Section 3), decouple the effects of microscopic diffusion anisotropy from orientation dispersion (Section 4), probe displacement correlations, study exchange, or suppress fast diffusing compartments (Section 6). DDE measurements can also be used to improve the robustness of biophysical models (Section 5) and study intra-cellular diffusion via magnetic resonance spectroscopy of metabolites (Section 7). This review discusses all these topics as well as important practical aspects related to the implementation and contrast in preclinical and clinical settings (Section 9) and aims to provide the readers a guide for deciding on the right DDE acquisition for their specific application.
