Morgan Alasdair G, Thrippleton Michael J, Wardlaw Joanna M, Marshall Ian
Brain Research Imaging Centre, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK.
UK Dementia Research Institute at The University of Edinburgh, Edinburgh Medical School, Edinburgh, UK.
J Cereb Blood Flow Metab. 2021 Feb;41(2):206-218. doi: 10.1177/0271678X20952014. Epub 2020 Sep 16.
The brain's vasculature is essential for brain health and its dysfunction contributes to the onset and development of many dementias and neurological disorders. While numerous in vivo imaging techniques exist to investigate cerebral haemodynamics in humans, phase-contrast magnetic resonance imaging (MRI) has emerged as a reliable, non-invasive method of quantifying blood flow within intracranial vessels. In recent years, an advanced form of this method, known as 4D flow, has been developed and utilised in patient studies, where its ability to capture complex blood flow dynamics within any major vessel across the acquired volume has proved effective in collecting large amounts of information in a single scan. While extremely promising as a method of examining the vascular system's role in brain-related diseases, the collection of 4D data can be time-consuming, meaning data quality has to be traded off against the acquisition time. Here, we review the available literature to examine 4D flow's capabilities in assessing physiological and pathological features of the cerebrovascular system. Emerging techniques such as dynamic velocity-encoding and advanced undersampling methods, combined with increasingly high-field MRI scanners, are likely to bring 4D flow to the forefront of cerebrovascular imaging studies in the years to come.
大脑的血管系统对大脑健康至关重要，其功能障碍会导致许多痴呆症和神经疾病的发生与发展。虽然存在多种用于研究人体脑血流动力学的体内成像技术，但相位对比磁共振成像（MRI）已成为一种可靠的、非侵入性的量化颅内血管内血流的方法。近年来，这种方法的一种先进形式，即所谓的四维血流成像，已被开发并应用于患者研究中，其在采集容积内的任何主要血管中捕捉复杂血流动力学的能力，已被证明在单次扫描中收集大量信息方面是有效的。尽管作为一种研究血管系统在脑部相关疾病中作用的方法极具前景，但四维数据的采集可能很耗时，这意味着数据质量必须与采集时间进行权衡。在此，我们回顾现有文献，以研究四维血流成像在评估脑血管系统生理和病理特征方面的能力。诸如动态速度编码和先进欠采样方法等新兴技术，再加上越来越高场强的MRI扫描仪，很可能在未来几年将四维血流成像推向脑血管成像研究的前沿。
