MR Neurophysics and Translational Neuroscience, UCL Queen Square Institute of Neurology London, London, England, UK.
Radiology, Nationwide Children's Hospital and The Ohio State University, Columbus, OH, USA.
Br J Radiol. 2022 Jun 1;95(1134):20220034. doi: 10.1259/bjr.20220034. Epub 2022 May 12.
Arterial spin labeling (ASL) is a powerful noncontrast MRI technique for evaluation of cerebral blood flow (CBF). A key parameter in single-delay ASL is the choice of postlabel delay (PLD), which refers to the timing between the labeling of arterial free water and measurement of flow into the brain. Multidelay ASL (MDASL) utilizes several PLDs to improve the accuracy of CBF calculations using arterial transit time (ATT) correction. This approach is particularly helpful in situations where ATT is unknown, including young subjects and slow-flow conditions. In this article, we discuss the technical considerations for MDASL, including labeling techniques, quantitative metrics, and technical artefacts. We then provide a practical summary of key clinical applications with real-life imaging examples in the pediatric brain, including stroke, vasculopathy, hypoxic-ischemic injury, epilepsy, migraine, tumor, infection, and metabolic disease.
动脉自旋标记 (ASL) 是一种强大的非对比 MRI 技术，用于评估脑血流 (CBF)。单延迟 ASL 的一个关键参数是后标记延迟 (PLD) 的选择，它是指动脉游离水标记与脑内血流测量之间的时间间隔。多延迟 ASL (MDASL) 使用多个 PLD 利用动脉通过时间 (ATT) 校正来提高 CBF 计算的准确性。这种方法在 ATT 未知的情况下特别有帮助，包括年轻受试者和低流速情况。本文讨论了 MDASL 的技术注意事项，包括标记技术、定量指标和技术伪影。然后，我们提供了一个实用的总结，介绍了儿科大脑中的关键临床应用，包括中风、血管病变、缺氧缺血性损伤、癫痫、偏头痛、肿瘤、感染和代谢性疾病，并提供了真实的成像示例。
