Assessment of Cerebrovascular Reserve in the Setting of Moyamoya Disease Using Arterial Spin-Labeling and Acetazolamide Challenge

Arterial spin-labeling is a safe, noninvasive, contrast-free MR imaging technique that can be used to assess CBF. In this review, we will briefly discuss the advantages and disadvantages of arterial spin-labeling juxtaposed to previously established modalities of cerebral perfusion imaging, summarize the materials and methods required for arterial spin-labeling, and provide clinical case examples in which application of arterial spin-labeling combined with an acetazolamide challenge was used safely to improve patient outcomes in the setting of Moyamoya disease. Arterial spin-labeling takes advantage of the directionality of arterial blood flow by labeling the patient's own endogenous water within the neck via radiofrequency pulse and imaging of the downstream brain after an appropriate delay. This tool allows repeatable intra- and intersession estimation of CBF to better assess postinterventional outcomes in patients with cerebrovascular dysfunction. One specific example of the utility of arterial spin-labeling is its application in patients with Moyamoya disease by selection and stratification of those most likely to benefit from surgical intervention. The combination of arterial spin-labeling with acetazolamide challenge is an effective way to assess cerebrovascular reserve in Moyamoya disease and is easily adaptable on a clinical 3T MR imaging scanner using a commercially available arterial spin-labeling pulse sequence to generate augmentation and steal maps. The entire study can be completed in only 20 minutes in a routine clinical setting.

Learning Objective: To describe the implementation and interpretation of arterial spin-labeling combined with an acetazolamide challenge