Acetazolamide-challenged ASL shows comparable performance to CT perfusion for angiographic outcomes in moyamoya...

Moyamoya angiopathy is a chronic steno-occlusive cerebrovascular disorder in which assessment of cerebral hemodynamics, particularly cerebrovascular reserve (CVR), is essential for risk stratification and surgical planning. Because PET is not widely available and CT perfusion (CTP) involves radiation and contrast exposure, arterial spin labeling (ASL) MRI with an acetazolamide challenge may offer a noninvasive alternative. We evaluated the ability of ASL-derived CBF and CVR to predict angiographic severity and compared ASL- and CTP-based predictive models.

In this single-center retrospective study, 39 patients with moyamoya angiopathy underwent MRI with pCASL (baseline and post-acetazolamide), CTP when available, and digital subtraction angiography (DSA). Territory-specific CBF was extracted in ACA, MCA, and PCA regions, and CVR was calculated as percent CBF change after acetazolamide. Logistic regression models incorporating CBF, CVR, and age were evaluated using ROC analysis for dichotomized Suzuki stage, proximal A1/M1 stenosis, and postsurgical collateral status.

ASL-based models demonstrated moderate to good discrimination for angiographic outcomes (AUC 0.71-0.85). The highest performance was observed for prediction of postoperative collateral status (AUC 0.85). CTP-based models showed comparable discrimination for shared endpoints (AUC 0.69-0.74). No significant differences in AUC were observed between modalities.

Acetazolamide-challenged ASL-derived perfusion metrics demonstrated moderate predictive performance for angiographic features in moyamoya angiopathy. In our cohort, its discriminatory performance was comparable to that of CTP. However, these findings should be interpreted within the methodological scope of the study, and their clinical implications remain to be established.