Longitudinal Reproducibility of CO₂-Triggered BOLD MRI for the Hemodynamic Evaluation of Adult Patients with Moyamoya Angiopathy

Background and Purpose: Hemodynamic evaluation of moyamoya patients is crucial to decide the treatment strategy. Recently, CO 2 -triggered BOLD MRI has been shown to be a promising tool for the hemodynamic evaluation of moyamoya patients. However, the longitudinal reliability of this technique in follow-up examinations is unknown. This study aims to analyze longitudinal follow-up data of CO 2 -triggered BOLD MRI to prove the reliability of this technique for long-term control examinations in moyamoya patients. Methods: Longitudinal CO 2 BOLD MRI follow-up examinations of moyamoya patients with and without surgical revascularization have been analyzed for all 6 vascular territories retrospectively. If revascularization was performed, any directly (by the disease or the bypass) or indirectly (due to change of collateral flow after revascularization) affected territory was excluded based on angiography findings (group 1). In patients without surgical revascularization between the MRI examinations, all territories were analyzed (group 2). Results: Eighteen moyamoya patients with 39 CO 2 BOLD MRI examinations fulfilled the inclusion criteria. The median follow-up between the 2 examinations was 12 months (range 4–29 months). For 106 vascular territories analyzed in group 1, the intraclass correlation coefficient was 0.784, p < 0.001, and for group 2 (84 territories), it was 0.899, p < 0.001. Within the total follow-up duration of 140 patient months, none of the patients experienced a new stroke. Conclusions: CO 2 BOLD MRI is a promising tool for mid- and long-term follow-up examinations of cerebral hemodynamics in moyamoya patients. Systematic prospective evaluation is required prior to making it a routine examination.