Evaluation of cerebrovascular reactivity impairment using resting-state BOLD MRI in symptomatic patients with unilateral intracranial artery occlusion.

OBJECTIVES

Cerebral vascular reactivity (CVR) is an independent predictor of poor prognosis for patients with symptomatic middle cerebral artery (MCA)/internal carotid artery (ICA) occlusion. This study assessed CVR impairment using resting-state blood oxygenation level-dependent (RS BOLD) MRI in this population and aimed to identify feasible pre-surgical markers.

METHODS

The study included 45 patients with symptomatic unilateral MCA/ICA occlusion and 20 healthy controls. Of these, 16 underwent extracranial-intracranial (EC-IC) bypass with follow-up MRI. RS BOLD data were collected using a 3.0 T PET/MR system. Voxel-wise CVR maps were computed with a general linear model, and the mean CVR in the MCA perfusion territory was calculated. Interhemispheric CVR asymmetry index (CVR-AI) was assessed. Group differences were analyzed, and ROC analysis was used to evaluate CVR's diagnostic performance. Pearson correlation was used to assess relationships between baseline CVR and post-surgical changes.

RESULTS

Affected-side CVR was significantly lower compared to the contralateral side and controls (P < 0.01). Individual analysis showed significant differences in the proportions of decreased, normal, and increased CVR between the affected and contralateral sides (P < 0.0001). CVR-AI showed high predictive efficiency for discriminating patients from controls (AUC = 0.762). Post-surgery, the affected-side CVR increased significantly, whereas CVR-AI decreased but remained higher than in controls (P < 0.05). Preoperative CVR-AI positively correlated with post-surgery affected-side CVR increase (R = 0.725) and CVR-AI decrease (R = 0.635).

CONCLUSION

This study proposes CVR-AI as a novel imaging marker for pre-surgical evaluation in patients with unilateral intracranial arterial occlusion.