Abstract:

Objective To apply ¹³N-ammonia PET/CT cerebral blood perfusion imaging combined with methazolamide challenge for cerebrovascular reserve (CVR) evaluation in ischemic cerebrovascular diseases. Methods From January, 2014 to December, 2016, 56 ischemic stroke patients with serious stenosis of unilateral internal carotid artery or middle cerebral artery accepted basal and stress PET/CT with methazolamide challenge. The patients were divided into normal-CVR group (n = 29) and reduced-CVR group (n = 27) according to the results of CVR, and followed up for 24 months. The ischemic cerebrovascular events and cerebral blood flow were observed. Results The incidence of transient ischemic attack was more in the reduced-CVR group than in the normal-CVR group (χ² = 4.389, P < 0.05), while the incidence of ischemic stroke increased a little with no significant difference between the two groups ( P > 0.05). The CBF was improved in normal-CVR group after treatment ( t = 2.409, P < 0.05), and the improvement was not significant in reduced-CVR group ( t = 0.648, P > 0.05). Conclusion ¹³N-ammonia PET/CT cerebral blood flow perfusion imaging combined with methazolamide challenge can be used to evaluate CVR to predict the outcome for patients with cerebral ischemic disease, which is helpful for early intervention.

Key words: ischemic cerebrovascular diseases, cerebrovascular reserve, nitrogen radioisotopes, methazolamide, positronemission tomography, computerized tomography, ischemic preconditioning