Correlation of the unilateral middle cerebral artery stenosis ratio and cerebrovascular reserve / 中华神经科杂志

ABSTRACT

Objective To investigate the correlation between the unilateral middle cerebral artery (MCA)stenosis ratio and cerebrovascular reserve(CVR) using computed tomography perfusion (CTP) and CO2 inhalation test in patients with unilateral middle cerebral artery stenosis.Methods CTP were performed in 31 patients who were diagnosed as unilateral middle cerebral stenosis before and after CO2 inhalation.The basal ganglia and radial dimension were selected as interested regions (thickness 8 mm).The value of cerebral blood flow (CBF) was measured and the mean CBF values of all interested regions in each MCA territory were harvested separately.Then the CVR of each MCA territory was calculated according to the following formulaCVR =(CBF after CO2 inhalation test-CBF before CO2 inhalation test)/ CBF before CO2 inhalation test × 100％.Patients were divided into two groupsthe severe stenosis group and the moderate stenosis group.The association between the MCA stenosis ratio and the CVR values was investigated.Results In 31 patients,different changes of CBF were found in affected MCA territory after CO2 inhalation.CBF increased in 17 cases,unchanged in 2 cases and decreased in 12 cases.A decreased CVR was detected in 51.6％ of the patients(16/31) and more likely found in the severe stenosis group (13/19) than that in the moderate stenosis group(3/12,P =0.029).The degree of stenosis in MCA was also significantly correlated with the changes of CVR(r =0.423,P =0.018).Conclusions CVR is decreased in some patients with unilateral MCA stenosis and significantly correlates with the severity of stenosis in MCA.