Regional disparities in cerebral perfusion and brain tissue microstructure damage in adult patients with Moyamoya syndrome

In Moyamoya syndrome (MMS), cerebral perfusion and tissue microstructure are impaired, but regional differences remain unclear. This study analyzed 22 adult MMS patients using CT perfusion (CTP) and intravoxel incoherent motion (IVIM). All hemispheres were classified into four ischemia grades based on symptoms and imaging. CTP parameters (CBF, CBV, MTT, TTP) and IVIM parameters (ADC, D, D*, f) were measured in the temporal lobe and basal ganglia. The relative values of CTP parameters and absolute values of IVIM parameters were compared across hemispheres with different ischemia grades. Additionally, correlation analyses were conducted between CTP and IVIM parameters. Results showed that in the temporal lobe, rMTT and rTTP were significantly increased (p = 0.018 and 0.002, respectively) with higher ischemia grades, while basal ganglia changes were similar but milder, with only rTTP delay being significant (p = 0.011). IVIM analysis revealed significantly elevated ADC values in association with higher ischemia grades (overall p = 0.011). Additionally, significant variations were observed in both D* (overall p = 0.041) and the perfusion fraction f (overall p = 0.043). In the basal ganglia, IVIM parameters showed no significant differences across ischemia grades. Weak or insignificant correlations were found between IVIM parameters and CTP parameters. The study suggested that perfusion and microstructural damage in the basal ganglia were less severe than in the temporal lobe, and that IVIM offers insights into microvascular status that are complementary to those from hemodynamic perfusion imaging.