Different hemodynamics of basal ganglia between moyamoya and non-moyamoya diseases using intravoxel incoherent motion imaging and single-photon emission computed tomography.

Background: Moyamoya disease (MMD) and non-MMD have different pathogenesis, clinical presentation, and treatment policy.

Purpose: To identify differences in hemodynamics between MMD and non-MMD using intravoxel incoherent motion (IVIM) magnetic resonance imaging (MRI) and single-photon emission computed tomography (SPECT).

Material And Methods: Patients who had undergone Tc-ECD or I-IMP SPECT, and IVIM imaging were retrospectively studied. IVIM imaging was acquired using six different b-values. Cerebral blood flow ratio (CBF) in the basal ganglia was calculated using a standardized volume-of-interest template. The cerebellum was used as a reference region. IVIM perfusion fraction (f) was obtained using a two-step fitting algorithm. Elliptical regions of interest were placed in bilateral basal ganglia on the IVIM f map. Patients were classified into MMD and non-MMD groups. The correlation between CBF and mean IVIM f (f) in the basal ganglia was evaluated using Spearman's rank correlation coefficient.

Results: In total, 20 patients with MMD and 28 non-MMD patients were analyzed. No significant differences in f were observed among MMD, affected hemisphere with non-MMD (non-MMD), and unaffected hemispheres with non-MMD (non-MMD). A negative correlation was seen between f and CBF in the MMD group (r = -0.40,  = 0.0108), but not in the non-MMD group (non-MMD, r = 0.07,  = 0.69; non-MMD, r = -0.22,  = 0.29). No significant differences were found among MMD and non-MMD patients, irrespective of SPECT tracers.

Conclusion: The combination of IVIM MRI and SPECT appears to allow non-invasive identification of differences in hemodynamics between MMD and non-MMD.