Cortical and subcortical vascular hypointensity on T2* weighted imaging in moyamoya disease

Decreased cortical and subcortical vascular signals in gradient echo T2* weighted imaging have been reported in acute stroke due to major artery occlusion. The purpose of this study was to evaluate this cortical and subcortical vascular hypointensity (CSVH) in patients with moyamoya disease.

Subjects were 20 consecutive patients with moyamoya disease. The numbers of CSVH in each hemisphere were counted and the numbers were compared between patients with moyamoya disease and controls. The distribution of CSVH, clinical features of cases exhibiting large numbers of CSVH and post-operative changes were analysed.

Patients with moyamoya disease had significantly more CSVH in the middle cerebral artery territory (p < 0.001) and the anterior cerebral artery territory (p < 0.001) compared with controls. The number of CSVH was correlated significantly with regional cerebral blood flow, as shown through simple regression analysis (R = 0.461, p = 0.006), and the numbers of CSVH were significantly higher in patients with higher magnetic resonance angiography scores (p = 0.017). A given patient's total number of CSVH per hemisphere was significantly decreased after surgery (p = 0.018).

CSVH on T2* WI may be a useful tool for diagnosing and evaluating the extent of moyamoya disease. Our small series study shows that revascularization surgery can decrease the number of CSVH.