Validation of the Berlin Grading System for moyamoya angiopathy with the use of [O]HO PET.

The Berlin Grading System assesses clinical severity of moyamoya angiopathy (MMA) by combining MRI, DSA, and cerebrovascular reserve capacity (CVRC). Our aim was to validate this grading system using [O]HO PET for CVRC. We retrospectively identified bilateral MMA patients who underwent [O]HO PET examination and were treated surgically at our department.