Magnetic Resonance Imaging/Gadolinium-enhanced Vessel Wall Image after Bypass Surgery in Moyamoya Disease.

OBJECTIVE
After bypass surgery in patients with moyamoya disease, several changes on magnetic resonance imaging (MRI)/fluid attenuated inversion recovery (FLAIR) have been recognized, while findings on MRI/gadolinium-enhanced (Gd) vessel wall imaging (VWI) have never been reported. The purposes of this study were to investigate postoperative changes on MRI/Gd VWI and to clarify the relationship between the MRI/Gd VWI and MRI/FLAIR findings.


METHODS
Consecutive patients who underwent bypass surgery at our hospital from September 2020 to March 2022 were candidates.


RESULTS
In 20 patients with moyamoya disease, 25 operated hemispheres were investigated. In all hemispheres, hyperintensities in the cortical sulci on MRI/FLAIR and enhancement in the cortical sulci on MRI/Gd VWI appeared after bypass surgery. The maximum appearance of sulci enhancement on MRI/Gd VWI occurred earlier than the maximum appearance of the sulci hyperintensity on MRI/FLAIR, and this difference was significant (p = 0.001).


CONCLUSIONS
MRI/Gd VWI demonstrated that the peak of the enhancement changes preceded the peak of hyperintensity changes on MRI/FLAIR. These MRI changes may reflect alterations in blood-brain barrier permeability after bypass surgery in patients with moyamoya disease.