Association between posterior cerebral artery involvement and arterial wall enhancement in moyamoya disease: a cross-sectional study with vessel wall imaging.

PURPOSE: Early detection and activity assessment of posterior cerebral artery (PCA) involvement in moyamoya disease (MMD) are challenging. We aimed to assess the cross-sectional association between PCA involvement and PCA wall enhancement on vessel wall MRI (DANTE T1-SPACE).

METHODS

We analyzed consecutive patients with MMD who underwent both non-contrast-enhanced and contrast-enhanced DANTE T1-SPACE. Positive wall enhancement was defined as location-appropriate arterial wall enhancement with an enhancement ratio ≥ 1.5. PCA involvement was graded 0-2 on MRA obtained during the same period.

RESULTS

Of 368 hemispheres from 184 patients, 56 (15.2%) showed PCA involvement and 17 (4.6%) showed PCA wall enhancement. PCA involvement was present in 94.1% of enhancement-positive hemispheres versus 11.4% of enhancement-negative hemispheres (p < 0.001). The difference was consistent across age, Suzuki stage, and RNF213 genotype strata. Enhancement most often involved the P2A segment. Topographical correspondence between enhancement and the stenoocclusive lesion was excellent (overall percent agreement, 94.1%). PCA wall enhancement was observed in 0.3%, 61.5%, and 18.6% of hemispheres with grade 0, 1, and 2 PCA involvement, respectively. Positive enhancement was more frequent in grade 1 PCA involvement than in grade 2 (adjusted p = 0.02).

CONCLUSIONS

Statistical and topographical findings suggest a strong cross-sectional association between PCA involvement and PCA wall enhancement. The enhancement may be associated with disease activity and may facilitate detection of early-stage PCA involvement with high specificity; these hypotheses require confirmation in longitudinal cohorts.