Intimal predominant calcification is associated with plaque instability in the vertebrobasilar artery by vessel wall magnetic resonance imaging and computed tomography

Background and aimsIt remains unknown about the relationship between vertebrobasilar artery (VBA) calcification and plaque instability. We aimed to investigate the characteristics of VBA calcification using vessel wall magnetic resonance imaging (MRI) and computed tomography (CT) and its association with acute cerebral infarction (ACI).MethodsNine hundred and thirty patients with VBA stenosis who underwent vessel wall MRI and CT examinations were evaluated retrospectively. Calcification morphology was classified as either intimal or non-intimal predominant using a CT-pathology-validated grading method. Qualitative and quantitative plaque MRI variables and calcification characteristics were compared between culprit and non-culprit lesions. The association between VBA calcification and the occurrence of culprit lesions was investigated using multivariate logistic regression.ResultsA total of 150 patients with ACI and 142 patients without ACI were eligible for subsequent analyses, respectively. In the qualitative analysis, T1 hyperintensity (p<0.001) and intimal predominant calcification (p=0.021) were more frequently observed in the culprit than non-culprit lesions. In the quantitative analyses, culprit lesions had a larger stenosis degree, plaque length, normal wall index, contrast enhancement ratio, lower calcification density and smaller calcification volume than non-culprit lesions (p all <0.05). Intimal predominant calcification (odds ratio [OR], 2.51; 95% confident interval [CI], 1.31-4.82, p=0.006) and calcification density (OR, 0.53; 95% CI, 0.35-0.78, p=0.001) were independently associated with the presence of ACI after adjusting for clinical risk factors and plaque variables.ConclusionsIntimal predominant calcification in vertebrobasilar atherosclerosis is associated with the likelihood of having caused acute cerebral infarction. The morphology and density of VBA calcification may provide insight into stroke risk stratification in the posterior circulation.