Background: Identification of novel prognostic factors associated with the risk of stroke recurrence in patients with symptomatic intracranial atherosclerosis (ICAS) is needed. Intraplaque post-contrast enhancement (PCE) in high-resolution MRI (HRMRI) has been proposed as a potential marker of plaque activity. We aimed to study intraplaque PCE prevalence, temporal evolution and their associated factors, in patients with symptomatic ICAS.
Methods: We studied 10 consecutive patients with symptomatic ICAS who underwent HRMRI within the first 15 days after stroke onset and a control HRMRI three months thereafter. At each timepoint, symptomatic plaque and wall area were measured in T2 sequences, whereas plaque and wall signal intensity were measured with and without gadolinium contrast in T1 sequence. All HRMRI data were post-processed by two independent readers using Osirix imaging software.
Results: Baseline HRMRI showed PCE in 70% of patients. Among baseline variables, a significant correlation was found between T1 spontaneous intraplaque intensity and postcontrast intraplaque intensity. We could not observe a homogeneous temporal evolution of postcontrast intraplaque intensity during the first 3 months, with half of the patients showing a decrease and the remaining having stable or increased values. No significant associations with intraplaque intensity variation were found.
Conclusion: Intraplaque PCE was found in the majority (70%) of symptomatic intracranial atherosclerotic plaques during the acute phase. Interestingly, spontaneous and postcontrast intraplaque T1 signal intensities were highly correlated. Intraplaque PCE declined during the first three months in half of the patients.