Intracranial carotid artery calcification as an imaging marker in plain computed tomography for intracranial atherosclerotic disease in ischemic stroke patients: A retrospective observational cohort study.

OBJECTIVE: Intracranial carotid artery calcification (ICAC) refers to calcification located in the cavernous or supraclinoid segment of the internal carotid artery, which is readily visualized on plain computed tomography (CT) of the brain. ICAC has been identified as a risk factor of stroke, but existing limited studies on its impact on angiographic features reported inconsistent results. This study evaluates its association with co-existing intracranial atherosclerotic disease (ICAD) on angiography.

METHODS: Anterior circulation ischemic stroke patients who underwent angiography in a Hong Kong hospital with comprehensive stroke services were reviewed retrospectively over a 2-year period. Eligible patients were categorized into ICAC and no-ICAC groups for comparison. Subgroup analyses based on ICAC severity and pattern were also performed.

RESULTS: There were 193 ICAC (65.6%) and 101 no-ICAC patients (34.4%) identified and analyzed. ICAD incidence was comparable in ICAC and no-ICAC groups. After adjustment for confounders, the subgroup with more severe ICAC was associated with co-existing ICAD (adjusted odds ratio [aOR]: 2.93, p = 0.032 vs mild calcification; aOR: 3.15, p = 0.029 vs no calcification). Those with severe ICAC were also less likely to have good collateral status in an exploratory post-hoc univariate analysis (OR: 0.30, p = 0.015 vs mild calcification; OR: 0.36, p = 0.038 vs no calcification). No significant difference in the above angiographic features was detected among different calcification patterns.

CONCLUSION: ICAC with high calcific burden may serve as an imaging marker for co-existing ICAD in ischemic stroke patients, whereas the presence of calcification itself is insignificant. Correlation between ICAC and collateral status warrants further studies.