To determine whether the presence of calcification in the cavernous segment of the internal carotid artery seen on head computed tomography (CT) performed in the emergency department shows any relationship to the existence of systemic disease. Significant and consistent relationships could be used as predictors in suggesting the presence of systemic disease in those patients receiving head CTs for unrelated symptoms.
A retrospective investigation was performed on 295 consecutive patients presenting to the Massachusetts General Hospital emergency department for head CT scan during the course of 1 month. Head CT images were analyzed for carotid siphon calcifications. Data regarding multiple predictors of disease including gender, age, hypertension, diabetes, smoking, hypercholesterolemia, cardiac disease, and alcohol and intravenous drug abuse were abstracted from the medical record for each patient.
Strong univariate correlation was noted in the comparison between the presence of carotid siphon calcification and gender, age, diabetes, hypertension, smoking, and cardiac disease while alcohol and intravenous drug abuse correlated poorly. Multivariate models including categorized age and gender demonstrated a consistently strong interaction with diabetes, cardiac disease, and smoking while hypertension and hypercholesterolemia showed a loss of significance. Interaction term analysis indicated a strong (ie, significant) interaction between gender and both hypertension and hypercholesterolemia.
Carotid siphon calcifications are strong predictors of existing medical disease in simple cases. In patients with a combination of diseases, a strong interaction between covariates is noted, suggesting a more complex interaction contributing to the formation of carotid siphon disease.