Evaluation of Arteriosclerotic Changes in the Intracranial Carotid Artery Using the Calcium Score Obtained on Plain Cranial Computed Tomography Scan

Purpose: This study evaluated the correlation between quantified calcification of the carotid siphon and arteriosclerotic changes on angiography as well as clinical outcome. We used the calcium score obtained from intracranial carotid arteries viewed on plain CT. Method/Materials: We examined carotid siphons of 72 consecutive patients who had undergone both plain CT and angiography of the brain. We calculated calcium scores of the carotid siphon. Arteriosclerotic changes on angiography were categorized as "smooth," "irregular," or "stenosis." We assessed the correlation between the scores and arteriosclerotic changes both in the carotid siphon and the bifurcation. We reviewed clinical records approximately 2 years after examination and evaluated the scores of patients who did and did not experience cerebral strokes. Results: In the evaluation between angiographic findings of siphon and calcium score of the siphon, there were statistically significant differences between the "smooth" and "irregular", "irregular" and "stenosis" and the "smooth" and "stenosis". In the evaluation between angiographic findings of bifurcation and the score of the siphon, a statistically significant difference was only seen between "smooth" and "stenosis". No significant differences in calcium scores were observed between patients groups who did or did not experience a cerebral stroke. Conclusions: There were a positive correlation between calcium scores on CT and angiographic changes of arteriosclerosis in the siphon as well as bifurcation, indicating angiographic changes can be predicted using calcium scores. However, the degree of calcification in the siphon cannot be used to predict the possibility of a future cerebral stroke.