Clinical Implication of Cerebral Artery Calcification on Brain CT

Abstract

Background and Purpose: Arterial calcification is a process of atherosclerosis, usually taking place within advanced atheromatous plaque. In the coronary arteries, calcification seen on computed tomography (CT) often indicates severe stenosis, and is noted in almost all patients with coronary symptoms. Calcification of the cerebral arteries is also frequently observed on brain CT, but its clinical significance has yet to be clarified. To evaluate the clinical significance of cerebral arterial calcification on brain CT, we investigated the angiographic and transcranial Doppler ultrasonography (TCD) findings of calcified cerebral arteries. Methods: The subjects were 57 patients with ischemic stroke, all of whom underwent brain CT, digital subtraction cerebral angiography and TCD. Stroke subtypes were defined according to TOAST classification. Two clinicians who were blinded in respect to the patients’ clinical history and to each other’s interpretation, determined the presence of cerebral arterial calcification and the degree of angiographic stenosis. Results: Cerebral artery calcification was noted in 23 patients (40%) out of a total of 46 arteries, consisting of 23 internal carotid, 15 vertebral, 5 basilar, 2 middle cerebral and 1 anterior cerebral artery. The patients with calcification were significantly older and more hypertensive than those without calcification. All the patients with calcification showed either large artery atherosclerosis or lacunar stroke. Hemodynamic alterations measured by TCD were rarely observed in calcified arteries. The severity and extent of the atherosclerotic changes were significantly greater in the patients with calcification than those without calcification. Conclusion: These results suggest that cerebral arterial calcification does not directly indicate hemodynamically significant atherosclerotic stenosis involving calcified segments, but indicates the underlying etiology of either large artery atherosclerosis or lacunar stroke, and raises the possibility of a diffuse atherosclerotic process being present in the cerebral circulation.

High Prevalence of Intracranial Artery Calcification in Stroke Patients with CKD

“…Furthermore, the association between IAC and CKD is not restricted to patients hospitalized for stroke but is also found in a population of patients hospitalized for other neurologic disorders. The prevalence of IAC in stroke patients in the present study (76.2%) was higher than that observed in work by Sohn et al (40%) (16). This discrepancy may be due to the different methods used to determine IAC; Sohn et al used conventional CT with a slice thickness of 5 mm, whereas we used the more sensitive 64-slice MDCT (16).…”

“…The prevalence of IAC in stroke patients in the present study (76.2%) was higher than that observed in work by Sohn et al (40%) (16). This discrepancy may be due to the different methods used to determine IAC; Sohn et al used conventional CT with a slice thickness of 5 mm, whereas we used the more sensitive 64-slice MDCT (16). In contrast, a more recent study performed in China with the same technique as used here (i.e.…”

Intracranial Internal Carotid Artery Calcifications: Association with Vascular Risk Factors and Ischemic Cerebrovascular Disease

“…Consequently, previous studies made use of a qualitative grading system. [8][9][10][11][12] Although Taoka et al 13 used commercially available software to assess the Agatston score of intracranial calcifications, they had to eliminate the contamination of bone attenuation on wide-windowed CT images. We developed custom-made software for quantification of intracranial calcifications.…”

“…Age, sex, smoking, hypercholesterolemia, a history of cardiac disease, and a history of ischemic cerebrovascular disease were independently related to the presence or volume of intracranial internal carotid artery calcifications. Associations between cardiovascular risk factors and intracranial calcifications have been studied in patients referred for brain CT. [10][11][12] One study had a prevalence of 36% in a group of patients with a mean age of 51 years, 11 whereas the second study found a prevalence of 67% in a group of patients with a mean age of 63 years. 10 Both studies confirmed the association between age and calcifications, an association that was also found in coronary artery studies.…”

“…Previous studies [8][9][10][11][12] had a binary or a qualitative (5-point scale) grading system for classification of intracranial calcifications, probably because quantification difficulties arose due to the close relationship between calcifications and the bony structures of the skull. Taoka et al 13 were able to use commercially available software for quantification of intracranial calcifications, but they had to eliminate the contamination of bone attenuation on wide-windowed CT images.…”