Rinsho Shinkeigaku (Clinical Neurology)

Original Article

Clinical and pathological significance of carotid siphon calcification observed on bone condition of brain CT

Hideyuki Matsumoto, M.D., Hirotoshi Hamaguchi, M.D., Takahiro Nakayama, M.D., Tetsuya Oda, M.D., Takashi Ikagawa, M.D. and Ichiro Imafuku, M.D.

Department of Neurology, Yokohama Rosai Hospital

[Purpose] On plain brain computed tomography (CT), it is difficult to evaluate stenosis of internal carotid artery (ICA) because ICA is surrounded by structures, even though we can observe calcification of carotid siphon in some patients by using bone condition. However the pathologic significance has not been well known. We studied the pathologic significance of carotid siphon calcification observed on bone condition of brain CT. [Methods] A total of 112 patients who were diagnosed or suspected as cerebrovascular diseases were registered. We classified the calcification into four levels (none, mild, moderate, severe) based on the degree of calcification. Then we compared it with the degree of stenosis of carotid siphon seen on brain magnetic resonance angiography (MRA) and with max intima-medial thickness (IMT) from common carotid artery (CCA) to ICA on carotid ultrasonography. [Result] The mean±standard deviation of max IMT to none, mild, moderate and severe in the degree of calcification were 1.03±0.64 (0.4-2.8), 1.65±0.83 (0.5-4.1), 2.03±0.83 (0.8-4.1) and 2.81±1.15 (0.7-6.5) mm, respectively. The calcification on brain CT significantly correlated with the degree of stenosis on brain MRA and with max IMT on carotid ultrasonography. [Conclusion] The calcification of carotid siphon on bone condition of brain CT correlated with stenosis of the same portion and atherosclerosis of CCA bifurcation. Recently, on DICOM viewer, clinicians can convert plain condition into bone condition on brain CT due to popularization of PACS. We should pay attention to calcification of carotid siphon in patients with ischemic cerebrovascular diseases because we can estimate the atherosclerosis of both carotid siphon and CCA bifurcation easily and immediately.
Full Text of this Article in Japanese PDF (530K)

(CLINICA NEUROL, 48: 114|119, 2008)
key words: computed tomography, internal carotid artery, calcification, atherosclerosis, stroke

(Received: 20-Sep-07)