[Clinical and pathological significance of carotid siphon calcification observed on bone condition of brain CT].
OBJECTIVE
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.


RESULTS
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.


CONCLUSIONS
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.
Matsumoto
Hideyuki
H
Department of Neurology, Yokohama Rosai Hospital
Hamaguchi
Hirotoshi
H
Nakayama
Takahiro
T
Oda
Tetsuya
T
Ikagawa
Takashi
T
Imafuku
Ichiro
I
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000000981:diagnostic imaging*; D002114:Calcinosis; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging* / Q000473:pathology*; D016893:Carotid Stenosis / Q000000981:diagnostic imaging* / Q000473:pathology*; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D020521:Stroke / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014463:Ultrasonography