title: [Clinical and pathological significance of carotid siphon calcification observed on bone condition of brain CT].
abstract: 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.
authors.affiliation: Department of Neurology, Yokohama Rosai Hospital
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Matsumoto
authors.forename: Hirotoshi
authors.initials: H
authors.lastname: Hamaguchi
authors.forename: Takahiro
authors.initials: T
authors.lastname: Nakayama
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Oda
authors.forename: Takashi
authors.initials: T
authors.lastname: Ikagawa
authors.forename: Ichiro
authors.initials: I
authors.lastname: Imafuku
mesh_terms: 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