title: Correlation of cerebrovascular symptoms and microembolic signals with the stratified gray-scale median analysis and color mapping of the carotid plaque.
abstract: OBJECTIVE
  To determine whether a stratified gray-scale median (GSM) analysis of the carotid plaque combined with color mapping correlated better with the presence of neurological symptoms and microembolic signals (MES) than a whole plaque measurement.
  
  
  METHODS
  A total of 131 patients presenting 167 carotid stenoses between 30% and 99% were analyzed by ultrasound. Emboli detection was performed by transcranial Doppler. For each plaque, the GSM values at depth 0 mm (surface) and at one third (30) and one half (50) of the plaque thickness were compared with the values obtained for the whole plaque. The plaque pixels were mapped into 3 colors: red, yellow and green, depending on their GSM value.
  
  
  RESULTS
  Mean GSM values were lower among symptomatic plaques, but a statistically significant difference between values of the whole plaque and those of the surface was obtained only for MES+ stenoses (P<0.01). In a proportional odds logistic regression model based on 4 subgroups with an increasing clinical risk (MES-/symptoms-; MES-/symptoms+; MES+/symptoms-; +; MES+/symptoms+), low mean GSM values and the predominant red color at the surface were independent factors associated with the presence of symptoms or MES (P<0.0005). Furthermore, compared with a whole plaque measurement, analysis of the surface values predicted systematically with a greater sensitivity and specificity (receiver operating characteristic curves) each one of these 4 subgroups.
  
  
  CONCLUSIONS
  Low mean GSM values and predominance of the red color at the surface correlated with most of the symptomatic or MES+ stenoses. This combined approach should be further investigated in a longitudinal study.
authors.affiliation: Department of Neurology, University Hospital Geneva and Medical School, Switzerland. Roman.Sztajzel@hcuge.ch
authors.forename: Roman
authors.initials: R
authors.lastname: Sztajzel
authors.forename: Isabelle
authors.initials: I
authors.lastname: Momjian-Mayor
authors.forename: Mario
authors.initials: M
authors.lastname: Comelli
authors.forename: Shahan
authors.initials: S
authors.lastname: Momjian
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002339:Carotid Arteries / Q000473:pathology*; D002340:Carotid Artery Diseases / Q000175:diagnosis / Q000473:pathology; D016893:Carotid Stenosis; D002561:Cerebrovascular Disorders / Q000175:diagnosis* / Q000473:pathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008137:Longitudinal Studies; D008875:Middle Aged; D015233:Models, Statistical; D016017:Odds Ratio; D012372:ROC Curve; D012044:Regression Analysis; D012306:Risk; D012307:Risk Factors; D020521:Stroke; D013997:Time Factors; D018615:Ultrasonography, Doppler, Color / Q000379:methods*; D017585:Ultrasonography, Doppler, Transcranial