title: Relation between B-mode gray-scale median and clinical features of carotid stenosis vulnerability.
abstract: BACKGROUND
  Vulnerability of the carotid plaque might be useful as a predictor for ischemic stroke risk. The gray-scale median (GSM) of the carotid plaque at B-mode imaging has been described as an objective tool to quantify vulnerability. However, its use is disputed in the published literature. This study sought to validate the GSM as a predictor for carotid plaque vulnerability.
  
  
  METHODS
  We included 89 consecutive patients (64 men; mean ± SD age: 68 ± 1 years) who were evaluated for carotid endarterectomy. The GSM was derived from preoperative B-mode images and related to the presence of clinical symptoms, the presence of ipsilateral infarction on neuroimaging, and to the number of intraoperative ipsilateral microemboli (ME) detected by transcranial Doppler ultrasonography. In addition, we combined the GSM with its standard deviation (GSM-SD), which we hypothesized to be a measure for plaque heterogeneity and thereby vulnerability.
  
  
  RESULTS
  B-mode imaging revealed a wide variety in GSM among all plaques (median: 36; range: 6-89). The GSM could not be related to cardiovascular risk factors and was not different between symptomatic and asymptomatic patients (37.8 ± 8.9 vs 37.6 ± 17.1; P = 0.97). The GSM of plaques in patients with ipsilateral ischemic lesions on neuroimaging did also not differ from plaques in patients without (36.0 ± 14.6 vs 37.8 ± 16.9; P = 0.64). Finally, no relation between GSM and the presence of intraoperative ME (Spearman correlation; n = 73; ρ = 0.039; P = 0.75) was found. Combining GSM with its GSM-SD also could not identify more vulnerable plaques.
  
  
  CONCLUSIONS
  No relation was found between the GSM and any clinical, radiologic, or intra- and postoperative neurologic phenomena. These data showed no additional value of the use of GSM in evaluating plaque vulnerability.
authors.affiliation: Division of Vascular Surgery, Department of Surgery, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: Joé L
authors.initials: JL
authors.lastname: Kolkert
authors.affiliation: Department of Surgery, Medical Spectrum Twente, Enschede, The Netherlands.
authors.forename: Robbert
authors.initials: R
authors.lastname: Meerwaldt
authors.affiliation: Division of Vascular Surgery, Department of Surgery, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: Jan
authors.initials: J
authors.lastname: Loonstra
authors.affiliation: Division of Clinical Neurophysiology, Department of Neurology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: Miranda
authors.initials: M
authors.lastname: Schenk
authors.affiliation: Department of Clinical Epidemiology, Medical Spectrum Twente, Enschede, The Netherlands.
authors.forename: Job
authors.initials: J
authors.lastname: van der Palen
authors.affiliation: Division of Vascular Surgery, Department of Surgery, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: Jan J
authors.initials: JJ
authors.lastname: van den Dungen
authors.affiliation: Division of Vascular Surgery, Department of Surgery, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands. Electronic address: czeebregts@hotmail.com.
authors.forename: Clark J
authors.initials: CJ
authors.lastname: Zeebregts
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D058070:Asymptomatic Diseases; D002545:Brain Ischemia / Q000209:etiology; D002339:Carotid Arteries / Q000000981:diagnostic imaging* / Q000601:surgery; D016893:Carotid Stenosis / Q000150:complications / Q000000981:diagnostic imaging* / Q000601:surgery; D016894:Endarterectomy, Carotid; D006801:Humans; D002546:Ischemic Attack, Transient / Q000209:etiology; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D058226:Plaque, Atherosclerotic; D011237:Predictive Value of Tests; D012042:Registries; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012422:Rupture, Spontaneous; D020521:Stroke / Q000209:etiology; D016896:Treatment Outcome; D018615:Ultrasonography, Doppler, Color; D018616:Ultrasonography, Doppler, Duplex; D017585:Ultrasonography, Doppler, Transcranial