title: A new method for characterizing carotid plaque: multiple cross-sectional view echomorphology.
abstract: OBJECTIVE
  This study compares the ability of computer-derived B-mode ultrasound gray-scale measurements from a single longitudinal view (SLV) versus multiple cross-sectional views (MCSV) to differentiate symptomatic from asymptomatic carotid plaque causing more than 70% stenosis.
  
  
  METHODS
  Seventy-four internal carotid artery (ICA) stenoses (70%-99%; 33 asymptomatic, 41 symptomatic within 3 months) were imaged to obtain the "best" SLV and five to eight MCSV images at 5 mm intervals from the carotid bifurcation. Digitized sonograms were computerized and normalized to the gray scale median (GSM) of blood (0) and vessel adventitia (200). Plaque GSM was determined for each frame (image analysis, MATLAB 5.3). General risk factors for stroke and plaque echogenicity (SLV GSM; minimum MCSV GSM; cross-sectional axial heterogeneity (highest minus lowest MCSV GSM) were determined for each group.
  
  
  RESULTS
  Risk factors for stroke were similar in both groups, as was mean SLV GSM: symptomatic, 34 (95% confidence interval [CI], 24.8-43.0), asymptomatic, 43 (CI, 32.6-53.2); P =.1. Minimum MCSV GSM was lower for symptomatic plaque: 7 (CI, 4.2-9.8] vs 18.3 (CI, 12.2-24.5); P =.002. Greater axial GSM heterogeneity was present in symptomatic plaque: 34.5 (CI, 27.2-41.9) vs 16 (CI, 11.0-20.8); P =.0001.
  
  
  CONCLUSIONS
  MCSV cross-sectional imaging that enables objective assessment of regional plaque echolucency and heterogeneity is more sensitive than SLV sonography for differentiating symptomatic from asymptomatic plaque.
authors.affiliation: General Infirmary at Leeds, England.
authors.forename: S M
authors.initials: SM
authors.lastname: Wijeyaratne
authors.forename: S
authors.initials: S
authors.lastname: Jarvis
authors.forename: L A
authors.initials: LA
authors.lastname: Stead
authors.forename: S G
authors.initials: SG
authors.lastname: Kibria
authors.forename: J A
authors.initials: JA
authors.lastname: Evans
authors.forename: M J
authors.initials: MJ
authors.lastname: Gough
mesh_terms: D000368:Aged; D019412:Anatomy, Cross-Sectional / Q000379:methods; D001783:Blood Flow Velocity / Q000502:physiology; D002339:Carotid Arteries / Q000000981:diagnostic imaging*; D016893:Carotid Stenosis / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018616:Ultrasonography, Doppler, Duplex / Q000379:methods* / Q000639:trends