title: Contrast-enhanced ultrasound imaging of intraplaque neovascularization in carotid arteries: correlation with histology and plaque echogenicity.
abstract: OBJECTIVE
  This study was designed to evaluate contrast-enhanced ultrasound imaging of carotid atherosclerosis as a clinical tool to study intraplaque neovascularization.
  
  
  BACKGROUND
  Plaque neovascularization is associated with plaque vulnerability and symptomatic disease; therefore, imaging of neovascularization in carotid atherosclerosis may represent a useful tool for clinical risk stratification and monitoring the efficacy of antiatherosclerotic therapies.
  
  
  METHODS
  Thirty-two patients with 52 carotid plaques were studied by standard and contrast-enhanced ultrasound imaging. In 17 of these patients who underwent endarterectomy, the surgical specimen was available for histological determination of microvessel density by CD31/CD34 double staining. Plaque echogenicity and degree of stenosis at standard ultrasound imaging were evaluated for each lesion. Contrast-agent enhancement within the plaque was categorized as absent/peripheral (grade 1) and extensive/internal (grade 2).
  
  
  RESULTS
  In the surgical subgroup, plaques with higher contrast-agent enhancement showed a greater neovascularization at histology (grade 2 vs. grade 1 contrast-agent enhancement: median vasa vasorum density: 3.24/mm(2) vs. 1.82/mm(2), respectively, p = 0.005). In the whole series of 52 lesions, echolucent plaques showed a higher degree of contrast-agent enhancement (p < 0.001). Stenosis degree was not associated with neovascularization at histology or with the grade of contrast-agent enhancement.
  
  
  CONCLUSIONS
  Carotid plaque contrast-agent enhancement with sonographic agents correlates with histological density of neovessels and is associated with plaque echolucency, a well-accepted marker of high risk lesions, but it is unrelated to the degree of stenosis. Contrast-enhanced carotid ultrasound imaging may provide valuable information for plaque risk stratification and for assessing the response to antiatherosclerotic therapies, beyond that provided by standard ultrasound imaging.
authors.affiliation: Department of Cardiothoracic and Vascular Diseases, University Vita-Salute, San Raffaele Scientific Institute, Milan, Italy. coli.stefano@hsr.it
authors.forename: Stefano
authors.initials: S
authors.lastname: Coli
authors.forename: Marco
authors.initials: M
authors.lastname: Magnoni
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Sangiorgi
authors.forename: Massimiliano M
authors.initials: MM
authors.lastname: Marrocco-Trischitta
authors.forename: Giulio
authors.initials: G
authors.lastname: Melisurgo
authors.forename: Alessandro
authors.initials: A
authors.lastname: Mauriello
authors.forename: Luigi
authors.initials: L
authors.lastname: Spagnoli
authors.forename: Roberto
authors.initials: R
authors.lastname: Chiesa
authors.forename: Domenico
authors.initials: D
authors.lastname: Cianflone
authors.forename: Attilio
authors.initials: A
authors.lastname: Maseri
mesh_terms: D000368:Aged; D002339:Carotid Arteries / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D016893:Carotid Stenosis / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D003287:Contrast Media; D004691:Endarterectomy; D005260:Female; D006305:Health Status Indicators; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D009389:Neovascularization, Pathologic / Q000000981:diagnostic imaging* / Q000601:surgery; D018570:Risk Assessment; D014463:Ultrasonography
chemical_list: D003287:Contrast Media