title: Identification of carotid 'vulnerable plaque' by contrast-enhanced ultrasonography: correlation with plaque histology, symptoms and cerebral computed tomography.
abstract: BACKGROUND
  Indication to carotid revascularisation is commonly determined by percent of stenosis as well as neurological symptoms and clinical conditions. High plaque embolic potential is defined as 'vulnerability'; however, its characterisation is not universally used for carotid revascularisation. We investigated the role of contrast-enhanced ultrasonography (CEUS) to identify carotid vulnerable plaque.
  
  
  METHODS
  Patients undergoing carotid endarterectomy were preoperatively evaluated by cerebral computed tomography (CT) scan and CEUS. Contrast microbubbles detected within the plaque indicated neovascularisation and were quantified by decibel enhancement (dB-E). Plaques were histologically evaluated for five features: (microvessel density, fibrous cap thickness, extension of calcification, inflammatory infiltrate and lipid core) and blindly scored 1-5 to assess plaque vulnerability. Analysis of variance (ANOVA), Fisher's and Student's t-test were used to correlate patients' characteristics, histological features and dB-E.
  
  
  RESULTS
  In 22 patients, dB-E (range 2-7.8, mean 4.85 ± 1.9 SD) was significantly greater in symptomatic (7.40 ± 0.5) vs. asymptomatic (3.5 ± 1.4) patients (p = 0.002). A higher dB-E was significantly associated with thinner fibrous cap (<200 μm, 5.96 ± 1.5 vs. 3 ± 1, p = 0.01) and greater inflammatory infiltrate (3.2 ± 0.9 vs. 6.4 ± 1.2, p = 0.03). Plaques with vulnerability score of 5 had significantly higher dB-E compared with those with vulnerability score of 1 (7.6 ± 0.2 vs. 2.5 ± 0.6, respectively, p = 0.001). Preoperative ipsilateral embolic lesions at CT were correlated with higher dB-E (5.96 ± 1.5 vs. 3.0 ± 1.0, p = 0.01).
  
  
  CONCLUSIONS
  CEUS with dB-E is indicative of the extent of plaque neovascularisation. It can be used therefore as a marker for vulnerable plaque.
authors.affiliation: Department of Specialistic Surgeries and Anesthesiological Sciences, University of Bologna, Policlinico S Orsola, via Massarenti 9, 40138 Bologna, Italy. gianluca.faggioli@unibo.it
authors.forename: G L
authors.initials: GL
authors.lastname: Faggioli
authors.forename: R
authors.initials: R
authors.lastname: Pini
authors.forename: R
authors.initials: R
authors.lastname: Mauro
authors.forename: G
authors.initials: G
authors.lastname: Pasquinelli
authors.forename: S
authors.initials: S
authors.lastname: Fittipaldi
authors.forename: A
authors.initials: A
authors.lastname: Freyrie
authors.forename: C
authors.initials: C
authors.lastname: Serra
authors.forename: A
authors.initials: A
authors.lastname: Stella
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D002114:Calcinosis / Q000473:pathology; D016893:Carotid Stenosis / Q000150:complications / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D002533:Cerebral Angiography / Q000379:methods*; D003287:Contrast Media; D016894:Endarterectomy, Carotid; D005260:Female; D005355:Fibrosis; D006801:Humans; D007150:Immunohistochemistry; D020766:Intracranial Embolism / Q000000981:diagnostic imaging* / Q000209:etiology; D002546:Ischemic Attack, Transient / Q000000981:diagnostic imaging* / Q000209:etiology; D007558:Italy; D008055:Lipids / Q000032:analysis; D008297:Male; D045423:Microbubbles; D009389:Neovascularization, Pathologic / Q000473:pathology; D011237:Predictive Value of Tests; D011379:Prognosis; D012720:Severity of Illness Index; D020521:Stroke / Q000000981:diagnostic imaging* / Q000209:etiology; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography
chemical_list: D003287:Contrast Media; D008055:Lipids