title: Semiautomated Magnetic Resonance Imaging Assessment of Carotid Plaque Lipid Content.
abstract: BACKGROUND
  The composition of a carotid plaque is important for plaque vulnerability and stroke risk. The main aim of this study was to assess the potential of semiautomated segmentation of carotid plaque magnetic resonance imaging (MRI) in the assessment of the size of the lipid-rich necrotic core (LRNC).
  
  
  METHODS
  Thirty-four consecutive patients with carotid stenosis of 70% or higher, who were scheduled for carotid endarterectomy, underwent a clinical neurological examination, Color duplex ultrasound, 3-T MRI with an 8-channel carotid coil, and blood tests. All examinations were performed less than 24 hours prior to surgery and plaques were assessed histologically immediately following endarterectomy. Plaques were defined as symptomatic when associated with ipsilateral cerebral ischemic symptoms within 30 days prior to inclusion. The level of agreement between the size of the LRNC and calcification on MRI to the histological estimation of the same tissue components, plaque echolucency on ultrasound, and symptoms was assessed.
  
  
  RESULTS
  The size of the LRNC on MRI was significantly correlated to the percentage amount of lipid per plaque on histological assessment (P = .010, r = .5), and to echogenicity on ultrasound with echolucent plaques having larger LRNC than echogenic plaques (P = .001, r = -.7).
  
  
  CONCLUSIONS
  In this study, we found that semiautomated MRI assessments of the percentage LRNC in carotid plaques were significantly correlated to the percentage LRNC per plaque on histological assessment, and to echogenicity on ultrasound with echolucent plaques having larger LRNC than echogenic plaques.
authors.affiliation: Department of Neurology, Oslo University Hospital, Norway; Institute of Clinical Medicine, University of Oslo, Norway. Electronic address: kskagen@ous-hf.no.
authors.forename: Karolina
authors.initials: K
authors.lastname: Skagen
authors.affiliation: Department of Neurology, Oslo University Hospital, Norway; Vestre Viken, Drammen Hospital, Norway.
authors.forename: Kristin
authors.initials: K
authors.lastname: Evensen
authors.affiliation: Department of Pathology, Oslo University Hospital, Norway.
authors.forename: Helge
authors.initials: H
authors.lastname: Scott
authors.affiliation: Department of Thoracic and cardiovascular surgery, Oslo University Hospital, Norway.
authors.forename: Kirsten
authors.initials: K
authors.lastname: Krohg-Sørensen
authors.affiliation: The Intervention Centre, Oslo University Hospital, Norway.
authors.forename: Svein Are
authors.initials: SA
authors.lastname: Vatnehol
authors.affiliation: Institute of Clinical Medicine, University of Oslo, Norway; The Intervention Centre, Oslo University Hospital, Norway.
authors.forename: Per Kristian
authors.initials: PK
authors.lastname: Hol
authors.affiliation: Department of Neurology, Oslo University Hospital, Norway.
authors.forename: Mona
authors.initials: M
authors.lastname: Skjelland
authors.affiliation: Department of Neurology, Oslo University Hospital, Norway; Institute of Clinical Medicine, University of Oslo, Norway.
authors.forename: David
authors.initials: D
authors.lastname: Russell
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002339:Carotid Arteries / Q000000981:diagnostic imaging*; D016893:Carotid Stenosis / Q000000981:diagnostic imaging* / Q000473:pathology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D050356:Lipid Metabolism; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010930:Plague / Q000000981:diagnostic imaging*; D013223:Statistics as Topic; D018709:Statistics, Nonparametric; D014463:Ultrasonography
keywords: Carotid stenosis; carotid magnetic resonance imaging; carotid ultrasound; ischemic stroke