title: Assessment of human atherosclerotic carotid plaque components with multisequence MR imaging: initial experience.
abstract: OBJECTIVE
  To prospectively determine, by using a stepwise logistic regression model, the optimal magnetic resonance (MR) weighting (ie, pulse sequence) combinations for plaque assessment and corresponding cutoff values of relative signal intensities (rSIs).
  
  
  METHODS
  Institutional review board approval and patient consent were obtained. Eleven patients (seven men, four women; mean age +/- standard deviation, 68 years +/- 4) with symptomatic carotid disease and stenosis of more than 70% were investigated at MR imaging before carotid endarterectomy. The MR images were matched with histologic features of the endarterectomy specimens (reference standard). The rSIs (compared with that of muscle tissue) from regions of interest were assessed qualitatively and semiquantitatively. For all major components (calcification, lipid core, intraplaque hemorrhage, and fibrous tissue), optimal cutoff points for the rSIs were determined for five MR weightings by means of receiver operating characteristic curves. The best predicting combinations of these five dichotomized MR weightings were selected by means of stepwise logistic regression analysis. The potential sensitivity and specificity of MR imaging for vulnerable plaque with hemorrhage and/or lipid core were determined.
  
  
  RESULTS
  The same optimal MR weighting combinations for identifying the four plaque components were found with qualitative and semiquantitative analysis. Sensitivity and specificity for vulnerable plaque were 93% (95% confidence interval: 77%, 99%) and 96% (95% confidence interval: 86%, 100%), respectively, for the qualitative analysis and 76% (95% confidence interval: 56%, 90%) and 100% (95% confidence interval: 93%, 100%) for the semiquantitative analysis.
  
  
  CONCLUSIONS
  This study demonstrates the potential of a systematic approach of atherosclerotic plaque assessment with multisequence MR imaging by using the information provided from five different MR weightings in a stepwise logistic regression model.
authors.affiliation: Department of Radiology, Cardiovascular Research Institute Maastricht, Maastricht University Hospital and Maastricht University, P. Debijelaan 25, 6229 HX Maastricht, the Netherlands.
authors.forename: Vincent C
authors.initials: VC
authors.lastname: Cappendijk
authors.forename: Kitty B J M
authors.initials: KB
authors.lastname: Cleutjens
authors.forename: Alfons G H
authors.initials: AG
authors.lastname: Kessels
authors.forename: Sylvia
authors.initials: S
authors.lastname: Heeneman
authors.forename: Geert Willem H
authors.initials: GW
authors.lastname: Schurink
authors.forename: Rob J T J
authors.initials: RJ
authors.lastname: Welten
authors.forename: Werner H
authors.initials: WH
authors.lastname: Mess
authors.forename: Mat J A P
authors.initials: MJ
authors.lastname: Daemen
authors.forename: Jos M A
authors.initials: JM
authors.lastname: van Engelshoven
authors.forename: M Eline
authors.initials: ME
authors.lastname: Kooi
mesh_terms: D000368:Aged; D001161:Arteriosclerosis / Q000175:diagnosis* / Q000473:pathology; D002340:Carotid Artery Diseases / Q000175:diagnosis* / Q000473:pathology; D016893:Carotid Stenosis / Q000175:diagnosis / Q000473:pathology; D004691:Endarterectomy; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012372:ROC Curve; D012044:Regression Analysis; D012680:Sensitivity and Specificity