title: Carotid Plaque Morphological Classification Compared With Biomechanical Cap Stress: Implications for a Magnetic Resonance Imaging-Based Assessment.
abstract: OBJECTIVE
  Two approaches to target plaque vulnerability-a histopathologic classification scheme and a biomechanical analysis-were compared and the implications for noninvasive risk stratification of carotid plaques using magnetic resonance imaging were assessed.
  
  
  METHODS
  Seventy-five histological plaque cross sections were obtained from carotid endarterectomy specimens from 34 patients (>70% stenosis) and subjected to both a Virmani histopathologic classification (thin fibrous cap atheroma with <0.2-mm cap thickness, presumed vulnerable) and a peak cap stress computation (<140 kPa: presumed stable; >300 kPa: presumed vulnerable). To demonstrate the implications for noninvasive plaque assessment, numeric simulations of a typical carotid magnetic resonance imaging protocol were performed (0.62×0.62 mm(2) in-plane acquired voxel size) and used to obtain the magnetic resonance imaging-based peak cap stress.
  
  
  RESULTS
  Peak cap stress was generally associated with histological classification. However, only 16 of 25 plaque cross sections could be labeled as high-risk (peak cap stress>300 kPa and classified as a thin fibrous cap atheroma). Twenty-eight of 50 plaque cross sections could be labeled as low-risk (a peak cap stress<140 kPa and not a thin fibrous cap atheroma), leading to a κ=0.39. 31 plaques (41%) had a disagreement between both classifications. Because of the limited magnetic resonance imaging voxel size with regard to cap thickness, a noninvasive identification of only a group of low-risk, thick-cap plaques was reliable.
  
  
  CONCLUSIONS
  Instead of trying to target only vulnerable plaques, a more reliable noninvasive identification of a select group of stable plaques with a thick cap and low stress might be a more fruitful approach to start reducing surgical interventions on carotid plaques.
authors.affiliation: From the Departments of Biomedical Engineering-Thoraxcenter (F.J.H.G., H.A.N., J.J.W., A.F.W.v.d.S.), Vascular Surgery (H.J.M.V.), and Radiology (A.v.d.L.), Erasmus MC, Rotterdam, The Netherlands; and Department of Applied Sciences, Delft University of Technology, Delft, The Netherlands (A.F.W.v.d.S.). f.gijsen@erasmusmc.nl.
authors.forename: Frank J H
authors.initials: FJ
authors.lastname: Gijsen
authors.affiliation: From the Departments of Biomedical Engineering-Thoraxcenter (F.J.H.G., H.A.N., J.J.W., A.F.W.v.d.S.), Vascular Surgery (H.J.M.V.), and Radiology (A.v.d.L.), Erasmus MC, Rotterdam, The Netherlands; and Department of Applied Sciences, Delft University of Technology, Delft, The Netherlands (A.F.W.v.d.S.).
authors.forename: Harm A
authors.initials: HA
authors.lastname: Nieuwstadt
authors.affiliation: From the Departments of Biomedical Engineering-Thoraxcenter (F.J.H.G., H.A.N., J.J.W., A.F.W.v.d.S.), Vascular Surgery (H.J.M.V.), and Radiology (A.v.d.L.), Erasmus MC, Rotterdam, The Netherlands; and Department of Applied Sciences, Delft University of Technology, Delft, The Netherlands (A.F.W.v.d.S.).
authors.forename: Jolanda J
authors.initials: JJ
authors.lastname: Wentzel
authors.affiliation: From the Departments of Biomedical Engineering-Thoraxcenter (F.J.H.G., H.A.N., J.J.W., A.F.W.v.d.S.), Vascular Surgery (H.J.M.V.), and Radiology (A.v.d.L.), Erasmus MC, Rotterdam, The Netherlands; and Department of Applied Sciences, Delft University of Technology, Delft, The Netherlands (A.F.W.v.d.S.).
authors.forename: Hence J M
authors.initials: HJ
authors.lastname: Verhagen
authors.affiliation: From the Departments of Biomedical Engineering-Thoraxcenter (F.J.H.G., H.A.N., J.J.W., A.F.W.v.d.S.), Vascular Surgery (H.J.M.V.), and Radiology (A.v.d.L.), Erasmus MC, Rotterdam, The Netherlands; and Department of Applied Sciences, Delft University of Technology, Delft, The Netherlands (A.F.W.v.d.S.).
authors.forename: Aad
authors.initials: A
authors.lastname: van der Lugt
authors.affiliation: From the Departments of Biomedical Engineering-Thoraxcenter (F.J.H.G., H.A.N., J.J.W., A.F.W.v.d.S.), Vascular Surgery (H.J.M.V.), and Radiology (A.v.d.L.), Erasmus MC, Rotterdam, The Netherlands; and Department of Applied Sciences, Delft University of Technology, Delft, The Netherlands (A.F.W.v.d.S.).
authors.forename: Antonius F W
authors.initials: AF
authors.lastname: van der Steen
mesh_terms: D016893:Carotid Stenosis / Q000145:classification* / Q000175:diagnosis* / Q000601:surgery; D016894:Endarterectomy, Carotid; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000145:classification* / Q000379:methods; D008297:Male; D013314:Stress, Mechanical
keywords: carotid artery plaque; histology; magnetic resonance imaging; mechanics; risk assesment; stroke