title: Imaging the intracranial atherosclerotic vessel wall using 7T MRI: initial comparison with histopathology.
abstract: OBJECTIVE
  Several studies have attempted to characterize intracranial atherosclerotic plaques by using MR imaging sequences. However, dedicated validation of these sequences with histology has not yet been performed. The current study assessed the ability of ultra-high-resolution 7T MR imaging sequences with different image contrast weightings to image plaque components, by using histology as criterion standard.
  
  
  METHODS
  Five specimens of the circle of Wills were imaged at 7T with 0.11 × 0.11 mm in-plane-resolution proton attenuation-, T1-, T2-, and T2*-weighted sequences (through-plane resolution, 0.11-1 mm). Tissue samples from 13 fiducial-marked locations (per specimen) on MR imaging underwent histologic processing and atherosclerotic plaque classification. Reconstructed MR images were matched with histologic sections at corresponding locations.
  
  
  RESULTS
  Forty-four samples were available for subsequent evaluation of agreement or disagreement between plaque components and image contrast differences. Of samples, 52.3% (n = 23) showed no image contrast heterogeneity; this group comprised solely no lesions or early lesions. Of samples, 25.0% (n = 11, mostly advanced lesions) showed good correlation between the spatial organization of MR imaging heterogeneities and plaque components. Areas of foamy macrophages were generally seen as proton attenuation-, T2-, and T2*- hypointense areas, while areas of increased collagen content showed more ambiguous signal intensities. Five samples showed image-contrast heterogeneity without corresponding plaque components on histology; 5 other samples showed contrast heterogeneity based on intima-media artifacts.
  
  
  CONCLUSIONS
  MR imaging at 7T has the image contrast capable of identifying both focal intracranial vessel wall thickening and distinguishing areas of different signal intensities spatially corresponding to plaque components within more advanced atherosclerotic plaques.
authors.affiliation: Radiology (A.G.v.d.K., J.J.M.Z., F.V., D.W.J.K., P.R.L., J.H.) A.G.vanderKolk@umcutrecht.nl.
authors.forename: A G
authors.initials: AG
authors.lastname: van der Kolk
authors.affiliation: Radiology (A.G.v.d.K., J.J.M.Z., F.V., D.W.J.K., P.R.L., J.H.) Image Sciences Institute (J.J.M.Z.), University Medical Center Utrecht, Utrecht, the Netherlands.
authors.forename: J J M
authors.initials: JJ
authors.lastname: Zwanenburg
authors.affiliation: Department of Pathology (N.P.D., M.J.A.P.D.), Academic Medical Center Amsterdam, Amsterdam, the Netherlands.
authors.forename: N P
authors.initials: NP
authors.lastname: Denswil
authors.affiliation: From the Departments of Pathology (A.V., W.G.M.S.).
authors.forename: A
authors.initials: A
authors.lastname: Vink
authors.affiliation: From the Departments of Pathology (A.V., W.G.M.S.).
authors.forename: W G M
authors.initials: WG
authors.lastname: Spliet
authors.affiliation: Department of Pathology (N.P.D., M.J.A.P.D.), Academic Medical Center Amsterdam, Amsterdam, the Netherlands.
authors.forename: M J A P
authors.initials: MJ
authors.lastname: Daemen
authors.affiliation: Radiology (A.G.v.d.K., J.J.M.Z., F.V., D.W.J.K., P.R.L., J.H.) Philips Healthcare (F.V.), Best, the Netherlands.
authors.forename: F
authors.initials: F
authors.lastname: Visser
authors.affiliation: Radiology (A.G.v.d.K., J.J.M.Z., F.V., D.W.J.K., P.R.L., J.H.).
authors.forename: D W J
authors.initials: DW
authors.lastname: Klomp
authors.affiliation: Radiology (A.G.v.d.K., J.J.M.Z., F.V., D.W.J.K., P.R.L., J.H.).
authors.forename: P R
authors.initials: PR
authors.lastname: Luijten
authors.affiliation: Radiology (A.G.v.d.K., J.J.M.Z., F.V., D.W.J.K., P.R.L., J.H.).
authors.forename: J
authors.initials: J
authors.lastname: Hendrikse
mesh_terms: D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D002537:Intracranial Arteriosclerosis / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D058226:Plaque, Atherosclerotic / Q000473:pathology*