title: Increasing the Spatial Resolution of 3T Carotid MRI Has No Beneficial Effect for Plaque Component Measurement Reproducibility.
abstract: OBJECTIVE
  Different in-plane resolutions have been used for carotid 3T MRI. We compared the reproducibility, as well as the within- and between reader variability of high and routinely used spatial resolution in scans of patients with atherosclerotic carotid artery disease. Since no consensus exists about the optimal segmentation method, we analysed all imaging data using two different segmentation methods.
  
  
  METHODS
  In 31 patient with carotid atherosclerosis a high (0.25 × 0.25 mm2; HR) and routinely used (0.50 × 0.50 mm2; LR) spatial resolution carotid MRI scan were performed within one month. A fully blinded closed and a simultaneously open segmentation were used to quantify the lipid rich necrotic core (LRNC), calcified and loose matrix (LM) plaque area and the fibrous cap (FC) thickness.
  
  
  RESULTS
  No significant differences were observed between scan-rescan reproducibility for HR versus LR measurements, nor did we find any significant difference between the within-reader and between-reader reproducibility. The same applies for differences between the open and closed reads. All intraclass correlation coefficients between scans and rescans for the LRNC, calcified and LM plaque area, as well as the FC thickness measurements with the open segmentation method were excellent (all above 0.75).
  
  
  CONCLUSIONS
  Increasing the spatial resolution at the expense of the contrast-to-noise ratio does not improve carotid plaque component scan-rescan reproducibility in patients with atherosclerotic carotid disease, nor does using a different segmentation method.
authors.affiliation: Department of Vascular Medicine, Academic Medical Center, Amsterdam, the Netherlands.
authors.forename: Diederik F
authors.initials: DF
authors.lastname: van Wijk
authors.affiliation: Department of Vascular Medicine, Academic Medical Center, Amsterdam, the Netherlands.
authors.forename: Aart C
authors.initials: AC
authors.lastname: Strang
authors.affiliation: Department of Vascular Medicine, Academic Medical Center, Amsterdam, the Netherlands.
authors.forename: Raphael
authors.initials: R
authors.lastname: Duivenvoorden
authors.affiliation: Department of Vascular Medicine, Academic Medical Center, Amsterdam, the Netherlands.
authors.forename: Dirk-Jan F
authors.initials: DJ
authors.lastname: Enklaar
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, Academic Medical Center, Amsterdam, the Netherlands.
authors.forename: Aeilko H
authors.initials: AH
authors.lastname: Zwinderman
authors.affiliation: Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Rob J
authors.initials: RJ
authors.lastname: van der Geest
authors.affiliation: Department of Vascular Medicine, Academic Medical Center, Amsterdam, the Netherlands.
authors.forename: John J P
authors.initials: JJ
authors.lastname: Kastelein
authors.affiliation: Department of Vascular Medicine, Academic Medical Center, Amsterdam, the Netherlands.
authors.forename: Eric
authors.initials: E
authors.lastname: de Groot
authors.affiliation: Department of Vascular Medicine, Academic Medical Center, Amsterdam, the Netherlands.
authors.forename: Erik S G
authors.initials: ES
authors.lastname: Stroes
authors.affiliation: Department of Radiology, Academic Medical Center, Amsterdam, the Netherlands.
authors.forename: Aart J
authors.initials: AJ
authors.lastname: Nederveen
mesh_terms: D000368:Aged; D002339:Carotid Arteries / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D005355:Fibrosis; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009336:Necrosis; D058226:Plaque, Atherosclerotic / Q000175:diagnosis / Q000000981:diagnostic imaging*; D011859:Radiography; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity