title: Degree of synovitis on MRI by comprehensive whole knee semi-quantitative scoring method correlates with histologic and macroscopic features of synovial tissue inflammation in knee osteoarthritis.
abstract: OBJECTIVE
  To evaluate the association between synovitis on contrast enhanced (CE) MRI with microscopic and macroscopic features of synovial tissue inflammation.
  
  
  METHODS
  Forty-one patients (mean age 60 years, 61% women) with symptomatic radiographic knee OA were studied: twenty underwent arthroscopy (macroscopic features were scored (0-4), synovial biopsies obtained), twenty-one underwent arthroplasty (synovial tissues were collected). After haematoxylin and eosin staining, the lining cell layer, synovial stroma and inflammatory infiltrate of synovial tissues were scored (0-3). T1-weighted CE-MRI's (3 T) were used to semi-quantitatively score synovitis at 11 sites (0-22) according to Guermazi et al. Spearman's rank correlations were calculated.
  
  
  RESULTS
  The mean (SD) MRI synovitis score was 8.0 (3.7) and the total histology grade was 2.5 (1.6). Median (range) scores of macroscopic features were 2 (1-3) for neovascularization, 1 (0-3) for hyperplasia, 2 (0-4) for villi and 2 (0-3) for fibrin deposits. The MRI synovitis score was significantly correlated with total histology grade [r = 0.6], as well as with lining cell layer [r = 0.4], stroma [r = 0.3] and inflammatory infiltrate [r = 0.5] grades. Moreover, MRI synovitis score was also significantly correlated with macroscopic neovascularization [r = 0.6], hyperplasia [r = 0.6] and villi [r = 0.6], but not with fibrin [r = 0.3].
  
  
  CONCLUSIONS
  Synovitis severity on CE-MRI assessed by a new whole knee scoring system by Guermazi et al. is a valid, non-invasive method to determine synovitis as it is significantly correlated with both macroscopic and microscopic features of synovitis in knee OA patients.
authors.affiliation: Department of Rheumatology, Leiden University Medical Center, Leiden, The Netherlands. Electronic address: b.j.e.de_lange@lumc.nl.
authors.forename: B J E
authors.initials: BJ
authors.lastname: de Lange-Brokaar
authors.affiliation: Department of Rheumatology, Leiden University Medical Center, Leiden, The Netherlands. Electronic address: A.Ioan@lumc.nl.
authors.forename: A
authors.initials: A
authors.lastname: Ioan-Facsinay
authors.affiliation: Department of Rheumatology, Leiden University Medical Center, Leiden, The Netherlands. Electronic address: E.Yusuf@lumc.nl.
authors.forename: E
authors.initials: E
authors.lastname: Yusuf
authors.affiliation: Department of Rheumatology, Leiden University Medical Center, Leiden, The Netherlands. Electronic address: A.W.Visser@lumc.nl.
authors.forename: A W
authors.initials: AW
authors.lastname: Visser
authors.affiliation: Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands. Electronic address: H.M.J.A.Kroon@lumc.nl.
authors.forename: H M
authors.initials: HM
authors.lastname: Kroon
authors.affiliation: Department of Rheumatology, Leiden University Medical Center, Leiden, The Netherlands. Electronic address: S.N.Andersen@lumc.nl.
authors.forename: S N
authors.initials: SN
authors.lastname: Andersen
authors.affiliation: Department of Rheumatology, Leiden University Medical Center, Leiden, The Netherlands. Electronic address: L.van_Toorn@lumc.nl.
authors.forename: L
authors.initials: L
authors.lastname: Herb-van Toorn
authors.affiliation: Department of Orthopaedics and Otorhinolarynogology, Erasmus MC, University Medical Center, Rotterdam, The Netherlands. Electronic address: g.vanosch@erasmusmc.nl.
authors.forename: G J V M
authors.initials: GJ
authors.lastname: van Osch
authors.affiliation: TNO, Leiden, The Netherlands. Electronic address: anne-marie.zuurmond@tno.nl.
authors.forename: A-M
authors.initials: AM
authors.lastname: Zuurmond
authors.affiliation: Janssen Research & Development, LLC, Spring House, PA, USA. Electronic address: VStojano@its.jnj.com.
authors.forename: V
authors.initials: V
authors.lastname: Stojanovic-Susulic
authors.affiliation: Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands. Electronic address: J.L.Bloem@lumc.nl.
authors.forename: J L
authors.initials: JL
authors.lastname: Bloem
authors.affiliation: Department Orthopaedics, Leiden University Medical Center, Leiden, The Netherlands. Electronic address: R.G.H.H.Nelissen@lumc.nl.
authors.forename: R G H H
authors.initials: RG
authors.lastname: Nelissen
authors.affiliation: Department of Rheumatology, Leiden University Medical Center, Leiden, The Netherlands. Electronic address: T.W.J.Huizinga@lumc.nl.
authors.forename: T W J
authors.initials: TW
authors.lastname: Huizinga
authors.affiliation: Department of Rheumatology, Leiden University Medical Center, Leiden, The Netherlands; Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, The Netherlands. Electronic address: G.Kloppenburg@lumc.nl.
authors.forename: M
authors.initials: M
authors.lastname: Kloppenburg
mesh_terms: D000368:Aged; D001182:Arthroscopy; D005260:Female; D006801:Humans; D007249:Inflammation / Q000473:pathology; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging / Q000473:pathology*; D011859:Radiography; D012720:Severity of Illness Index; D013583:Synovial Membrane / Q000473:pathology*; D013585:Synovitis / Q000473:pathology*
keywords: MRI; Macroscopy; Osteoarthritis; Synovial tissue; Synovitis