title: Comparison between semiquantitative and quantitative methods for the assessment of knee synovitis in osteoarthritis using non-enhanced and gadolinium-enhanced MRI.
abstract: To compare different semiquantitative and quantitative methods using both non-enhanced and gadolinium-enhanced MRI techniques for the assessment of synovitis in knee osteoarthritis (OA).
  
  
  
  Knees with end-stage clinical OA in patients undergoing total knee replacement surgery were included in this cross-sectional study. MRI was performed on all knees. Standard non-enhanced and gadolinium-enhanced sequences were acquired. Using non-enhanced MRI, we semiquantitatively assessed two features widely used as surrogates for synovitis: effusion-synovitis and Hoffa-synovitis. Using gadolinium-enhanced sequences, we semiquantitatively assessed synovial thickness. We quantitatively evaluated the total synovial volume on the gadolinium-enhanced sequences as well. We assessed the correlations of effusion-synovitis and Hoffa-synovitis with synovial thickness and volume, applying Spearman correlation analysis. The diagnostic performance of both synovitis features on non-enhanced MRI was assessed using synovial thickness on gadolinium-enhanced MRI as the reference.
  
  
  
  A total of 104 subjects (one knee per subject) were included. Correlations of effusion-synovitis with synovial thickness and volume were r = 0.41 and r = 0.43 (P < .001) r = 0.32 and r = 0.39 (P < .0001).
  
  
  
  Using synovial thickness assessed on gadolinium-enhanced sequences as the reference, effusion-synovitis showed superior correlations and sensitivity. Effusion-synovitis should be preferred over Hoffa-synovitis as a surrogate marker for synovial thickening, in studies of knee OA for which gadolinium-enhanced sequences are not available.
authors.affiliation: Quantitative Imaging Center, Department of Radiology, Boston University School of Medicine, Boston, MA, USA; Department of Radiology, Saint-Antoine Hospital, Paris VI University, Paris, France. Electronic address: michelcrema@gmail.com.
authors.forename: M D
authors.initials: MD
authors.lastname: Crema
authors.affiliation: Quantitative Imaging Center, Department of Radiology, Boston University School of Medicine, Boston, MA, USA; Department of Radiology, University of Erlangen, Erlangen, Germany.
authors.forename: F W
authors.initials: FW
authors.lastname: Roemer
authors.affiliation: Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA.
authors.forename: L
authors.initials: L
authors.lastname: Li
authors.affiliation: Pfizer Neuroscience, Cambridge, MA, USA.
authors.forename: R C
authors.initials: RC
authors.lastname: Alexander
authors.affiliation: AZ Neuro, Cambridge, United Kingdom.
authors.forename: I P
authors.initials: IP
authors.lastname: Chessell
authors.affiliation: AZ Neuro, Cambridge, United Kingdom.
authors.forename: A D
authors.initials: AD
authors.lastname: Dudley
authors.affiliation: Department of Surgical Sciences/Anaesthesiology & Intensive Care, Uppsala University, Uppsala, Sweden.
authors.forename: R
authors.initials: R
authors.lastname: Karlsten
authors.affiliation: Flex Pharma, Boston, MA, USA.
authors.forename: L B
authors.initials: LB
authors.lastname: Rosen
authors.affiliation: Quantitative Imaging Center, Department of Radiology, Boston University School of Medicine, Boston, MA, USA.
authors.forename: A
authors.initials: A
authors.lastname: Guermazi
mesh_terms: D000368:Aged; D003287:Contrast Media / Q000627:therapeutic use; D003430:Cross-Sectional Studies; D005260:Female; D005682:Gadolinium / Q000627:therapeutic use; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging* / Q000473:pathology; D013583:Synovial Membrane / Q000000981:diagnostic imaging / Q000473:pathology; D013585:Synovitis / Q000000981:diagnostic imaging* / Q000473:pathology
chemical_list: D003287:Contrast Media; D005682:Gadolinium
keywords: Knee; Magnetic resonance imaging; Osteoarthritis; Synovitis