title: Synovial volume vs synovial measurements from dynamic contrast enhanced MRI as measures of response in osteoarthritis.
abstract: Synovium is increasingly a target of osteoarthritis (OA) treatment, yet its optimal measurement is unclear. Using dynamic contrast enhanced (DCE) MRI in knee OA patients before and after intraarticular steroid injection, we compared the responsiveness of static synovial volume measures to measures of dynamic changes in synovial enhancement, changes that are strongly related to synovial vascularity.
  
  
  
  Ninety three patients underwent DCE-MRI before and 1-2 weeks after intra-articular injection of 80 mg methylprednisolone. Synovium was segmented and volume, relative enhancement rate (RER), maximum relative enhancement (REmax), late relative enhancement (RElate) and pharmacokinetic parameters (K(trans), ve) were calculated. KOOS (​knee injury and osteoarthritis outcome score) pain score was recorded before and after injection. Standardized change scores were calculated for each parameter. Linear regression and Pearson's correlations were used to investigate the relationship between change in MRI parameters and change in pain.
  
  
  
  The change in standardized score for the measures of synovial enhancement, RElate and REmax were -0.58 (95% CI -0.79 to -0.37) and -0.62 (95% CI -0.83 to -0.41) respectively, whereas the score for synovial volume was -0.30 (-0.52 to -0.09). Further, change in knee pain correlated more strongly with changes in enhancement (for both REmax and RElate, r = -0.27 (95% CI -0.45 to -0.07)) than with changes in synovial volume -0.15 (-0.35 to 0.05).
  
  
  
  This study suggests DCE-MRI derived measures of synovial enhancement may be more sensitive to the response to treatment and more strongly associated with changes in pain than synovial volume and may be better outcomes for assessment of structural effects of treatment in OA.
authors.affiliation: Wolfson Molecular Imaging Centre, The University of Manchester, Manchester, UK; Centre for Imaging Sciences, Institute of Population Health, The University of Manchester, Manchester, UK.
authors.forename: A D
authors.initials: AD
authors.lastname: Gait
authors.affiliation: Centre for Imaging Sciences, Institute of Population Health, The University of Manchester, Manchester, UK; NIHR Manchester Musculoskeletal Biomedical Research Unit, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK; Central Manchester University Hospitals NHS Foundation Trust, Manchester, UK.
authors.forename: R
authors.initials: R
authors.lastname: Hodgson
authors.affiliation: Arthritis Research UK Centre for Epidemiology, Centre for Musculoskeletal Research, Institute for Inflammation and Repair, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK; NIHR Manchester Musculoskeletal Biomedical Research Unit, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK.
authors.forename: M J
authors.initials: MJ
authors.lastname: Parkes
authors.affiliation: Warwick Medical School, The University of Warwick, Coventry, UK.
authors.forename: C E
authors.initials: CE
authors.lastname: Hutchinson
authors.affiliation: Arthritis Research UK Centre for Epidemiology, Centre for Musculoskeletal Research, Institute for Inflammation and Repair, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK; NIHR Manchester Musculoskeletal Biomedical Research Unit, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK; Department of Rheumatology, Salford Royal NHS Foundation Trust, Salford, UK.
authors.forename: T W
authors.initials: TW
authors.lastname: O'Neill
authors.affiliation: Arthritis Research UK Centre for Epidemiology, Centre for Musculoskeletal Research, Institute for Inflammation and Repair, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK; NIHR Manchester Musculoskeletal Biomedical Research Unit, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK; Department of Rheumatology, Salford Royal NHS Foundation Trust, Salford, UK.
authors.forename: N
authors.initials: N
authors.lastname: Maricar
authors.affiliation: Arthritis Research UK Centre for Epidemiology, Centre for Musculoskeletal Research, Institute for Inflammation and Repair, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK.
authors.forename: E J
authors.initials: EJ
authors.lastname: Marjanovic
authors.affiliation: Centre for Imaging Sciences, Institute of Population Health, The University of Manchester, Manchester, UK.
authors.forename: T F
authors.initials: TF
authors.lastname: Cootes
authors.affiliation: Arthritis Research UK Centre for Epidemiology, Centre for Musculoskeletal Research, Institute for Inflammation and Repair, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK; NIHR Manchester Musculoskeletal Biomedical Research Unit, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK; Clinical Epidemiology Unit, Boston University School of Medicine, Boston, MA, USA. Electronic address: dfelson@bu.edu.
authors.forename: D T
authors.initials: DT
authors.lastname: Felson
mesh_terms: D003287:Contrast Media; D006801:Humans; D007270:Injections, Intra-Articular; D007719:Knee Joint; D008279:Magnetic Resonance Imaging; D020370:Osteoarthritis, Knee; D013583:Synovial Membrane; D013585:Synovitis
chemical_list: D003287:Contrast Media
keywords: DCE-MRI; Magnetic resonance imaging; Osteoarthritis; Pain; Synovial volume; Synovitis