title: Characteristics of synovial inflammation in early arthritis analysed by pixel-by-pixel time-intensity curve shape analysis.
abstract: OBJECTIVE
  Dynamic contrast-enhanced (DCE-MRI) time-intensity curve (TIC) shape analysis has previously been used in oncology, where fast initial enhancement and early washout are associated with malignancy. As RA synovium has some tumour-like features, we investigated DCE-MRI TIC shape expression in early arthritis in relationship to diagnosis.
  
  
  METHODS
  Twenty-eight DMARD-naïve, early arthritis patients (<1 year) with inflammation of at least one knee joint were included. At baseline DCE-MRI of the inflamed knee joint was performed, and the TIC shape type expression, maximal enhancement, maximum slope of increase and total volume of enhancing pixels were calculated. In addition, disease activity parameters were determined. At 2 years of follow-up, patients were classified as RA or non-RA according to established classification criteria.
  
  
  RESULTS
  Type 4 TIC shape, characterized by fast initial enhancement followed by a quick washout phase, was significantly higher in patients fulfilling classification criteria for RA after 2 years of follow-up compared with non-RA patients (15.6 and 7.9%, respectively, P = 0.02). All other DCE-MRI parameters showed no differences between the groups, highlighting the specificity of this observation.
  
  
  CONCLUSIONS
  A high expression of aggressive DCE-MRI TIC shape Type 4 is associated with RA. Our results are consistent with the view that increased vascularity plays a key role in the pathogenesis of RA. This study underlines the rationale for further studies investigating the prospect of DCE-MRI TIC shape analysis as a diagnostic tool in early arthritis and the relationship with development of destructive disease.
authors.affiliation: Division of Clinical Immunology and Rheumatology, Department of Internal Medicine, Academic Medical Center/University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands.
authors.forename: Marleen G H
authors.initials: MG
authors.lastname: van de Sande
authors.forename: Christiaan
authors.initials: C
authors.lastname: van der Leij
authors.forename: Cristina
authors.initials: C
authors.lastname: Lavini
authors.forename: Carla A
authors.initials: CA
authors.lastname: Wijbrandts
authors.forename: Mario
authors.initials: M
authors.lastname: Maas
authors.forename: Paul P
authors.initials: PP
authors.lastname: Tak
mesh_terms: D000888:Antibodies, Anti-Idiotypic / Q000276:immunology / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D003937:Diagnosis, Differential; D018450:Disease Progression; D042241:Early Diagnosis; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005500:Follow-Up Studies; D053804:Granzymes / Q000276:immunology; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D007075:Immunoglobulin M / Q000276:immunology / Q000378:metabolism; D007719:Knee Joint / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000150:complications / Q000175:diagnosis* / Q000378:metabolism; D011379:Prognosis; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013583:Synovial Membrane / Q000276:immunology / Q000378:metabolism / Q000473:pathology*; D013585:Synovitis / Q000175:diagnosis* / Q000209:etiology / Q000378:metabolism; D013997:Time Factors
chemical_list: D000888:Antibodies, Anti-Idiotypic; D015415:Biomarkers; D007075:Immunoglobulin M; D053804:Granzymes