title: Subchondral bone in osteoarthritis: association between MRI texture analysis and histomorphometry.
abstract: Magnetic resonance imaging (MRI) texture analysis is a method of analyzing subchondral bone alterations in osteoarthritis (OA). The objective of this study was to evaluate the association between MR texture analysis and ground-truth subchondral bone histomorphometry at the tibial plateau.
  
  
  
  The local research ethics committee approved the study. All subjects provided written, informed consent. This was a cross-sectional study carried out at our institution between February and August 2014. Ten participants aged 57-84 with knee OA scheduled for total knee arthroplasty (TKA) underwent pre-operative MRI of the symptomatic knee at 3T using a high spatial-resolution coronal T1 weighted sequence. Tibial plateau explants obtained at the time of TKA underwent histological preparation to allow calculation of bone volume fraction (BV.TV), trabecular thickness (Tb.Th), trabecular separation (Tb.Sp) and trabecular number (Tb.N). Texture analysis was performed on the tibial subchondral bone of MRI images matched to the histological sections. Regression models were created to assess the association of texture analysis features with BV.TV, Tb.Th, Tb.Sp and Tb.N.
  
  
  
  MRI texture features were significantly associated with BV.TV (R2= 0.76), Tb.Th (R2= 0.47), Tb.Sp (R2= 0.75) and Tb.N (R2= 0.60, all P < 0.001). Simple gray-value histogram based texture features demonstrated the highest standardized regression coefficients for each model.
  
  
  
  MRI texture analysis features were significantly associated with ground-truth subchondral bone histomorphometry at the tibial plateau.
authors.affiliation: Department of Radiology, Norfolk & Norwich University Hospital, Norwich, UK; Department of Radiology, University of Cambridge, Cambridge, UK. Electronic address: jwm37@cam.ac.uk.
authors.forename: J W
authors.initials: JW
authors.lastname: MacKay
authors.affiliation: Department of Radiology, Norfolk & Norwich University Hospital, Norwich, UK. Electronic address: philip.murray@nnuh.nhs.uk.
authors.forename: P J
authors.initials: PJ
authors.lastname: Murray
authors.affiliation: Department of Radiology, Norfolk & Norwich University Hospital, Norwich, UK. Electronic address: bahman.kasmai@nnuh.nhs.uk.
authors.forename: B
authors.initials: B
authors.lastname: Kasmai
authors.affiliation: Department of Radiology, Norfolk & Norwich University Hospital, Norwich, UK; Norwich Medical School, University of East Anglia, Norwich, UK. Electronic address: glyn.johnson@uea.ac.uk.
authors.forename: G
authors.initials: G
authors.lastname: Johnson
authors.affiliation: Norwich Medical School, University of East Anglia, Norwich, UK; Department of Trauma & Orthopaedics, Norfolk & Norwich University Hospital, Norwich, UK. Electronic address: simon.donell@nnuh.nhs.uk.
authors.forename: S T
authors.initials: ST
authors.lastname: Donell
authors.affiliation: Department of Radiology, Norfolk & Norwich University Hospital, Norwich, UK; Norwich Medical School, University of East Anglia, Norwich, UK. Electronic address: andoni.toms@nnuh.nhs.uk.
authors.forename: A P
authors.initials: AP
authors.lastname: Toms
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D019645:Arthroplasty, Replacement, Knee / Q000379:methods; D001707:Biopsy, Needle; D002358:Cartilage, Articular / Q000000981:diagnostic imaging / Q000473:pathology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008592:Menisci, Tibial / Q000000981:diagnostic imaging* / Q000473:pathology*; D008875:Middle Aged; D015588:Observer Variation; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D011379:Prognosis; D018570:Risk Assessment; D012720:Severity of Illness Index; D016896:Treatment Outcome; D006113:United Kingdom
keywords: Histomorphometry; Magnetic resonance imaging; Osteoarthritis; Subchondral bone; Texture analysis