title: Association between quantitative MRI and ICRS arthroscopic grading of articular cartilage.
abstract: OBJECTIVE
  To investigate the association of quantitative magnetic resonance imaging (qMRI) parameters with arthroscopic grading of cartilage degeneration. Arthroscopy of the knee is considered to be the gold standard of osteoarthritis diagnostics; however, it is operator-dependent and limited to the evaluation of the articular surface. qMRI provides information on the quality of articular cartilage and its changes even at early stages of a disease.
  
  
  METHODS
  qMRI techniques included T 1 relaxation time, T 2 relaxation time, and delayed gadolinium-enhanced MRI of cartilage mapping at 3 T in ten patients. Due to a lack of generally accepted semiquantitative scoring systems for evaluating severity of cartilage degeneration during arthroscopy, the International Cartilage Repair Society (ICRS) classification system was used to grade the severity of cartilage lesions. qMRI parameters were statistically compared to arthroscopic grading conducted with the ICRS classification system.
  
  
  RESULTS
  qMRI parameters were not linearly related to arthroscopic grading. Spearman's correlation coefficients between qMRI and arthroscopic grading were not significant. The relative differences in qMRI parameters of superficial and deep cartilage varied with degeneration, suggesting different macromolecular alterations in different cartilage zones.
  
  
  CONCLUSIONS
  Results suggest that loss of cartilage and the quality of remaining tissue in the lesion site may not be directly associated with each other. The severity of cartilage degeneration may not be revealed solely by diagnostic arthroscopy, and thus, qMRI can have a role in the investigation of cartilage degeneration.
authors.affiliation: Department of Radiology, University of Oulu, POB 50, 90029, Oulu, Finland. victor.casula@oulu.fi.|Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland. victor.casula@oulu.fi.
authors.forename: Victor
authors.initials: V
authors.lastname: Casula
authors.affiliation: Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland.|Department of Medical Technology, University of Oulu, Oulu, Finland.
authors.forename: Jukka
authors.initials: J
authors.lastname: Hirvasniemi
authors.affiliation: Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland.|Department of Anatomy, University of Oulu, Oulu, Finland.|Department of Surgery, Oulu University Hospital, Oulu, Finland.
authors.forename: Petri
authors.initials: P
authors.lastname: Lehenkari
authors.affiliation: Department of Radiology, University of Oulu, POB 50, 90029, Oulu, Finland.
authors.forename: Risto
authors.initials: R
authors.lastname: Ojala
authors.affiliation: Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland.
authors.forename: Marianne
authors.initials: M
authors.lastname: Haapea
authors.affiliation: Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland.|Department of Medical Technology, University of Oulu, Oulu, Finland.|Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland.
authors.forename: Simo
authors.initials: S
authors.lastname: Saarakkala
authors.affiliation: Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland.|Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland.
authors.forename: Eveliina
authors.initials: E
authors.lastname: Lammentausta
authors.affiliation: Department of Radiology, University of Oulu, POB 50, 90029, Oulu, Finland.|Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland.|Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland.
authors.forename: Miika T
authors.initials: MT
authors.lastname: Nieminen
mesh_terms: D000328:Adult; D000368:Aged; D001182:Arthroscopy; D002358:Cartilage, Articular / Q000000981:diagnostic imaging*; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA
keywords: Arthroscopy; Articular cartilage; MRI; Osteoarthritis