title: Reliability and convergent validity of different BOLD MRI frameworks for data acquisition in experimental arthritis.
abstract: OBJECTIVE
  The clinimetric properties of blood oxygen level‒dependent (BOLD) magnetic resonance imaging (MRI) for assessment of musculoskeletal changes have been poorly investigated. The study objectives were to assess the interframework reliability of data acquisition of BOLD MRI and to test its convergent validity in chronic arthritis in a rabbit model of inflammatory arthritis as compared with corresponding clinical and laboratory measures.
  
  
  METHODS
  One of the knees of 12 New Zealand male white rabbits was injected with a 1% carrageenin solution, and the contralateral (control) one was not. Twelve rabbits were euthanized on day 28 of arthritis (chronic arthritis). Clinical (joint diameters), laboratory (serum amyloid A concentration), and BOLD MRI measurements were obtained on days 0, 1, and 28 of arthritis. Twenty paradigms of data acquisition and analysis were applied.
  
  
  RESULTS
  The most reliable MRI parameters set, regardless of threshold values used for data analysis, was spiral technique (level 1), 40 ms of echo time (level 2), 60 seconds of on_ and off_ paradigm (level 3) and carbogen mixture of gases (95% O2 + 5% CO2) (level 4). With regard to construct validity, BOLD imaging correlated moderately (r = -.54, P < .0001) with knee diameters, and weakly (r = -.35, P = .01) with laboratory indices (high threshold for analysis).
  
  
  CONCLUSIONS
  BOLD MRI has a substantial or excellent interframework reliability for assessment of arthritic rabbit knees; however, it correlates only moderately or poorly with clinical and laboratory measures. Nevertheless, this study supports further validation of BOLD MRI for assessment of soft tissue changes in a rabbit model of arthritis.
authors.affiliation: Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto, ON, Canada. andrea.doria@sickkids.ca
authors.forename: Andrea S
authors.initials: AS
authors.lastname: Doria
authors.forename: Chenghua
authors.initials: C
authors.lastname: Wang
authors.forename: Anguo
authors.initials: A
authors.lastname: Zhong
authors.forename: Tammy
authors.initials: T
authors.lastname: Rayner
authors.forename: Jaques
authors.initials: J
authors.lastname: Belik
authors.forename: Rahim
authors.initials: R
authors.lastname: Moineddin
authors.forename: Adrian
authors.initials: A
authors.lastname: Crawley
mesh_terms: D000818:Animals; D001169:Arthritis, Experimental / Q000175:diagnosis; D007719:Knee Joint / Q000098:blood supply / Q000000981:diagnostic imaging / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009929:Organ Size; D010100:Oxygen / Q000097:blood*; D011817:Rabbits; D011859:Radiography; D015203:Reproducibility of Results
chemical_list: D010100:Oxygen