title: Improved wrist pannus volume measurement from contrast-enhanced MRI in rheumatoid arthritis using shuffle transform.
abstract: BACKGROUND
  Contrast-enhanced MRI is of value in assessing rheumatoid pannus in the hand, but the images are not always easy to quantitate.
  
  
  OBJECTIVE
  To develop and evaluate an improved measurement of volume of enhancing pannus (VEP) in the hand in human rheumatoid arthritis (RA).
  
  
  METHODS
  MR images of the hand and wrist were obtained for 14 patients with RA at 0, 1 and 13 weeks. Volume of enhancing pannus was measured on images created by subtracting precontrast T1-weighted images from contrast-enhanced T1-weighted images using a shuffle transformation technique. Maximum intensity projection (MIP) and 3D volume rendering of the images were used as a guide to identify the pannus and any contrast-enhanced veins.
  
  
  RESULTS
  Visualisation of pannus was much improved following the shuffle transform. Between 0 weeks and 1 week, the mean value of the within-subject coefficient of variation (CoV) was 0.13 and the estimated total CoV was 0.15. There was no evidence of significant increased variability within the 13-week interval for the complete sample of patients.
  
  
  CONCLUSIONS
  Volume of enhancing pannus can be measured reproducibly in the rheumatoid hand using 3D contrast-enhanced MRI and shuffle transform.
authors.affiliation: Imaging Science and Biomedical Engineering, University of Manchester, Manchester M13 9PT, UK.
authors.forename: Emily
authors.initials: E
authors.lastname: Xanthopoulos
authors.forename: Charles E
authors.initials: CE
authors.lastname: Hutchinson
authors.forename: Judith E
authors.initials: JE
authors.lastname: Adams
authors.forename: Ian N
authors.initials: IN
authors.lastname: Bruce
authors.forename: Anthony F P
authors.initials: AF
authors.lastname: Nash
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Holmes
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Taylor
authors.forename: John C
authors.initials: JC
authors.lastname: Waterton
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000473:pathology*; D003287:Contrast Media; D005260:Female; D005384:Finger Joint / Q000473:pathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D014955:Wrist Joint / Q000473:pathology*
chemical_list: D003287:Contrast Media