title: Accurate quantitative assessment of synovitis in rheumatoid arthritis using pixel-by-pixel, time-intensity curve shape analysis.
abstract: OBJECTIVE
  To improve on the reproducibility and sensitivity of the assessment of patients with rheumatoid arthritis (RA), two semi-automated measurement methods of the area of enhancing pannus (AEP), based on thresholding (AEP_THRES) and pixel-by-pixel time-intensity curve analysis (AEP_TIC), were evaluated as an alternative for the gold-standard manual contouring method (AEP_MANUAL).
  
  
  METHODS
  8 patients (7 females and 1 male) with RA of the wrist or finger joints participated in the study. A three-dimensional contrast-enhanced dynamic sequence was used at 3 T. After identifying the most relevant time-intensity curve (TIC) shape in terms of synovitis by comparing with the synovitis score using the RA-MRI scoring system, three different approaches for measuring the AEP were performed. Spearman's test of rank correlation was used to compare AEPs via two semi-automated methods (AEP_THRES and AEP_TIC) against manual segmentation (AEP_MANUAL) in the entire hand region as well as the wrist and the finger regions.
  
  
  RESULTS
  The TIC shape of "washout after fast initial enhancement" had excellent correlation with synovitis score (r = 0.809). The correlation coefficient between AEP_TIC and AEP_MANUAL was evaluated to be better than that of AEP_THRES and AEP_MANUAL in the wrist region (AEP_THRES: r = 0.716, AEP_TIC: r = 0.815), whereas these were of comparable accuracy for the entire hand and the finger regions.
  
  
  CONCLUSIONS
  This study suggests that TIC analysis may be an alternative to manual contouring for pannus quantification and provides important clinical information of the extent of the disease in patients with RA.
  
  
  CONCLUSIONS
  TIC shape analysis can be applied for new quantitative assessment for RA synovitis in the wrist.
authors.affiliation: 1 Graduate School of Health Sciences, Hokkaido University, Sapporo, Hokkaido, Japan.
authors.forename: Taro
authors.initials: T
authors.lastname: Sakashita
authors.affiliation: 2 Faculty of Health Sciences, Hokkaido University, Sapporo, Hokkaido, Japan.
authors.forename: Tamotsu
authors.initials: T
authors.lastname: Kamishima
authors.affiliation: 3 Department of Health Sciences, Hokkaido University, Sapporo, Hokkaido, Japan.
authors.forename: Yuto
authors.initials: Y
authors.lastname: Kobayashi
authors.affiliation: 4 Department of Radiology, Hokkaido University Hospital, Sapporo, Hokkaido, Japan.|5 Department of Clinical Support for Medical Practice, Hokkaido University Hospital, Sapporo, Hokkaido, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Sugimori
authors.affiliation: 1 Graduate School of Health Sciences, Hokkaido University, Sapporo, Hokkaido, Japan.
authors.forename: Minghui
authors.initials: M
authors.lastname: Tang
authors.affiliation: 6 Graduate School of Medicine, Hokkaido University, Sapporo, Hokkaido, Japan.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Sutherland
authors.affiliation: 7 Internal Medicine 2, Hokkaido University Hospital, Sapporo, Hokkaido, Japan.|8 Division of Rheumatology, Endocrinology and Nephrology, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Noguchi
authors.affiliation: 7 Internal Medicine 2, Hokkaido University Hospital, Sapporo, Hokkaido, Japan.|8 Division of Rheumatology, Endocrinology and Nephrology, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors.forename: Michihito
authors.initials: M
authors.lastname: Kono
authors.affiliation: 7 Internal Medicine 2, Hokkaido University Hospital, Sapporo, Hokkaido, Japan.|8 Division of Rheumatology, Endocrinology and Nephrology, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Atsumi
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000150:complications / Q000473:pathology*; D003287:Contrast Media; D005260:Female; D005385:Fingers / Q000473:pathology; D006225:Hand / Q000473:pathology; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D013585:Synovitis / Q000150:complications / Q000473:pathology*; D014955:Wrist Joint / Q000473:pathology
chemical_list: D003287:Contrast Media