title: Detection of synovitis in the hands of patients with rheumatologic disorders: diagnostic performance of optical imaging in comparison with magnetic resonance imaging.
abstract: OBJECTIVE
  To prospectively compare an indocyanine green (ICG)-enhanced optical imaging system with contrast-enhanced magnetic resonance imaging (MRI) for the detection of synovitis in the hands of patients with rheumatologic disorders.
  
  
  METHODS
  Forty-five patients (30 women [67%], mean ± SD age 52.6 ± 13.4 years) in whom there was a clinical suspicion of an inflammatory arthropathy were examined with a commercially available device for ICG-enhanced optical imaging as well as by contrast-enhanced 3T MRI as the standard of reference. Three independent readers graded the degree of synovitis in the carpal, metacarpophalangeal, proximal interphalangeal, and distal interphalangeal joints of both hands (1,350 joints), using a 4-point ordinate scale (0 = no synovitis, 1 = mild, 2 = moderate, 3 = severe). Statistical analyses were performed using a logistic generalized estimating equation approach. Agreement of optical imaging ratings made by the different readers was estimated with a weighted kappa coefficient.
  
  
  RESULTS
  When MRI was used as the standard of reference, optical imaging showed a sensitivity of 39.6% (95% confidence interval [95% CI] 31.1-48.7%), a specificity of 85.2% (95% CI 79.5-89.5%), and accuracy of 67.0% (95% CI 61.4-72.1%) for the detection of synovitis in patients with arthritis. Diagnostic accuracy was especially limited in the setting of mild synovitis, while it was substantially better in patients with severely inflamed joints. Moderate interreader and intrareader agreement was observed.
  
  
  CONCLUSIONS
  The evaluated ICG-enhanced optical imaging system showed limitations for the detection of inflamed joints of the hand in comparison with MRI.
authors.affiliation: Technische Universität München, Munich, Germany. reinhardt.meier@gmail.com
authors.forename: Reinhard
authors.initials: R
authors.lastname: Meier
authors.forename: Klaus
authors.initials: K
authors.lastname: Thürmel
authors.forename: Philipp
authors.initials: P
authors.lastname: Moog
authors.forename: Peter B
authors.initials: PB
authors.lastname: Noël
authors.forename: Carmen
authors.initials: C
authors.lastname: Ahari
authors.forename: Matti
authors.initials: M
authors.lastname: Sievert
authors.forename: Franziska
authors.initials: F
authors.lastname: Dorn
authors.forename: Simone
authors.initials: S
authors.lastname: Waldt
authors.forename: Christoph
authors.initials: C
authors.lastname: Schaeffeler
authors.forename: Daniel
authors.initials: D
authors.lastname: Golovko
authors.forename: Bernhard
authors.initials: B
authors.lastname: Haller
authors.forename: Carl
authors.initials: C
authors.lastname: Ganter
authors.forename: Sabine
authors.initials: S
authors.lastname: Weckbach
authors.forename: Klaus
authors.initials: K
authors.lastname: Woertler
authors.forename: Ernst J
authors.initials: EJ
authors.lastname: Rummeny
mesh_terms: D000328:Adult; D000368:Aged; D050824:Carpal Joints / Q000473:pathology; D003952:Diagnostic Imaging / Q000379:methods*; D005260:Female; D005384:Finger Joint / Q000473:pathology; D050823:Hand Joints / Q000473:pathology*; D006801:Humans; D007208:Indocyanine Green; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008662:Metacarpophalangeal Joint / Q000473:pathology; D008875:Middle Aged; D015588:Observer Variation; D055096:Optical Devices; D011446:Prospective Studies; D012216:Rheumatic Diseases / Q000150:complications*; D012680:Sensitivity and Specificity; D013585:Synovitis / Q000175:diagnosis* / Q000209:etiology / Q000473:pathology*
chemical_list: D007208:Indocyanine Green