title: Apparent diffusion coefficients of sacroiliitis in patients with established ankylosing spondylitis.
abstract: OBJECTIVE
  To compare apparent diffusion coefficients (ADCs) of sacroiliac joints (SIJs) in ankylosing spondylitis (AS) patients during advanced-active and advanced-nonactive stages.
  
  
  METHODS
  AS patients with chronic-active (n=19), chronic-nonactive (n=6), and controls with normal SIJs (n=8) were included. Mean ADCs through 43 subchondral bone marrow edema lesions (SBMELs) were calculated.
  
  
  RESULTS
  Mean ADCs were 1.60+/-0.32 × 10-3 mm(2)/s over SBMELs, 0.57+/-0.23 × 10-3 mm(2)/s at periphery of SBMELs, 0.57+/-0.24 × 10-3 mm(2)/s in chronic-nonactive group, and 0.61+/-0.19 × 10-3 mm(2)/s for controls.
  
  
  CONCLUSIONS
  ADCs lower than 0.69 × 10-3 mm(2)/s, obtained at subchondral aspect of SIJs of established AS patients with chronic changes, which this number represents the receiver operating characteristic (ROC) best cutoff value, can be considered as normal without possible residual inflammation of concern.
authors.affiliation: Department of Radiology, Gulhane Military Medical Academy, Medical Faculty, Gn.Tevfik Saglam Cad., Etlik-Kecioren, Ankara, Turkey. tubasanal@gmail.com
authors.forename: Hatice Tuba
authors.initials: HT
authors.lastname: Sanal
authors.forename: Sedat
authors.initials: S
authors.lastname: Yilmaz
authors.forename: Ismail
authors.initials: I
authors.lastname: Simsek
authors.forename: Muhammet
authors.initials: M
authors.lastname: Cinar
authors.forename: Hakan
authors.initials: H
authors.lastname: Erdem
authors.forename: Salih
authors.initials: S
authors.lastname: Pay
authors.forename: Ayhan
authors.initials: A
authors.lastname: Dinc
authors.forename: Cem
authors.initials: C
authors.lastname: Tayfun
mesh_terms: D000293:Adolescent; D000328:Adult; D002908:Chronic Disease; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D012372:ROC Curve; D012446:Sacroiliac Joint / Q000473:pathology; D058566:Sacroiliitis / Q000150:complications / Q000175:diagnosis*; D013167:Spondylitis, Ankylosing / Q000150:complications* / Q000473:pathology; D055815:Young Adult