title: Bone scintigraphy in axial seronegative spondyloarthritis patients: role in detection of subclinical peripheral arthritis and disease activity.
abstract: OBJECTIVE
  To detect subclinical peripheral arthritis and disease activity in axial seronegative spondyloarthritis (SpA) patients using bone scintigraphy.
  
  
  METHODS
  Seronegative SpA patients with an established diagnosis and no clinically evident arthritis at the time of the study were included. After excluding symptomatic cases, 20 patients were recruited; 18 with ankylosing spondylitis (AS) and another two with psoriatic arthritis (PsA). Conventional bone scintigraphy was performed to detect the distribution of increased uptake, blood vascular pool (vascularity) and activity.
  
  
  RESULTS
  The peripheral joints in all the patients were asymptomatic with no signs of arthritis on clinical examination. Disease activity was higher in those with hypervascularity and activity (75%) detected by scintigraphy. Scintigraphic activity of the sacroiliac joints was found in 10 patients (50%) with a mean sacroiliac joint index of 2.4 ± 0.6. Subclinical involvement of the hips, knees, shoulders, ankles, small joints of the hands, ankles and sternoclavicular joints, as well as the small joints of the feet were detected with descending frequencies (25%, 25%, 20%, 20%, 15%, 10% and 10%, respectively). Dorsal spine increased uptake was found in 35% and hypervascularity of the skull in two cases. Avascular necrosis of the hip was present in one case with hypovascularity.
  
  
  CONCLUSIONS
  The spectrum of joint involvement in seronegative SpAs should not be limited to sacroiliitis. Bone scintigraphy provides a cost-effective method for detecting the extent of involvement in this group of autoimmune systemic diseases (axial SpA) without clinical evidence of peripheral arthritis.
authors.affiliation: Department of Rheumatology, Cairo University, Cairo, Egypt.
authors.forename: Tamer A
authors.initials: TA
authors.lastname: Gheita
authors.affiliation: Department of Rheumatology, Cairo University, Cairo, Egypt.
authors.forename: Ghada S
authors.initials: GS
authors.lastname: Azkalany
authors.affiliation: Pharmacology Department, Faculty of Pharmacy, Cairo University, Cairo, Egypt.
authors.forename: Sanaa A
authors.initials: SA
authors.lastname: Kenawy
authors.affiliation: Department of Nuclear Medicine, Faculty of Medicine, Cairo University, Cairo, Egypt.
authors.forename: Ahmed A
authors.initials: AA
authors.lastname: Kandeel
mesh_terms: D000328:Adult; D001168:Arthritis / Q000175:diagnosis* / Q000000981:diagnostic imaging*; D015535:Arthritis, Psoriatic / Q000000981:diagnostic imaging; D001368:Axis, Cervical Vertebra / Q000000981:diagnostic imaging*; D001842:Bone and Bones / Q000000981:diagnostic imaging*; D003362:Cost-Benefit Analysis; D005260:Female; D006801:Humans; D007596:Joints / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging / Q000191:economics / Q000379:methods*; D012446:Sacroiliac Joint / Q000000981:diagnostic imaging; D012720:Severity of Illness Index; D013131:Spine / Q000000981:diagnostic imaging; D025241:Spondylarthritis / Q000000981:diagnostic imaging*; D013167:Spondylitis, Ankylosing / Q000000981:diagnostic imaging; D013669:Technetium Tc 99m Medronate
chemical_list: D013669:Technetium Tc 99m Medronate
keywords: ankylosing spondylitis; bone scintigraphy; psoriatic arthritis; seronegative spondyloarthritis