title: Additional value of positron emission tomography in diagnosis and follow-up of patients with large vessel vasculitides.
abstract: OBJECTIVE
  To determine the value of Positron Emission Tomography (PET) in the diagnosis of Takayasu arteritis (TA) and giant cell arteritis (GCA) and its value in the assessment of disease activity and response to therapy.
  
  
  METHODS
  In 5 consecutive patients diagnosed with TA or GCA, PET using the tracer F18-deoxyglucose (FDG) was performed when disease activity was suspected based on clinical and laboratory parameters. PET was repeated after therapeutic intervention when disease remission was achieved. PET findings were compared with angiography, MRA and clinical parameters.
  
  
  RESULTS
  PET visualised inflamed arteries in all 5 patients, but there was a discrepancy between PET and angiography or MRA. In 8 arteries of 4 patients only PET showed disease involvement, while in 5 arteries of 2 patients only angiography or MRA showed involvement. After treatment and the disappearance of clinical symptoms, FDG uptake was clearly reduced compared to the initial scan in all patients. In all but one the acute phase response declined. In that patient a urinary tract infection explained the elevated acute phase response, as this normalised after antibiotic treatment.
  
  
  CONCLUSIONS
  PET is a promising new technique for the diagnosis of large vessel vasculitides. Furthermore, PET appears to be a valuable tool for the assessment of disease activity during follow-up and of the response to therapy.
authors.affiliation: Department of Clinical Immunology, University Hospital, Groningen, The Netherlands.
authors.forename: K
authors.initials: K
authors.lastname: de Leeuw
authors.forename: M
authors.initials: M
authors.lastname: Bijl
authors.forename: P L
authors.initials: PL
authors.lastname: Jager
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002097:C-Reactive Protein / Q000032:analysis; D016572:Cyclosporine / Q000627:therapeutic use; D004359:Drug Therapy, Combination; D005260:Female; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D013700:Giant Cell Arteritis / Q000175:diagnosis* / Q000188:drug therapy; D006801:Humans; D018810:Magnetic Resonance Angiography; D049268:Positron-Emission Tomography; D011239:Prednisolone / Q000627:therapeutic use; D011379:Prognosis; D013625:Takayasu Arteritis / Q000175:diagnosis* / Q000188:drug therapy; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D019788:Fluorodeoxyglucose F18; D016572:Cyclosporine; D002097:C-Reactive Protein; D011239:Prednisolone