title: Comparison of [18 F]FDG PET/CT and MRI in the diagnosis of active osteomyelitis.
abstract: OBJECTIVE
  In diagnosing osteomyelitis (OM) both MRI and [18 F]FDG PET-CT proved to be accurate modalities. In anticipation of the advent of hybrid PET/MRI scanners we analyzed our patient group to give direction to future imaging strategies in patients with suspected OM.
  
  
  METHODS
  In this retrospective study all patients of a tertiary referral center who underwent both an MRI and a PET for the diagnosis of OM were included. The results of those scans were evaluated using patient's histology, microbiological findings, and clinical/radiological follow-up. Additionally, ROC curve analysis of the SUVmax and the SUVmax ratio on the PET scans was performed. Two imaging strategies were simulated: first MRI followed by PET, or vice versa.
  
  
  RESULTS
  Twenty-seven localizations in 26 patients were included. Both MRI and PET were shown to be accurate in our patients for the qualitative detection of OM. A cut-off value for the SUVmax of 3 gave optimal results (a specificity of 90 % with a sensitivity of 88 %). The SUVmax ratio gave a worse performance. The two simulated imaging strategies showed no difference in the final diagnosis in 20 out of 27 cases. Remarkably, 6 equivocal cases were all correctly diagnosed by the second modality, i.e., PET or MRI.
  
  
  CONCLUSIONS
  Both MRI and [18 F]FDG PET were accurate in diagnosing OM in a tertiary referral hospital population. Simulation of imaging strategies showed that a combined sequential strategy was optimal. It seems preferable to use MRI as a primary imaging tool for uncomplicated unifocal cases, whereas in cases with (possible) multifocal disease or a contraindication for MRI, PET is preferred. This combined sequential strategy looks promising, but needs to be confirmed in a larger prospective study.
authors.affiliation: Department of Nuclear Medicine, University Hospital of Maastricht, Maastricht, The Netherlands.
authors.forename: Anastas
authors.initials: A
authors.lastname: Demirev
authors.forename: René
authors.initials: R
authors.lastname: Weijers
authors.forename: Jan
authors.initials: J
authors.lastname: Geurts
authors.forename: Felix
authors.initials: F
authors.lastname: Mottaghy
authors.forename: Geert
authors.initials: G
authors.lastname: Walenkamp
authors.forename: Boudewijn
authors.initials: B
authors.lastname: Brans
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D010019:Osteomyelitis / Q000175:diagnosis*; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18