title: Value of18F-FDG PET/MRI for the outcome of CT-guided facet block therapy in cervical facet syndrome: initial results.
abstract: BACKGROUND
  The aim of this study was to evaluate the ability of18F-fluorodeoxyglucose positron emission tomography/magnetic resonance imaging (18F-FDG PET/MRI) to detect PET-positive cervical facet arthropathy and identify patients who benefit from facet block therapy.
  
  
  METHODS
  Ten patients with cervical facet syndrome (mean age: 65 ± 12 years) underwent18F-FDG PET/MRI of the neck. Focal18F-FDG uptake in PET-positive facet joints served as target for computed tomography (CT)-guided facet blocks. In PET-negative patients, the target joint for facet block therapy was selected by current clinical standards considering the level of maximum facet arthrosis and pain. Neck pain was measured on visual analogue scale (VAS) before and after therapy. Bone marrow signal intensity (SI) ratio on turbo inversion recovery magnitude (TIRM) images and maximum standard uptake values (SUVmax) was calculated for each facet joint. Pearson's correlation coefficient (r) was calculated between bone marrow SI ratios on TIRM and SUVmax.
  
  
  RESULTS
  18F-FDG PET/MRI detected PET-positive facet arthropathy in six patients. Patients with PET-positive facet arthropathy had significantly less pain compared with the pretreatment pain 3 h (P = 0.002), 4 weeks (P = 0.002) and 3 months (P = 0.026) after facet block therapy. Pain did not change significantly in patients with PET-negative facet arthropathy. TIRM SI ratio was higher in PET-positive facet arthropathy than in PET-negative facet arthropathy (P < 0.001). Correlation was strong between bone marrow SI ratio on TIRM images and SUVmax (r = 0.7; P < 0.001).
  
  
  CONCLUSIONS
  18F-FDG PET/MRI can detect PET-positive cervical facet arthropathy and help to identify patients benefitting from facet block therapy. Bone marrow TIRM SI ratio might be a surrogate for PET-positive facet arthropathy.
authors.affiliation: Department of Diagnostic and Interventional Radiology, Medical Faculty, University Dusseldorf, Dusseldorf, Germany.|Department of Diagnostic and Interventional Radiology and Neuroradiology, Medical Faculty, University Duisburg-Essen, Essen, Germany.
authors.forename: Lino M
authors.initials: LM
authors.lastname: Sawicki
authors.affiliation: Department of Diagnostic and Interventional Radiology, Medical Faculty, University Dusseldorf, Dusseldorf, Germany.
authors.forename: Benedikt M
authors.initials: BM
authors.lastname: Schaarschmidt
authors.affiliation: Department of Diagnostic and Interventional Radiology, Medical Faculty, University Dusseldorf, Dusseldorf, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Heusch
authors.affiliation: Department of Diagnostic and Interventional Radiology, Medical Faculty, University Dusseldorf, Dusseldorf, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Buchbender
authors.affiliation: Department of Nuclear Medicine, Medical Faculty, University Duisburg-Essen, Essen, Germany.
authors.forename: Sandra
authors.initials: S
authors.lastname: Rosenbaum-Krumme
authors.affiliation: Department of Diagnostic and Interventional Radiology and Neuroradiology, Medical Faculty, University Duisburg-Essen, Essen, Germany.
authors.forename: Lale
authors.initials: L
authors.lastname: Umutlu
authors.affiliation: Department of Neurosurgery, Medical Faculty, University Hamburg, Hamburg, Germany.
authors.forename: Sven O
authors.initials: SO
authors.lastname: Eicker
authors.affiliation: Department of Nuclear Medicine, Medical Faculty, University Duisburg-Essen, Essen, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Bockisch
authors.affiliation: Department of Diagnostic and Interventional Radiology, Medical Faculty, University Dusseldorf, Dusseldorf, Germany.
authors.forename: Gerald
authors.initials: G
authors.lastname: Antoch
authors.affiliation: Department of Neurosurgery, Medical Faculty, University Dusseldorf, Dusseldorf, Germany.
authors.forename: Frank W
authors.initials: FW
authors.lastname: Floeth
mesh_terms: D000368:Aged; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D064847:Multimodal Imaging / Q000379:methods*; D019547:Neck Pain / Q000000981:diagnostic imaging* / Q000188:drug therapy*; D009407:Nerve Block / Q000379:methods*; D049268:Positron-Emission Tomography; D015641:Radiography, Interventional; D019275:Radiopharmaceuticals; D013577:Syndrome; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: 
  FDG
  ; 
  MRI
  ; PET/MRI; facet; joint