title: 18F-FDG-PET/MR increases diagnostic confidence in detection of bone metastases compared with 18F-FDG-PET/CT.
abstract: OBJECTIVE
  The aim of this study was to compare detection, lesion conspicuity and reader confidence of F-fluorodeoxyglucose (F-FDG)-PET/MR and F-FDG-PET/computed tomography (CT) in patients with F-FDG avid bone metastases.
  
  
  METHODS
  In this prospective study, a total of 30 PET/CT and PET/MRI data sets were performed in 24 patients. Each examination was evaluated for the presence of PET-positive bone lesions consistent with metastatic involvement. Conspicuity of PET-positive bone lesions was evaluated on the corresponding PET/CT and PET/MR images and compared using the Wilcoxon signed-ranks test. Reader confidence was determined to evaluate whether PET/CT or PET/MR was more useful for the assessment of the bone metastases and was compared using Student's t-test.
  
  
  RESULTS
  Overall, in both examinations, PET/CT and PET/MRI detected 86 F-FDG-positive bone lesions. On all 30 PET/MRI examinations, at least one morphological correlate for F-FDG-positive bone lesions was found on the MR component (82 out of 86 lesions). PET/CT imaging allowed identification of corresponding structural changes on the CT component in 23 out of 30 studies (65 out of 86 lesions). In lesion-by-lesion analysis, the mean lesion conspicuity was significantly better on T1 fat MR imaging compared with CT imaging (P=0.005). In seven out of 30 studies, a significant increase in reader confidence of PET/MRI compared with PET/CT was found.
  
  
  CONCLUSIONS
  PET/MRI offers higher reader confidence and improved conspicuity in bone metastases compared with PET/CT. However, the overall detection rate was not different. The highest possible clinical impact of PET/MRI appears to be in patients with limited, early bone metastatic disease.
authors.affiliation: Departments of aNuclear Medicine bDiagnostic and Interventional Radiology cDepartment of Neuroradiology, University Hospital Zurich, University of Zurich dUniversity of Zurich, Zurich, Switzerland eDepartment of Medical Radiology, North Estonia Medical Centre, Tallinn, Estonia.
authors.forename: Andrei
authors.initials: A
authors.lastname: Samarin
authors.forename: Martin
authors.initials: M
authors.lastname: Hüllner
authors.forename: Marcelo A
authors.initials: MA
authors.lastname: Queiroz
authors.forename: Paul
authors.initials: P
authors.lastname: Stolzmann
authors.forename: Irene A
authors.initials: IA
authors.lastname: Burger
authors.forename: Gustav
authors.initials: G
authors.lastname: von Schulthess
authors.forename: Patrick
authors.initials: P
authors.lastname: Veit-Haibach
mesh_terms: D000328:Adult; D000368:Aged; D001859:Bone Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000556:secondary*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed; D051598:Whole Body Imaging
chemical_list: D019788:Fluorodeoxyglucose F18