title: Diagnostic accuracy and agreement between whole-body diffusion MRI and bone scintigraphy in detecting bone metastases.
abstract: OBJECTIVE
  This study was done to determine the diagnostic value of whole-body magnetic resonance using diffusion-weighted imaging with background suppression (WB-DWIBS) for detecting bone metastases compared with whole-body bone scintigraphy (WB-BS).
  
  
  METHODS
  Twenty-three patients with solid tumours underwent both WB-DWIBS imaging and WBBS. A nuclear medicine specialist interpreted WB-BS images and two blinded radiologists, first independently and then jointly, interpreted the WB-DWIBS images by completing a reading grid categorising the skeletal segments. Cohen's k statistic was used to determine interobserver agreement in reading the WB-DWIBS images and the agreement between WB-BS and WB-DWIBS. Sensitivity and specificity were calculated per patient and per lesion.
  
  
  RESULTS
  Interobserver agreement in reading the WBDWIBS images was substantial or good, with κ=0.68. Analysis of agreement between the nuclear physician's and the radiologists' readings provided κ=0.87 [95% confidence interval (CI)=0.76-0.98)] Per-lesion analysis gave a sensitivity of 80% (95% CI=75-85) and a specificity of 98.2% (95% CI=96.5-99.8).
  
  
  CONCLUSIONS
  We found a good level of interobserver agreement for the WB-DWIBS images and an excellent level of agreement in the subjective judgement of presence or absence of disease between WB-BS and WB-DWIBS after consensual double reading. WB-DWIBS has the same specificity as WB-BS in detecting bone metastases. The anatomical sites exhibiting the highest level of disagreement between WB-DWIBS and WB-BS are the pelvis, the coccyx, and the sternum, all sites at which detection with WB-BS has the greatest limitations.
authors.affiliation: SCDU Radiologia, AOU Maggiore della Carità, Università del Piemonte Orientale A. Avogadro, Novara, Italy. a.stecco@libero.it
authors.forename: A
authors.initials: A
authors.lastname: Stecco
authors.forename: M
authors.initials: M
authors.lastname: Lombardi
authors.forename: L
authors.initials: L
authors.lastname: Leva
authors.forename: M
authors.initials: M
authors.lastname: Brambilla
authors.forename: E
authors.initials: E
authors.lastname: Negru
authors.forename: S
authors.initials: S
authors.lastname: Delli Passeri
authors.forename: A
authors.initials: A
authors.lastname: Carriero
mesh_terms: D000328:Adult; D001859:Bone Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D004164:Diphosphonates; D005260:Female; D006801:Humans; D008297:Male; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D017556:Technetium Compounds; D051598:Whole Body Imaging / Q000379:methods*
chemical_list: D004164:Diphosphonates; D019275:Radiopharmaceuticals; D017556:Technetium Compounds; C029045:technetium Tc 99m diphosphonate