title: Newly diagnosed lymphoma: initial results with whole-body T1-weighted, STIR, and diffusion-weighted MRI compared with 18F-FDG PET/CT.
abstract: OBJECTIVE
  The purpose of this study was to compare whole-body MRI including diffusion-weighted imaging (DWI) with (18)F-FDG PET/CT in the staging of newly diagnosed lymphoma.
  
  
  METHODS
  Twenty-two consecutively registered patients with newly diagnosed lymphoma prospectively underwent whole-body MRI (22 with T1-weighted, STIR, and DWI sequences and 21 with T1-weighted and STIR sequences but not DWI) and FDG PET/CT. Whole-body MRI-DWI was independently evaluated by two blinded observers. Interobserver agreement was assessed, and whole-body MRI-DWI was compared with FDG PET/CT.
  
  
  RESULTS
  The kappa values for interobserver agreement on whole-body MRI-DWI for all nodal regions together and for all extranodal regions together were 0.676 and 0.452. The kappa values for agreement between whole-body MRI-DWI and FDG PET/CT for all nodal regions together and for all extranodal regions together were 0.597 and 0.507. Ann Arbor stage according to whole-body MRI-DWI findings was concordant with that of FDG PET/CT findings in 77% (17/22) of patients. Understaging and overstaging relative to the findings with FDG PET/CT occurred in 0% (0/22) and 23% (5/22) of cases. In the care of 9% (2/22) of patients, overstaging with whole-body MRI-DWI relative to staging with FDG PET/CT would have had therapeutic consequences.
  
  
  CONCLUSIONS
  Our early results indicate that overall interobserver agreement on whole-body MRI-DWI findings is moderate to good. Overall agreement between whole-body MRI-DWI and FDG PET/CT is moderate. In the care of patients with newly diagnosed lymphoma, staging with whole-body MRI-DWI does not result in underestimation of stage relative to the results with FDG PET/CT. In a minority of patients, reliance on whole-body MRI-DWI leads to clinically important overstaging relative to the results with FDG PET/CT. FDG PET/CT remains the reference standard for lymphoma staging until larger-scale studies show that use of whole-body MRI-DWI results in correct staging in this minority of cases.
authors.affiliation: Department of Radiology, University Medical Center Utrecht, The Netherlands. h.m.e.quarlesvanufford@umcutrecht.nl
authors.forename: Henriëtte M E Quarles
authors.initials: HM
authors.lastname: van Ufford
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Kwee
authors.forename: Frederik J
authors.initials: FJ
authors.lastname: Beek
authors.forename: Maarten S
authors.initials: MS
authors.lastname: van Leeuwen
authors.forename: Taro
authors.initials: T
authors.lastname: Takahara
authors.forename: Rob
authors.initials: R
authors.lastname: Fijnheer
authors.forename: Rutger A J
authors.initials: RA
authors.lastname: Nievelstein
authors.forename: John M H
authors.initials: JM
authors.lastname: de Klerk
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008223:Lymphoma / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D014057:Tomography, X-Ray Computed / Q000379:methods*; D051598:Whole Body Imaging / Q000379:methods*
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18