title: Bone metastases from prostate, breast and multiple myeloma: differences in lesion conspicuity at short-tau inversion recovery and diffusion-weighted MRI.
abstract: OBJECTIVE
  The objective of this study was to compare the relative conspicuity of bone metastases on short-tau inversion recovery (STIR) and diffusion-weighted MRI (DWI) whole-body MR sequences for breast, prostate and myeloma malignancies.
  
  
  METHODS
  44 whole-body MRI scans were reviewed retrospectively (coronal T(1) weighted, STIR and DWI with b=800). On each scan, up to four of the largest bone lesions were identified on T(1) weighting, and the region of interest signal intensity was measured on STIR and DWI, as well as the background signal intensity. The mean lesion signal to background ratio was calculated for each patient and then for each malignancy group.
  
  
  RESULTS
  In prostate cancer patients, the DWI signal/background ratio was greater than that of STIR in 22 out of 24 patients (mean DWI lesion/background ratio 3.91, mean STIR lesion/background ratio 2.31; p=0.0001). In multiple myeloma, the DWI ratio was higher in 6/7 patients (DWI group mean ratio 7.59, STIR group mean ratio 3.7; p=0.0366). In 13 breast cancer patients, mean STIR and DWI signal/background were similar (DWI group mean ratio 4.13, group mean STIR ratio 4.26; p=0.8587).
  
  
  CONCLUSIONS
  Bone lesion conspicuity measured by lesion/background signal intensity was higher on DWI b=800 than on STIR in patients with prostate cancer and multiple myeloma. DWI should be used in whole-body MR oncology protocols in these conditions to maximise lesion detection.
authors.affiliation: Department of Diagnostic Imaging, Musgrove Park Hospital, Taunton, UK.
authors.forename: T
authors.initials: T
authors.lastname: Pearce
authors.forename: S
authors.initials: S
authors.lastname: Philip
authors.forename: J
authors.initials: J
authors.lastname: Brown
authors.forename: D M
authors.initials: DM
authors.lastname: Koh
authors.forename: P R
authors.initials: PR
authors.lastname: Burn
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001859:Bone Neoplasms / Q000473:pathology / Q000556:secondary*; D001943:Breast Neoplasms; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma; D011471:Prostatic Neoplasms; D012189:Retrospective Studies; D051598:Whole Body Imaging / Q000379:methods