title: Iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL) imaging of multiple myeloma: initial clinical efficiency results.
abstract: OBJECTIVE
  To evaluate the effectiveness of the iterative decomposition of water and fat with echo asymmetric and least-squares estimation (IDEAL) MRI to quantify tumour infiltration into the lumbar vertebrae in myeloma patients without visible focal lesions.
  
  
  METHODS
  The lumbar spine was examined with 3 T MRI in 24 patients with multiple myeloma and in 26 controls. The fat-signal fraction was calculated as the mean value from three vertebral bodies. A post hoc test was used to compare the fat-signal fraction in controls and patients with monoclonal gammopathy of undetermined significance (MGUS), asymptomatic myeloma or symptomatic myeloma. Differences were considered significant at P < 0.05. The fat-signal fraction and β(2)-microglobulin-to-albumin ratio were entered into the discriminant analysis.
  
  
  RESULTS
  Fat-signal fractions were significantly lower in patients with symptomatic myelomas (43.9 ±19.7%, P < 0.01) than in the other three groups. Discriminant analysis showed that 22 of the 24 patients (92%) were correctly classified into symptomatic or non-symptomatic myeloma groups.
  
  
  CONCLUSIONS
  Fat quantification using the IDEAL sequence in MRI was significantly different when comparing patients with symptomatic myeloma and those with asymptomatic myeloma. The fat-signal fraction and β(2)-microglobulin-to-albumin ratio facilitated discrimination of symptomatic myeloma from non-symptomatic myeloma in patients without focal bone lesions.
  
  
  CONCLUSIONS
  • A new magnetic resonance technique (IDEAL) offers new insights in multiple myeloma. • Fat-signal fractions were lower in patients with symptomatic myelomas than in those with asymptomatic myelomas. • The β2-microglobulin-to-albumin ratio also aided discrimination of symptomatic myeloma. • The fat-signal fraction may provide information about the myeloma cell mass.
authors.affiliation: Department of Diagnostic Radiology, Graduate School of Biomedical Sciences, Hiroshima University, 1-2-3, Kasumi, Minamiku, Hiroshimashi 734-8551, Japan. my-takasu@syd.odn.ne.jp
authors.forename: Miyuki
authors.initials: M
authors.lastname: Takasu
authors.forename: Chihiro
authors.initials: C
authors.lastname: Tani
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Sakoda
authors.forename: Miho
authors.initials: M
authors.lastname: Ishikawa
authors.forename: Keizo
authors.initials: K
authors.lastname: Tanitame
authors.forename: Shuji
authors.initials: S
authors.lastname: Date
authors.forename: Yuji
authors.initials: Y
authors.lastname: Akiyama
authors.forename: Akira
authors.initials: A
authors.lastname: Sakai
authors.forename: Hideki
authors.initials: H
authors.lastname: Asaoku
authors.forename: Toshio
authors.initials: T
authors.lastname: Kajima
authors.forename: Kazuo
authors.initials: K
authors.lastname: Awai
mesh_terms: D000273:Adipose Tissue / Q000473:pathology*; D000368:Aged; D000465:Algorithms; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D016018:Least-Squares Analysis; D008159:Lumbar Vertebrae / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000473:pathology*; D010865:Pilot Projects; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013131:Spine / Q000473:pathology*; D013382:Subtraction Technique; D014867:Water / Q000032:analysis*
chemical_list: D014867:Water