title: Breast density assessment using a 3T MRI system: comparison among different sequences.
abstract: OBJECTIVE
  To compare MRI sequences for breast density measurements on a 3T MRI system using IDEAL (Iterative Decomposition of water and fat with Echo Asymmetry and Least squares estimation) as possible physiology-like reference.
  
  
  METHODS
  MRI examination was performed in 48 consecutive patients (mean age 41, years; range, 35-67 years) on a 3.0T scanner and 46 were included. All (fertile) women, were examined between days 5 and 15 of their menstrual cycle. MRI protocol included: T1-turbo spin-echo (T1-tSE), T2-turbo spin-echo (T2-tSE), VIBRANT (Volume Imaging for Breast Assessment) before and after injection of contrast media and IDEAL. Breast density was calculated with semi-automated software. Statistical analysis was performed with non-parametric tests.
  
  
  RESULTS
  Mean percentage of breast density calculated in each sequence was: T1-tSE = 56%; T2-tSE  = 52%; IDEAL FatOnly  = 55%; IDEAL WaterOnly  = 53%, VIBRANT = 55%. Significant differences were observed between T2-tSE and both T1-tSE (p<0.001), VIBRANT sequences (p = 0.009), T1-tSE and both IDEAL WaterOnly (p = 0.007) and IDEAL FatOnly (p = 0.047). Breast density percentage showed a positive linear correlation among different sequences: r ≥ 0.93.
  
  
  CONCLUSIONS
  Differences exist between MRI sequences used to assess breast density percentage. T1-weighted sequences values were similar to IDEAL sequences.
authors.affiliation: Institute of Anatomy, Department of Experimental Medicine, University of Genova, Genova, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Tagliafico
authors.affiliation: Radiology Department, University of Genova, Genova, Italy.
authors.forename: Bianca
authors.initials: B
authors.lastname: Bignotti
authors.affiliation: CNR-IMATI, Consiglio Nazionale delle Ricerche, Istituto di Matematica Applicata e Tecnologie Informatiche, Genova, Italy.
authors.forename: Giulio
authors.initials: G
authors.lastname: Tagliafico
authors.affiliation: Radiology Department, University of Genova, Genova, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Astengo
authors.affiliation: Radiology Department, University of Genova, Genova, Italy.
authors.forename: Lucia
authors.initials: L
authors.lastname: Martino
authors.affiliation: Radiology Department, University of Genova, Genova, Italy.
authors.forename: Sonia
authors.initials: S
authors.lastname: Airaldi
authors.affiliation: Institute of Statistics, Department of Health Sciences, University of Genova, Genova, Italy.
authors.forename: Alessio
authors.initials: A
authors.lastname: Signori
authors.affiliation: Institute of Statistics, Department of Health Sciences, University of Genova, Genova, Italy.
authors.forename: Maria Pia
authors.initials: MP
authors.lastname: Sormani
authors.affiliation: Screening and Test Evaluation Program (STEP), School of Public Health, Sydney Medical School, University of Sydney, Sydney, Australia.
authors.forename: Nehmat
authors.initials: N
authors.lastname: Houssami
authors.affiliation: Department of Diagnostic Senology, Ist Istituto Nazionale per la Ricerca sul Cancro, IRCCS Azienda Ospedaliera Universitaria San Martino, Genova, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Calabrese
mesh_terms: D000328:Adult; D000368:Aged; D001940:Breast / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D012984:Software