title: Dixon imaging-based partial volume correction improves quantification of choline detected by breast 3D-MRSI.
abstract: OBJECTIVE
  Our aim was to develop a partial volume (PV) correction method of choline (Cho) signals detected by breast 3D-magnetic resonance spectroscopic imaging (3D-MRSI), using information from water/fat-Dixon MRI.
  
  
  METHODS
  Following institutional review board approval, five breast cancer patients were measured at 3 T. 3D-MRSI (1 cm(3) resolution, duration ~11 min) and Dixon MRI (1 mm(3), ~2 min) were measured in vivo and in phantoms. Glandular/lesion tissue was segmented from water/fat-Dixon MRI and transformed to match the resolution of 3D-MRSI. The resulting PV values were used to correct Cho signals. Our method was validated on a two-compartment phantom (choline/water and oil). PV values were correlated with the spectroscopic water signal. Cho signal variability, caused by partial-water/fat content, was tested in 3D-MRSI voxels located in/near malignant lesions.
  
  
  RESULTS
  Phantom measurements showed good correlation (r = 0.99) with quantified 3D-MRSI water signals, and better homogeneity after correction. The dependence of the quantified Cho signal on the water/fat voxel composition was significantly (p < 0.05) reduced using Dixon MRI-based PV correction, compared to the original uncorrected data (1.60-fold to 3.12-fold) in patients.
  
  
  CONCLUSIONS
  The proposed method allows quantification of the Cho signal in glandular/lesion tissue independent of water/fat composition in breast 3D-MRSI. This can improve the reproducibility of breast 3D-MRSI, particularly important for therapy monitoring.
authors.affiliation: Department of Biomedical Imaging and Image-guided Therapy, MR Center of Excellence, Medical University of Vienna, Lazarettgasse 14, 1090, Vienna, Austria.
authors.forename: Lenka
authors.initials: L
authors.lastname: Minarikova
authors.forename: Stephan
authors.initials: S
authors.lastname: Gruber
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Bogner
authors.forename: Katja
authors.initials: K
authors.lastname: Pinker-Domenig
authors.forename: Pascal A T
authors.initials: PA
authors.lastname: Baltzer
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Helbich
authors.forename: Siegfried
authors.initials: S
authors.lastname: Trattnig
authors.forename: Marek
authors.initials: M
authors.lastname: Chmelik
mesh_terms: D000273:Adipose Tissue / Q000473:pathology; D001834:Body Water; D001940:Breast / Q000473:pathology; D001943:Breast Neoplasms / Q000473:pathology*; D002794:Choline / Q000378:metabolism; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D009929:Organ Size; D019047:Phantoms, Imaging; D015203:Reproducibility of Results
chemical_list: D002794:Choline