title: Assessment of breast tissue changes on hormonal replacement therapy using MRI: a pilot study.
abstract: OBJECTIVE
  The purpose of this study was to investigate, using MRI, the potential morphologic effects of hormonal replacement therapy (HRT) on breast tissue in post-menopausal women.
  
  
  METHODS
  Five subjects were enrolled who were treated subsequently with both estrogen (2 mg/day) and a combination of estrogen (2 mg/day) and progestagen (1 mg/day). T1-weighted (TR 11 ms, TE 4.65 ms, flip angle 35 degrees, two excitations) 3D MR scans were acquired on a 1.5 T whole-body scanner before therapy and after each regimen. With use of a segmentation algorithm and histogram evaluation, parenchymal tissue/fat ratios were calculated over targeted volumes and changes were assessed.
  
  
  RESULTS
  An increase in these ratios was observed in two subjects after receiving the combined therapy, indicating a change in parenchymal pattern, whereas no obvious changes were detected in any of the subjects during the estrogen-based therapy.
  
  
  CONCLUSIONS
  MRI is able to detect and quantitate changes in breast parenchyma during HRT.
authors.affiliation: Institut für Diagnostische und Interventionelle Radiologie, Friedrich-Schiller Universität, Jena, Germany.
authors.forename: J R
authors.initials: JR
authors.lastname: Reichenbach
authors.forename: C
authors.initials: C
authors.lastname: Przetak
authors.forename: G
authors.initials: G
authors.lastname: Klinger
authors.forename: W A
authors.initials: WA
authors.lastname: Kaiser
mesh_terms: D000328:Adult; D000465:Algorithms; D001940:Breast / Q000033:anatomy & histology*; D005260:Female; D020249:Hormone Replacement Therapy; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D010865:Pilot Projects; D017698:Postmenopause