title: Changes in magnetic resonance mammography due to hormone replacement therapy.
abstract: BACKGROUND
  The aim of the present article is to investigate effects of hormone replacement therapy (HRT) on contrast medium enhancement patterns in postmenopausal patients during magnetic resonance mammography (MRM).
  
  
  METHODS
  Two hundred and fifteen patients receiving hormonal medication were divided into four groups: 150 patients with 1 MRM during HRT (group A), 13 patients with 2 MRMs under HRT (group B), 30 patients with 1 MRM during HRT and 1 MRM after HRT withdrawal (group C), and 22 women with 1 MRM after HRT withdrawal (group D). Dynamic MRM was performed at 1.5 Tesla. Signal intensity changes were characterized by five time curves: minimal enhancement (type I), weak continuous enhancement (type II), strong continuous enhancement (type III), and a steep initial slope followed by a plateau phenomenon (type IV) or a washout effect (type V).
  
  
  RESULTS
  Of all 193 patients under HRT (group A + group B + group C), 60 patients (31.1%) showed curve type I, 88 patients (45.6%) showed type II and 45 patients (23.3%) showed type III. There were significant differences to 52 patients after HRT withdrawal (group C + group D) (P < 0.0001), with 42 patients (80.8%) for curve type I, 8 patients (15.4%) for type II, and 2 patients (3.8%) for type III. In both MRM sessions in group B, 69% of the patients showed identical curve types without significant differences (P = 0.375). In group C, 28 of 30 patients (93%) dropped to lower curve types with significant differences in curve types during and after HRT (P < 0.0001).
  
  
  CONCLUSIONS
  The majority of patients receiving postmenopausal HRT showed bilateral symmetrical, continuous enhancement without evidence of a plateau phenomenon or a washout effect due to HRT in MRM. Hormonal effects could be proven and were reproducible and reversible.
authors.affiliation: Institute of Diagnostic and Interventional Radiology, Friedrich-Schiller-University, Jena, Germany. stefan.pfleiderer@med.uni-jena.de
authors.forename: Stefan O R
authors.initials: SO
authors.lastname: Pfleiderer
authors.forename: Steffen
authors.initials: S
authors.lastname: Sachse
authors.forename: Dieter
authors.initials: D
authors.lastname: Sauner
authors.forename: Christiane
authors.initials: C
authors.lastname: Marx
authors.forename: Ansgar
authors.initials: A
authors.lastname: Malich
authors.forename: Susanne
authors.initials: S
authors.lastname: Wurdinger
authors.forename: Werner A
authors.initials: WA
authors.lastname: Kaiser
mesh_terms: D000273:Adipose Tissue / Q000187:drug effects; D000328:Adult; D001940:Breast / Q000033:anatomy & histology / Q000187:drug effects*; D003238:Connective Tissue / Q000187:drug effects; D003287:Contrast Media; D005260:Female; D005500:Follow-Up Studies; D020249:Hormone Replacement Therapy; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D017698:Postmenopause; D012189:Retrospective Studies; D028761:Withholding Treatment
chemical_list: D003287:Contrast Media