title: Healthy premenopausal breast parenchyma in dynamic contrast-enhanced MR imaging of the breast: normal contrast medium enhancement and cyclical-phase dependency.
abstract: OBJECTIVE
  To define the range of normal contrast medium enhancement, the variability in contrast medium enhancement patterns in healthy premenopausal breast parenchyma, and the implications for management strategies in cases with incidental contrast medium-enhancing foci on breast magnetic resonance (MR) images.
  
  
  METHODS
  Twenty healthy volunteers (aged 21-41 years) were examined on a 1.5-T system (dynamic two-dimensional gradient-echo protocol with subtraction postprocessing) during each week of a menstrual cycle (group 1) or over 4 months (group 2). The authors evaluated changes in the number of enhancing foci and the respective enhancement patterns within a cycle and between cycles.
  
  
  RESULTS
  Both diffuse and nodular enhancement of breast parenchyma occurred during all phases of the menstrual cycle, especially in weeks 1 and 4. Enhancement was lowest in week 2. A total of 60 enhancing foci (73% of which resolved completely during follow-up) were found in 16 of 20 volunteers. Twenty-six foci demonstrated enhancement velocities beyond the malignancy threshold (>80% increase in the 1st minute).
  
  
  CONCLUSIONS
  Contrast-enhancing foci are normal in healthy premenopausal breasts, even when formal malignancy criteria of enhancement velocity are met. This has to be kept in mind to avoid false-positive results, especially in younger patients.
authors.affiliation: Department of Radiology, University of Bonn, Germany.
authors.forename: C K
authors.initials: CK
authors.lastname: Kuhl
authors.forename: H B
authors.initials: HB
authors.lastname: Bieling
authors.forename: J
authors.initials: J
authors.lastname: Gieseke
authors.forename: B P
authors.initials: BP
authors.lastname: Kreft
authors.forename: T
authors.initials: T
authors.lastname: Sommer
authors.forename: G
authors.initials: G
authors.lastname: Lutterbey
authors.forename: H H
authors.initials: HH
authors.lastname: Schild
mesh_terms: D000328:Adult; D001940:Breast / Q000033:anatomy & histology*; D003287:Contrast Media; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D017697:Premenopause; D011446:Prospective Studies; D012016:Reference Values; D013382:Subtraction Technique
chemical_list: D003287:Contrast Media