Hormone replacement therapy in postmenopausal women: Breast tissue perfusion determined with MR imaging - Initial observations

PURPOSE: To use magnetic resonance (MR) imaging to evaluate tissue perfusion in the normal breast parenchyma of postmenopausal women with current or recent hormone replacement therapy (HRT). MATERIALS AND METHODS: The study was approved by the institutional subcommittee on human studies, and informed consent was obtained from all patients prior to MR imaging. Sixty postmenopausal women (age range, 44-77 years) were grouped according to HRT received: estrogen replacement therapy (ERT) (n = 13), combined (estrogen and progesterone) replacement therapy (CRT) (n = 16), selective estrogen receptor modulator (SERM) therapy (n = 8), and no (hormone replacement) therapy (NT) (n = 23). MR imaging with a 1.5-T magnet was performed by using gradient-echo and dynamic contrast material-enhanced echoplanar pulse sequences before and after gadopentetate dimeglumine injection. Precontrast T1 relaxation times were measured, after which extraction-flow product (EFP) maps were calculated with a multicompartmental model. Analysis of variance was performed. RESULTS: Age did not significantly differ between the groups (P>.3). Women receiving ERT or CRT at the time of MR imaging had higher EFP values (7.3 m L . 100 g(-1). min(-1) +/- 2.6 and 7.1 mL . 100 g(-1) . min(-1) +/- 3.8, respectively) than did women receiving NT (4.4 mL . 100 g(-1) . min(-1) +/- 2.1) (P =.012 and P =.008, respectively) or SERM therapy (3.9 mL . 100 g(-1) . min(-1) +/- 1.1) (P =.015 and P =.013, respectively). Women who ended ERT or CRT 1-47 months before MR examination had lower EFP values than did women with current ERT or CRT and had higher EFP values than did women receiving NT or SERM therapy (6.2 mL . 100 g(-1) . min(-1) +/- 2.4 and 5.9 ML . 100 g(-1). min(-1) +/- 3.8, respectively), but the observed differences were not significant (P > .1). Differences in T1 between all groups were not significant (P > .5). CONCLUSION: Higher breast tissue perfusion is observed in postmenopausal women receiving HRT. (C) RSNA, 2005.