[MR-imaging of the breast at 0.5 Tesla: menstrual-cycle dependency of parenchymal contrast enhancement in healthy volunteers with oral contraceptive use?].

INTRODUCTION: To evaluate changes of contrast medium enhancement of the breast parenchyma due to menstrual cycle in healthy volunteers with oral contraceptive use in MR-imaging of the breast.
MATERIAL AND METHODS: 15 healthy volunteers (age: 22 - 36, mean 28,2) without breast disease were examined two times during one menstrual cycle (days 7 - 14 and days 21 - 2). Two volunteers were examined only in the second part of the cycle (days 21 - 2). All volunteers used oral contraceptives for more than 6 month continuously. Examinations were performed with a 0,5 T magnet (dynamic 3D-gradient echo protocol with subtraction postprocessing). We evaluated the number of enhancing foci and the parenchymal contrast medium enhancement during the different phases of the cycle by region of interest.
RESULTS: Only a total of two enhancing foci were found in 2 of 17 volunteers. Time/signal intensity diagrams in these both cases were not suspicious (< 80 % initial signal increase after of contrast medium injection, no wash-out phenomenon) and sonography of the breast in these two cases was inconspicuous. Contrast medium enhancement of breast parenchyma in cycle days 7 - 14 (mean enhancement: 0.12 - 0.26, minutes 1 - 9 p. i.) was not significantly different (p = 0.2209; Wilcoxon signed rank test) from cycle days 21 - 2 (mean: 0.13 - 0.32).
CONCLUSION: Menstrual cycle dependency of parenchymal contrast medium enhancement seems to be of minor relevance for premenopausal women with use of oral contraceptives.