CHANGES IN FIBROGLANDULAR VOLUME AND WATER-CONTENT OF BREAST-TISSUE DURING THE MENSTRUAL-CYCLE OBSERVED BY MR-IMAGING AT 1.5 T

MR imaging at 1.5 T was used to investigate variations in breast paren chyma during the menstrual cycle. Seven subjects were examined twice w eekly over at least one menstrual cycle. A three-point Dixon technique (TE = 19 msec, TR = 2000 msec) provided images of fat, water, and sta tic magnetic held (B-O), from which two quantitative whole breast para meters were calculated: the mean relative volumetric water content, < WC >, and the mean volumetric fibroglandular fraction, < FV >. Four of seven subjects showed unequivocal cyclic variations in < WC > and < F V > consistent with expected histologic changes; < WC > and < FV > val ues were elevated during menses and reduced in mid-cycle. The maximum deviation measured for each of the four subjects was less than or equa l to 10% in < WC > and < FV > units, These variations probably do not influence significantly the clinical interpretation of unenhanced MR b reast images. Quantitative measurements of breast parenchyma, however, should recognize these effects.