Changes in fibroglandular volume and water content of breast tissue during the menstrual cycle observed by MR imaging at 1.5 t

Abstract

Abstract MR imaging at 1.5 T was used to investigate variations in breast parenchyma during the menstrual cycle. Seven subjects were examined twice weekly over at least one menstrual cycle. A three‐point Dixon technique (TE = 19 msec, TR = 2000 msec) provided images of fat, water, and static magnetic field (B₀), from which two quantitative whole breast parameters 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 〈FV〉 consistent with expected histologic changes; 〈WC〉 and 〈FV〉 values were elevated during menses and reduced in mid‐cycle. The maximum deviation measured for each of the four subjects was ≦10% in 〈WC〉 and 〈FV〉 units. These variations probably do not influence significantly the clinical interpretation of unenhanced MR breast images. Quantitative measurements of breast parenchyma, however, should recognize these effects.