Menstrual variation of normal breast NMR relaxation parameters.

Nuclear magnetic resonance (NMR) offers great promise in noninvasively distinguishing normal, benign, and malignant tissues in the breast. However, well-documented changes that occur in breast tissues during the normal menstrual cycle suggest that lesion detectability will depend on knowledge of the variations in NMR parameters that occur as a consequence of these changes. Correct selection of optimal NMR pulse sequences and interpulse times, based on spin density and T1 and T2 values, to maximize tissue contrast and lesion detectability, will likewise depend on our understanding of variations in NMR parameters of normal breast tissues. The purpose of this study is to determine the range and variability of NMR parameters (spin density, T1 and T2) associated with changes in normal breast tissues during the menstrual cycle, as measured by NMR imaging. Initial findings suggest that there are measurable differences between breast tissues as a function of time in the menstrual cycle.