DWI and Breast Physiology Status

The normal breast parenchyma undergoes marked alterations in response to different hormonal states, from puberty onset and fluctuations in the menstrual cycle through pregnancy, lactation, and menopause. Diffusion-weighted imaging (DWI) holds the potential to not only improve the diagnosis and biological characterization of breast cancer but also probe the physiological changes in the water-diffusion process within the healthy fibroglandular tissue and provide a noninvasive imaging means to track functional and microstructural processes in this dynamic organ. As opposed to other imaging modalities, in particular dynamic contrast-enhanced magnetic resonance imaging (DCE MRI), the diffusivity changes in different hormonal states seem negligible from a clinical standpoint. The immunity of DWI to many of the hormonal-induced drawbacks of breast imaging suggests an opportunity for this method to obtain a larger clinical role in these settings.