Miho Ikura MD,PhD, Presenter: Nothing to Disclose

Hirohiko Ikura MD, Abstract Co-Author: Nothing to Disclose

Shouzou Ohsumi MD, Abstract Co-Author: Nothing to Disclose

Shigemitsu Takashima MD, Abstract Co-Author: Nothing to Disclose

Mammary gland has been well known to vary the volume and density in menstrual cycle. The purpose of our study is to investigate the variation of ADC values of normal mammary gland in menstrual cycle using DWMRI.

Twenty women (40 breasts) (mean age 43, range 34-50) of non-climacteric attended this study, who were diagnosed within normal at the breast cancer screening for health-checkup using palpation, mammography (MMG), and sonography. All of them agreed with this study by documents approved by our hospital reviewer board. Their menstrual cycles were regular, from 27 to 30 days. DWMRI was performed on a 1.5T MR unit. The data were acquired using a sequence of diffusion-weighted single shot EPI. The menstrual cycle was divided into four periods, period A (n=8) for one week before menstruation-start, period B (n=6) during menstruation, period C (n=16) for one week after menstruation-end, period D (n=10) excluded period A, B, and C. The detectability and ADC values (×1000 mm²/sec) in DWMRI were evaluated between menstrual periods. Unpaired t-test was used to estimate ADC values.

The ADC values of mammary gland were 1.95±0.10 in period A, 2.28±0.25 in period B, 2.23±0.21 in period C, and 2.29±0.17 in period D. The average ADC values differ between period A and the others, as p=0.0061 in period A to B, p= 0.0018 in period A to C, p= 0.0001 in period A to D. On the other hand, average ADC value did not differ significantly between group B, C, and D.

The depiction of mammary grand with DWMRI had variation by menstrual cycle. The ADC value in the period for one week before menstruation-start was in particular less than those in comparison with other periods.

This study indicates women before menopause should avoid one week before menstruation start for breast imaging using DWMRI, as well as MMG.

Ikura, M, Ikura, H, Ohsumi, S, Takashima, S, Variation of Apparent Diffusion Coefficient (ADC) Values of Normal Mammary Gland in Menstrual Cycle Using Diffusion-weighted Magnetic Resonance Imaging (DWMRI).  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8011062.html