T1 -based sensing of mammographic density using single-sided portable NMR.

A single-sided NMR instrument was used to investigate the ability of the T1 relaxation constant to distinguish between regions of low and high mammographic density in human breast tissue.Measurements were performed on 5 breast slices obtained from 3 women undergoing breast reduction surgery or prophylactic mastectomy.T1 values measured in regions of high mammographic density in both the full breast slices (T1  = 170 ± 30 ms) and excised regions (T1  = 160 ± 30 ms) were found to be significantly different (P < .001) from those measured in regions of low mammographic density, in which T1  = 120 ± 10 ms was observed both in full slices and excised regions. There was no statistically significant difference between the T1 values measured in the full breast slices and those measured in the excised regions.The findings suggest that portable NMR may provide a low-cost means of assessing mammographic density in vivo.