MR measurement of relative water content and multicomponent T2 relaxation in human breast

MR techniques providing accurate measurement of relative volumetric water content and multicomponent T2 relaxation times from a large volume of interest, have been implemented for characterization of breast tissue in vivo. In a sequence of 20-s breath-holds, data are obtained from much of the breast volume while suppressing signal from the chest wall and torso. Relative water content of each breast is calculated from one-dimensional fat and water profiles obtained using a hybrid two-point Dixon method (TE/TR = 17/5000 ms). Multicomponent T2 relaxation measurements are calculated from T2 decay curves obtained using a CPMG train of rectangular pulses (TE/TR = 8/5000 ms, 140 echoes) preceded by saturation pulses to localize longitudinal magnetization spatially. These techniques, validated in phantoms and human volunteers, are suitable for quantitative study of breast tissue in vivo, and in particular to investigate the potential role of MR for assessment of breast cancer risk.