3D QALAS is a promising new technique that simultaneously maps T1, T2, and PD in a single 3D acquisition. However, the presence of fat can confound multi-parameter mapping of voxels with mixed species. We modified the sequence to acquire dualecho readouts and apply a joint field map estimation across all echoes to produce water-only images for multi-parameter fitting. The technique was applied in the breast and parameter maps were compared with those generated from a 2D unsuppressed acquisition. By eliminating partial volume effects of fat, the technique potentially extends the use of 3D multi-parameter mapping into body, breast, and spine.