Fig. 1.

Automated measurement of contrast enhancement kinetic variables from normal parenchyma. a Automated segmentation of breasts (red contour) and fibroglandular tissue (green contour) from pre-contrast sequences. b The first time point subtraction (i.e., post-contrast–pre-contrast) sequence with superimposed segmentation. c The second time point subtraction sequence. d The third time point subtraction sequence. e Background parenchymal enhancement (BPE) (color-coded voxels in purple) quantified from the first time point subtraction (SUB) sequence. f Illustration of signal enhancement ratio (SER) quantification. The kinetics of each voxel was color-coded, based on the defined range of the voxel-wise SER values (see [10, 18]), as persistent (blue), plateau (yellow), or washout (red). SER volume is calculated as the total volume of voxels having SER ≥0.9 (i.e., those voxels that have either plateau or washout kinetics). g Calculation of wash-in slope from peak enhancement and time to peak, for each voxel of fibroglandular tissue; here peak enhancement and time to peak were identified voxel-wise through all three sequential subtraction sequences