Table 2 Features extracted for each voxel (x) within the breast (M)

f _dce

DCE-MRI intensity values for each frame of the DCE-MRI time series

f_dce(x) ≔ {I_dce(x, i), j ≤ i ≤ j + 25}, where j is the first frame with contrast-enhancement and i is the frame number in the DCE sequence

26

f _δdce

Difference of DCE-MRI intensity values between two frames with distance 2

\( {\mathbf{f}}_{\updelta \mathrm{dce}}\left(\mathbf{x}\right):= \left\{\frac{{\mathbf{I}}_{\mathrm{dce}}\left(\mathbf{x},i+2\right)-{\mathbf{I}}_{\mathrm{dce}}\left(\mathbf{x},i\right)}{t_{i+2}-{t}_i}|j\le i\le j+25\right\} \), where t_i is the time point of acquisition of frame i

25

f _nsumdce

Normalised sum of DCE-MRI intensities

\( {\mathbf{f}}_{\mathrm{nsumdce}}\left(\mathbf{x}\right):= \frac{{\mathbf{f}}_{\mathrm{sumdce}}\left(\mathbf{x}\right)}{\max_{y\in M}\left({\mathbf{f}}_{\mathrm{sumdce}}(y)\right)} \) where \( {\mathbf{f}}_{\mathrm{sumdce}}\left(\mathbf{x}\right):= {\sum}_{i=j}^{j+25}{\mathbf{I}}_{\mathrm{dce}}\left(\mathbf{x},i\right) \)

1

f _mri

Intensity values for high-resolution MRI: I_dcepre, I_dcepeak, and I_dcepost

f_mri(x) ≔ {I_dcepre(x), I_dcepeak(x), I_dcepost(x)}

3

f _δmri

Difference in intensity values for high-resolution MR images

f_δmri(x) ≔ {I_dcepost(x) − I_dcepre(x), I_dcepeak(x) − I_dcepre(x), I_dcepost(x) − I_dcepeak(x)}

3

f _dwi

DWI intensity value

f_dwi(x) ≔ {I_dwi b0(x), I_dwi b850(x), I_adc(x)}

3

f _pet

PET intensity value

f_pet(x) ≔ {I_pet(x)}

1