“…Second, ROI is another influencing factor because of the heterogeneity of the breast tissue. 23,26,27 As for cellularity, tumour cells are not homogeneously distributed in the whole tumour. As is always the case, the ROIs in ADC and FA maps cannot be precisely corresponded to the FOVs for calculating the cellularity in the specimens; it will influence the evaluation of the correlation between ADC, FA and cellularity.…”