Ma W, et al. - Whether quantitative radiomics features extracted from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) were associated with Ki67 expression of breast cancer was examined in this institutional review board-approved retrospective study. Participants in the study were 377 Chinese women who were diagnosed with invasive breast cancer in 2015. 53 low-Ki67 expression (Ki67 proliferation index less than 14%) and 324 cases with high-Ki67 expression (Ki67 proliferation index more than 14%) were included in this cohort. The findings from the present study suggested that quantitative radiomics imaging features of breast tumour extracted from DCE-MRI were correlated with breast cancer Ki67 expression.