[en] It is investigated the relationship between ¹⁸F-FDG PET parameters and apparent diffusion coefficient (ADC) values obtained by diffusion weighted MRI (DWI) in patients with invasive ductal carcinoma (IDC). In addition, the prognostic utility of PET/MR mammography parameters was compared with that of known histologic prognostic factors. Forty-six women aged 50.7±10.5 years underwent a preoperative PET/MR mammography assessment using an integrated PET/MR scanner. T1w, T2w, DWI (b value: 50, 400, and 800 s/mm2), dynamic contrast enhancement sequences, and ¹⁸F-FDG PET imaging were performed. IDCs were assessed using SUVmax values and intratumoral heterogeneities (IH) from the ¹⁸F-FDG PET images and mean (ADCmean) and minimum ADC (ADCmin) values were measured using the DWI images. Relationships between the PET parameters and ADC values were evaluated. Furthermore, SUVmax and ADC values were compared with histologic factors, tumor size, nodal status, lymphovascular invasion, Ki-67 expression and triple negative breast cancer (TNBC). In total 46 IDCs (2.1-7.5 cm in size) were analyzed. SUVmax (P=0.012) and elevated IH (P=0.041) were negatively correlated with ADCmin, then TNBC (P=0.013) and high Ki-67 expression (P=0.002) were associated with higher SUVmax. IDC with lymphovascular invasion had low ADCmin values (P=0.045). In conclusion, ¹⁸F-FDG PET metabolic parameters and ADCmin were negatively correlated. PET parameters and ADC values might reflect the expression of biological features of tumors and tumor invasiveness, respectively. Integrated PET/MR mammography seemed like to have potential of a one-stop method for evaluating and predicting the prognosis of IDC.