Objective To investigate the predictive value of early efficacy of neoadjuvant chemotherapy(NAC)in patient with breast cancer via full quantitative parameters of dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI).Methods Forty patients with breast cancer were selected.The 18 fluorodeoxyglucose positron emission tomography/computed tomography(18F-FDG PET/CT)and DCE-MRI were performed before and after two cycles of NAC.According to the decrease rate of maximum standardized uptake value(ΔSUVmax)of PET/CT before and after two cycles of NAC,all patients were divided into two groups,including good response group(24 cases)(ΔSUVmax>40%)and general response group(16 cases)(ΔSUVmax≤40%).The changes of full quantitative parameters of DCE-MRI between the two groups were observed and analyzed.Results There were statistically significant differences in changes of Ktrans and Kep between the two groups(P<0.05),however,there was no significant difference in the change of Ve between the two groups(P>0.05).There was a significant positive correlation between ΔKtrans and ΔSUVmax(r=0.850,P<0.001).There was a high positive correlation between ΔKtrans and ΔKep(r=0.727,P<0.001).Conclusion The full quantitative parameters of DCE-MRI are helpful to evaluate the early efficacy of NAC in breast cancer,which can reflect the changes of microcirculation in the lesion,further reflect the therapeutic effect of NAC,guide the clinical optimization of treatment plan in time,and achieve accurate evaluation and individualized treatment.