Abstract: Objective To explore the application of dynamic contrast enhanced-magnetic resonance imaging (DCE-MRI) and diffusion weighted imaging (DWI) in the diagnosis of breast cancer and their prognostic value. 
Methods We performed a retrospective analysis of clinical data from 80 patients with breast masses. All patients were examined with DCE-MRI and DWI, and the diagnostic efficacy of DCE-MRI and DWI was analyzed based on pathological biopsy as the gold standard. The patients diagnosed with breast cancer needed relevant treatment, and were divided into a good prognosis group (survival/no progression, n=58) and a poor prognosis group (death/progression, n=6) according to the prognosis of the patients (with or without survival as the final study endpoint). Receiver operating characteristic (ROC) curve was used to analyze the predictive efficacy of DCE-MRI and DWI for prognosis. 
Results The diagnostic accuracy of DCE-MRI and DWI was 70.00% and 81.25% respectively, and the combined diagnostic accuracy of the two was 96.25%. The early enhancement rate of malignant masses was higher than that of benign masses, and the apparent diffusion coefficient (ADC) value was lower than that of benign masses (P＜0.05). Moreover, the time-signal intensity curve (TIC) of malignant masses was mainly type II and type III when plotted, and the TIC types of benign masses are mainly type Ⅰ and type Ⅱ. According to ROC curve analysis, the are under the ROC curve (AUC) of DCE-MRI, DWI, and their combination in the diagnosis of malignant breast tumors were 0.625, 0.766, and 0.953, respectively. In the meantime, the early enhancement rate of patients with good prognosis was lower than that of patients with poor prognosis, and the ADC value was higher than that of patients with poor prognosis. According to the ROC analysis, the AUC of the early enhancement rate, ADC value, and their combination in predicting patient prognosis were 0.816, 0.763, and 0.945, respectively. 
Conclusion DCE-MRI DCE-MRI combined with DWI has certain value in distinguishing benign and malignant breast masses, and can predict the prognosis of breast cancer patients, with high efficiency.

Key words: breast neoplasms, dynamic contrast enhanced-magnetic resonance imaging, diffusion magnetic resonance imaging