The best prognostic factor following neoadjuvant chemotherapy is the pathological complete response (pCR). pCR is defined as the absence of invading cells in the breast and lymph nodes following neoadjuvant chemotherapy treatment. Since patients with pCR have a better prognosis than those without pCR, some studies have evaluated different methods to predict pCR early in treatment. Thus, patients who do not respond optimally to treatment could be identified early and changed treatment in order to maximize the chances of pCR and avoid the morbidity of poorly effective treatments. To do this, several modalities have been proposed, including MRI, mammography, ultrasound, positron emission tomography, elastography, and serial biopsies, but these techniques have shown predictive and sometimes expensive. Nevertheless, assessment of tumor response after cycle 2 has been suggested to be appropriate for the prediction of pCR. The main objective of this study is to compare the performance of two diagnostic modalities, namely CESM and MRI, in the evaluation of the response of a malignant breast tumor to neoadjuvant chemotherapy and the prediction of pCR. The radiological response will also be compared to the clinical response.