Anthracyclines (e.g. Doxorubicin) are an important and highly effective chemotherapeutic. They are used in various tumor entities and are established for breast cancer treatment. The most significant prognostic side effect is cardiotoxicity, which occurs in up to 50 patients. Female gender must be considered an independent risk factor for the incidence and severity of associated heart failure. The aim of this study is to demonstrate that dose-dependent anthracycline-induced cardiotoxicity has a measurable effect on T2 mapping on MRI. The second aim is to demonstrate if the combination of diastolic strain (echo and MRI) and T2 mapping can detect earlier anthracycline-induced myocardial damage than via the established method of the echocardiographic measurement of LV-EF and the conventional quantification of diastolic function.

In order to answer the question, patients with breast cancer, who will undergo a chemotherapeutic treatment with antracycline, will be examined before chemotherapy (including cmr and echocardiography) and after chemotherapy at different times within one year.

Inclusion Criteria:

• Planned therapy with an anthracycline and at least 1 year follow up
• >18 years of age
• written informed consent

Exclusion Criteria:

• prior cardiovascular disease
• diabetes mellitus
• previous therapy with anthracyclines