Investigation of the diagnostic efficacy and safety of Dotarem® in MR mammography and investigation of the safety of the contrast agent.In order to investigate the safety of Dotarem® and the diagnostic efficacy and safety of the contrast agent in MR mammography, post-marketing surveillance of 1,537 patients in 15 centres was carried out between January 2012 and October 2013. In addition to data on medical history, dose and safety, the doctors’ diagnosis and the assessment of the image quality by the doctors (5-point scale from very good to very poor) were documented. After the MR mammography a cytological examination was carried out on some of the patients. The cytology results were also documented. Safety was assessed on the basis of the frequency, severity of adverse events, causal relationship and outcome of the adverse events. In order to assess the efficacy and safety of Dotarem® in MR mammographies, checks were carried out to establish whether there was a correlation between the doctors’ diagnoses and the cytological results.Patient age ranged from 16 to 88 years. The mean (± SD) age was 51.4 (± 12.3) years. MR mammography was predominantly performed in order to exclude a recurrence (43.4%). Other reasons for the MR mammography were early detection in patients at high risk (27.4%) and for clarifying inconclusive findings (16.5%). Most of the patients underwent an MRI because of their personal case histories (41.4%). The group of patients with personal case histories as well as family and personal case histories comprised 65.1% of all patients. Only twenty-two of 1,537 patients (1.4%) had a BRCA gene mutation. For two of the 22 patients, the mutation of the gene was not specified. Of the remaining 20 patients, 16 patients (80.0%) had a BRCA1 gene mutation and 4 patients (20.0%) a BRCA2 gene mutation. Most of patients (65.5%) were injected with 11 to 15 ml of contrast agent. The mean (± SD) amount of injected contrast agent was 15.1 (±4.3) ml. In 91.6% of the examinations, the image quality ranged from excellent to good. Image quality was rated as poor or very poor in only 0.7% of the examinations. Poor to very poor image quality was due to movement artefacts in seven cases and poor fat saturation in one case. Diagnoses were made by radiologists in 99.2% of the cases. In 0.8% of the examinations, diagnosis could not be assessed (3 due to technical problems, 9 for other reasons). The most frequent diagnoses were benign change (56.5%) and normal finding (21.3%). 232 of 1,537 patients (15.1%) underwent a cytology test. Cytology tests were predominantly performed following a diagnosis of carcinoma in situ (100%) and invasive ductal carcinoma (86.1%). 72 of 1,537 patients (4.7%) were diagnosed with an invasive ductal carcinoma. The cytology test results for 62 of the 72 patients diagnosed with an invasive ductal carcinoma were known. The diagnosis of an invasive ductal carcinoma was confirmed in 93.5% of the patients (58 of 62 patients). Adverse reactions occurred in 5 of 1,537 patients (0.3%). One of the 5 adverse reactions was serious (tachycardia, dysphagia, urticarial, rash). All of the patients with adverse reactions recovered fully after the examination.The non-interventional post-marketing surveillance study has shown that MR mammography with Dotarem® is an excellent and safe method for identifying invasive ductal carcinoma. According to the cytology test results, MR mammography confirmed diagnoses of invasive ductal carcinoma in 93.5% of the patients. Adverse drug reactions were observed in 5 patients (0.3%). They all fully recovered. The study results show Dotarem® to be a safe contrast agent for use in MR mammography.