Magnetic contrast agents are substances used in medical diagnostics to improve visibility and contrast in magnetic resonance (MR) images. MR is an advanced non-invasive imaging technique that uses a strong magnetic pole and radio frequency waves to generate detailed three-dimensional images of internal tissues and organs in the body. Magnetic contrast agents are paramagnetic substances that contain atoms with unpaired electrons. When applied to the patient's body before an MR examination, they react with the magnetic field of the MR device and generate local magnetic moments. These moments change the local magnetic field, which results in increased contrast in the MR image. This improved visibility allows medical professionals to better identify and assess disease, damage or other abnormalities. They are used in various clinical scenarios, such as tumor detection, blood vessel diagnostics, monitoring of brain diseases and bone marrow lesions. Depending on the type of examination, they can be administered intravenously, orally or locally. It is important to note that they have potential risks and side effects. Some people may be allergic to these substances, so it is important to take an anamnesis and check the history of allergies before use. Magnetic contrast agents are an important tool in diagnostic radiology, especially in MR imaging. They help to improve contrast on MR images and enable more accurate diagnosis and disease monitoring.