The device takes pictures of slices or cross-sections the same way as a CT would, but instead of X-rays it uses electromagnetic resonance. It produces delicate and detailed images. Although the MR is suitable for examining any part of the body, it is mostly used for scanning the nervous system (the brain and the spinal cord) and the spinal column (e.g. for a herniated disk).
Although the MR does not use radiation, screening is not possible if the patient has any kind of metallic implant in his/her body.
Another specific area of MRI examinations is the investigation of heart muscle viability: it helps to decide whether a specific non-moving area of the heart is the result of a necrosed heart muscle or severely damaged blood circulation.