Definition

A procedure that combines the pictures from a positron emission tomography (PET) scan and a magnetic resonance imaging (MRI) scan. A PET scan uses a radioactive tracer to highlight abnormal areas in the body. An MRI scan uses radio waves and a powerful magnet to take detailed pictures of tissues in the body. For a PET-MRI scan, the scans are done at the same time with the same machine. The combined scans give more detailed pictures of areas inside the body than either scan gives by itself. The overall amount of radiation a person is exposed to is also reduced. A PET-MRI scan may be used to help diagnose disease, such as cancer, plan treatment, or find out how well treatment is working. Also called positron emission tomography-magnetic resonance imaging scan.