Magnetic Resonance Imaging (MRI) is an imaging method that uses non-ionizing radiation to create useful diagnostic images.
MRI scanners use radio waves and strong magnets, and unlike CT and PET-CT, MRI gives no radiation to the patient. An MRI scanner consists of a large, powerful magnet inside which the patient lies. Signals are sent to the body by a radio wave antenna, which in turn receives signals back. The patterns of the returning signal are converted by a computer into very detailed images of parts of the body.
To improve the visibility of the body structures, MRI contrast agents, also called MRI imaging drugs or dye, can be administered to the patient prior to the MRI scanning procedure. The MRI contrast agent is a drug substance that can make abnormalities, such as metastases, appear clearer due to the special magnetic properties of the elements in the contrast agent and thereby increase the sensitivity and/or specificity (information value) of the images.
In patients that have, may have, or have had a primary tumor originating outside the liver (solid extrahepatic cancer disease), MRI liver imaging with a contrast agent is used to visualize, detect, and localize potential liver metastases (certain type of focal liver lesions). The contrast agent assists in diagnosing liver cancer and metastases and helps to guide treatment decisions and planning. MRI with a contrast agent is generally considered to be a sensitive and useful imaging method to assess and select patients eligible for surgery (metastatic resection) or locally directed non-surgical treatment. MRI with contrast is also used to determine if a given treatment has been effective, and/or for surveillance of possible recurrence of disease.