After malignant mesothelioma has been diagnosed, tests are done to find out if cancer cells have spread to other parts of the body

The process used to find out if cancer has spread outside the pleura or peritoneum is called staging. The information gathered from the staging process determines the stage of the disease. It is important to know the spread of the cancer in order to plan treatment. The following tests and procedures may be used in the staging process:
. Chest x-ray: An x-ray of the organs and bones inside the chest. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body.
. CT scan (CAT scan): A procedure that makes a series of detailed pictures of the chest and abdomen, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.
. MRI (magnetic resonance imaging): A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of the chest or abdomen. This procedure is also called nuclear magnetic resonance imaging (NMRI).