If from the symptoms and medical examination the doctor suspects mesothelioma or other asbestos related disease, the doctor may order several diagnostic tests for the patient. Nowadays, tests are being developed so that mesothelioma can be diagnosed at an early stage so prompt treatment can be started as early as possible. Imaging tests to be performed include X-Ray, CT scan (Computer Tomography), MRI (Magnetic Resonance Imaging) and PET scan (Positron Emission Tomography Scan)

Usually the first imaging test to be performed is the X-ray, where the doctor can have a look at the chest or abdomen. From the X-Ray the doctor will decide either or not to continue pursuing his suspected diagnosis of mesothelioma and order additional tests. If the X-ray identifies something such as pleural effusion (fluid in the lungs), tumors, scarring, pleural plaques and pleural calcification, more sophisticated tests may be ordered. This is also because generally the chest X-ray test is not very effective for early detection of mesothelioma. These other tests can help the general practitioner to get a more comprehensive and accurate look at the affected organs.

CT scan (Computer Tomography)
A CT-scan will provide a more detailed image of the areas examined.  The CT- scan is similar to an X-Ray, but while in an X-Ray the beams are focused towards one area, a CT-scan takes many images as it rotates around the patient. These pictures are then combined in an image of a part (slice) of the patient's body. A CT-scan provides the physician with a detailed cross sectional image of the inside of the body. A CT-Scan can be performed either in a hospital as well as in an outpatient facility. In a CT-scan the patients are given a dye in order to outline the structures of the body. The injection can cause some discomforts to the patients such as flushing or allergic reactions to the dye. Some individuals might have trouble breathing and a low blood pressure but these last two side effects are rare. A CT-scan is also more tiring than a normal X-ray since it takes longer to be performed. It is often used to make the initial diagnosis of mesothelioma and is also helpful to determine how much has the cancer advanced.

MRI (Magnetic Resonance Imaging)
An MRI-scan uses a different technology from that used by X-Ray scan and CT-scan.  While An X-Ray scan and a CT-scan use X-rays an MRI-scan uses radio waves and magnetic fields. An MRI-scan produces a very detailed image of the parts of the body. A dye can be injected as it is the case of a CT-scan, but nowadays it is much less used. In an MRI-scan patients are required to lie on a table and are moved through the MRI machine. This machine directs radio waves towards the body of the patient. The full procedure is harmless but may be a little stressful if the patient suffers from claustrophobia (fear of closed spaces). In this case a sedative may be given before the test is done. Some patients may also feel that the noise made by the machine is disturbing. In this case headphones with relaxing music may be provided. The MRI procedure takes approximately 1 hour. An MRI-scan is very effective to detect tumors in or around the lungs and to examine the diaphragm.  MRI-Scan is also more effective than CT scans in determining the extent of enlargement of the lymph nodes which lie between the lungs.

PET scan (Positron Emission Tomography Scan)
A PET-scan is very effective in determining if the thickening of a tissue is a cancer or just a scar. A PET-scan procedure involves the injection of a radioactive sugar into the veins of the individual. Cancers use sugar at a much faster rate than normal tissues do. So a cancerous tissue will take up the radioactive sugar. A scanner can spot these radioactive deposits. A PET-scan is the most effective device in spotting tumors and the most effective in determining the staging of mesothelioma. CT scans and PET scans can be combined into a single scan that is very effective in determining the best treatment for the patient.