Sometimes the treating physician will advise you to go for the Positron emission tomography or PET scan where radioactive glucose will be administered to your veins by intravenous injections.  It is a medically established fact that cancerous tissues will consume sugar at a faster rate compared to the normal ones and as a result if the scanner is put to use, it can easily spot any radioactive deposits present in your tissues. It becomes easier for the doctor to say whether the swelling or thickening of the tissues has been caused by mesothelioma or whether it is simple tissue scar. 

The Magnetic resonance imaging or the MRI scan is different in the sense that it uses radio waves and magnets in place of the traditional x-rays.  When the tissues absorb the energy emitted by the radio waves, a pattern is formed in the tissues making the detection of mesothelioma symptoms convenient.  

The data thus collected is studied with the use of computer as it represents before you on the screen all features of the parts of your body.  The advantage of MRI over CT scanner is that it can produce both cross section slices of your body structure like the CT scanner as well as the parallel section body slices. 

In both PET and MRI scanning, contrast material is required to be injected in the body of the patient.  MRI scan, though extremely useful for brain and spinal cord scans, takes longer time compared to CT scan and may make the patient uncomfortable.  Your trouble is worth taking since detection of mesothelioma cancer becomes easier with MRI scanning.