PET scan stands for Positron Emission Tomograpy scan. It is a diagnostic imaging test that uses radioactively labeled molecules to help visualize focal areas of high metabolism in the body. It is actually just a CT scan
, but with one key difference. A molecule called FDG (fluoro deoxy glucose) is given prior to performing the test. FDG is essentially glucose (sugar) that has a radioactively labeled molecule attached to it which causes it to "light up" on the scan.
The idea behind this is that these molecules enter the blood circulation but then go to areas that are highly metabolically active. For example, this test is often used to look for tumors or metastases from cancer, because cancer cells are hyperactive and have high metabolism. They therefore require a lot of sugar and thereby eagerly concentrate and consume (FDG). This causes the FDG to localize to the tumor cells and in turn causes this area to "light up." One of the pitfalls of this test is that it can also cause any area of general inflammation to light up as well because inflammation causes normal cells in the body to become more metabolically active as well.
There is nothing really that he should do to prepare for the scan per se. That being said, your dad should definitely be encouraged to stop smoking, not just for the scan but for his overall health. There are multiple options out there including nicotine gum, patches and even medications that can help quit smoking. A primary care physician
can help with smoking cessation counseling and therapy and it is highly encouraged that he sees a doctor
and formulates a smoking cessation plan.