The NCRI PET Research Network has produced this video to give patients an idea of what is involved when you have a PET scan. PET stands for 'Positron Emission Tomography'. The video also explains the science behind a PET scan, and the ways PET might be used in cancer clinical trials. This information is aimed at adults, as the process for PET scans in children is different, and covers the general principles of having a scan -- it does not replace individualised information that you receive from your doctor or nurse. 2012.