The Effect of Fasting on Positron Emission Tomography (PET) Imaging: A Narrative Review

As a nuclear approach, Positron Emission Tomography (PET) is a functional imaging technique which is based on the detection of gamma ray pairs emitted by a positron-emitting radionuclide. There are certain limitations to this technique such as normal tissue uptake. Therefore, it has been recommended that patients prepare before scanning. Fasting for a short while before PET imaging is an example of such preparation. In this paper, we attempted to collect the studies evaluating the effects of fasting in the three sections of cardiac, brain and abdominal PET imaging. Conclusively, we found that the effects of fasting on PET imaging can be different depending on the type of PET scanning, radiotracer, patient’s diseases, fasting duration and in case of any additional dietary plans. It is proposed that further study be conducted on this subject in order to determine such effects in more detail.