Q: What is the basic difference between PET (Positron emission tomography) scan and other radiological workup such as CT scan or MRI?
Answer: Imaging scans such as CT and MRI displays anatomic changes in the body, PET is capable of detecting areas of molecular biology detail even prior to anatomic change. PET scanning does this using radiolabelled molecular probes that have different rates of uptake depending on the type and function of tissue involved. Changing of regional blood flow in various anatomic structures (as a measure of the injected positron emitter) can be visualized and relatively quantified with a PET scan.
See below an example of PET scan. Non-small cell lung cancer of the right lung showing spread to the mediastinum and right neck.
