Question

What is PET— what kind of image does it create and how?

Why use PET with CT rather than CT alone? Give the main reason/application.

What sort of radiation is involved? Is PET “perfectly safe”? If not, what are the dangers?

Answer 1

A PET (Positron Emission Tomography) uses radiation to show what's going on inside a human body. It produces a multi-dimensional , colored images of inside working of organs. In this , the radiation is detected by a tracer which consists of a radioactive material combined with glucose. This tracer is then injected into body where it travels to cell which need glucose. In this way an image comprised of hot and cold spots is created.

One reason might be high radiation level in CT alone. In PET-CT combined, the radiation levels are under control. Their combination can produce sequential images which are combined into single image. Functional imaging (like how organs are functioning) from PET is combined with anatomic imaging from CT is combined.

PET is not safe for everyone. As it involves use of radioactive material . A pregnant women should not opt for PET as radioactive may harm the fetus. Some people may have allergic reaction to the radioactive tracer. Apart from that, it is mostly safe.