CT or Computed Tomography and PET or Positron Emission Tomography scans are two types of scans that are used to diagnose patients by taking pictures of their internal organs to assist the doctor to effectively diagnose them. Both can be used to detect cancer and to examine the brain. One of the major differences between Computed tomography scan and positron emission tomography scan is that CT scan makes use of a computer to take different cross-sectional images of all the organs, tissues, bones, including blood vessels that are in the body, while PET scan makes use of a particular camera that will be injected through the arm.
The injected camera is a radioactive tracer. The moment it gets into the body, it gives different images of all the internal organs in the body. Another difference between the two scans is that it can easily detect how the cells are changing metabolically.