CT Scan or Pet Scan

Are these the same or are they two different procedures?

[HeinrikMD]

Hi,
They are different procedures. Sort of like using two different kinds of cameras.
The CT scan takes a look at the structure, the size and shape of organs, and any abnormalities within them.  Usually the CT scan uses a contrast material which may be intravenous (and hence areas where blood goes are emphasized), oral, and rectal (hence areas of the throat, stomach, and the bowels are highlighted).
The PET scan, looks at the amount of radioactive sugar that a particular area of interest (for this forum, we usually refer to the cancerous tumor) takes up. Since cancers are metabolically active, such areas will become prominent on PET. Other metabolically active areas (which may mean infectious nodules) may show similar activities. However, areas that are scar tissue (which may look similar to malignancy on CT) from long ago will not take up any sugar.
Specific conditions will dictate which to use. PET looks attractive on the surface, but even bumps and bruises may be PET positive - so it by no means can replace CT.
Usually, the CT and the PET scans are correlated in some cases.

[oldmama]

Thank you, I had know idea they were different.  I had the CT so hopefully I will not have to have the pet.  I have spots on my lungs.  They are under 5mm, but on both sides.  I am waiting for my appointment on the 29th. Can't get in sooner.  I am on Chantix.  Day nine.  Have not had one today yet! I am so happy.  Have a good day.

[HeinrikMD]

Hi,
The role of PET is in a state of flux.
For patients with known cancer, and who are considering surgery, PET has been shown to be useful.
For screening, there is no clear role yet for PET though it seems to improve upon the CT for lesions as small as 1 cm (not really a slamdunk application for your 5 mm) so it is not routinely performed.