[chrisy]

I get a Pet/CT, with contrast. It is all in the same machine. They do the CT first, then immediately follow with the Pet. This is so they can match up the locations of the CT and the Pet. They both provide information, the CT does show "size" and is measurable, the Pet as you know shows metabolic activity. So, either one gives you information but in combination they give you BETTER info.

The CT shows what structurally is going on - things growing, or shrinking, or appearing or disappearing. The Pet shows how metabolically active "it" is. So you can have metabolic activity due to inflammation or something that has NO correlate on the CT. Or you can have a lesion on the CT that is or is not metabolically active - the latter inferring that it is necrosis rather than an active tumor.

There are 2 things that might be injected - for the pet it is a radioactive sugar (layman's term!) and you always need that for the pet. For the CT there may or may not be contrast.

I can't tell from your post if they are doing them separately, or just in the opposite sequence. Either way, the best eval comes from using the 2 in conjunction.

hope that helps.

And, hope the information is not only useful, but favorable.