Are PET and SPECT scans almost identical? (1 Viewer)

[VenomP]

I'm trying to deduce differences in the diagnosing processes for each, but the only thing I have come up with so far is:

PET identifies tissue function
SPECT identifies organ function

As for anything else, I can't find it.

How would a single photon emission (SPECT) have such a different effect to many photo emissions(PET)?

 

[helper]

Both use Radionuclide.
Both are used to study function.

SPECT uses direct gamma emmison and is just measuring frequency of emmision.

PET uses positron emmision. The positron collides with an electron and annilihates, producing two gamma rays in the same plane but travelling in opposite directions. The PET scanner only registers if two gamma rays strike in the same plane in a short period of time. This enables a much more accurate picture to be obtained.