Single photon emission computed tomography (SPECT) and positron emission tomography (PET) are nuclear medicine imaging techniques which provide metabolic and functional information unlike CT and MRI.
They have been combined with CT and MRI to provide detailed anatomical and metabolic information.
Positron emission tomography (PET)
- very expensive
- uses positron emitting radioisotope (tracer)
- better contrast and spatial resolution
Single-photon emission computed tomography (SPECT)
- lower cost
- uses gamma emitting radioisotope (tracer)
- less contrast and spatial resolution (c.f. PET)