What are the indications for PET vs. SPECT?
SPECT (Single Photon Emission Computerized Tomography)
• Monitors level of biological activity within a 3-D region.• Cane be used to complement any gamma imaging study where a true 3D representation would be helpful
(e.g.
1. tumor imaging.
2. infection (leukocyte) imaging.
3. thyroid imaging.
4. bone scintigraphy).
• Can be used to provide information about localised function in internal organs (e.g. functional cardiac or brain imaging).
Examples:
• Bone scan (where bone is being created or destroyed).
• White cell scan.
• Myocardial Perfusion scan (Diagnosis of ischemic heart disease).
• Sestamibi parathyroid scan.
• Brain scan (primarily cerebral blood flow).
• Neuroendocrine tumor.
PET = Positron Emission Tomography
o Nuclear/functional imaging of functional processes within the body.o Main indication = cancer metastasis (90% of scans).
o May also be used for neuroimaging cardiac pharmacodynamics etc.
PET is a nuclear medicine/functional imaging.
• 3D image of functional processes in the body.
• Accompanied by a CT X-ray scan performed on the patient during the same session allowing for anatomic localization.
• Detects pairs of gamma rays emitted indirectly by a positron-emitting radionuclide (tracer) which is introduced into the body on a biologically active molecule [fludeoxyglucose (FDG)] the concentrations of tracer imaged will indicate tissue metabolic activity by virtue of the regional glucose uptake.
If the answers is incorrect or not given, you can answer the above question in the comment box. If the answers is incorrect or not given, you can answer the above question in the comment box.