PET Frequently Asked Questions
How does PET work?
First, a patient is injected with a radionuclide glucose marker (FDG) and allowed to rest so the patient's body can uptake the radionuclide. The patient then goes into the PET scanner, and the PET scanner detector arrays record the gamma ray signals emitting from the patient. Cancerous cells have a higher metabolic rate than normal cells, so they uptake more of the radionuclide. The PET scanner displays the accumulation, pinpointing denser areas, which are then interpreted by a nuclear medicine physician. PET scans are also useful in diagnosing certain cardiovascular and neurological diseases by highlighting areas with increased, decreased or diminished metabolic activity, indicating problems.
What are the advantages of a PET/CT scan?
Due to the sensitivity of PET, and the fact that it checks metabolic activity versus structure, can often see signs of disease before other imaging techniques may visualize a problem. It can be used to determine the presence and severity of cancer, neurological conditions or cardiovascular disease. It can also monitor cancer treatment efficacy and recurrences. A CT scan allows the visualization of body structures. A PET/CT scanner combines these scans, for a more accurate reading and placement of potential disease.
Who can order a PET or PET/CT scan?
Any medical physician licensed to practice medicine in the state of California can order this exam. Insurance may not pay in certain instances.
How much radiation does the patient receive?
The amount of radiation from the injected radionuclide is low and decays rapidly. It is equivalent to a chest CT scan.
How does PET compare to MRI and CT (computed tomography)?
PET measures cell metabolism while MRI and CT visualize structures. It can be better suited than these modalities in determining benign and malignant lesions, and in differentiating malignant from non-malignant masses such as scar tissue versus malignancy. PET is often combined, or fused, with CT or MRI images to optimize the strengths of both scans. We have a new, "open" PET/CT scanner that combines both of the exams.
When do I order PET versus SPECT versus MRI versus CT?
Good question...
Will anything (such as a pacemaker) affect Cardiac PET imaging?
Well...it depends...
When are Cardiac MRI or PET appropriate or the preferred imaging study?
Depends on a lot of "things"
