What Does Metabolic Activity On A PET Scan Mean?

What does low grade metabolic activity mean?

Cells in the body metabolize this sugar for energy, so high concentrations of FDG seen on PET indicate areas of high metabolic activity (as in cancer).

Areas of low or no metabolic activity can indicate areas of reduced blood flow or blockages due to stroke or heart attacks..

What activities are involved in metabolism?

Metabolism is a balancing act involving two kinds of activities that go on at the same time:building up body tissues and energy stores (called anabolism)breaking down body tissues and energy stores to get more fuel for body functions (called catabolism)

What is abnormal FDG uptake?

Abstract. Objective: FDG PET is frequently used as part of the diagnostic workup in cancer patients. Visualization of radiotracer-avid foci suggests the presence of malignant disease. … Conclusion: Unexplained focal abdominal FDG uptake is an unusual finding with causes that include malignant and benign processes.

How small a tumor can a PET scan detect?

Conclusion: Among nuclear medicine’s armamentarium, PET is the closest modality to CT or MR imaging in terms of limits of detection. Modern clinical PET scanners have a resolution limit of 4 mm, corresponding to the detection of tumors with a volume of 0.2 ml (7 mm diameter) in 5:1 T/B ratio.

What is metabolically active disease?

Tumor cells are usually metabolically active (hungry) and will take up more sugar (glucose) than normal cells. The more glucose the cells take up, the more the cells light up. PET scans take advantage of this difference to help distinguish active from inactive tumor masses.

What does metabolic activity mean?

Metabolic activity, as defined by the uptake of 18F-fluorodeoxyglucose (FDG) on positron emission tomography (PET), takes advantage of the physiologic preferential use of anaerobic glycolysis over oxidative phosphorylation used by malignant cells for their energetic needs.

Can PET scans be wrong?

FDG is not only a cancer specific imaging agent, false positive results may be observed with benign diseases. False positive results are commonly observed in areas of active inflammation or infection (Gupta et al., 20000), with a reported false positive rate of 13% and false negative rate of 9% (Alavi et al., 2002).

What cancers do not show up on a PET scan?

On the other hand, tumors with low glycolytic activity such as adenomas, bronchioloalveolar carcinomas, carcinoid tumors, low grade lymphomas and small sized tumors have revealed false negative findings on PET scan.

Does inflammation show up on PET scan?

It is important to remember that a PET scan can show many things. The scans can’t tell the difference between activity due to a tumor and activity due to non-cancerous processes, such as inflammation or infection.

What does a PET scan show in the lungs?

It uses a radioactive substance (called a tracer) to look for disease in the lungs such as lung cancer. Unlike magnetic resonance imaging (MRI) and computed tomography (CT) scans, which reveal the structure of the lungs, a PET scan shows how well the lungs and their tissues are working.

Can PET scans show false positives?

In cancer cells, there is an overproduction of glucose transporters and, as a result, increased FDG uptake. However, not all PET-positive lesions are cancer, and in many instances, PET findings can be false positive.”