Understanding PET scan

PET (Positron Emission Tomography) is a painless diagnostic test that allows radiologists a unique view of your body’s biological functions by looking at your body’s metabolic activity. Almost all diseases alter your body’s biological processes. PET is able to discover these changes in their earliest stages, often before any symptoms appear. It can sometimes eliminate the need for other invasive procedures and, by correctly staging cancers, may prevent unnecessary surgical procedures. It helps in faster initiation of effective treatment plans.

Understanding CT scan

CT scan accurately evaluates anatomy (pinpoint the exact location, size and shape) of the diseased tissue or tumour.

Understanding PET CT scan

PET CT is a combination of a PET scan and a CT scan obtained at a single instance and by a single piece of equipment. By combining these studies, the identification and accuracy of diagnosing a disease is greatly enhanced. Physicians are able to detect disease earlier, determine the extent of the disease and assess response to and effectiveness of treatments. It eliminates the need for multiple work-up procedures such as site specific CTs, ultrasound, MRI and bone scans.

Understanding how PET CT scan work

All human cells consume glucose. But cancer cells require more glucose than healthy cells to grow. PET scan utilizes a radioactive tracer that is similar to glucose called FDG. FDG accumulates within malignant cells due to their high rate of glucose metabolism. When a patient is scanned, the resulting images show the distribution of the radio-labeled glucose throughout the body. Areas of increased metabolism appear as hot spots on the images showing disease presence.

Benefits of PET CT
• It is fast and convenient – has shorter scanning time and improved image quality
• It helps in early and accurate diagnosis of the disease due to its superior sensitivity
• It helps surgeon prevent from ineffective or unnecessary surgical procedures by accurately characterizing tumors as benign or malignant
• It is clinically proven, cost-effective and safe method for imaging a variety of cancers
• It is particularly effective in identifying whether cancer is present or not, if it has spread, if it is responding to treatment, and if a person is cancer free after treatment.

Side effects and safety

There are no side effects associated with PET CT. It is safe for patients of any age and is painless. The total radiation dose is less than 1½ times the standard whole body CT scans. The FDG degrades quickly (T1/2-110 minutes) and eliminates from the body through urine. Family members are not at risk of exposure and the patient can interact with them after the scan.

Radioactive substance may expose radiation to the fetus in pregnant patients or infants of beast-feeding women. If you are pregnant or think you might be, please inform the PET imaging staff before your scan.