PET CT SCAN - All you need to know

What is a PET CT scan?

                                         

This advanced nuclear imaging technique combines positron emission tomography (PET) and computed tomography (CT) into one machine. A PET/CT scan reveals information about both the structure and function of cells and tissues in the body during a single imaging session.

A PET CT scan can identify changes in functioning of organs at a very early stage, often before structural changes take place. The study utilizes small amounts of radioactive tracers, which when injected into the body, give information about different body functions.

How is it different from CT or MRI?

CT, MRI and other radiological modalities like X ray, ultrasonography are structural imaging modalities, which means, they look at the size and shape of organs and other body structures.

PET imaging on the other hand, looks at functions within the body.

Hence when combined with CT, they give more information than a CT or MRI alone and pick up altered function due to disease process at a much earlier stage, before structural changes happen.

Why have I been recommended a PET CT scan?

The commonest use of this scan is in cancers, where it is used to detect and identify the areas of spread of the cancer, monitor response to treatment or plan for radiotherapy, or to guide biopsy.

PET CT scanning can also be used to evaluate certain heart diseases or neurological conditions.

Is PET safe ?

                                                     

The risks associated with PET scan are very low. PET scan involves a very small amount of radioactive tracer injected into your body which decays by itself with time and is also excreted out by the body continuously through urine. The total radiation exposure during a PET CT scan roughly equals two CT scans of abdomen and pelvis.

The injected contrast material used for the CT part of the study may cause some allergy rarely, in a few patients.

Family members of the patient undergoing the scan are not at risk due to radiation because most of the radioactive medicine injected decays by the time the scan is over.

However, this radioactive exposure carries a risk for a pregnant woman carrying an unborn child and any radioactive tests should not be performed during pregnancy. Please inform your doctor before the procedure if you suspect to be pregnant.

What happens during a PET scan? Is it painful?

                  

A PET CT scanner machine is quite similar to a CT machine and not a closed tunnel like MRI.

The patient is asked to come fasting for the test and an intravenous canulla is placed in one of the peripheral veins (on hands or arms usually). The radioactive tracer is injected and the patient is asked to rest in an isolation area for a stipulated time (usually 60-120 minutes) and sip some oral contrast material. The most commonly used radioactive tracer (Fluorodeoxyglucose) is an inert substance and does not cause any interaction or side effects in the body.

The scanning procedure per se is painless and intravenous CT contrast may or may not be used during the scan, as per the need and physician’s discretion. 

Thanks for reading and please keep visiting our blog to discover and appreciate more Yoddhas. 
Feel free to contact the Yoddhas team at team@yoddhas.com 
Join our free patients group https://www.facebook.com/groups/yoddhathewarrior/

Lastly, Praise the Yoddhas; Support the Yoddhas ; Love the Yoddhas!

Author- 

   

Dr.Sugandha Dureja

Founder Member,
MBBS, DNB, FEBNM
Fellow Theranostics (Germany)
At. Consultant, Nuclear Medicine
FMRI, Gurgaon
CNETS India.
Also Yoddhas Medical Expert Panelist