CT and PET: What’s the Difference?

To better diagnose health conditions, doctors need to see what’s going on inside the body. Of course, they don’t have to dissect the body to achieve that. All they have to do is to take pictures of it through an imaging technology.

Computed Tomography (CT) and Positron Emission Tomography (PET) are two of the few imaging technologies available today. Although they are both tomography (meaning they use some form of penetrating wave to capture images of enclosed tissues), they have some striking differences.

CT Scan

One of the oldest imaging method, CT produces cross-sectional images of the body using x-rays. Because the machine used for this test is more common than that of PET or MRI, this test can be seen performed in hospitals and outpatient offices.

During a CT scan, an IV will be inserted in a patient’s to introduce a contrast. The patient will then be asked to lie down on a narrow table placed in the middle of the donut-shaped scanner. As the bed moves into the scanner, the x-rays the scanner produces rotate around the body. The contrast that is now inside the patient’s body helps the scanner distinguish bad tissues from good ones.

PET Scan

The process followed during a PET scan is similar to that in a CT scan in that a substance that reacts to the electromagnetic wave used for scanning is introduced to the patient’s body. There are several apparent differences though. For instance, instead of being injected into the body, the tracers are mixed with a solution that the patient will be asked to drink.

Another difference is the time it would take for the entire test, from the introduction of tracers to the production of images. It would normally take up to four hours depending on the area of the body that needs imaging, whereas CT scans can last for only up to a few minutes.

These imaging techniques, as well as MRI, have significantly improved health care. With a clear picture of what’s really going on inside a patient’s body, it could be much easier for doctors to identify health problems, measure their extent, and come up with the most effective remedy.

Sources:

What Is a PET Scan?, healthline.com

CT Scan vs. PET Scan, diffen.com