Medical scans can be scary. You don’t know what to expect and you’ve never heard of some off the acronyms your doctor has just said to you. PET? CT? They’re both different types of scans your doctor can use to help diagnose problems, and they’re very different. Here’s the difference between a PET scan and a CT scan.
First, let’s start with a CT scan. A CT uses x-rays for its imaging, so there’s no radioactive materials involved. Basically, a CT scan takes x-ray pictures of your body that look like slices of bread. This way your doctor can look at those sections one by one, like flying through your body. In some cases, those x-ray images can be combined to create a 3D image of your body.
A CT scan focuses mainly on internal images, so it will give a good picture of your anatomy. It’s a good choice for doctors to use on patients with internal injuries. The x-ray “slices” let doctors see where the injuries are without cutting into their patients.
CT scans usually take about 30 seconds, but can last as long as five minutes. That puts them at the faster end of the scanning spectrum, and they’re less sensitive to patient movement. They are painless and noninvasive, but do pose a slight risk of irradiation. they’re not recommended for children or pregnant women unless absolutely necessary. That said, the dose of x-ray radiation you get from a CT scan is about the same amount you’d get from background radiation over three to five years.
If a CT scan see how your internal organs look, a PET scan measures what’s going on with those organs. PET scans measure what’s going on inside your cells, like metabolism.
It works by using nuclear medicine. Patients are injected with a radioactive isotope that emits radiation. As your body metabolizes the isotope, the radioactive material flows to your cells. That radiation is then measured as it exits the patient’s body, then analyzed in a computer and translated into a picture.
PET scans work well diagnosing and staging conditions like cancer and diagnosing Alzheimer’s. That’s because it can more accurately measure the function of the parts of the body that cause those diseases.
The radiation risk is higher than a CT scan, since it does use radioactive materials. It also involves an injection, so it’s not non-invasive. It also takes a lot longer than a CT scan…between two and four hours.
Your doctor will decide which scan is the best for you. And in some cases, your doctor might want both scans to get a better idea of what’s going on inside your body. Contact us for more information about CT and PET scans or to schedule your appointment today.