Doctors use PET and CT scans to look inside patients’ bodies so they can diagnose a range of health conditions, including cancer, poor blood flow, and brain abnormalities. Both are non-invasive options that give doctors a lot of diagnostic information. Although the two types of scans differ in some ways, they are very similar from the patient’s perspective.
If you’re asking “Why has my doctor ordered a PET/CT?” there’s a good chance that you have a condition commonly diagnosed with these imaging options.
What is a PET Scan?
A PET (positron emission topography) scan uses a radioactive substance, called a tracer, that lets doctors see how the body is functioning. The tracer is usually administered through an IV in the arm. It takes about an hour for the body to absorb enough of the tracer to give a clear view.
After the tracer has made its way through the body, you get into a PET machine that looks like what you might expect to find in a space station bedroom. It’s a large tube with a table you lie on during the scan.
The machine receives information from the tracer. This information gets turned into 3D images that show what’s going on inside the body.
Scans are commonly performed on the brain, breasts, heart, or lungs.
Although the tracer is radioactive, it presents a very low health risk.
Reasons to Get a PET Scan
Doctors often use PET scans to diagnose neurological conditions such as Alzheimer’s.
Doctors often want patients to get PET scans after they have received CT scans or X-rays. A PET scan provides a metabolic picture, meaning rather than showing the skeleton and organs, it shows how the cells are functioning. Cells in areas that gobble up more of the radiotracer give information to the radiologist about things like cancer or Alzheimers for instance. If your doctor sees something in an X-ray or CT or you receive a biopsy results that concerns her, she may schedule a PET scan to confirm or deny suspicions.
Healthcare professionals can also use PET scans to decide whether cancer treatments are working or to explore an area before surgery.
What is a CT Scan?
A CT (computed tomography) scan uses X-rays to create 3D images. Technicians take several X-rays of an area so software can turn the 2D images into three dimensions.
From the patient’s perspective, it’s much like receiving several X-rays. The computer software does all of the behind-the-scenes work to generate useful images.
CT scans are often used to diagnose problems with the lungs, brain, heart, abdomen, and pelvis. They are, however, useful throughout the body, including arms, hands, feet, and legs.
In some cases, doctors may want to use contrast dye or have you drink barium to get a clearer image.
Reasons to Get a CT Scan
Doctors use CT scans for many of the same reasons that they use PET scans. They’re effective at diagnosing things like blood clots, skull fractures, infections, and tumors. They can’t tell you for certain if a tumor is cancerous, however. That’s why you might get a PET scan too.
CT scans are often used to gather more information before a doctor makes a formal diagnosis. If an X-ray reveals something odd in your lungs or brain, your doctor may schedule a CT scan to get a better look at the area.
PET and CT scans aren’t as common as X-rays, but they are extremely common diagnostic tools used in medical facilities all over the world. If you have any questions about CT or PET scans, feel free to contact us for more information. We want to help you make an informed choice that protects your health.