Today’s medical field boasts many powerful technologies that allow us to better understand our health. In the past few decades, imaging technologies like x-rays, ultrasounds, and MRIs have become staples in helping physicians peek inside of us and figure out what’s making our complex bodies tick. The CT scan has become the most common imaging procedure out there, but most people don’t have a clue how it works. So, before your physician recommends a scan for you, let’s learn exactly what this procedure does, and how you can prepare yourself for it.

What is a CT scan, exactly?

A CT scan is a kind of x-ray. “CT” stands for “computed tomography.” This refers to a process in which snapshots of a specific part of a patient’s body are collected in cross-sectional pieces. A computer renders these cross-sections into a 3-dimensional image of the bone, muscle group, or organ being examined. This futuristic photography is made possible by exposing a patient to a low dose of radiation. Light waves then bounce off your body and back into sensors. Based on what these sensors observe, the computer traces a precise, high-resolution portrait. A radiologist then carefully examines this image.

A CT scan can help locate tumors and infections, diagnose bone and muscle disorders, and detect or monitor conditions like cancer and heart disease. Scans are often used to screen patients that display high risk factors for certain diseases.

So, your doctor recommends that you get a CT scan. What can you expect?

During the procedure, you must lay still on a table as it moves slowly through a metal ring. This ring contains the x-ray source and sensors. It rotates around the patient for the procedure’s duration. As you move through it, the ring sends out invisible light waves and measures how they bounce back.

A technologist will be in an adjoining room during the procedure. You can communicate with the technologist via intercom. They may tell you to hold your breath at times to avoid image blurring. Before the scan, you may have to change into a hospital gown, and you’ll have to remove all metallic items from your person. Your head and limbs may be secured in special fittings on the table. Based on what the scan is searching for, you may be injected with “contrast material.” This is a special, harmless dye that highlights blood vessels and other structures in order to create a more detailed final image. Contrast material may cause a feeling of warmth or a metallic taste on your tongue. If taken orally, contrast material can prolong the process because it takes 45-60 minutes to be digested. Then, the scan itself takes anywhere from a few seconds to several minutes. Once it’s over, you can get right back to your daily routine.

It’s as simple as that. The CT scan is an impressive piece of medical technology that has helped millions of people treat their health conditions. Now you’ve got a basic idea of how it might help you or a loved one in the future.