How Does a CT Scan Work?
Before the CT scan begins, you may get asked to consume a special dye (a “contrast material”) to help internal body structures show up more clearly on the imagery. You’ll also get asked to wear a hospital gown and remove any jewellery and other metallic objects.
In some cases, you may also get asked to not eat anything for four or five hours before your scan. That’s because undigested food in the stomach can make it difficult for clear images to get taken.
You will then get asked to lie on a special table facing upwards. The table then moves into the CT scanner, and you’ll hear a series of clicks or other noises, along with the scanner moving around you; when that happens, the scanner is taking image “slices” of your body.
The whole process takes between 20 minutes and one hour, depending on the imagery required in the procedure.
Some people may wonder if CT/MRI/PET scans are all the same. They are similar but aren’t entirely identical; here’s why:
CT Scans vs MRI Scans
CT and MRI (Magnetic Resonance Imaging) scans both get used for capturing a series of images that reflect the inside of a person’s body. Perhaps the main difference between the two technologies is how they achieve that goal.
CT scans use x-ray technology to capture images, whereas MRI scans use radio waves and magnets. MRI scans cause radio waves and magnetic fields to bounce off the body’s fat and water molecules, resulting in the desired images.
CT Scans vs PET Scans
PET stands for Positron Emission Tomography and is another type of imaging test used to identify diseases in the body. As with CT scans, the person consumes a special dye before the test to help provide clear imagery of the body’s internal organs and functions.
When a doctor requests a PET scan, they do so because they want to see what’s happening at a cellular level; that’s something a CT scan cannot do.
What Equipment Do You Use for CT Scans?
At Trinity Medical Centre, our imaging centre has the latest Philips iCT Elite. It’s a state of the art, low-radiation CT scanner, and we’re only one of four medical practice service providers in all of Hong Kong to feature it.
The Philips iCT Elite boasts 256-slice CT technology, meaning it can take more detailed imagery than most other CT scanners. Another advantage of the device is it only emits one-sixth the radiation of standard CT scanners.