Why get a CT scan?
A computed tomography scan, or CT scan, is a common test ordered in hospitals for a variety of patients. It uses X-rays to create pictures of cross-sections of the body.
You can get a CT scan of any part of the body. You might have a CT scan if you have had a stroke or experienced a head trauma or broken bone. Patients with unexplained stomach, chest or head pain might also get a CT scan. A CT scan can also help diagnose unexplained confusion or a neurological problem. Also, cancer patients get CT scans frequently for follow-up studies.
Through the years, the CT scan has started to supplement the physical diagnosis and help doctors become more specific. There is some debate that the CT scan is overused.
What happens when you get a CT scan?
Before the test, it's important to tell the medical staff whether you're pregnant and also whether you're allergic to the contrast dye they sometimes use, which is generally an iodine-based dye.
To begin, you will lie down on a table. The table will lift, and generally, you'll be placed through a doughnut-shaped scanner. Unlike an MRI scanner where you're enclosed, the CT scanner is open, and you will be able to see around you. It's important to remain as still as possible.
Once the scanner starts, the X-ray beam will go through you, rotating around you. The test usually takes between five and 15 minutes, depending on the machine being used.
Does it hurt?
The dye used during a CT scan is inserted through an intravenous needle. This dye can help make parts of your body more visible in the images the scanner provides. The needle injection likely will be the only pain associated with your test. Otherwise, it should be painless.
What are the risk factors?
Patients who undergo CT scans are exposed to more radiation than they would have been with a plain X-ray. Studies have shown a small potential to increase your risk of cancer. If you're pregnant, your doctor might want to use a different test, for there's some concern about the impact of the radiation on the fetus. Also, if you don't know that you're allergic to iodine, you can have an allergic reaction to the dye.
What's the follow-up?
The number of times you'll have a CT scan will depend on your diagnosis and what you and your doctor decide works best. For example, if you are a cancer patient, you likely will undergo several CT scans.
If there's a finding on your CT scan that doctors can't quite figure out, you might have a follow-up scan to see if anything is growing.
For example, it's common to find benign nodules in the chest.
Sometimes they're too small, and doctors can't figure out whether they're actually benign. In that case, your doctor might have you undergo a CT scan periodically to ensure that the nodules aren't cancerous and growing tumors.
Dr. James Hendrix, a radiologist at Mercy Hospital Oklahoma City; the National Institutes of Health;
The Mayo Clinic.