A computerized tomography scan (CT scan) is a procedure that can allow doctors to see inside your body. It combines X-rays and a computer to create cross-sectional images of your bones, organs as well as other tissues. It can show more detail as compared to a regular X-ray.
CT scan is a painless procedure which can be performed on any part of your body. It doesn’t take a long time either. It is mostly used to quickly examine people who may have had internal injuries due to an accident or any kind of trauma.
A doctor can recommend a CT scan for various purposes which can include:
- Diagnosing bone and muscle disorders, such as fractures or bone tumors
- Pinpointing the location of the tumor, blood clot or infection
- Guiding procedures such as biopsy, surgery or radiation therapy
- Detecting and monitoring diseases and conditions such as cancer, heart diseases, lung nodules and liver masses
- Detecting internal injuries as well as internal bleeding
- Monitoring the effectiveness of certain treatments, like cancer treatment.
Depending on which part of your body is being scanned, you might be asked to:
- Take off some or all of your clothing and change into a hospital gown
- Remove any metal objects, such as jewelry, belt, dentures, eyeglasses, as these kinds of objects might interfere with image results
- Refrain from eating or drinking for some time after your scan
In some CT scans, a special kind of dye is needed which helps in highlighting the areas of the body being examined. The contrast material can block X-rays and appears white on images, which can help emphasize intestines, blood vessels and other such structures.
Contrast Material might be given to you:
- By mouth- If your esophagus or stomach is being scanned, you might need to swallow a liquid that contains contrast material. This drink might have an unpleasant taste though.
- By injection- Contrast agents can be injected through a vein in your arm to aid your gallbladder, liver, urinary tract or blood vessels to stand out on the images. You may feel warm during the injection or a metallic taste in your mouth.
- By enema- Contrast material can also be inserted in your rectum to help in visualizing your intestines. This procedure might also cause discomfort as well as make you feel bloated.
- A CT scan is done in a hospital or an outpatient facility- CT scans are painless and newer machines can finish the procedure in just a matter of minutes. The whole process usually takes around 30 minutes.
A CT scanner resembles a huge doughnut standing on its side. You need to lie on a narrow, motorized table that slides through the opening into a tunnel. Straps and pillows might help you stay in position. During a heart scan, the table might be fitted with a special kind of cradle that can hold your head still.
While the table will move you into the scanner, the detectors as well as the X-ray tube will rotate around you. Each rotation yields several images of thin slices in your body. During this time, you might hear whirring and buzzing noises.
A technologist in a separate room will be able to see and hear you. You will also be able to communicate with the technologist via intercom. At certain points, the technologist might ask you to hold your breath to avoid blurring the pictures.
After the procedure
Risks and side effects
CT scans use X-rays which produce ionizing radiation. According to research, this kind of radiation can cause damage to your DNA and might even lead to cancer. However, the risk is quite small and can be estimated to be around 1 in 2000.
However, the effects of radiation can add up over your lifetime. Therefore, your risk increases with every CT scan you get. It is important that you talk to your doctor regarding the potential dangers of the procedure, as well as benefits.
Ionizing radiation can prove to be more harmful in children because they are still growing.
Inform your physician if you’re pregnant. If you require imaging for the stomach area, your doctor may be recommending another exam that doesn’t use radiation, such as an ultrasound.
There might be few other side effects of the procedure. Some people can be allergic to the contrast materials, though most of the time the reaction is mild. However, in some cases, the dye can trigger a life-threatening reaction, due to which your healthcare provider might want to monitor you for a short time after the scan. If you have any kind of allergies, you should let your doctor know.
You should also let your doctor know if you are having diabetes or any kind of kidney problem.