A CT scan—also known as a computed tomography scan or CAT scan—is a quick, precise imaging exam that uses specialized X-rays to create cross-sectional pictures, or slices, of structures inside the body, including bones, muscles, organs, blood vessels, blood clots and tumors. Once the exam is complete, a radiologist can examine the slices one by one or combine them to create a single, 3D image. CT images are much more detailed than regular X-ray images, and physicians use them to diagnose injuries and conditions, determine cancer stages, plan procedures and gauge the success of treatments.
A CT scan and an MRI scan share some similarities, but they differ in several key ways. CT scans are usually faster, and the way the two machines generate images differ in ways that make one more suitable for diagnosing certain conditions than the other.
Reasons to Have a CT Scan
A CT scan is one of the most important tools physicians have to look for injury or disease inside the body. Radiologic technologists can perform many types of CT scan, and your scan will depend on your physician’s orders and the part of your body that needs to be examined.
CT scans help physicians identify a variety of illnesses and injuries, including heart disease, bone and muscle conditions, sinusitis and many types of cancer, among other conditions.
Your physician may order a CT scan to:
- Check the condition of your blood vessels and look for signs of cardiovascular disease
- Diagnose cancer or determine a cancer’s stage
- Find out why you’re having chest pain or difficulty breathing
- Look for a fracture or an injury to a muscle or organ
- Plan surgery or radiation therapy for cancer
What a CT Scan Can Show
A CT scan can allow radiologists to see:
- Arteries and veins
- Blood clots
- Bones, including those of the skull
- Compression fractures
- Herniated discs
- Kidney stones
- Muscles and other soft tissues
- Neck masses
- Organs, including the heart, lungs, liver, kidneys and intestines
- Spinal cord injuries
- Spinal stenosis
- Tumors, including those of the spine
What to Expect
Getting a CT scan takes little time and requires minimal preparation. On the day of your exam, be sure to wear loose-fitting clothing and leave metal objects, such as jewelry, at home, if possible—you’ll be asked to remove any metal objects you bring with you.
You may need to fast for a few hours before your exam if you’ll be undergoing a scan that requires a contrast dye. If your exam does require a contrast dye, you’ll receive it before the exam begins as either a flavorless drink or an injection. A contrast injection helps the radiologist see blood vessels, certain tissues and organs more clearly, while an oral contrast dye helps to produce clearer images of your stomach and bowels.
During the exam, you’ll lie still on a cushioned table that will move into the CT machine, which is a large cylinder that, from the front, looks like a giant doughnut. The machine will rotate around the table to capture image slices. A technologist will monitor the scan from a neighboring room, and you’ll be able to communicate with him or her at all times.
Scans typically take just minutes, and many last only seconds. Your entire exam, including the scan itself, will likely last no more than 30 minutes. Your physician will receive the results of your scan within 24 hours and share them with you.
Frequently Asked Questions
For patients with unusual or tough-to-understand symptoms, a computed tomography (CT) scan is one of the best tools for helping physicians make accurate diagnoses. A CT machine uses a rotating series of X-rays to produce cross-sectional pictures of your body. These pictures appear as “slices” of a specific body part, and they offer much greater detail than traditional, flat X-rays.
Like MRI, CT is safe, painless, and noninvasive. While an MRI is most often used to examine muscles, organs, and tumors, CT is generally applied to fractures, blood clots, and abdominal injuries. In all cases, our skilled healthcare professionals will consult with your doctor to determine which scan will deliver the most accurate and informative results.
If your doctor has ordered a CT scan, they’re likely looking for details that are impossible to spot with traditional X-rays. These details may include small injuries to bones, soft tissues, and blood vessels, any of which may help your doctor determine the underlying causes of your symptoms. Your CT scan may also help to determine the best locations to perform biopsies, detect tumors, or investigate chronic diseases.
A key advantage of CT is its ability to display the details of bones, blood vessels, and soft tissues in the same image – something much harder to achieve with MRI and traditional X-rays. Given its ability to reveal tumors, CT is also one of the best diagnostic imaging tools for cancer patients. Finally, it is commonly used to diagnose vascular diseases, osteoporosis, and traumatic injuries to internal organs.
In addition to its diagnostic imaging benefits, CT is also faster and cheaper than MRI. It also exposes patients to minimal radiation – less than a single traditional X-ray. Overall, the amount of radiation a patient receives fr
Unlike MRI, CT does not require your body to be immersed in an imaging machine. Instead, you’ll lie on a table that slides into a donut-shaped scanner, which will be positioned only around the area of your body being imaged. As you lie still, the scanner will rotate around you, allowing multiple X-ray devices to capture a three-dimensional image.
Depending upon the body part being imaged and the specific type of CT scan your doctor has ordered, your exam may require the use of a contrast dye. These dyes contain iodine, which illuminates certain tissues and helps radiologists see finer details in organs, bones, and blood vessels.
If your exam does require a contrast dye, it will be administered through an intravenous injection just before your exam, or as an oral solution several hours prior to your exam. These dyes are safe and well-tested, and our staff will examine your medical history to determine whether there is any risk of allergic reaction.
The newest CT scanning machines can provide a full-body series of images in as little as 30 seconds. Including preparation time, your entire exam will likely take between 15 and 30 minutes.
Your preparation will depend upon your exam type, medical history and whether or not you will need a contrast dye. In all cases, AHI will provide full instruction prior to your exam, offering you ample time to prepare.
Absolutely. CT does not require sedatives, and the process is quick and pain-free. Whether your exam requires a contrast dye or not, you’ll be able to drive home immediately.
Your radiologists will review and interpret your CT scan as soon as it’s completed. Within 24 hours, your doctor will receive a written report, as well as copies of the images for their own inspection.
CT scan costs vary widely, and the price of an exam may differ by hundreds of dollars between various hospitals and imaging centers. Typically, the cost is a combination of technical and professional fees. Technical fees include the costs of the imaging procedure itself, and professional fees are paid to the radiologists who analyze the results.
Another important factor is the specific type of CT scan being performed. Some types, such as brain scans, involve a more complex process and thorough analysis. Others, such as abdominal scans, are simpler to perform and assess.