CT Scan Test
Overview
A CT scan, or computed tomography scan, is a medical imaging test that uses X-rays along with computers to generate cross-sectional pictures of the body. This technology helps show clear images of bones, blood vessels, and soft tissues.
Compared to regular X-rays, CT scans provide more detailed images, making it easier for doctors to analyze internal structures.
CT scans are commonly used to:
- Detect diseases and injuries
- Plan treatments such as surgery or radiation therapy
- Monitor medical conditions
Reasons for Performing a CT Scan
Health professionals rely on CT scans to examine different parts of the body. This type of imaging helps detect abnormalities and supports decisions about diagnosis and treatment.
1. Detecting Different Types of Tumors and Cancers
Doctors often use CT scans to find and measure the size and spread of tumors. CT imahing helps detect cancers in the brain, lungs, liver, kidneys, breast, colon, stomach, or bones.
It is especially useful for identifying tumors in hard-to-examine areas. CT scans can also show whether cancer has spread (metastasized) to nearby tissues or distant organs, supporting more accurate staging and treatment planning.
2. Assessing Bone Problems and Fractures
CT scans provide clear images of bone conditions. Doctors use them to identify fractures, bone tumors, arthritis, bone infections, and complex injuries in areas like the ankle, wrist, or spine.
| Condition | What CT Scan Shows |
|---|---|
| Fractures | Broken bones |
| Bone tumors | Size and shape of tumor |
| Arthritis | Joint changes |
| Osteoporosis | Bone loss |
3. Finding Blood Clots and Internal Bleeding
Doctors use CT scans to find blood clots in the lungs (pulmonary embolism) or brain (stroke). A CT scan can also identify internal bleeding, which is especially useful after an accident or trauma.
By showing the exact location and severity of clots or bleeding, CT scans help doctors make fast, accurate treatment decisions.
4. Diagnosing Organ Issues and Diseases
CT scans help examine organs such as the liver, kidneys, pancreas, and lungs. They can detect:
- Kidney stones or kidney cancer
- Liver tumors or cirrhosis
- Pancreatic cysts or cancer
- Lung nodules or pneumonia
Images may reveal swelling, abnormal masses, or other changes inside the organs.
5. Guiding Medical Procedures
Doctors use CT scans to help plan and carry out surgeries, biopsies, and radiation treatments. CT images show the exact place for surgery or where to take a tissue sample. This guidance makes procedures safer and more successful.
6. Checking for Heart and Blood Vessel Conditions
Doctors use CT scans to check for problems with the heart or blood vessels, such as blocked arteries, heart disease, or blood vessel swelling (aneurysm).
| Issue | CT Scan Can Detect |
| Coronary artery disease | Blockages in heart arteries |
| Aortic aneurysm | Swelling in the aorta |
| Blood clots | Location and size |
| Arteriosclerosis | Hardening of the arteries |
7. Assessing Trauma and Internal Injuries
After accidents, CT scans help quickly assess internal injuries. Doctors use them to find damage to the brain, chest, or abdomen, and to detect bleeding, broken bones, or organ injuries that may not be immediately visible.
8. Virtual Colonoscopy
Doctors sometimes use a CT scan to perform a virtual colonoscopy, which creates detailed images of the colon and rectum to check for polyps, cancer, or other abnormalities.
This can be a helpful option for people unable to undergo traditional colonoscopy.
9. Identifying and Watching Infections
CT scans help detect infections such as abscesses or pneumonia. The scan shows the location and severity of the infection and may help in monitoring recovery.
10. Monitoring Treatments Progress
Doctors may use CT scans to track how well treatments are working. For example, after cancer therapy, a CT scan shows if a tumor is getting smaller or if it has disappeared.
11. Diagnosing Kidney and Urinary Problems
CT scans are helpful in identifying kidney stones, bladder stones, tumors, or urinary tract issues. These insights help guide the treatment plan.
12. Additional Applications of CT Scans
CT scans are sometimes used in less common but important situations, such as diagnosing appendicitis, evaluating unexplained pain, or locating abnormal fluid collections.
Risks
Exposure to Ionizing Radiation
CT scans use a type of energy called ionizing radiation to create detailed images of the body. The amount of radiation from a CT scan is higher than from a basic X-ray, which means patients receive more exposure each time.
While one scan usually does not lead to long-term problems, having multiple scans can slightly raise a person’s chance of developing cancer in their lifetime. Children have a higher risk compared to adults because their bodies are still growing.
Healthcare providers aim to reduce this risk by using the lowest amount of radiation needed for each exam. Modern CT scanners and improved methods also help by lowering the overall radiation dose.
Patients should talk with their health professional about both the risks and the benefits before having a scan.
| Factor | Possible Risk | Who is Most Affected |
|---|---|---|
| Radiation (Single scan) | Very low effect | All patients |
| Repeated scans | Small increase in cancer risk | Children, frequent users |
| Lowered dose techniques | Decreased risk | All patients |
Risks to Pregnant Women and Babies
Pregnant women should inform their healthcare provider before getting a CT scan. If the scan focuses on the belly or pelvic area, the radiation could reach the unborn baby.
Most scans do not cause direct harm, but there is still a minor chance of risk, depending on the body part scanned.
Doctors may choose other tests, such as an ultrasound or MRI, to avoid exposing the unborn baby to radiation. These other tests do not use ionizing radiation and are safer during pregnancy.
Use of Special Dyes During Scans
Some CT scans require a dye, often called a contrast agent, to help certain areas of the body appear more clearly. The dye can be given in several ways:
- Oral Use: A patient may drink a liquid with the dye to highlight the stomach or esophagus.
- Injection: The dye can be injected into a vein or artery, which may cause a warm feeling or a metallic taste.
- Rectal Administration (Enema): A contrast dye may be introduced into the rectum to enhance the visibility of the intestines during imaging. This may cause temporary bloating or discomfort.
Allergic or Side Effects from Contrast Dyes
Some people may experience allergic reactions or side effects when given a contrast dye. Most side effects are mild and can include an itchy rash or minor discomfort.
In rare cases, the reaction may be more serious and could require urgent medical attention. Anyone who has had a reaction to contrast dye before should tell their healthcare provider before having another scan.
Even though most reactions do not last long, it is important to be aware of the signs of an allergic response and report any unusual symptoms right away.
Steps to Get Ready
Helping Your Child Get Ready for Their Scan
Before a CT scan, your child might need to wear a hospital gown and remove anything metal, such as jewelry, belts, or eyeglasses. Metal objects can create problems with the images.
For some tests, your child might need to go without food or drinks for several hours. If a contrast dye with iodine or IV contrast is used, the medical team will watch for allergic reactions.
Younger children, like infants or toddlers, may move during the scan. If this happens, a sedative may be suggested to help your child stay still. Talk to your child’s healthcare provider to learn how to make the experience easier.
What You Can Expect
What Happens During the Scan
A CT scanner is a large, round machine with an open center. The person lies on a slim table that moves into the center part of the scanner. Straps and cushions may keep the body still, which is important for clear images.
For head exams, a soft device might hold the head in position. The CT scanner uses x-ray equipment that moves around the body, capturing many detailed pictures from different angles.
The scanner makes noises like buzzing and whirring while it works. A technologist operates the machine from a separate control room and can speak to the patient through an intercom system.
Sometimes, the person will need to hold their breath for a few seconds—this helps prevent blurry images. The procedure is generally brief, lasting only a few minutes.
| Imaging Feature | Purpose |
|---|---|
| X-ray beam | Creates cross-sectional images |
| Multiple angles | Shows internal structures clearly |
| CT scanner movement | Captures detailed images |
| Stillness required | Avoids blurry results |
What To Expect When the Scan Is Over
After the CT scan, most people can go back to their usual activities right away. If a contrast dye was used to make certain areas show up on the images, there may be a short wait to check for any side effects.
Drinking extra water can help flush the dye from the system.
The CT scanner saves the pictures as computer files, which can be viewed on a screen. A radiologist reviews these images and writes a summary.
This report is added to the patient’s medical records. The healthcare provider then goes over the findings with the patient.
