A CT or computed tomography scan, sometimes known as a CAT scan, is a diagnostic tool that, unlike traditional x-rays, provides a more detailed picture of the inside of a patient's body by scanning it from several angles at once. These images help medical practitioners diagnose a range of conditions. The scans are conducted by qualified radiographers, in the hospital.

What does a CT scan show?

CT scans are capable of creating complex and detailed images of a variety of internal body parts, enabling doctors and other medical professionals to get a clear view of a patient's organs. CT scans can also generate images of the circulatory system's blood vessels in minute detail, or examine a patient's bones.

CT scans

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Why might a CT scan be necessary?

Doctors primarily use CT scans to diagnose conditions that would be more difficult to detect using other methods. CT scan can help diagnose circulatory problems, stroke, cancer, and internal organ injuries. A CT scan may also be used as part of planning treatment by creating a complex picture of a tumor before radiotherapy. CT scanning also monitors medical conditions to see how they respond to treatment.

CT scan

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What does a CT scanner look like?

A CT scanner looks something like a donut. It encircles the relevant part of the patient's body completely, which allows it to take multiple images from a variety of angles, creating the detailed images for which the tool is popular. Unlike an MRI scanner, the patient will not be put into a 'tunnel' to have their scan. Therefore, CT scans are less likely to trigger a claustrophobic reaction than some other methods of scanning.

CaT scans

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How do you prepare for a CT scan?

Sometimes, the medical practitioner will inject a dye into the patient's bloodstream or have him or her drink a substance containing the dye. This makes it easier for the radiographer to see the internal structures during the scan. The dye can cause nausea, so in such cases, individuals are asked to abstain from eating and drinking for a period beforehand. The patient will also be required to remove any metal items such as jewelry, and may also need to change into a special gown. Most patients will not be sedated, although those who are anxious about the procedure may have that option.

CaT scan

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What happens during the scan?

During the scan, the patient will be asked to lie very still on his or her back, on the scanner bed. The bed will move slowly through the scanner, which makes a quiet whirring sound and should not be loud enough to cause any concern. Occasionally, the patient may need to lie face-down. The procedure is usually quick and only takes a few minutes. The radiographer will exit the room before the scan begins and observe from behind a screen. He or she may give the patient instructions to hold the breath for short periods during the scan, if necessary.

during scans CT scans

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What happens after a CT scan?

Patients are almost always sent home as soon as a CT scan is complete. If they were sedated or required an injection of consumption of the dye, they might be asked to remain in the hospital for a few hours until they have recovered from any effects. It is unlikely that the results will be available immediately, as they take time and skill to interpret. Instead, the doctor will review the images and present feedback to patients in due course.

after CT scans


Are there any risks?

CT scans are generally believed to be safe and are completely painless. The main risk of a CT scan arises from any dye used, although this is not always necessary; some people have adverse reactions to the ingredients. CT scans expose patients to a small amount of radiation, and though radiation can cause cancer, it's highly unlikely this miniscule quantity will cause any problems. Doctors will weigh up this potential risk against the benefits of having the scan before they recommend the procedure.

risk CT scans

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What are the potential side effects?

If a patient experiences side effects from the dye, they are likely to occur shortly after the medical professional has administered the dye. So, these symptoms almost always begin while the patient is still in the hospital. Common side effects include nausea, itchy skin, and difficulties in breathing or swallowing.

side effets CT scans

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Are CT scans suitable for everyone?

CT scans are considered suitable and safe for all patients regardless of age or medical history. The only exception is pregnant women, who should not have their abdomens scanned due to risk to their unborn baby. Pregnant women with life-threatening conditions are the exception. Mothers who are breastfeeding can have CT scans, and can even receive the dye if necessary.

CT Exams

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Is it safe to take medication before a CT scan?

Medication does not affect a CT scan, so patients can take their regular medicines on the day of their appointment. However, people with diabetes may not be able to take medications if they require the dye -- in some cases, the dye can affect the way the kidneys process common diabetes medicines. Patients with diabetes should consult with the doctor before their scan to determine a plan regarding their medication.

CAT exam

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