CT Scan

Computed Tomography

CT scanning is a sensitive diagnostic tool that uses X-rays to take a series of two dimensional cross-sectional images (‘slices’) around an axis. Also known as a CAT scan, it is used to image many conditions and injuries. Visit our Scan Glossary for details of conditions scans are used for.

Important things to tell us before having a CT scan

It’s important that you tell us before the scan if you:

  • are diabetic and taking metformin
  • have any allergies or asthma
  • have decreased renal (kidney) function
  • are pregnant or are breast-feeding

Having a CT scan

CT Scan
  • If we’re scanning your abdomen or pelvis, we might ask you to drink a certain amount of water or contrast agent ; you will be given details if this is necessary.
  • It might be necessary for you to stop eating or drinking for a specified time before your scan; you will be given the details if this is necessary.
  • Please wear loose, comfortable clothing.
  • Please confirm your appointment prior to your scan if requested and arrive in plenty of time.
  • Please let us know if you have any disabilities so that we can ensure we are able to offer you the highest quality service
  • Once you’ve checked in at reception (don’t forget to bring your appointment letter), a member of the radiography team will meet you, explain the procedure and ask you to sign a consent form.
  • We might ask you to change into a hospital gown. We’ll provide somewhere to store your personal possessions. You’ll be looked after by the radiography team throughout the procedure – they will explain what’s happening and will be there if you experience any discomfort.
  • You’ll have the opportunity to ask any questions about the procedure.
  • We might need to give you an injection (known as a contrast medium) to increase the amount of information we can get from the scan. Depending on the area we’re scanning, we might ask you to drink the contrast medium instead of injecting it – in this case you might have to wait for anything up to an hour before you can be scanned.
  • You need to let the Radiographer know if you’ve ever reacted to an injection given for a kidney X-ray (IVP or IVU) or a previous CT scan.
  • The Radiographer operating the scanner will be able to see and hear you throughout the procedure.
  • We’ll ask you to lie down on the scanner bed and we’ll make sure you’re comfortable so you can stay as still as possible – we might have to ask you to hold your breath or not to swallow when the scanner is taking the images.
  • Most scan sessions last between 15 and 30 minutes.
  • You’re welcome to bring a friend or a relative with you, but for safety reasons we won’t allow them into the examination room.
  • There are no restrictions on normal activity – you can eat and drink normally, drive and return to work immediately after the scan.
  • If we’ve given you a contrast medium injection there is a very small risk of an allergic reaction so we’ll ask you to stay with us for half an hour after the scan.
  • A Radiologist will examine the images shortly after your visit and send a report to your Doctor or Consultant, normally within a few days.
  • For ethical and professional reasons, we cannot discuss results with you. Only your Doctor or Consultant can do this.

Is my CT scan covered by my health insurance plan?

It is best to contact your insurer directly to find out if your CT scan is covered by your plan on any of our sites.


Does a CT scan hurt?

No, a CT scan is a painless examination.


Why do I need to drink contrast?

The oral contrast fills the colon and small-bowel for better visualisation of the images.


Why do I need the IV contrast?

The IV contrast enhances all of the vascular structures on the images (i.e. liver, pancreas, kidneys). It will also characterise potential pathology.


Could I have a reaction to the IV contrast?

Yes, but the chances are minimal. It is the same risk for a reaction as any medication dose, which is why we use contrast screening forms – to flag possible patients who are at risk of having a reaction to the contrast.


Why is a head CT scan done must frequently without IV?

Most pathology can be detected in the brain without IV contrast. If there is a suspicion, contrast may be given, or an MRI might be suggested for further evaluation.


Is it okay that I took my medications this morning before I came?

Yes. Any type of medication is fine to take the morning before your exam. For patients who are NPO, please do not take any medication two hours before your exam. If you take a certain kind of diabetic medication you may be asked to withhold for 48 hours after the exam.


What is the CT scan going to show?

A CT scan is good way to image and evaluate bones, internal organs, the brain and vascular structures within the neck, chest, abdomen, and pelvis.

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