CT Scans

CT stands for computerised tomography. You sometimes also hear them called CAT scans, which stands for computed axial tomography. A CT scanner is essentially a more sophisticated X-ray machine. But instead of taking a single 2D snapshot of your knee, it takes a whole series of images by moving the scanner in a spiral around your body. The computer then takes these images and turns them into a cross-sectional image of your knee joint. This gives us a very detailed view into the internal structure of your knee, from bones to soft tissues and blood vessels.

Is a CT scan safe?

Like a traditional X-ray, a CT scan exposes you to a small amount of radiation (this is known as the “radiation dose”). This will vary depending on the type of CT scan you’re having. But, as Nuffield Health points out, the scanners are designed to ensure you’re not exposed to an unnecessarily high radiation dose: “Generally, the amount of radiation you’re exposed to during each scan is the equivalent of between a few months and a few years of exposure to natural radiation from the environment.”

Why might I need a CT scan for my knee?

CT scans play a key role in preparing for Mako robotic knee replacement surgery. The process begins by taking a low-radiation CT scan of the hip, knee and ankle. This allows us to look at the alignment of the joints and the knee anatomy. The system can produce a 3D virtual model of the knee, which enables us to create a bespoke plan for the operation, from optimal implant size to the best angles for surgery.

Because CT scans can give us a very detailed picture of what’s going on inside your knee, they also help us assess and diagnose a range of other problems in the joint. For example:

Bone damage – to assess breaks, fractures and dislocations
Infection – to verify and check the extent of an infection in your knee
Soft tissue damage – to view a tear in a ligament or tendon in detail
Cancers – to get a closer look at a tumour inside your knee joint
Arthritis – to view arthritis damage to the bones in your knee

How do I book my scan?

You will need a referral to have a CT scan. This is something Mr Bailey can arrange when he sees you in the clinic. If he decides that you need a CT scan, he will fill out a referral form. You can take the form to the hospital radiology department to make your booking right away. Alternatively, you can just leave it with us when you leave; we'll forward it to the radiologists, who will call you to arrange a date for your scan.

How long will I have to wait for my CT scan?

If you see us in the daytime, it may be possible to have the scan shortly after your consultation with Mr Bailey. Just take your referral form to the hospital radiology department. If the CT scanner is free, the radiographers may be able to book your CT within the next few hours (or even immediately). If you’re having an evening consultation, the team will be in touch to arrange a suitable date for your scan. In most cases, it’s generally possible to have one within a week of your assessment.

I already have some scans. Can I bring them to my appointment with Mr Bailey?

Yes. If you’ve had a CT scan recently via a GP or other medical professional, we can arrange for them to forward the images to us before your appointment with Mr Bailey. Just let us know that you’ve had the scans when you contact us to book a consultation. It normally takes about two days for the images to reach us.

Where will I have my CT scan?

Your CT scan will be at one of our two clinic locations – either the Sarum Road Hospital in Winchester or the Nuffield Wessex Hospital in Chandler’s Ford, depending on which is most convenient for you. When you arrive, head to the main reception and look for Imaging and Radiology. At Sarum Road, it’s right alongside the main reception area. At the Wessex Hospital, turn left at the main reception and head to the next desk down.

What will I need to bring with me?

We recommend wearing loose-fitting clothes to your scan – either trousers that you can pull up above the knee, a pair of shorts, or a skirt or dress. If possible, avoid wearing clothes that have a metal zip or buttons, and make sure you remove any metal objects, such as coins and keys, from your pockets. Bear in mind, though, that the Radiographers may give you a hospital gown to wear instead. This can increase the quality of the scan.

What happens during the CT scan?

The radiographers will ask you to lie down on a table for your CT scan. They’ll position your leg correctly and make sure you’re comfortable. The table then slides into the scanner, which is shaped like a large hoop. Although most CT appointments are about 30 minutes long, the scan itself usually takes less than 10 seconds. While the machine operating, you may briefly hear some whirring sounds as the scanners circle around your knee. To avoid blurring the images, it’s important to remain still during the scan. Some CT scans use a contrast dye to make the images clearer. This involves having an injection shortly before the scan starts. You may feel a sensation of warmth after the dye has been administered, and some people experience a temporary metallic taste. The radiology team will let you know if your CT scan requires a contrast dye before you come in for the appointment.

How much will my CT scan cost?

If you don’t have health insurance, or if your insurance policy won’t cover the imaging (see below), you can choose to pay for your CT scan privately. The cost varies depending on the type of scans you need. For the latest pricing, call Circle Health Sarum Road on 01962 656157 or the Nuffield Wessex on 02380 266377. You can also view guide prices on the Nuffield and Circle Health Group websites: for the Nuffield, see Treatment prices at Wessex Hospital in Hampshire and, for Circle, see The cost of a private CT scan.

Will my health insurance cover my CT scan?

It’s possible but please check with your insurance provider first. When you come to the Radiology and Imaging department for your CT scan, bring your insurance registration documents and a completed and signed claim form (or proof of pre-authorisation by your insurer). You can find more information about private medical insurance on the Sarum Road and Nuffield Wessex hospital websites: click here for Sarum Road and here for the Nuffield Wessex.

When will I get my CT results?

This varies. Results are usually available within a week of your scan. The radiologist will check them, contact you to say they’re ready, and make them available for Mr Bailey to review. If you’ve arranged to have your CT scan the same day as your consultation, however, we should be able to see the images almost immediately.