About a CT scan of the thoracic spine
The thoracic spine is the middle section of the spine, made up of 12 vertebrae (T1 to T12) between the neck and the lower back. Each vertebra is joined to a pair of ribs, which makes this part of the spine stiffer and more stable. The spinal cord runs through it. A CT (computed tomography) scan uses X-rays and a computer to make detailed cross-section pictures of the vertebrae, which can be turned into 3D images.
Upper back pain is often caused by muscle strain or posture and usually gets better without a scan. When a scan is needed for symptoms such as pain that wraps around the chest, or numbness or weakness in the legs, a thoracic spine MRI is usually the right test, as it shows the discs, nerves and spinal cord much more clearly and does not use radiation.
A thoracic spine CT is used when the question is about the bones, for example:
- fractures, including collapse of a vertebra caused by osteoporosis (a vertebral compression fracture), fractures after an injury, and how they are healing
- whether a fracture is stable, and planning treatment or surgery
- calcified (hardened) discs and ligaments, and bony narrowing of the spinal canal
- the position of screws and rods after spinal surgery
- bone lumps and changes in the shape of the spine, such as kyphosis
- back problems when MRI is not possible, for example if you have a pacemaker or other device that is not safe for MRI
If several parts of the spine need to be seen, a whole spine CT may be used. You can read more in our article on thoracic spine imaging.
What happens during the scan
You lie on your back on the scanner bed with your arms raised above your head, and a cushion under your knees if needed. The bed moves through a short, open ring while your upper back is scanned. The radiographer controls the scanner from the next room, but can see, hear and talk to you throughout. The scan itself takes only a few minutes. Contrast dye is not usually needed; where contrast is needed, it is charged separately.
Is CT safe?
CT uses X-rays, which are a type of ionising radiation. A thoracic spine CT covers part of the chest, so the dose is usually lower than for a full chest CT (about 8 mSv). The breasts are in the scan area, so the scan is only done when it is likely to help. The risk from a single scan is very small, and every CT scan is checked by a radiologist or radiographer to make sure the benefit of the scan outweighs the risk, as required by the Ionising Radiation (Medical Exposure) Regulations. If you have had other CT scans recently, tell us when you book.
What the scan can show
A CT scan of the thoracic spine can help to look at:
- fractures, including osteoporotic collapse
- fracture stability and healing
- calcified discs and ligaments
- bony narrowing of the spinal canal
- screws and rods after spinal surgery
- kyphosis and bone lumps
When to get urgent help: call 999 or go to A&E if you have back pain after a fall or accident, new weakness or numbness in your legs, difficulty walking, or new problems controlling your bladder or bowel. If you have had cancer and develop new upper back pain, contact your cancer team straight away. Do not wait for a private scan.
Preparing for your scan
No special preparation is needed, and you can eat and drink normally. If lying flat is painful, you may want to take your usual painkillers before your appointment. Upload any previous X-ray, MRI or scan reports and letters from your surgeon when you book.
Wear loose, comfortable clothing without metal zips, poppers or buttons, and leave jewellery at home, as metal in the scan area can affect the pictures. You may be asked to change into a gown. Unlike MRI, CT is not affected by pacemakers or most metal implants, and the scanner is a short open ring rather than a tunnel, so it is usually easier for people who feel anxious in enclosed spaces.
Tell the team before your scan if you are, or might be, pregnant or breastfeeding, if you have kidney problems, diabetes (especially if you take metformin), asthma, thyroid problems or allergies, or if you have had a reaction to contrast dye before. If you need contrast, you may be asked for a recent kidney blood test result.
Frequently asked questions
Should I have a CT or MRI of my upper back?
For most symptoms, including trapped nerves and spinal cord problems, MRI is better and does not use radiation. CT is better for the bones, such as fractures and checking spinal surgery. Your referrer will say which is needed; if you are unsure, contact us before booking.
Can a CT show an osteoporotic fracture?
Yes. CT shows the shape of the vertebrae clearly, including collapse caused by osteoporosis. MRI can show whether a fracture is new or old, so sometimes both are used.
I have metalwork in my spine. Can I have a CT?
Yes. CT is often used after spinal surgery to check screws and rods. Tell us about any implants when you book.
Do I need a referral?
Because CT uses radiation, each scan has to be justified by a qualified professional before it can go ahead. Upload a referral from your GP or consultant when you book if you have one. If you do not, select “no referral” and the scanning centre will review your request and confirm the next steps with you, which may include arranging a referral.
Sources
- NICE NG41 – Spinal injury: assessment and initial management
- Thoracic disc herniations: diagnosis, surgical techniques, and complication insights (PMC)
- NHS – Osteoporosis
- NHS – Kyphosis
- RadiologyInfo.org – CT of the Spine
- NHS – CT scan
- UKHSA – Patient dose information: guidance
The information on this page has been gathered from various sources and is provided for general information only. It is not medical advice. TOP MRI is not liable for the accuracy or completeness of this information. Please speak to your doctor or the scanning centre about your own situation.