Computed Tomography (CT) scans use x-rays to give detailed cross sectional images of soft tissue, blood vessels and bone. CT is commonly used at NHNN to diagnose many diseases and injuries including acute stroke and intracranial bleeds, neurovascular diseases, hydrocephalus (swelling of the CSF spaces in the brain), spinal diseases and injuries. The CT department at NHNN also provide a CT guided steroid injection service to spinal patients who are suffering from chronic pain and/or associated numbness. This is a procedure where the radiologist will inject a mixture of steroid and local anaesthetic into, or around, a joint or nerve root in the affected area of the spine.
Please read your appointment letter for guidance on arrival time and eating and drinking before your scan.
Before your scan the radiographer may ask you to change into a hospital gown, where necessary. Please feel free to bring your own dressing gown or metal-free clothing with you.
The radiographer will verbally confirm if you are happy to proceed with your scan. If you do not wish to have the scan or are undecided, please inform the radiographer.
Please contact Neuroradiology before your appointment if any of the following apply:
- You have diabetes mellitus, or take metformin as a blood test to check renal (kidney) function is sometimes required before your appointment
- You have a history of thyroid problems
- You are expecting to undergo radioisotope scanning of your thyroid
- You have a history of renal problems
- You have a known allergy/previous reaction to iodine-based contrast
- There is any possibility of pregnancy
- You require an interpreter.
The length of the scan will vary depending on the area of the body to be examined; this should take no longer than 20 minutes. You will be asked to lie on a couch and keep as still as possible. You may also be asked to follow breathing instructions during your scan, depending on the area being examined.
During a CT scan it is sometimes necessary to give you an injection of iodine-based contrast (a type of dye that highlights blood vessels and other structures in the body) to provide more detail and information to your referring clinician. This contrast injection will be administered by a radiographer through a cannula (small plastic tube), usually placed in a vein in your arm. You may experience a warm feeling all over your body during the contrast injection but this will pass very quickly.
The use of x-rays during the scan presents a very small risk. Our state-of-the-art imaging equipment and modern techniques ensure the radiation dose is as low as possible. In addition, your referring doctor or nurse will have made a judgement about your risk and benefit.
Patients of child-bearing capacity between the ages of 12 and 55 years are required by law to be asked about possible pregnancy when undergoing examinations involving x-ray. Patients who either are, or think they may be, pregnant must inform the Neuroradiology department as soon as possible. In some urgent cases the scan may still go ahead but with additional precautions in place. If your scan requires contrast we can provide you with up-to-date guidance on your breastfeeding.
During your scan you may require a contrast agent. Contrast agents are safe drugs; however as with all drugs, they have the potential to cause an allergic reaction. The department and staff are fully equipped to deal with reactions in the rare event of this happening.
Following your scan you will be able to go home. You can eat, drink and resume your normal activities straight away. If you had a contrast injection, you may be required to remain in the waiting room for up to 30 minutes; following this your cannula will be removed. You may be advised to gently increase your fluids for the rest of the day.
Your scans will be reported by a neuroradiologist and your results will be sent back to your referring clinician, available for your next scheduled consultation.