Nerve blocks at Cambridge Hospital

What is a Computed Tomography (CT) Guided Nerve Block?

A CT scan produces a series of images of an area of your body using X-rays (radiation). These images are then used to guide the Consultant Radiologist or Anaesthetist in delivering the injection of local anaesthetic and steroid to an exact area in your body. Images will be taken before, during and after the injection is given. A nerve root injection is a diagnostic and therapeutic injection, where a local anaesthetic and steroid are injected around the nerve which is thought to be causing your pain.

Before your procedure

You will be collected from the radiology waiting area near to the time of your procedure and a pre-procedure check will take place, you may be asked to change into a gown and to remove your jewellery. The Consultant Radiologist will explain the procedure and gain your consent outlining any risks involved before the procedure begins you will be able to ask any questions at this point.

What will the procedure involve?

You will be instructed to lie on the scan table and a sticky grid is placed over the injection area and some planning scans are taken, you will lie still as the table passes in and out of the scanner. Once the planning scans are done your consultant will review these and decide on the exact location for the injection. An accurate mark will be made on your back with a marker demonstrating the site of the injection. Your skin will be cleaned with an antiseptic solution and this may feel cold on your skin.

Some local anaesthetic will be injected first to numb the area before the main injection, this may cause a bee sting-like feeling. Once the area is numb the combined injection of local anaesthetic and steroid will be injected. This may feel a bit uncomfortable but shouldn’t be painful. Some patients experience a shooting nerve type pain if having a nerve root block. This is due to the closeness of the injection to the nerve. A final scan is performed after the injection and a sterile dressing is applied to the injection site.

After the scan

You will be assisted off the CT scan table by one of the CT team, once the post-procedure checks are complete and normal, you will be able to go home. Some people may feel weakness in their limb(s) following the injection. This can sometimes take 24 hours to resolve but is normal. If you do have limb weakness you will be assessed before leaving the department. It is normal to experience some pain at the site of injection and pain relief can be taken to relieve this.