Dynamic CT Myelograms

You are receiving this because the doctor you have seen has sent you for a special X ray test called a Dynamic CT Myelogram. The reasons for this should have been explained to you by the doctor who has requested the test but will be discussed again on the day of the test.

What is a Dynamic CT Myelogram ?

This is a specialist procedure to look at the spine. It is used in patients suspected of having a spinal fluid leak and to help identify its location. A CT scan is performed immediately upon injection of a dye (contrast) into the spinal canal by lumbar puncture, to make the spinal fluid visible and demonstrate any leakage.

Preparation

• There are no special preparations before the procedure.
• If you are on a medication to thin your blood the person who phoned you to arrange your appointment will have discussed this. These drugs include
  • Clopidogrel (Plavix)
  • Ticlopidine (Ticlid)
  • Warfarin (Coumadin)
  • Rivaroxaban (Xarelto)
  • Dabigatran (Pradaxa)
  • Apixiban (Eliquis)
• Please note that the above list may not be complete. You may be told to stop taking a blood thinning medication before the test.
• You should take all other medication as normal. It is sensible to have a light breakfast and is advisable to drink more fluids than usual in the 12 hours before the examination to reduce the risk of headache.
• This is an X ray technique and uses radiation to obtain the images, you should not have this test if you are (or could be) pregnant.
• Please let us know if you have any history of allergy, particularly related to iodine /iodine containing agents.
• Please also let us know if you have any kidney disease.

What happens

• You will be given a bed or chair, usually on Jefferson ward and one of the nurses will check you in, this includes checking blood pressure etc. If you have been on a medication called warfarin a blood sample may be taken to check your blood clotting.
• A doctor from the Radiology team will come to see you on the ward. They will go through the reason for doing the test, explain what the test involves, inform you of any possible side effects or complications (see below) and answer any questions you may have. If you are happy to go ahead with the test you will be asked to sign a consent form, you can keep a copy of this if you wish.
• If you would rather not get changed into a surgical gown you need to bring with you clothes that have no metal on them (zips etc.) and allow access to your lower back. Pyjamas or “sports” clothes are ideal.
• You will be brought to the Radiology department and asked to lie on your side on the CT scan table with your knees slightly bent. Support under your pelvis will allow your head to be positioned at a lower level than your pelvis.
• It is important to lie very still throughout the procedure and follow the instructions provided by the radiology team.
• A lumbar puncture is then performed. This involves injection of local anaesthetic under the skin and into the underlying soft tissues the lumbar region ( lower back), followed by insertion of the tip of a long fine needle into the spinal canal. This is done under intermittent CT scanning to guide the needle safely into the spinal canal. The pressure of the spinal fluid is then measured and a small amount of the fluid may be collected for laboratory analysis.
• Dye is then injected through the needle into the spinal canal. This can give a “hot” or pressure sensation in the upper part of the leg or the side of the bottom.
• A CT scan is performed immediately upon injection of the dye.
• You will then be asked to change position on the CT scan table with assistance so that more dye is injected and a CT scan can be repeated in the new position.
• Your position may have to be changed a few times as scans may have to be performed in different positions to identify the exact site of leak.
• This test takes approximately 1 hour.

Side effects

• Most patients have no side effects during this procedure, the lumbar puncture is however a little uncomfortable. Afterwards some patients can develop a headache. This doesn’t usually last more than 2 or 3 days. Simple pain killers such as paracetamol can be taken and caffeine is said to help. The most important thing is to drink plenty of fluids.
• Persisting headache is unusual but does happen and may require further treatment.
• This is an X ray investigation and uses “ionising radiation” which means that you will get a dose of radiation.

Potential Complications

These are extremely rare and may include:

• Nerve damage
• Meningitis
• Infection in the spine that can damage the nerves causing paralysis
• Blood clot within the spine that can press on the nerves and cause paralysis.
• Allergic and non-allergic hypersensitivity reaction to dye. Very rare and usually causing mild symptoms like nausea  mild itching and rash. More severe symptoms involving lungs (causing wheezing) and heart are extremely rare. 

Aftercare

Following the procedure we generally advise you to sit up for the next few hours, this helps to stop too much dye entering your head causing a headache. Usually you can go home an hour or so after the test; the nurses will check on you and then let you go. We suggest that you do not drive yourself home after the test.

You should try and drink more fluids than usual for the next 24-48 hrs.

Results

These will be sent to the doctor who referred you for the procedure. If you have not heard from the hospital within 3-4 weeks then please call the secretary to the consultant you are under by contacting the hospital switchboard on 0151-529-3611

Should you need any further medical help after returning home please call NHS Direct / your GP/emergency dept. of your local hospital.

Access

This letter can be translated into another language or produced in another format such as Braille or audio. To find out more please contact the Patient Experience Team on 0151 556 3090.