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Radiology (Xray)

CT Scan & Nerve Root Injection

CT Appointments - RVI: (0191) 282 4330; Freeman Hospital: (0191) 223 1012

IntroductionShow [+]Hide [-]

We have received a request from your referring doctor for you to have a CT scan and Nerve Root Injection.  This leaflet is designed to give you some information about the CT scanner, to help you prepare for your scan and to give you some idea of what to expect when you attend.



What is a C.T. Scan?Show [+]Hide [-]

C.T. stands for Computerized Tomography and is a special type of x-ray that can look at various parts of the body including the brain, spine, chest, abdomen and pelvis.


The information from the x-rays is recorded in a series of cross sectional pictures or scans that can be built up into a three dimensional image of the area being examined.  A C.T. scan machine is also used to accurately position a needle for a targeted injection.



What is a Nerve Root Injection?Show [+]Hide [-]

A Nerve Root Injection is an injection of local anaesthetic and steroid around a nerve leaving the spine, to reduce pain and inflammation.



What if I cannot attend my appointment?Show [+]Hide [-]

If your appointment time is not convenient it is essential you contact the hospital department that you are attending immediately, (see contact details above) so that a more appropriate time can be arranged.  This will enable us to reallocate valuable scanning time to someone else.



What preparation will I need?Show [+]Hide [-]

Usually none.  Printed instructions will be given to you with your appointment information if any preparation is required.



I am a Diabetic. Does this change anything?Show [+]Hide [-]

Yes.  The preparation may change.  Please ring the department on Tel: (0191) 223 1012 and speak to a member of the medical staff, who will be able to advise you. (see next question also).



I take Metformin (Glucophage, Avandamet) Tablets. Does this change anything?Show [+]Hide [-]

Yes - Metformin (Glucophage, Avandamet) is most commonly taken by diabetic patients to control blood sugar, but occasionally is taken for other conditions.


If you are taking Metformin, your preparation for the procedure may change.  Please ring the department on the above telephone number (see contact details.) and speak to a member of staff, who will be able to advise you. 



What does the procedure involve?Show [+]Hide [-]

On arrival you will be asked to undress and put on a gown.  The Radiologist will explain the procedure.  You will be asked to lie on your tummy on a couch which enters a fairly wide, short tunnel, the C.T. scanner, where the X-rays are produced.  The doctor who arranged for you to have this examination has asked the Radiologist to give an injection of local anaesthetic and steroid medication in this test.  The Radiologist will explain how the injection will be performed and answer any questions you have about the injection at this time.  If you have concerns regarding the injection before the test, please contact the doctor who saw you in clinic who will be able to discuss the injection further with you.


Once the CT scan has been performed, the Radiologist will decide where to position the needle.  The skin over the area will be cleaned with a sterilising solution and local anaesthetic (see next section) injected into the skin to numb it.  The main needle will then be positioned and several small scans will be performed as the needle reaches the appropriate site next to the nerve thought to be causing your pain.  Once the needle is in the correct position, the injection of steroid and local anaesthetic will be given.  You may be aware of a numb or tingling feeling in the leg at this time.  The needle will then be removed and you may go home.  Before you leave you will be given a ‘Root Block’ form to record any change in your symptoms over the next day or so.  The Radiologist will explain how you are to complete this form before you leave.



Local AnaestheticShow [+]Hide [-]

  • Your radiologist will ask you to keep quite still while the injection is given.
  • You may notice a warm tingling feeling as the anaesthetic begins to take effect.
  • Your procedure will only go ahead when you and your radiologist are sure that the area is numb.
  • If you are not having sedation, you will remain alert and aware of your surroundings.
  • Your radiologist is always near to you and you can speak to him/her whenever you want to.


Who does the scan?Show [+]Hide [-]

The person who carries out the scan is called a Radiographer.  The injection will be performed be a doctor (Radiologist). It is important that you lie still while the pictures are being taken and the needle inserted.



How long will it take?Show [+]Hide [-]

The examination will take around 30 minutes.


Are there any side effects?Show [+]Hide [-]

The Radiologist will explain any potential side effects due to the injection.   Occasionally the leg can feel a little weak briefly after the injection.



What if I am pregnant?Show [+]Hide [-]

CT scanning of pregnant women should be avoided whenever possible.

If you think you may be pregnant it is very important that you tell the nurse or radiographer before your scan.  To avoid accidental irradiation, all females between the ages of 11 and 55 years are asked the date of their last menstrual period (LMP).  From this information X-ray staff will decide if there is cause for the CT examination to be postponed or if it is safe to continue.



Is a CT Scan dangerous?Show [+]Hide [-]

Like all X-ray machines, a CT scanner produces potentially harmful X-rays.  Modern equipment is designed to keep the dose to patients as low as possible.  If your doctor has asked for a scan, then he or she will have decided that the benefit of having the information that the scan gives, is greater than the risk of the small dose of radiation.  Since X-rays can harm unborn babies, if you are, or could be pregnant, please tell the radiographer or nurse before you have the scan.  This is very important.



What about the results?Show [+]Hide [-]

Once you have returned your ‘Root Block’ form, the Radiologist will send a report to the doctor who requested this examination.  You should make an appointment to see this doctor approximately two weeks after the test to discuss the results.


If you are undergoing planned investigations on a ward the results will be sent to the ward as soon as possible.  The doctors on the ward may be able to discuss the findings with you.



Can I drive home?Show [+]Hide [-]

We advise that you do not drive home immediately after an injection.  You should arrange alternative transport.



What if I need an ambulance. Do you arrange this?Show [+]Hide [-]

If you need an ambulance, you must ask your G.P’s surgery to arrange one, but you will need to give them three working days notice. However, it would be helpful if you could inform the department if you are arriving by ambulance as we will arrange your appointment time to fit with ambulance arrivals.



What if I have any comments, suggestions or questions?Show [+]Hide [-]

Should you have any suggestions or concerns, please make these known to the person conducting your examination, or by letter addressed to:


Freeman Hospital


The Departmental Manager 

Main Xray Department

Freeman Hospital

High Heaton

Newcastle upon Tyne  NE7 7DN


Tel: (0191) 282 1099


Royal Victoria Infirmary

The Departmental Manager

Xray Department, Level 3

Royal Victoria Infirmary

Queen Victoria Road

Newcastle upon Tyne



Tel: (0191) 282 1099


(Monday – Friday: 9.00am – 5.00pm)


All Newcastle Hospitals: Switchboard Tel: (0191) 233 6161


If you need to turn to someone for on-the-spot help, advice and support, please contact the Patient Advice and Liaison Service (PALS) on:


Freephone: 0800 032 02 02

Map details: Due to the transformations of the Newcastle Hospitals, please go to the 'Patient and Visitor Guides' to check for updates or alternatively, see local map details on how to get to the target="ioMain">Freeman Hospital.

All patient information is available in large print size for people with visual impairments or partial vision.  Please click on the link above, 'large print size' to view and print the document or alternatively, please click on the large 'A' at the top of the screen to read this information on-line.

Produced by: Dr G Hide, Clinical Directorate of Radiology

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