Advice after your nerve block for surgery
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Introduction
We have given you this factsheet because you have an appointment for an MRI arthrogram scan. Please make sure you read this information and follow the instructions carefully before your procedure. If you have any further questions, please speak to a member of your healthcare team who will be able to advise you.
The Procedure
Magnetic Resonance Imaging (MRI) is an examination using strong magnetic field and radio waves by lying on a flat table inside a scanner (a large, hollow tube open at both ends) that produces detailed cross-sectional images of your body. These images are cross-sectional (like slices) and are used to produce detailed 2D and 3D images of the organs and other internal structures inside of your body and helps us make a diagnosis or monitor your treatment. Unlike X-rays and CT (computed tomography) scans, MRI scans do not use radiation. It is a safe, painless technique with no known risks, provided the safety questionnaire is correctly completed.
Prior to the procedure, some contrast media (a special dye containing a magnetic metal in solution) will be injected into the joint and this will help to visualise the internal structure of the joint. These are done in the radiology department by a Radiologist (doctor specialising in medical imaging) by guiding a needle into the body under ultrasound and fluoroscopic control.
What is Fluoroscopy?
Fluoroscopy is a process that uses X-rays to produce a real time moving image on a
television monitor.
What is Ultrasound?
An ultrasound scan is an examination that uses sound waves to take pictures of the part of the body being examined. It does not involve X-rays.
Before your appointment
Due to the strong magnetic field used by the scanner, people with certain types of medical implants or devices may not be able to be scanned. Some examples: people fitted with a pacemaker, some types of head surgery, certain metal implants or if there has ever been any injury to the eyes involving metal fragments.
Please review the MRI safety questionnaire enclosed in this letter and fill this in before your appointment. This can be completed on paper and should be brought to the appointment.
Where indicated this can also be completed online.
If you answer yes to any of the questions, please call the department.
Please also let us know if:
- you normally require the Vascular Access Team for injections
- you have limited mobility and will require assistance to get on and off the scanner.
- you will need an interpreter. We are not able to use family members or friends to interpret.
- there is any possibility that you may be pregnant. All patients from 12-55 years of age (regardless of gender) who will undergo a Radiology procedure will be asked about the possibility of them being pregnant.
- you are severely claustrophobic as we can contact your referrer who may prescribe medication to help you relax. Please await our further instructions for when to take the medication on the day of scan and you will be unable to drive following the procedure. We cannot prescribe this medication for you in the MRI department.
In order to make your appointment run more smoothly, please let us know if any of these apply, in advance, by calling our bookings team (contact details are displayed on the main Radiology page).
On Arrival
Please arrive 10 minutes before your initial scan time. You will need to go to the radiology department first for the contrast injection and will then be directed to the MRI scanner for the rest of the examination.
On arrival in the radiology department you should check in at the reception desk. Bring this letter with you and be prepared to confirm your details with the receptionist. You may eat and drink normally prior to the examination
What to wear
You will not be able to wear anything inside the MRI scanner room that contains any metal.
This includes zips, metal buttons, poppers or metallic print. Please wear suitable clothes to your appointment or bring them with you to change into. If required, we will provide you a hospital gown. Some makeup products also contain metal particles and should be avoided.
The procedure
- After positioning on an examination couch, the area being examined will be exposed you will have have an ultrasound or fluoroscopy to identify the access route into a joint.
- After sterilising the area, where appropriate your skin will be numbed with local anaesthetic. When the local anaesthetic is injected, it will sting to start with, but this soon wears off, and the skin and deeper tissues should then feel numb. The ultrasound or x-rays will be used to guide a needle to the correct position and the contrast will be injected. You will then be transferred to the MRI department.
- You may be asked to change into a hospital gown or your own clothing without metal components. We will provide a locker in which you can store your metal items, watches, credit cards etc. But these may be best left at home, as the Trust cannot accept responsibility for any lost or stolen items.
- We will ask you a series of questions to make sure the scan is safe and can then go ahead.
- When you are ready a Radiographer will call you through into the scan room and ask you to lie down on the MRI scanner table. We will use pads, cushions and supports to help make you more comfortable for the scan. It is important to be as comfortable as possible from the beginning to help you keep still throughout. A ‘receiving device’ like an aerial, may be placed behind or around the part of the body being examined. This detects the tiny radio signals emitted from the body during the scan.
- The MRI scanner will make very loud and unusual noises whilst taking your pictures.
Earphones and/or earplugs will be given, and you can listen to music while you are being scanned – you can bring a CD of your choice. - The radiographers will be in the MRI control room but you will be able to talk to them via an intercom, and they will be watching you all the time. You will also be given a buzzer to press if you need to attract our attention during your scan.
- During the scan you may experience tingling in your hands and feet and may feel an increase in body temperature. These are normal sensations.
- The scan itself can take between 15 - 45 minutes.
After the Examination
You will be free to resume your normal daily activities
The Results
The results of your scan will not be given to you immediately after the scan. The images are interpreted by a Radiologist (doctor specializing in medical imaging) and sent back to your Consultant or GP who referred you for the scan. The result will be sent to your referring Doctor. This can take up to 4 weeks.
Are there any risks?
Occasionally, unpredictable allergic reactions (such as a rash) might occur following the contrast dye injection. These effects are usually mild and of short duration but this is why we ask you to stay in the department for 15-30 minutes after the scan. If, however, they become more severe medical treatment is necessary. Staff in the Radiology Department are trained to deal with any complications and again the risk involved is very small. It is possible that an reaction can occur up to a week after, if you develop itching or a skin rash you should contact your GP or the A&E Department at the hospital.
If your injection is performed under X-ray guidance then this uses ionising radiation. We are all exposed to natural background radiation every day from the sun, food we eat, and the ground. Exposure to medical X-rays carries a small additional risk, but your doctor feels that this risk is outweighed by the benefits of having the procedure and the amount of radiation you will receive is kept to as low as reasonably possible
Contact us
If you have any queries relating to this information, please contact the Radiology service.
About this information
Service:
Radiology
Reference:
PILS-MRI.3
Approval date:
3 October 2024
Review date:
3 October 2027
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Important note
This page provides general information only. It is developed by clinical staff and is reviewed regularly every 3 years for accuracy. For personal advice about your health, or if you have any concerns, please speak to your doctor.