MRI of the Pelvis
This information is intended for those considering having a pelvic MRI scan. The purpose of the information is to explain what an MRI scan is, why and how it is carried out and whether there are any risks involved.
What is an MRI scan?
MRI stands for magnetic resonance imaging. It uses a strong magnetic field and radio waves to create pictures of tissues, organs and other structures inside the body on a computer. The images are detailed and can detect diseases at an earlier stage including some disorders that are difficult to see. It does not use x-rays. A radiographer carries out the scan and a radiologist looks at the images and reports the results. The images can be sent electronically, printed or copied to a CD.
In imaging of the pelvis, an MRI can be used to detect tumours and cysts of the pelvis, urinary tract, diseases of the small intestine as well as causes of pelvic pain in women such as fibroids, endometriosis, adenomyosis and other abnormalities of the reproductive organs. (Bazot 2004,Byrne 2006,Caramella 2008, Chamie 2009 and 2011, Chassang 2011, Parker 2011 )
Preparation for an MRI scan
People with certain types of medical implant cannot be scanned. You should inform your doctor and the MRI department about any electronic or metal implant/fragment in your body. Examples of these are implanted defibrillators, pacemakers, nerve stimulators, stents, programmable hydrocephalus’s shunt, surgical staples or cochlear (ear) implants.
If you are taking medication you should continue to do so unless you are advised not to by your doctor. You may continue to eat and drink normally unless you have been told otherwise.
You will be shown to a cubicle, given a gown to wear and asked to undress down to your underwear. You should not wear jewellery (except a wedding ring) , hairpieces, hair slides, hair grips or body piercings as these could spoil the images and could cause you injury.
What does an MRI scan involve?
Before the scan a radiographer will explain what they are going to do. You will be able to talk to the radiographer during the scan. You may need to have a partially full bladder.
Sometimes an injection may be needed. (Buscopan and/or Gadolinium) This is given into a vein into the arm and helps to clarify the scan.
The MRI scanner is in the shape of a tunnel. It is surrounded by a circular magnet. You cannot feel the magnetic field. You lie on a table which moves in and out of the machine. A device called a coil is placed over the part of the body being scanned. This device detects radio signals from the body.
Patient being positioned for a pelvic MR scan:
During a scan of the pelvis most of your body is in the tunnel. It is necessary to lie flat and to keep still while the pictures are being taken otherwise they can be blurred. This takes around 20 -30 minutes. It takes 3-5 minutes at a time to obtain a sequence of images. If you are in pain beforehand or you are claustrophobic you should talk to the doctor who has sent you. It may be possible to prescribe something to help you with this. During the scan you can talk to the radiographer who observes at all times on a monitor close to the scanner. The scanner is noisy. You will be given headphones or earplugs to reduce the noise. Sometimes you can listen to the radio, a CD or MP3 player.
Are there any limitations or possible complications?
MRI scans are painless and thought to be safe. However pregnant women are usually advised not to have an MRI scan unless it is urgent. This is because long-term effects of strong magnetic fields on a developing baby are not known.
A person who is very large may not fit into the opening of a conventional MRI machine.
There are no after-effects from the scan and you can return to your normal activities as soon as the scan is over.
Sagittal MRI scan of a normal female pelvis: