An MRI scan produces a high quality picture of the tissues of the body and, unlike an X-Ray or CT, it does not expose you to radiation as it uses a magnetic field.
An MRI examination of the spine shows the structures that make up the spine including the bony vertebrae, the disks, the ligaments that hold the vertebrae together as well the neural structures (spinal cord and the nerves) and the exit holes (foraminae) through which nerves pass out from the spine..
You will need to remove all jewellery and any other metal, and will usually be asked to undress and wear a gown. Very occasionally, a contrast dye will need to used, which is administered intravenously through a small cannula in your hand or arm. This contrast is called gadolinium, and will be flushed out naturally after the scan.
Some people cannot have an MRI scan. Common reasons include if you have a pacemaker fitted or have metal clips or shards in the brain or eyes. You will be asked to complete a questionnaire before your scan to see if it is safe for you. If you have any doubts please speak to the MRI staff before your scan.
You will be positioned on the table. Sometimes supports are used to hold you in the right position and to reduce movement. The table will then move into the scanner which is like a tunnel. If you do suffer with claustrophobia, please speak to the staff or to the radiographers about this before your scan: They will then take extra time to guide you through each step.
You will need to stay very still throughout the procedure which can take between 20 and 60 minutes depending on which levels of your spine are being viewed. The scanner is quite noisy so ear plugs or music are provided.
All images are viewed by Mr Cass and reported by an experienced consultant radiologist.
Computerised Tomography (CT) scanning give very detailed cross section images and three dimensional images of the vertebrae. It can also be used to look at soft tissues & blood vessels.
Whilst CT is not as good at looking at the discs & nerves, sometimes it has to be used if you are unable to have an MRI for any reason.
During the scan you will be asked to lie on a table, this table moves backwards and forwards in and out of the polo-shaped scanner which rotates around your body as you pass through it. This does not surround your whole body at once so you should not feel claustrophobic.
The radiographer will be in the next room whilst the scan is taking place, and you can communicate easily via a microphone.
The scan will usually take up to 10 minutes.
In some cases a “contrast dye” will need to be used to give a more enhanced picture of the spine and surrounding tissues. This is usually done intravenously through a small cannula in your arm,which is inserted before the scan. Some people report noticing a “warm, flushing sensation” when the dye is first administered, this only lasts for a moment. This dye is iodine based and is harmless to the body and will be flushed out naturally. Once the scan is completed the cannula will be removed.
CT scans also use X-Ray radiation.
The images will be viewed by Mr Cass and reported by an experienced consultant radiologist.
Single Photon Emission Computed Tomography or SPECT Scan is a sensitive diagnostic test that demonstrates excess bone activity (a sign of stress in the bone) superimposed over images of the vertebra, discs, facet joint and sacro-iliac joint.
It can provide valuable information about where inflammation & pain in the spine may be coming from.
A small cannula will be inserted into your arm and a small amount of radioactive dye will be injected intravenously prior to the scan.
It is a relatively new & specialised study which is only done in a few specialist units. You may be asked to go to London for the scan, though hopefully local centres will be offering it soon.
During the scan you will lie on a table which moves backwards and forwards in and out of the large, ring scanner, as in the CT scan detailed above. It is extremely important that you lie completely still throughout. This may take between 20 and 40 minutes to complete.
The dye will be flushed out of your body naturally, although you may be advised to drink plenty of fluids to assist with this.
Again these images will be viewed by Mr Cass and reported by an experienced consultant radiologist.
Neurophysiological tests are used to assess the function of the nervous system. They measure the electrical signals through the nerves and the response in the muscles. The most common tests used on patients with suspected spinal conditions are nerve conduction studies (NCS) and electromyography (EMG).
NCS measure how quickly a nerve impulse travels from one point to another along the nerve. The aim is to measure the speed and effectiveness of nerves in the arms and legs in sending messages to the muscles. This signal will be altered if the nerve is damaged, diseased or trapped.
During the study a small electrode will be attached to the skin and then another electrode is used to stimulate the skin. This produces small, electrical pulses which can be described as a sharp tap sensation. This is then repeated on different nerves. it shouldn't cause pain but some people may find it a little uncomfortable.
EMG records the electrical activity of the muscles. It involve inserting a small needle into the muscle, sometimes you will be asked to contract the muscle, this allows the clinician to view and listen to the electrical activity generated in the muscle. There may be a small amount of discomfort when the needle is inserted, although as a tiny needle is used it shouldn't be too uncomfortable. As with all needles, there may be some minor bruising and it may feel a little sore.
Blood tests may sometimes be requested to assist with diagnosing some conditions, such as inflammation, infection or metabolic conditions.
An X-Ray provides an image mainly of bony structures & joints, including the spine.
X-rays are rarely used for diagnosis in spinal conditions these days, having largely been superseded by MRI and CT. Some exceptions exist including looking at whether you have an unusual curve of your spine (e.g. scoliosis or kyphosis) or if you have a mal-alignment of the vertebrae.
X-rays are more commonly used following some surgeries such as a fusion or disc replacement.
You are exposed to a low dose of radiation when having an X-Ray.