19 Dec MRI scan – head
MRI scan – head
Alternative Names: Magnetic resonance imaging scan
An MRI (magnetic resonance imaging) scan of the head uses, not X-rays, but strong magnetic fields and radio waves to create detailed images of structural problems and abnormalities in the skull, brain, and other nearby structures (e.g. sinuses) — problems such as head injuries, headaches, nerve symptoms, and seizures or epilepsy. An MRI head scan helps doctors to diagnose e.g. stroke, brain tumours, bleeding around the brain (intracerebral haemorrhage), swelling of the brain (cerebral oedema), a brain abscess, or sinusitis. An MRI scanner is a tunnel-like machine in which you lie while it takes a series of detailed images. A special dye (contrast media), which contains iodine, may be injected into a vein in your arm to enhance the images; some people are allergic to this dye. Because of the strong magnetic fields of the MRI, people with pacemakers and other implants, such as cochlear implants and artificial heart valves, cannot be scanned.
What is it?
An MRI scan of the head is an imaging technique that uses a strong magnetic field, combined with radio waves, to create detailed images. MRI scans do not use X-Ray radiation.
An MRI scan is done in a radiology facility, usually located in a hospital. It takes about an hour (sometimes longer) to perform.
Why is it done?
An MRI scan is done to look for any structural problems in the skull, brain and other nearby structures (e.g. sinuses). There are many indications for doing a brain scan but some of the common ones include:
Investigating problems such as:
- Head injury
- Weakness or other neurological (nerve) symptoms
- Seizures and epilepsy
It is often done when considering diagnoses such as:
- Brain tumours
- Intracerebral haemorrhage (bleeding within or around the brain)
- Cerebral oedema (swelling of the brain)
- Brain abscess
- Sinusitis and other sinus problems
Before – how to prepare
You will need to sign a consent form but no other special preparations are needed. Any jewellery, or other metal objects, should be removed.
During – how the test is done
You will need to lie within the MRI scanner – you lie on a couch with the tunnel-like scanner around you. It is essential that you lie very still while the machine takes a sequence of images. The machine may be quite noisy, and some people feel a little claustrophobic inside the “tunnel” but there is no pain or discomfort involved at all.
A special dye, called contrast media, may be injected into a vein in your arm, to enhance the images.
After the test
The initial results should be available within an hour or so, but detailed analysis and interpretation of the images may take longer.
Risks and Compilations
For most people there are no major risks associated with MRI, but the strong magnetic fields involved mean that people with pacemakers, or other implants (e.g. cochlear implants, artificial heart valves) cannot be scanned.
Some people are allergic to the dye/contrast media, which usually contains iodine.
An MRI (magnetic resonance imaging) scan of the head uses, not X-rays, but strong magnetic fields and radio waves to create detailed images of structural problems and abnormalities in the skull, brain, and other nearby structures (e.g. sinuses) — problems such as head injuries, headaches, nerve symptoms, and seizures or epilepsy.
Magnetic resonance imaging scan, MRI, MRI scan, MRI head scan