A head MRI (magnetic resonance imaging) is an imaging test that uses powerful magnets and radio waves to produce pictures of the brain and surrounding nerve tissues.
Other names use to describe MRI brain scan are:
- Nuclear magnetic resonance – cranial;
- Magnetic resonance imaging – cranial;
- MRI of the head;
- MRI – cranial; NMR – cranial;
- Cranial MRI;
- Brain MRI;
- MRI – brain;
- MRI – head.
It does not use radiation.
How a Brain MRI Test is Performed
Head MRI is done in the healthcare facility or radiology center.
You lie on a narrow table, which moves into a big tunnel-shaped scanner.
Some MRI exams require an unique dye, called contrast material. The dye is usually provided before the test through a vein (IV) in your hand or lower arm. The dye helps the radiologist see particular areas more plainly.
During the MRI, the individual who runs the maker enjoys you from another room. The test usually lasts 30 to 60 minutes, but may take longer.
How to Prepare for the Test
You might be asked not to eat or drink anything for 4 to 6 hours prior to the scan.
Inform your healthcare supplier if you are afraid of close spaces (have claustrophobia). You may get medicine to help you feel drowsy and less nervous. Or your provider might recommend an “open” MRI, in which the machine is not as close to the body.
You may be asked to use a medical facility gown or clothing without metal ties (such as sweatpants and a tee shirt). Particular types of metal can cause fuzzy images.
Prior to the test, inform your service provider if you have:
- Brain aneurysm clips
- A synthetic heart valves
- Heart defibrillator or pacemaker
- Inner ear (cochlear) implants
- Kidney disease or dialysis (you might not be able to receive contrast).
- Recently placed artificial joint.
- A blood vessel stent.
- Dealt with sheet metal in the past (you may require tests to look for metal pieces in your eyes).
- Allergy to iodine, which is used in the contrast material.
The MRI contains strong magnets. Metal items are not permitted into the room with the MRI scanner. This consists of:
- Pens, pocketknives, and eyeglasses.
- Items such as jewelry, watches, charge card, and hearing aids.
- Pins, hairpins, metal zippers, and similar metallic products.
- Detachable dental work.
How a MRI Brain Scanning will Feel
An MRI test causes no pain. If you have trouble lying still or are very anxious, you might be provided a medication to relax. Too much movement can blur the images and cause mistakes.
The table might be difficult or cold, but you can ask for a blanket or pillow. The maker makes loud thumping and humming noises when switched on. You can request for ear plugs to help decrease the sound.
An intercom in the space enables you to speak with somebody at any time. Some MRIs have tvs and unique earphones that can help you kill time or obstruct the scanner noise.
There is no recovery time, unless you were provided a medication to relax. After an MRI scan, you can go back to your normal diet, activity, and medicines.
Why a Head MRI is Performed
An MRI supplies detailed images of the brain and nerve tissues.
A brain MRI can be used to diagnose and keep an eye on numerous diseases and conditions that affect the brain, consisting of:
- Birth defect.
- Bleeding (subarachnoid bleed or bleeding in the brain tissue itself).
- Family history of aneurysms.
- Infection, such as brain abscess.
- Tumors (cancerous and noncancerous).
- Hormone conditions (such as acromegaly, galactorrhea, and Cushing syndrome).
- Multiple sclerosis.
An MRI scan of the head can likewise determine the reason for:
- Muscle weak point or numbness and tingling.
- Changes in believing or behavior.
- Hearing loss.
- Headaches when specific other symptoms or signs exist.
- Speaking difficulties.
- Vision issues.
A special type of MRI called magnetic resonance angiography (MRA) might be done to take a look at blood vessels in the brain.
What Abnormal Results of Head MRI Mean
Abnormal outcomes might be due to:
- Infection of the skull bones (osteomyelitis).
- Fluid gathering around the brain (hydrocephalus).
- Structural problems in the brain.
- Several sclerosis.
- Damage to the brain from an injury.
- Loss of brain tissue.
- Brain infection.
- Brain tissue swelling.
- Abnormal capillary in the brain (arteriovenous malformations of the head).
- Brain tumors.
- Bleeding in the brain.
- Bulging of the blood vessel in the brain (aneurysm).
- Stroke or short-term ischemic attack (TIA).
- Growth of the nerve that links the ear to the brain (acoustic neuroma).
Is Brain MRI Scan Dangerous?
MRI uses no radiation. To this day, no side effects from the electromagnetic fields and radio waves have actually been reported.
The most common kind of contrast (color) used is gadolinium. It is very safe. Allergies to the compound seldom happen. However, gadolinium can be hazardous to people with kidney problems who are on dialysis. If you have kidney issues, inform your supplier before the test.
The strong magnetic fields developed during an MRI can make heart pacemakers and other implants not work too. It can also cause a piece of metal inside your body to move or shift.
Factors to consider
MRI is used more often than CT scan. This is due to the fact that it can easily discover problems in the soft tissue. Likewise, it is safe during pregnancy.
Tests that might be done rather of an MRI of the head include:
- Head CT scan.
- Positron emission tomography (PET) scan of the brain.
A CT scan may be preferred in the following cases, because it is faster and normally offered right in the emergency clinic:
- Acute injury of the head and face.
- Bleeding in the brain (within the first 24 to 48 hours).
- Early symptoms of stroke.
- Skull bone disorders and conditions including the bones of the ear.