Magnetic Resonance imaging (MRI) Head

Magnetic  resonance imaging (MRI)is a diagnostic test to take description of the body parts and give information more advance then x-ray, ultrasound and CT scan. For head mri they do with same mri machine with using a imaging test with powerful magnetic and radio waves to create the picture of the brain.

Mri procedure doesn’t use radiation, only lie of your head inside the machine scanner using strong magnet then it will show pathologic problem such as tissue damage, disease, infection, inflammation or tumor. In the same time the result can be store in the computer and film or CD can be made.

Maybe in some cases, injection of dye or contrast material need, to see detail pictures such as in vascular study.

Magnetic resonance imaging (MRI) of the head is done to:

Look for the cause of headaches.

MRI of head can help to find the source of headache, stroke or blood vessel problem in the head. It will show in the picture an aneurysm or abnormal blood vessels formation during birth its called an arteriovenous malformation. Check source of bleeding , head injury, brain diseases such as Huntington’s disease, multiple sclerosis, Parkinson’s disease, or Alzheimer’s disease. Check retention fluid in the brain called hydrocephaly, look for tumor, infection, an abscess, or figure conditions of the brain or brain stem, such as encephalitis or meningitis. Check the eyes, the nerves from the eyes of the brain (optic nerves), the ears, and the nerves from the ears of the brain (auditory nerves).

How the Test is Performed

You may be asked to wear a hospital gown or clothing without metal fasteners (such as sweatpants and a t-shirt). Certain types of metal can cause blurry images, and you will lie on a narrow table, which slides into a large tunnel-shaped scanner. Some exams require a special dye (contrast). The dye is usually given before the test through a vein (IV) in your hand or forearm. The dye helps the radiologist see certain areas more clearly. During the MRI, the person who operates the machine will watch you from another room. The test most often lasts 30 - 60 minutes, but it may take longer.

How to Prepare for the Test

You may be asked not to eat or drink anything for 4 - 6 hours before the scan. Tell your doctor if you are afraid of close spaces (have claustrophobia). You may receive medicine to help you feel sleepy and less anxious, or your doctor may suggest an "open" MRI, in which the machine is not as close to the body.

Before the test, tell your health care provider if you have:

Brain aneurysm clips

Certain types of artificial heart valves

Heart defibrillator or pacemaker

Inner ear (cochlear) implants

Kidney disease or dialysis (you may not be able to receive contrast)

Recently placed artificial joints

Certain types of vascular stents

Worked with sheet metal in the past (you may need tests to check for metal pieces in your eyes)

The MRI contains strong magnets. Metal objects are not allowed into the room with the MRI scanner. This includes:

Pens, pocketknives, and eyeglasses

Items such as jewelry, watches, credit cards, and hearing aids

Pins, hairpins, metal zippers, and similar metallic items

Removable dental work

How the Test Will Feel

An MRI exam causes no pain. If you have difficulty lying still or are very nervous, you may be given a medicine to relax you. Too much movement can blur MRI images and cause errors. The table may be hard or cold, but you can request a blanket or pillow. The machine produces loud thumping and humming noises when turned on. You can wear ear plugs to help reduce the noise. An intercom in the room allows you to speak to someone at any time. Some MRIs have televisions and special headphones that you can help you pass the time or block the scanner noise. There is no recovery time, unless you were given a medicine to relax. After an MRI scan, you can go back to your normal diet, activity, and medications.

Why the Test is Performed

MRI provides detailed pictures of the brain and nerve tissues.

A brain MRI can be used to diagnose and monitor many diseases and disorders that affect the brain, including:

Birth defect of the brain

Bleeding in the brain (subarachnoid or intracranial hemorrhage)

Brain infection

Brain tumors

Hormonal disorders (such as acromegaly, galactorrhea, and Cushing syndrome)

Multiple sclerosis

Stroke

An MRI scan of the head can also determine the cause of:

Muscle weakness or numbness and tingling

Changes in thinking or behavior

Hearing loss

Headaches when certain other symptoms or signs are present

Speaking difficulties

Vision problems

A special type of MRI called magnetic resonance angiography (MRA) may be done to look at blood vessels in the brain.

What Abnormal Results Mean

Abnormal results may be due to:

Abnormal blood vessels in the brain (arteriovenous malformations of the head)

Acoustic neuroma

Bleeding in the brain

Brain abscess

Brain aneurysms

Brain tissue swelling

Brain tumors

Damage to the brain from an injury

Hydrocephalus (fluid collecting around the brain)

Infection of the bones (osteomyelitis)

Loss of brain tissue

Multiple sclerosis

Optic glioma

Pituitary tumor

Stroke or transient ischemic attack (TIA)

Structural problems in the brain, blood vessels, or pituitary gland

Risks

MRI uses no radiation. To date, no side effects from the magnetic fields and radio waves have been reported.

The most common type of contrast (dye) used is gadolinium. It is very safe. Allergic reactions to the substance rarely occur. However, gadolinium can be harmful to patients with kidney problems who require dialysis. If you have kidney problems, please tell your health care provider before the test.

The strong magnetic fields created during an MRI can make heart pacemakers and other implants not work as well. It can also cause a piece of metal inside your body to move or shift.

Considerations

Tests that may be done instead of an MRI of the head include:

Cranial CT scan

Positron emission tomography (PET) scan of the brain

Skull x-ray

A CT scan may be preferred in the following cases, since it is faster and usually available right in the emergency room:

Acute trauma of the head and face

Bleeding in the brain (within the first 24 - 48 hours)

Early symptoms of stroke

Skull bone disorders and disorders involving the bones of the ear

Alternative Names

Nuclear magnetic resonance - cranial; Magnetic resonance imaging - cranial; MRI of the head; MRI - cranial; NMR - cranial; Cranial MRI; Brain MRI; MRI - brain; MRI - head