St. Luke's Hospital
Main Number: 314-434-1500 Emergency Dept: 314-205-6990 Patient Billing: 888-924-9200
Find a Physician Payment Options Locations & Directions
Follow us on: facebook twitter Mobile Email Page Email Page Print Page Print Page Increase Font Size Decrease Font Size Font Size
America's 50 Best Hospitals
Meet the Doctor
Spirit of Women
Community Health Needs Assessment
Home > Health Information

Multimedia Encyclopedia

    Print-Friendly
    Bookmarks

    Head MRI

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

    A head MRI (magnetic resonance imaging) scan of the head is a imaging test that uses powerful magnets and radio waves to create pictures of the brain and surrounding nerve tissues.

    It does not use radiation.

    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.

    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

    References

    Wilkinson ID, Paley MNJ. Magnetic resonance imaging: basic principles. In: Grainger RC, Allison D, Adam, Dixon AK, eds. Diagnostic Radiology: A Textbook of Medical Imaging. 5th ed. New York, NY: Churchill Livingstone; 2008:chap 5.

    Saunders D, Jäger HR, Murray AD, Stevens JM. Skull and brain: methods of examination and anatomy. In: Grainger RC, Allison D, Adam, Dixon AK, eds. Diagnostic Radiology: A Textbook of Medical Imaging. 5th ed. New York, NY: Churchill Livingstone; 2008:chap 55.

    BACK TO TOP

    • Brain

      illustration

    • Head MRI

      illustration

    • Lobes of the brain

      illustration

      • Brain

        illustration

      • Head MRI

        illustration

      • Lobes of the brain

        illustration

      A Closer Look

        Talking to your MD

          Self Care

            Tests for Head MRI

            Review Date: 12/10/2012

            Reviewed By: Javed Qureshi, MD, American Board of Radiology, Victoria Radiology Associates, Victoria, TX. Review provided by VeriMed Healthcare Network. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, David R. Eltz, and Stephanie Slon.

            The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.
            adam.com

            A.D.A.M. content is best viewed in IE9 or above, Fire Fox and chrome browser.


            Back  |  Top
            About Us
            Contact Us
            History
            Mission
            Locations & Directions
            Quality Reports
            Annual Reports
            Honors & Awards
            Community Health Needs
            Assessment

            Newsroom
            Services
            Brain & Spine
            Cancer
            Heart
            Maternity
            Orthopedics
            Pulmonary
            Sleep Medicine
            Urgent Care
            Women's Services
            All Services
            Patients & Visitors
            Locations & Directions
            Find a Physician
            Tour St. Luke's
            Patient & Visitor Information
            Contact Us
            Payment Options
            Financial Assistance
            Send a Card
            Mammogram Appointments
            Health Tools
            My Personal Health
            mystlukes
            Spirit of Women
            Health Information & Tools
            Clinical Trials
            Health Risk Assessments
            Employer Programs -
            Passport to Wellness

            Classes & Events
            Classes & Events
            Spirit of Women
            Donate & Volunteer
            Giving Opportunities
            Volunteer
            Physicians & Employees
            For Physicians
            Remote Access
            Medical Residency Information
            Pharmacy Residency Information
            Physician CPOE Training
            Careers
            Careers
            St. Luke's Hospital - 232 South Woods Mill Road - Chesterfield, MO 63017 Main Number: 314-434-1500 Emergency Dept: 314-205-6990 Patient Billing: 888-924-9200
            Copyright © St. Luke's Hospital Website Terms and Conditions  |  Privacy Policy  |  Patient Notice of Privacy Policies PDF Sitemap St. Luke's Mobile