brain scan

5 Frequently Asked Questions About Brain Scans for Alzheimer's

Christine Kennard Health Pro March 08, 2012
  • Brains scans were first used in the 1970s when CT (computed tomography) scans began to be used to look at the structure of the brain and other parts of the body. Now there are many types of scans available and they have transformed medicine. Brain scans are accurate and non invasive and have been shown to be a cost-effective imaging tool for a wide range of clinical problems. But why are brain scans done? What types of scans are there? Are they painful? These and other frequently asked questions are answered in this sharepost.

     

    Why are Brain Scans Used?

    A brain scan (neuro imaging) is an investigation that your doctor or specialist will refer you for. The scan results are used as an important diagnostic tool for symptoms that may be Alzheimer's disease. At the present time Alzheimer's disease can only be confirmed at autopsy but our knowledge of what Alzheimer's is, and what might cause it, is being strongly influenced by this type of technology. Brain scans can:

    • Help identify structural changes in the brain such as atrophy (tissue death), tumors, hemorrhage, bone trauma or calcification.
    • Dyes can be administered with a brain scan so they can track and identify blood supply abnormalities in the brain to exclude them as the cause of the symptoms of Alzheimer's.
    • Cutting edge brain scan technology can look at in-time changes in the brain that occur during motor movement, during behavioral changes or during radical changes in electrical activity in the brain due to epileptic type seizures.
    • In preventative medicine, brain scans, as part of whole body scans, are increasingly being offered as a tool for preventative medicine. As before, these can identify changes in the brain that may indicate early Alzheimer's.
    • Brain scans are also being used for research into Alzheimer's. They look at structural changes at the different stages of the disease. More recently, advanced scans have been used to look at the genetic variants that may play a role in the disease. They can also, for instance, look at changes that occur in the brain linked to behavior, plaque build up and brain shrinkage.

    What are the Different Types of Brain Scans Called?

    The technology of scanning the body is evolving all the time. New imaging technology can reduce or even eliminate surgical procedures. For example Yale University designed a brain scan that maps blood flow and the electrical activity, and biochemical activity in the brain at the same time.  I will look at the three main types of brain scan in common use for investigative tests for Alzheimer's disease. They are;

    MRI (Magnetic resonance imaging)

    PET (Positron Emission Tomography)

    CT (Computed tomography).

    The above links give information on each test, what they are used for and what to expect from the imaging scan.

     

    Do Brain Scans Hurt?

    Brain scans are not painful. The procedure however can be uncomfortable because you have to lie on a hard, cold table, for quite a long time. Pillows and a blanket can help reduce discomfort. Where a dye is injected into a vein, such as in CTA and MRA scans, the dye can sting a bit, but that does not last.

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    People who are claustrophobic can feel very anxious as in most cases you have to lie inside a large cylinder as the table moves in and out of the machine. Mild sedatives can be given before a scan to minimize fear. They can be also be used to calm the confused patient so that they lie still and following instructions from the radiologist or doctor as much as possible.  

     

    What Happens to the Brain Scan Results?

    A physician, usually a radiologist with expertise in supervising and interpreting radiology examinations, will analyze the images and send a signed report to your primary care physician or the physician who referred you for the exam.

     

    Are There any Dangers or Side Effects to Brain Scans?

    Some brain scan technology, for example the  MRI, cannot be used if you have metal objects such as pacemakers, surgical clips, certain types of stents, implants or valves in your body. There is a small theoretical risk to the fetus in the first 12 weeks of pregnancy, and therefore scans are not generally performed unless essential, on pregnant women during this time.

    Very rarely some people have an allergic reaction to the contrast mediums or radioactive substances used in some tests. Tests can be repeated to give doctors information about how the person's memory is changing and whether it is due to physical changes in the brain.