Vertigo : Tests

A physical exam may reveal: Eye movement problems, involuntary eye movements (nystagmus; Lack of coordination and balance, difficulty walking; Hearing loss; Weakness. Tests to determine the cause of vertigo may include: Blood tests; Brainstem audi...

A neurological examination is an essential component of a comprehensive physical examination . It is a systematic examination that surveys the functioning of nerves delivering sensory information to the brain and caring motor commands (Peripheral nervous system) and impulses back to the brain for processing and coordinating (Central nervous system).

During a physical examination, a health care provider studies a patient's body to determine the presence or absence of physical problems. A typical physical examination includes: Inspection (looking at the body; Palpation (feeling the body with hands; Auscultation (listening to sounds; Percussion (producing sounds.

Electronystagmography is a test to look at voluntary and involuntary eye movements. It evaluates the acoustic nerve, which aids with hearing and balance.

Caloric stimulation is a test which uses differences in temperature to diagnose ear nerve damage.

A magnetic resonance imaging (MRI) scan of the head is a noninvasive method to create detailed pictures of the brain and surrounding nerve tissues. Unlike x-rays and computed tomographic (CT) scans, which use radiation, MRI uses powerful magnets and radio waves. The MRI scanner contains the magnet. The magnetic field produced by an MRI is about 10 thousand times greater than the earth's. The magnetic field forces hydrogen atoms in the body to line up in a certain way (similar to how the needle on a compass moves when you hold it near a magnet. When radio waves are sent toward the lined-up hydrogen atoms, they bounce back, and a computer records the signal. Different types of tissues send back different signals. Single MRI images are called slices. The images can be stored on a computer or printed on film. One exam produces dozens or sometimes hundreds of images. See: MRI

Congenital brain defects are a group of disorders of brain development that are present at birth.

Brain abscess is a bacterial infection within the brain.

A brain biopsy is the removal of a small piece of brain tissue for the diagnosis of abnormalities of the brain, such as Alzheimer's disease , tumors, infection, or inflammation.

A brain tumor is an abnormal growth of tissue in the brain. Unlike other tumors, brain tumors spread by local extension and rarely metastasize (spread) outside the brain. A benign brain tumor is composed of non-cancerous cells and does not metastasize beyond the part of the brain where it originates. A brain tumor is considered malignant if it contains cancer cells, or if it is composed of harmless cells located in an area where it suppresses one or more vital functions.

Congenital brain defects are a group of disorders of brain development.

The brain is the part of the central nervous system located in the skull. It controls the mental processes and physical actions of a human being.

The brain is a large mass of soft nervous tissue made up of both neurons and supporting glial cells lying within the cranium of the skull. The brain contains both gray and white matter. Gray matter is primarily nerve cell bodies, whereas white matter contains myelinated nerve cell processes, giving it a white appearance. White matter is mostly found in the cortex (shell) of the cerebral hemispheres. The brain has a highly complex appearance, with convolutions referred to as gyri and valleys referred to as sulci. These convolutions create a greater surface area within the same size skull.

Magnetic resonance imaging (MRI) scanners rely on the principles of atomic nuclear-spin resonance. Using strong magnetic fields and radio waves, MRI collects and correlates deflections caused by atoms into images. MRIs (magnetic resonance imaging tests) offer relatively sharp pictures and allow physicians to see internal bodily structures with great detail. Using MRI technology, physicians are increasingly able to make diagnosis of serious pathology (e.g., tumors) earlier, and earlier diagnosis often translates to a more favorable outcome for the patient.

Traumatic brain injury (TBI) is the result of physical trauma to the head causing damage to the brain. This damage can be focal, or restricted to a single area of the brain, or diffuse, affecting more than one region of the brain. By definition, TBI requires that there be a head injury, or any physical assault to the head leading to injury of the scalp, skull, or brain. However, not all head trauma is associated with TBI.

The brain is the part of the central nervous system (CNS) inside the skull (the part outside the skull is the spinal cord ). It gives rise to cognitive thought processes and controls various body functions including muscular activity, speech, sight, hearing , breathing, and digestion.

A brain tumor is an abnormal growth of tissue, either malignant (cancerous) or benign (noncancerous), in the brain. Each year, more than 17,000 brain tumors are diagnosed in the United States.

Like all other parts of the body, the brain and central nervous system are made up of cells that ordinarily grow and divide to create new cells as needed. This is usually an orderly process; but when cells lose their ability to grow normally or to die off naturally, they divide too often and produce tumors that are made up of these extra cells.

Part of the central nervous system located in the skull. Controls mental and physical actions of the organism. The brain, with the spinal cord and network of nerves, controls information flow throughout the body, voluntary actions, such as walking, reading, and talking, and involuntary reactions, such as breathing and heartbeat. The human brain is a soft, shiny, grayish white, mushroom-shaped structure. Encased within the skull, the brain of an average adult weight about 3 lb (1.4 kg). At birth, the average human infant's brain weighs 13.7 oz (390 g); by age 15, the brain has nearly reached full adult size. The brain is protected by the skull and by a threelayer membrane called the meninges. Many bright red arteries and bluish veins on the surface of the brain penetrate inward. Glucose, oxygen, and certain ions pass easily from the blood into the brain, whereas other substances, such as antibiotics, do not. The four principal sections of the human brain are the brain stem, the diencephalon, the cerebrum, and the cerebellum.

A cranial computed tomography (CT) scan is an imaging method that uses x-rays to create cross-sectional pictures of the head, including the skull, brain, eye sockets, and sinuses. See: Computed tomography

A computed tomography (CT) scan is an imaging method that uses x-rays to create cross-sectional pictures of the body. See also: Cranial CT scan; Lumbosacral spine CT scan; Orbit CT scan; Thoracic CT scan.

Computed Tomography (CT)Computed tomography(CT) is a test that combines x-rays and computer scans. The result is a detailed picture that can show problems with soft tissues (such as the lining of your sinuses), organs (such as your kidneys or lung...

Detailed information on CT scan, including how the CT scan is performed and what happens after the procedure

Detailed information on ultrafast computed tomography scans, also called ultrafast CT scan or ultrafast CAT scan, including information on how the procedure is performed

Detailed information on computed tomography scans, also called CT scan or CAT scan, including information on how the procedure is performed

Detailed information on ultrafast computed tomography (CT) scan, including reasons for the procedure, risks of the procedure, what to expect, and discharge instructions

Computed tomography (CT) scanning is a valuable diagnostic tool that provides physicians with views of internal body structures. During a CT scan, multiple x rays are passed through the body, producing cross-sectional images, or "slices, " on a cathode-ray tube (CRT), a device resembling a television screen. These images can then be preserved on film for examination.

Computed tomography (CT), formerly referred to as computerized axial tomography (CAT), is a common diagnostic imaging procedure that uses x rays to generate images (slices) of the anatomy.

Computed tomography (CT) scans are completed with the use of a 360-degree x-ray beam and computer production of images. These scans allow for cross-sectional views of body organs and tissues.

Computed tomography scanning, also called CT scan, CAT scan, or computerized axial tomography, is a diagnostic tool that provides views of internal body structures using x rays. In the field of mental health, a CT scan may be used when a patient seeks medical help for symptoms that could possibly be caused by a brain tumor. These symptoms may include headaches, emotional abnormalities, or intellectual or memory problems. In these cases, a CT scan may be performed to "rule out" a tumor, so that other tests can be performed in order to establish an accurate diagnosis .

Computed tomography (also known as CT, CT scan, CAT, or computerized axial tomography) scans use x rays to produce precise cross-sectional images of anatomical structures.

What is the difference between a pelvic CT scan and an abdominal CT scan?

Is there an alternative to iodine as a contrast medium in a CT scan?

Magnetic resonance imaging (MRI) is a noninvasive way to take pictures of the body. Unlike x-rays and computed tomographic (CT) scans, which use radiation, MRI uses powerful magnets and radio waves. The MRI scanner contains the magnet. The magnetic field produced by an MRI is about 10 thousand times greater than the earth's. The magnetic field forces hydrogen atoms in the body to line up in a certain way (similar to how the needle on a compass moves when you hold it near a magnet. When radio waves are sent toward the lined-up hydrogen atoms, they bounce back, and a computer records the signal. Different types of tissues send back different signals. Single MRI images are called slices. The images can be stored on a computer or printed on film. One exam produces dozens or sometimes hundreds of images. For more information, see the specific MRI topics: Abdominal MRI; Chest MRI; Cranial MRI; Heart MRI; Lumbosacral spine MRI; Spine MRI.

Cardiac nuclear imaging is also called a “perfusion scan.” A radioactive tracer is delivered into the bloodstream. Then a camera scans the tracer in the blood as it flows through the heart muscle.

Detailed information on magnetic resonance imaging, including how the image is performed and what happens following the procedure

New MRI machines and new techniques result in images that show prostate cancer in much greater detail, allowing biopsies to be targeted more precisely, and thus cancer staging can be more accurate as well.

Magnetic Resonance Imaging (MRI)Magnetic resonance imaging(MRI) is a test that lets your doctor see detailed pictures of the inside of your body. MRI combines the use of strong magnets and radio waves to form an MRI image.Before Your TestMRI uses ...

A Harvard Medical School physician answers your question about the safety of MRIs for those who have stents.

Studies have found that MRI tests used in addition to mammography detected more cancers in women at high risk for breast cancer. Women at average risk would not necessarily benefit from the additional testing.

When I had an MRI of my knee, I was told the test was dangerous for people who have metal devices in their bodies. Since then, I developed angina and my cardiologist put in a metal stent. If I need an MRI in the future, will I be able to get one?

Persons with pacemakers cannot get an MRI because it conflicts with the pacemaker's function. Future pacemakers will likely be made MRI-safe, but this will probably take at least several more years.

For women at high genetic risk, adding MRI screening to mammography may improve early detection of breast cancer.

Is a regular MRI more accurate then an open MRI? Diana Post, M.D., is an assistant professor of medicine at Harvard Medical School and a member of the Department of Medicine at Brigham and Women's Hospital.

How safe is it for a baby who is 6 months old to have an MRI? Claire McCarthy, M.D., is a senior medical editor for Harvard Health Publications. She is an instructor in pediatrics at Harvard Medical School, an attending physician at Children's Hospital of Boston, and co-director of the pediatrics department at Martha Eliot Health Center, a neighborhood health service of Children's Hospital. The author of two books, "Learning How the Heart Beats" and "Everyone's Children", Dr. McCarthy was a regular columnist for "Sesame Street Parents Magazine" from 1995 to 1998 and is currently a contributing editor for "Parenting Magazine".

Magnetic resonance imaging (MRI) is one of the newest, and perhaps most versatile, medical imaging technology available. Doctors can get highly refined images of the body's interior without surgery using MRI. By using strong magnets and pulses of radio waves to manipulate the natural magnetic properties in the body, this technique makes better images of organs and soft tissues than those of other brain scanning technologies. MRI is particularly useful for imaging the brain and spine, as well as the soft tissues of joints and the interior structure of bones, as well as the liver. The entire body is visible with MRI, and the technique poses few known health risks.

Magnetic resonance imaging (MRI) is a diagnostic imaging procedure that uses radio waves, a magnetic field, and a computer to generate images of the anatomy.

Magnetic resonance imaging (MRI) is the newest, and perhaps most versatile, medical imaging technology available. Doctors can get highly refined images of the body's interior without surgery, using MRI. By using strong magnets and pulses of radio waves to manipulate the natural magnetic properties in the body, this technique makes better images of organs and soft tissues than those of other scanning technologies. MRI is particularly useful for imaging the brain and spine, as well as the soft tissues of joints and the interior structure of bones. The entire body is visible to the technique, which poses few known health risks.

Magnetic resonance imaging (MRI) is one of the newest diagnostic medical imaging technologies that uses strong magnets and pulses of radio waves to manipulate the natural magnetic properties in the body to generate a visible image. In the field of mental health, an MRI scan may be used when a patient seeks medical help for symptoms that could possibly be caused by a brain tumor. These symptoms may include headaches, emotional abnormalities, or intellectual or memory problems. In these cases, an MRI scan may be performed to "rule out" a tumor, so that other tests can be performed in order to establish an accurate diagnosis .

Magnetic resonance imaging (MRI) is a unique and versatile medical imaging modality. Doctors can obtain highly refined images of the body's interior using MRI. By using strong magnetic fields and pulses of radio waves to manipulate the natural magnetic properties in the body, this technique produces images not possible with other diagnostic imaging methods. MRI is particularly useful for imaging the brain and spine, as well as the soft tissues of joints and the interior structure of bones. The entire body can be imaged using MRI, and the technology poses few known health risks.

MRI produces a map of hydrogen atoms distributed in the body. Hydrogen is the simplest element known, the most abundant in biological tissue, and one that can be magnetically polarized. It will align itself within a strong magnetic field, like the needle of a compass. The earth's magnetic field is not strong enough to polarize a person's hydrogen atoms, but the superconducting magnet of an MRI machine can do this. The strength of the earth's magnetic field is approximately 1 gauss. Typical field strength of an MRI unit, with a superconducting magnet, is 1,500 gauss, expressed as 1.5 kilogauss or 1.5 Tesla units. This comprises the "magnetic" part of MRI. There are also low field units with 0.5 Tesla strength, often with open MRI units. Once a patient's hydrogen atoms have been aligned in the magnet, pulses of very specific radio wave frequencies jolt them out of alignment. The hydrogen atoms alternately absorb and emit radio wave energy, vibrating back and forth between their resting (polarized) state and their agitated (radio pulse) state. This comprises the "resonance" part of MRI. The patient does not detect this process. The MRI equipment detects the duration, strength, and source location of the signals emitted by the atoms as they relax. This data is translated into an image on a television monitor. The amount of hydrogen in diseased tissue differs from the amount in healthy tissue of the same type, making MRI particularly effective at identifying tumors and other lesions. In some cases, chemical agents such as gadolinium can be injected to improve the contrast between healthy and diseased tissue. A single MRI exposure produces a two-dimensional image of a slice through the entire target area. A series of these image slices closely spaced (usually less than half an inch [1.25 cm]) provides a virtual three-dimensional view of the area.

Detailed information on magnetic resonance imaging (MRI), including information on how the procedure is performed

People with certain kinds of pacemakers or ICDs can safely undergo an MRI, as long as a series of safety precautions is carefully followed.