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A Medical Dictionary of Medical Terminology
  

mri

MRI Scans

Magnetic resonance imaging (MRI) uses a large magnet and radio waves to look at organs and structures inside your body. Health care professionals use MRI scans to diagnose a variety of conditions, from torn ligaments to tumors. MRIs are very useful for examining the brain and spinal cord.

During the scan, you lie on a table that slides inside a tunnel-shaped machine. Doing the scan can take a long time, and you must stay still. The scan is painless. The MRI machine makes a lot of noise. The technician may offer you earplugs.

Before you get a scan, tell your doctor if you :

Heart Health Tests

Heart diseases are the number one killer in the U.S. They are also a major cause of disability. If you do have a heart disease, it is important to find it early, when it is easier to treat. Blood tests and heart health tests can help find heart diseases or identify problems that can lead to heart diseases. There are several different types of heart health tests. Your doctor will decide which test or tests you need, based on your symptoms (if any), risk factors, and medical history.

Cardiac Catheterization

Cardiac catheterization is a medical procedure used to diagnose and treat some heart conditions. For the procedure, your doctor puts a catheter (a long, thin, flexible tube) into a blood vessel in your arm, groin, or neck, and threads it to your heart. The doctor can use the catheter to:

Cardiac CT Scan

A cardiac CT (computed tomography) scan is a painless imaging test that uses x-rays to take detailed pictures of your heart and its blood vessels. Computers can combine these pictures to create a three-dimensional (3D) model of the whole heart. This test can help doctors detect or evaluate:

Before you have the test, you get an injection of contrast dye. The dye highlights your heart and blood vessels in the pictures. The CT scanner is a large, tunnel-like machine. You lie still on a table which slides you into the scanner, and the scanner takes the pictures for about 15 minutes.

Cardiac MRI

Cardiac MRI (magnetic resonance imaging) is a painless imaging test that uses radio waves, magnets, and a computer to create detailed pictures of your heart. It can help your doctor figure out whether you have heart disease, and if so, how severe it is. A cardiac MRI can also help your doctor decide the best way to treat heart problems such as:

The MRI is a large, tunnel-like machine. You lie still on a table which slides you into the MRI machine. The machine makes loud noises as it takes pictures of your heart. It usually takes about 30-90 minutes. Sometimes before the test, you might get an injection of contrast dye. The dye highlights your heart and blood vessels in the pictures.

Chest X-Ray

A chest x-ray creates pictures of the organs and structures inside your chest, such as your heart, lungs, and blood vessels. It can reveal signs of heart failure, as well as lung disorders and other causes of symptoms not related to heart disease.

Coronary Angiography

Coronary angiography (angiogram) is a procedure that uses contrast dye and x-ray pictures to look at the insides of your arteries. It can show whether plaque is blocking your arteries and how severe the blockage is. Doctors use this procedure to diagnose heart diseases after chest pain, sudden cardiac arrest (SCA), or abnormal results from other heart tests such as an EKG or a stress test.

You usually have a cardiac catheterization to get the dye into your coronary arteries. Then you have special x-rays while the dye is flowing through your coronary arteries. The dye lets your doctor study the flow of blood through your heart and blood vessels.

Echocardiography

Echocardiography, or echo, is a painless test that uses sound waves to create moving pictures of your heart. The pictures show the size and shape of your heart. They also show how well your heart's chambers and valves are working. Doctors use an echo to diagnose many different heart problems, and to check how severe they are.

For the test, a technician applies gel to your chest. The gel helps sound waves reach your heart. The technician moves a transducer (wand-like device) around on your chest. The transducer connects to a computer. It transmits ultrasound waves into your chest, and the waves bounce (echo) back. The computer converts the echoes into pictures of your heart.

Electrocardiogram (EKG), (ECG)

An electrocardiogram, also called an ECG or EKG, is a painless test that detects and records your heart's electrical activity. It shows how fast your heart is beating and whether its rhythm is steady or irregular.

An EKG may be part of a routine exam to screen for heart disease. Or you may get it to detect and study heart problems such as heart attacks, arrhythmia, and heart failure.

For the test, you lie still on a table and a nurse or technician attaches electrodes (patches that have sensors) to the skin on your chest, arms, and legs. Wires connect the electrodes to a machine that records your heart's electrical activity.

Stress Testing

Stress testing looks at how your heart works during physical stress. It can help to diagnose coronary artery disease, and to check how severe it is. It can also check for other problems, including heart valve disease and heart failure.

For the test, you exercise (or are given medicine if you are unable to exercise) to make your heart work hard and beat fast. While this is happening, you get an EKG and blood pressure monitoring. Sometimes you may also have an echocardiogram, or other imaging tests such as a nuclear scan. For the nuclear scan, you get an injection of a tracer (a radioactive substance), which travels to your heart. Special cameras detect the energy from the tracer to make pictures of your heart. You have pictures taken after you exercise, and then after you rest.

NIH: National Heart, Lung, and Blood Institute

Brain Tumors

A brain tumor is a growth of abnormal cells in the tissues of the brain. Brain tumors can be benign, with no cancer cells, or malignant, with cancer cells that grow quickly. Some are primary brain tumors, which start in the brain. Others are metastatic, and they start somewhere else in the body and move to the brain.

Brain tumors can cause many symptoms. Some of the most common are:

Doctors diagnose brain tumors by doing a neurologic exam and tests including an MRI, CT scan, and biopsy. Treatment options include watchful waiting, surgery, radiation therapy, chemotherapy, and targeted therapy. Targeted therapy uses drugs or other substances that attack cancer cells with less harm to normal cells. Many people get a combination of treatments.

NIH: National Cancer Institute

Prostate Cancer

What is prostate cancer?

Cancer is a disease in which cells in the body grow out of control. Prostate cancer begins in the cells of the prostate. The prostate is a gland in the male reproductive system. It lies just below the bladder. It makes fluid that is part of semen.

Prostate cancer is one of the most common types of cancer. It often grows very slowly. If it does not spread to other parts of the body, it may not cause serious problems. But sometimes prostate cancer can grow quickly and spread to other parts of the body. This kind of prostate cancer is serious.

What causes prostate cancer?

Researchers don't know for sure what causes prostate cancer. They do know that it happens when there are changes in the genetic material (DNA).

Sometimes these genetic changes are inherited, meaning that you are born with them. There are also certain genetic changes that happen during your lifetime that can raise your risk of prostate cancer. But often the exact cause of these genetic changes is unknown.

Who is more likely to develop prostate cancer?

Anyone who has a prostate can develop prostate cancer. But certain factors can make you more likely to develop it:

What are the symptoms of prostate cancer?

Prostate cancer doesn't always cause symptoms, especially at first. If it does cause symptoms, they may include:

But many of these symptoms may be from other common prostate problems that aren't cancer, such as an enlarged prostate.

You should discuss your prostate health with your health care provider if you:

What are prostate tests and how is prostate cancer diagnosed?

Tests which check for prostate cancer include:

If these tests show that you might have prostate cancer, the next step is usually a prostate biopsy. A biopsy is the only way to diagnose prostate cancer.

During a biopsy, a doctor uses a hollow needle to remove some prostate tissue. The tissue is studied under a microscope to look for cancer cells.

What are the treatments for prostate cancer?

Your treatment options usually depend on your age, your general health, and how serious the cancer is. Your treatment may include one or more of options:

Can prostate cancer be prevented?

Making healthy lifestyle changes may help to prevent some prostate cancers. These changes include:

NIH: National Cancer Institute

Brain Diseases

Your brain is the control center of your body. It controls your thoughts, memory, speech, and movement. It regulates the function of many organs. It's part of your nervous system, which also includes your spinal cord and peripheral nerves. The nervous system sends signals between your brain and the rest of the body. Your nerves take in information from your senses and send it to the brain to be processed. Your brain and nerves also communicate to help you move and to control your body's functions.

When the brain is healthy, it works quickly and automatically. But when you have a brain disease, it may affect how well you can function and do your daily activities. Some common brain diseases include:

The symptoms of brain diseases vary widely, depending on the specific problem. In some cases, damage is permanent. In other cases, treatments such as surgery, medicines, or therapies such as physical, occupational, and speech therapies, may cure the disease or improve the symptoms.

Acoustic Neuroma

An acoustic neuroma is a benign tumor that develops on the nerve that connects the ear to the brain. The tumor usually grows slowly. As it grows, it presses against the hearing and balance nerves. At first, you may have no symptoms or mild symptoms. They can include:

The tumor can also eventually cause numbness or paralysis of the face. If it grows large enough, it can press against the brain, becoming life-threatening.

Acoustic neuroma can be difficult to diagnose, because the symptoms are similar to those of middle ear problems. Ear exams, hearing tests, and scans can show if you have it.

If the tumor stays small, you may only need to have it checked regularly. If you do need treatment, surgery and radiation are options.

If the tumors affect both hearing nerves, it is often because of a genetic disorder called neurofibromatosis.

NIH: National Institute on Deafness and Communication Disorders

Adrenal Gland Cancer

Your adrenal, or suprarenal, glands are located on the top of each kidney. These glands produce hormones that you can't live without, including sex hormones and cortisol, which helps you respond to stress and has many other functions.

A number of disorders can affect the adrenal glands, including tumors. Tumors can be either benign or malignant. Benign tumors aren't cancer. Malignant ones are. Most adrenal gland tumors are benign. They usually do not cause symptoms and may not require treatment. Malignant adrenal gland cancers are uncommon.

Types of tumors include:

Symptoms depend on the type of cancer you have. Treatments may include surgery, chemotherapy, or radiation therapy.

Brain Malformations

Most brain malformations begin long before a baby is born. Something damages the developing nervous system or causes it to develop abnormally. Sometimes it's a genetic problem. In other cases, exposure to certain medicines, infections, or radiation during pregnancy interferes with brain development. Parts of the brain may be missing, abnormally small or large, or not fully developed.

Treatment depends upon the problem. In many cases, treatment only helps with symptoms. It may include antiseizure medicines, shunts to drain fluid from the brain, and physical therapy.

There are head malformations that do not involve the brain. Craniofacial disorders are the result of abnormal growth of soft tissue and bones in the face and head. It's common for new babies to have slightly uneven heads, but parents should watch the shape of their baby's head for possible problems.

NIH: National Institute of Neurological Disorders and Stroke

Breast Cancer

What is breast cancer?

Breast cancer is a cancer that starts in breast tissue. It happens when cells in the breast change and grow out of control. The cells usually form a tumor.

Sometimes the cancer does not spread any further. This is called "in situ." If the cancer spreads outside the breast, the cancer is called "invasive." It may just spread to nearby tissues and lymph nodes. Or the cancer may metastasize (spread to other parts of the body) through the lymph system or the blood.

Breast cancer is the second most common type of cancer in women in the United States. Rarely, it can also affect men.

What are the types of breast cancer?

There are different types of breast cancer. The types are based on which breast cells turn into cancer. The types include:

What causes breast cancer?

Breast cancer happens when there are changes in the genetic material (DNA). Often, the exact cause of these genetic changes is unknown.

But sometimes these genetic changes are inherited, meaning that you are born with them. Breast cancer that is caused by inherited genetic changes is called hereditary breast cancer.

There are also certain genetic changes that can raise your risk of breast cancer, including changes in the BRCA1 and BRCA2 genes. These two changes also raise your risk of ovarian and other cancers.

Besides genetics, your lifestyle and the environment can affect your risk of breast cancer.

Who is at risk for breast cancer?

The factors that raise your risk of breast cancer include:

What are the signs and symptoms of breast cancer?

The signs and symptoms of breast cancer include:

How is breast cancer diagnosed?

Your health care provider may use many tools to diagnose breast cancer and figure out which type you have:

If these tests show that you have breast cancer, you will have tests that study the cancer cells. These tests help your provider decide which treatment would be best for you. The tests may include:

Another step is staging the cancer. Staging involves doing tests to find out whether the cancer has spread within the breast or to other parts of the body. The tests may include other diagnostic imaging tests and a sentinel lymph node biopsy. This biopsy is done to see whether the cancer has spread to the lymph nodes.

What are the treatments for breast cancer?

Treatments for breast cancer include:

Can breast cancer be prevented?

You may be able to help prevent breast cancer by making healthy lifestyle changes such as:

If you are at high risk, your health care provider may suggest that you take certain medicines to lower the risk. Some women at very high risk may decide to get a mastectomy (of their healthy breasts) to prevent breast cancer.

It's also important to get regular mammograms. They may be able to identify breast cancer in the early stages, when it is easier to treat.

NIH: National Cancer Institute

Hydrocephalus

Hydrocephalus is the buildup of too much cerebrospinal fluid in the brain. Normally, this fluid cushions your brain. When you have too much, though, it puts harmful pressure on your brain.

Hydrocephalus can be congenital, or present at birth. Causes include genetic problems and problems with how the fetus develops. An unusually large head is the main sign of congenital hydrocephalus.

Hydrocephalus can also happen after birth. This is called acquired hydrocephalus. It can occur at any age. Causes can include head injuries, strokes, infections, tumors, and bleeding in the brain. Symptoms include:

Hydrocephalus can permanently damage the brain, causing problems with physical and mental development. If untreated, it is usually fatal. With treatment, many people lead normal lives with few limitations. Treatment usually involves surgery to insert a shunt. A shunt is a flexible but sturdy plastic tube. The shunt moves the cerebrospinal fluid to another area of the body where it can be absorbed. Medicine and rehabilitation therapy can also help.

NIH: National Institute of Neurological Disorders and Stroke

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