Medical Dictionary |
A Medical Dictionary of Medical Terminology
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Diagnostic imaging lets doctors look inside your body for clues about a medical condition. A variety of machines and techniques can create pictures of the structures and activities inside your body. The type of imaging your doctor uses depends on your symptoms and the part of your body being examined. They include:
Many imaging tests are painless and easy. Some require you to stay still for a long time inside a machine. This can be uncomfortable. Certain tests involve exposure to a small amount of radiation.
For some imaging tests, doctors insert a tiny camera attached to a long, thin tube into your body. This tool is called a scope. The doctor moves it through a body passageway or opening to see inside a particular organ, such as your heart, lungs, or colon. These procedures often require anesthesia.
Computed tomography (CT) is a type of imaging. It uses special x-ray equipment to make cross-sectional pictures of your body.
Doctors use CT scans to look for:
During a CT scan, you lie still on a table. The table slowly passes through the center of a large X-ray machine. The test is painless. During some tests you receive a contrast dye, which makes parts of your body show up better in the image.
NIH: National Cancer Institute
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 :
X-rays are a type of radiation called electromagnetic waves. X-ray imaging creates pictures of the inside of your body. The images show the parts of your body in different shades of black and white. This is because different tissues absorb different amounts of radiation. Calcium in bones absorbs x-rays the most, so bones look white. Fat and other soft tissues absorb less and look gray. Air absorbs the least, so lungs look black.
The most familiar use of x-rays is checking for fractures (broken bones), but x-rays are also used in other ways. For example, chest x-rays can spot pneumonia. Mammograms use x-rays to look for breast cancer.
When you have an x-ray, you may wear a lead apron to protect certain parts of your body. The amount of radiation you get from an x-ray is small. For example, a chest x-ray gives out a radiation dose similar to the amount of radiation you're naturally exposed to from the environment over 10 days.
Nuclear scans use radioactive substances to see structures and functions inside your body. They use a special camera that detects radioactivity.
Before the test, you receive a small amount of radioactive material. You may get it as an injection. Sometimes you swallow it or inhale it. Then you lie still on a table while the camera makes images. Most scans take 20 to 45 minutes.
Nuclear scans can help doctors diagnose many conditions, including cancers, injuries, and infections. They can also show how organs like your heart and lungs are working.
You've probably seen your chart at your doctor's office. In fact, you may have charts at several doctors' offices. If you've been in the hospital, you have a chart there, too. These charts are your medical records. They may be on paper or electronic. To keep track of all this information, it's a good idea to keep your own personal health record.
What kind of information would you put in a personal health record? You could start with:
Radiation therapy is a cancer treatment. It uses high doses of radiation to kill cancer cells and stop them from spreading. About half of all cancer patients receive it. The radiation may be external, from special machines, or internal, from radioactive substances that a doctor places inside your body. The type of radiation therapy you receive depends on many factors, including:
Radiation therapy can damage normal cells as well as cancer cells. Treatment must be carefully planned to minimize side effects. Common side effects include skin changes and fatigue. Other side effects depend on the part of your body being treated.
Sometimes radiation is used with other treatments, like surgery or chemotherapy.
NIH: National Cancer Institute
Your abdomen extends from below your chest to your groin. Some people call it the stomach, but your abdomen contains many other important organs. Pain in the abdomen can come from any one of them. The pain may start somewhere else, such as your chest. Severe pain doesn't always mean a serious problem. Nor does mild pain mean a problem is not serious.
Call your health care provider if mild pain lasts a week or more or if you have pain with other symptoms. Get medical help immediately if:
An abscess is a pocket of pus. You can get an abscess almost anywhere in your body. When an area of your body becomes infected, your body's immune system tries to fight the infection. White blood cells go to the infected area, collect within the damaged tissue, and cause inflammation. During this process, pus forms. Pus is a mixture of living and dead white blood cells, germs, and dead tissue.
Bacteria, viruses, parasites and swallowed objects can all lead to abscesses. Skin abscesses are easy to detect. They are red, raised and painful. Abscesses inside your body may not be obvious and can damage organs, including the brain, lungs and others. Treatments include drainage and antibiotics.
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