What are x-rays and radiographs?

X-rays are a form of electromagnetic energy, or radiation. Visible light and microwaves are other forms of electromagnetic energy. These different forms of energy have different wavelengths.

X-rays are able to penetrate body tissues. They are used to create pictures, or images, of body structures on film.

Sometimes the images on film produced by x-rays are also called x-rays. More correct names for the pictures on film are radiographs or x-ray images. However, the term x-ray is commonly used to refer to these images.

A radiograph is a painless procedure. Modern equipment produces high-quality images using the lowest possible amount of radiation. Many physicians' offices have their own x-ray equipment.

When are they used?

X-rays are used in the diagnosis of many diseases and disorders. They can show changes in the part of the body being examined.

How do I prepare for a radiograph?

There are no special preparations for most x-ray exams. If you are having a special x-ray exam that requires preparation, your doctor will give you special instructions.

What happens during the procedure?

Usually you undress to expose the area being examined. You may be placed on a table (sitting or lying down). You will get in a position that gives a clear view of the part of the body being examined.

The x-ray technician will put the x-ray machine in the proper position. The x-ray technician will leave the room or go behind a protective screen or wall to take the radiograph. This keeps his or her daily exposure to x-rays at a minimum.

It takes only a second for a simple radiograph to be taken (similar to taking a photo). You must remain perfectly still while the x-ray picture is being taken. Several radiographs may be taken for different views.

After the radiographs are taken, the film must be developed. The development takes just a few minutes. The x-ray technician will then check the images to make sure no other pictures need to be taken before you leave.

After the technician has checked the radiographs, a radiologist or your doctor will look at them and interpret them. Radiologists are doctors who have extensive training in the interpretation of radiographs and other types of images.

Special types of x-ray exams include:

• CT scan: A scan that uses x-rays and a computer to produce cross-sectional views of specific parts of the body. Sometimes dyes (called contrast media) are injected into your body to help the doctor see specific structures.

• Venography: A procedure in which a special liquid is injected into the veins. The path of the liquid as it travels through the body can be followed with a series of radiographs. An example of this is an IVP (intravenous pyelogram), which looks at the kidneys and bladder.

• Barium enema: A procedure in which a special liquid is passed into the large intestine through the rectum. The liquid appears as an opaque or white substance on the radiograph.

• Upper GI: A procedure similar to a barium enema except you swallow a special liquid and then radiographs are taken.

What are the benefits of this procedure?

Radiographs help your doctor see the inside of your body and thus make a better diagnosis of your problem.

What are the risks associated with a radiograph?

If you have radiographs frequently, it is considered unhealthy because of the increased exposure to radiation. However, you can have many, many radiographs during your lifetime without significant danger to your health.

You may have an allergic reaction to the contrast dye used in CT scans or venography.

If you are pregnant, you should not be exposed to x-rays unless you discuss the matter with your doctor first.

When should I call the doctor?

Call the doctor immediately if:

• You have any change or worsening of pain or symptoms.

Call the doctor during office hours if:

• You have questions about the procedure or its result.

• You want to make another appointment.