An X-ray is a quick, painless test that produces images of the structures inside your body — particularly your bones. An X-ray machine sends individual x-ray particles through the body. A computer is used to record the images that are created from a digital x-ray plate.
Structures that are dense (such as bone) will block most of the x-ray particles and will appear white. Metal and contrast media* will also appear white. Structures containing air will be black, and muscle, fat, and fluid will appear as shades of gray.
X-ray exams are performed in some of our outpatient imaging facilities by an x-ray technologist. The positioning of the patient, x-ray machine, and film depends on the type of study and area of interest. Multiple individual views may be requested.
*For some types of X-ray tests, a contrast medium (special dye) — such as iodine or barium — is introduced into your body to provide greater detail on the X-ray images.
Different types of X-rays require different preparations. Ask the imaging center to provide you with specific instructions when scheduling your appointment.
In general, you undress whatever part of your body needs examination. You may be asked to wear a gown during the exam, depending on which area is being X-rayed. You may also be asked to remove jewelry, eyeglasses and any metal objects that may obscure the X-ray image, because these objects can show up on an X-ray.
Inform the health care provider prior to the exam if you are pregnant, may be pregnant, or have an IUD inserted.
Before some types of X-rays you’re given a liquid called contrast medium. Contrast mediums, such as barium and iodine, help outline a specific area of your body on the X-ray image. You may swallow the contrast medium, or receive it as an injection or an enema.
If abdominal studies are planned and you have had a barium contrast study (such as a barium enema, upper GI series, or barium swallow) or taken medications containing bismuth (such as Pepto-Bismol) in the last 4 days, the test may be delayed until the contrast has fully passed.
What to Expect
An X-ray machine produces a tiny burst of radiation, at a safe level, that passes through your body and records an image on a specialized plate. You can’t feel the X-ray passing through you.
A technologist positions your body to obtain the necessary views. He or she may use pillows to help you hold the proper position. Much like conventional photography, motion causes blurry images on radiographs, and thus, patients may be asked to hold their breath or not move during the brief exposure (about 1 second).
An X-ray procedure may take only a few minutes for a bone X-ray, or more than an hour for more-involved procedures, such as those using a contrast medium.
After an X-ray, you generally can resume normal activities. Routine X-rays usually have no side effects. However, if you receive an injection of contrast medium before your X-rays, call your doctor if you experience pain, swelling or redness at the injection site.
Some people worry that X-rays aren’t safe because radiation exposure that may lead to illness. But the amount of radiation you’re exposed to during an X-ray is so small that the risk of any damage to your body is extremely low.
However, if you’re pregnant or suspect that you may be pregnant, tell your doctor before having an X-ray. Though the risk of most diagnostic X-rays to an unborn baby is small, your doctor may consider another imaging test, such as ultrasound.