Test Overview

An abdominal
X-ray is a picture of structures and
organs in the belly (abdomen). This includes the
stomach, liver, spleen, large and small intestines, and the diaphragm, which is
the muscle that separates the chest and belly areas. Often two X-rays will be
taken from different positions. If the test is being done to look for certain
problems of the kidneys or bladder, it is often called a KUB (for
kidneys, ureters, and bladder).

X-rays are a form of radiation, like
light or radio waves, that are focused into a beam, much like a flashlight
beam. X-rays can pass through most objects including the human body. X-rays make a picture by striking a detector that
either exposes a film or sends the picture to a computer. Dense tissues
in the body, such as bones, block (absorb) many of the X-rays and look white on
an X-ray picture. Less dense tissues, such as muscles and organs, block fewer
of the X-rays (more of the X-rays pass through) and look like shades of gray on
an X-ray. X-rays that pass mostly through air, such as through the lungs, look
black on the picture.

An abdominal X-ray may be one of the first
tests done to find a cause of belly pain, swelling, nausea, or vomiting. And
other tests (such as
ultrasound,
CT scan, or
intravenous pyelography) may be used to look for more
specific problems.

Why It Is Done

An abdominal X-ray is done to:

  • Look for a cause of pain or swelling in the belly or ongoing
    nausea and vomiting.
  • Find a cause of pain in the lower back on either side of the
    spine (flank pain). An abdominal X-ray can show the size, shape, and position
    of the liver, spleen, and kidneys.
  • Look for stones in the
    gallbladder,
    kidneys,
    ureters, or
    bladder.
  • Look for air outside of the bowel
    (intestines).
  • Find an object that has been swallowed or put into a body
    cavity.
  • Confirm the proper position of tubes used by your doctor in your
    treatment, such as a tube to drain the stomach (nasogastric tube), a feeding
    tube in the stomach, a tube to drain the kidney (nephrostomy tube), a catheter
    used for dialysis, a shunt to drain fluid from the brain into the stomach (V-P
    shunt), or other drainage tubes or catheters.

How To Prepare

Before the X-ray test, tell your
doctor if you are or might be pregnant. An abdominal X-ray is not usually done
during pregnancy because of the risk of radiation exposure to your baby (fetus). Many times an abdominal ultrasound is done
instead.

You may be asked to empty your bladder before the test.
You may need to take off any jewelry that may be in the way of the X-ray
picture, such as if you have a pierced belly button.

Talk to your
doctor about any concerns you have regarding the need for the test, its risks,
how it will be done, or what the results will mean. To help you understand the
importance of this test, fill out the
medical test information form (What is a PDF document?).

How It Is Done

An abdominal X-ray is taken by a
radiology technologist. The X-ray pictures are read by a
radiologist. Some other doctors, such as emergency
room doctors, can also look at abdominal X-rays to check for common problems,
such as a blocked intestine.

You may need to take off all or most
of your clothes. You will be given a gown to use during the test.

You will lie on your back on a table. A lead apron may be placed over
your lower pelvic area to protect it from the X-ray. A woman’s
ovaries cannot be protected during this test because
they lie too close to the belly organs that are X-rayed. A man’s
testicles can sometimes be protected during the
test.

After the X-ray machine is positioned over your belly, you
will be asked to hold your breath while the X-ray pictures are taken. You need
to lie very still so the pictures are clear.

Many times, two
pictures are taken: one while you are lying down (supine) and the other one
while you are standing (erect view). The erect view can help find a blockage of
the intestine or a hole (perforation) in the stomach or an intestine that is
leaking air. If you are not able to stand, the X-ray may be taken while you lie
on your side with your arm over your head.

An abdominal X-ray
takes about 5 to 10 minutes. You will be asked to wait about 5 minutes while
the X-rays are developed in case more pictures need to be taken. In some
clinics and hospitals, X-ray pictures can be made right away on a computer
screen (digitally).

How It Feels

You will feel no discomfort from the
X-rays. The X-ray table may feel hard and the room may be cool. You may find
that the positions you need to hold are uncomfortable or painful, especially if
you have an injury.

Risks

There is always a slight chance of damage to
cells or tissue from radiation, including the low levels of radiation used for
this test. But the chance of damage from the X-rays is usually very low
compared with the potential benefits of the test.

For example, the radiation exposure
from a chest X-ray is about equal to the natural radiation exposure received
during a round-trip airline flight from Boston to Los Angeles (Montreal to
Vancouver) or 10 days in the Rocky Mountains (Denver, Colorado).

Results

An abdominal
X-ray takes a picture of structures and
organs in the belly (abdomen). This includes the
stomach, liver, spleen, large and small intestines, and the diaphragm, which is
the muscle that separates the chest and belly areas. In an emergency, the
results of an abdominal X-ray are ready in a few minutes. Otherwise, a
radiologist usually has the official X-ray report
ready the next day.

Abdominal X-ray

Normal:

The pictures made by the
X-rays show that the stomach, small and large bowel, liver, spleen, kidneys,
and bladder are normal in size, shape, and location.

No growths, abnormal amounts
of fluid (ascites), or foreign objects are seen. Normal amounts
of air and fluid are seen in the intestines. Normal amounts of stool are seen
in the large intestine.

Abnormal:

A blocked intestine may be
seen because a portion of the intestine is larger than usual or areas in the
intestine have abnormal amounts of air or fluid in them.

A collection of air inside the
belly cavity but outside the intestines (caused by a hole in the stomach or
intestines) may be seen.

The walls of the intestines
may look abnormal or thick.

The size, shape, or location of the bladder or kidneys
may be abnormal. Kidney stones may be seen in the kidney, ureters, bladder, or
urethra.

In some cases,
gallstones can be seen on an abdominal X-ray.

Abnormal growths, such as
large tumors, or ascites may be seen.

A foreign object is seen or a
medical device looks abnormal or out of position.

What Affects the Test

Reasons you may not be able to
have the test or why the results may not be helpful include:

  • Being pregnant. If a view of a pregnant woman’s belly is needed,
    an ultrasound test may be done instead.
  • Not being able to lie still and hold your breath during the
    test.

What To Think About

References

Other Works Consulted

  • Fischbach FT, Dunning MB III, eds. (2009). Manual of Laboratory and Diagnostic Tests, 8th ed. Philadelphia: Lippincott Williams and Wilkins.
  • Pagana KD, Pagana TJ (2010). Mosby’s Manual of Diagnostic and Laboratory Tests, 4th ed. St. Louis: Mosby Elsevier.

Credits

ByHealthwise Staff
Primary Medical Reviewer Adam Husney, MD – Family Medicine
Specialist Medical Reviewer Howard Schaff, MD – Diagnostic Radiology

Current as ofOctober 9, 2017