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. When
X-rays strike a piece of photographic film, they make a picture. 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
CT scan, or
intravenous pyelography) may be used to look for more
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
- Look for air outside of the bowel
- Find an object that has been swallowed or put into a body
- 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.