What is an abdominal ultrasound?
An abdominal ultrasound (sonogram) is an imaging test used to assess the organs and
structures in the belly (abdomen). These include the:
Ultrasound lets your healthcare provider easily see the abdominal organs and structures
from outside the body. Ultrasound may also be used to assess blood flow to abdominal
An abdominal ultrasound uses a handheld probe (transducer). It sends out ultrasonic
sound waves at a frequency too high to be heard. When the transducer is placed on
the belly at certain locations and angles, the sound waves move through the skin and
other body tissues to the organs and structures of the belly. The sound waves bounce
off the organs like an echo and return to the transducer. The transducer picks up
the reflected waves. These are then converted into an electronic picture of the organs.
Different types of body tissues affect how fast sound waves travel. Sound travels
the fastest through bone tissue. It moves most slowly through air. The speed at which
the sound waves are returned to the transducer, as well as how much of the sound wave
returns, is translated by the transducer as different types of tissue.
Before the procedure, a clear, water-based gel is put on the skin. This lets the transducer
move smoothly over the skin. It also helps remove any air between the skin and the
An ultrasound can also be used to assess blood flow in the belly. The transducer that
does this contains a Doppler probe. The Doppler probe evaluates the speed and direction
of blood flow in vessels by making the sound waves easy to hear. The degree of loudness
of the sound waves indicates the rate of blood flow within a blood vessel. Absence
or faintness of these sounds may mean there is a blockage of blood flow.
Why might I need an abdominal ultrasound?
Abdominal ultrasound may be used to assess the size and location of organs and structures
in the belly. It can also be used to check the belly for conditions such as:
Collections of fluid (cysts)
Collections of pus (abscesses)
Clots in blood vessels
Abdominal aortic aneurysm
The size of the abdominal aorta can be measured by ultrasound. This may be done to
detect an aortic aneurysm. This is a ballooning and weakening of the blood vessel.
Stones in the gallbladder, kidneys, and ureters may also be found with ultrasound.
Abdominal ultrasound may be used to guide needles used to biopsy. A biopsy is the
removal of a piece of tissue for testing. Abdominal ultrasound is also used to drain
fluid from a cyst or a pus-filled infection (abscess).
This test can be used to assess blood flow in the belly.
There may be other reasons for your healthcare provider to advise an abdominal ultrasound.
What are the risks of an abdominal ultrasound?
There is no radiation used and generally no discomfort caused by moving the ultrasound
transducer over the skin. No radiation or contrast dyes are used. So ultrasound may
be safely used during pregnancy or in people with allergies to contrast dye.
There may be risks depending on your specific health condition. Discuss any concerns
with your healthcare provider before the test.
Certain factors or conditions may interfere with the results of the test. These include:
How do I get ready for an abdominal ultrasound?
Your healthcare provider will explain the test to you and you can ask questions.
You may be asked to sign a consent form that gives your permission to do the test.
Read the form carefully. Before you sign, ask questions if anything isn't clear.
Any preparation before the test, such as fasting (not eating) or sedation (using medicines
to make you sleepy), will be determined by the specific area to be examined. Your
healthcare provider will give you instructions if needed.
The gel placed on the skin during the test doesn't stain clothing. But the gel may
not be fully removed from your skin afterward. So you may want to wear older clothing.
Based on your health condition, your healthcare provider may request other specific
What happens during an abdominal ultrasound?
An abdominal ultrasound may be done on an outpatient basis. This means you go home
the same day. Or it may be done as part of a hospital stay. Tests may vary depending
on your condition and your healthcare provider's practices.
Generally, an abdominal ultrasound follows this process:
You will be asked to remove any clothing, jewelry, or other objects that may interfere
with the scan.
If asked to remove clothing, you will be given a gown to wear.
You will lie on an exam table. You will lie either on your side or on your back, depending
on the specific area of the belly to be examined.
A clear, water-based gel will be put on the skin over your belly.
The transducer will be pressed against the skin and moved around over the area being
If blood flow is being assessed, you may hear a whoosh, whoosh sound when the Doppler
probe is used.
Once the test is done, the gel will be wiped off.
The abdominal ultrasound test itself causes no pain. But having to lie still or flat
for the test may cause mild discomfort. And the gel may feel cool and wet. The technologist
will use all possible comfort measures. They will complete the test as quickly as
possible to reduce any discomfort.
What happens after an abdominal ultrasound?
There is no special care needed after an abdominal ultrasound. You may go back to
your normal diet and activities unless your healthcare provider tells you differently.
Your provider may give you other instructions after the test, depending on your particular
Before you agree to the test or the procedure make sure you know:
The name of the test or procedure
The reason you are having the test or procedure
What results to expect and what they mean
The risks and benefits of the test or procedure
What the possible side effects or complications are
When and where you are to have the test or procedure
Who will do the test or procedure and what that person’s qualifications are
What would happen if you did not have the test or procedure
Any alternative tests or procedures to think about
When and how you will get the results
Who to call after the test or procedure if you have questions or problems
How much you will have to pay for the test or procedure