An abdominal ultrasound (sonogram)
is an imaging test used to assess the organs and structures in the belly (abdomen).
These include the:
- Bile ducts
- Abdominal aorta
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
An abdominal ultrasound uses a
handheld probe (transducer). It sends out ultrasonic sound waves at a frequency too
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.
moves most slowly through air. The speed at which the sound waves are returned to
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 transducer.
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
rate of blood flow within a blood vessel. Absence or faintness of these sounds may
there is a blockage of blood flow.