Ultrasound examinations use special equipment that sends high-frequency sound waves into the body. These sound waves bounce back, or echo, off internal structures and organs. A computer converts the sound waves into moving images that are displayed in real time on a computer monitor.
An ultrasound exam, also known as sonography (sonogram), captures images that show the size, shape, consistency and position of internal organs or soft tissue. Ultrasound images are useful in the examination of most internal organs.
Ultrasound procedures are frequently performed during pregnancy.
Abdominal ultrasounds include images of the solid upper abdominal organs such as the liver, gallbladder, pancreas, aorta and spleen. These tests require that you do not eat, drink or smoke anything for 6 hours prior to the test. These exams usually take about 30–45 minutes to complete.
Pelvic and obstetric ultrasound tests to see the bladder, kidneys, ovaries, uterus, or fetus may require you to drink 32 oz of water 1 hour prior to the test to fill your bladder. These tests may take up to an hour.
Additionally, the exam is used to guide biopsies or the insertion of peripherally inserted central catheter (PICC) lines, as well as to examine some blood vessels such as the carotid arteries for plaque buildup and the leg veins for blood clots.
An ultrasound examination may be performed to detect, diagnose or treat problems with the:
- Blood vessels
- Uterus and ovaries
- Fetus (unborn child)
What can you expect during your exam?
When you arrive, you are positioned, usually face-up, on an exam table. A clear gel is applied to the area of the body under examination. A sonographer begins the scan by pressing a transducer—a device that sends and receives sound waves—to the gel-coated skin and gently moves the device around the targeted area. The ultrasound images are displayed and viewed in real-time on a video monitor. Sometimes patients are asked to wait while the images are interpreted.