An instrument called a transducer emits high-frequency sound, inaudible to human ears, and then records the echoes as the sound waves bounce back to determine the size, shape, and consistency of soft tissues and organs.
This information is relayed immediately to produce images on a computer screen. Ultrasound technicians, or sonographers, have special training in how to perform the test. Then a radiologist or your doctor will interpret the ultrasound images. This technology can help diagnose and treat certain conditions.
Depending on the type of ultrasound test you are having, your doctor may offer special instructions, such as not eating or drinking anything for a number of hours before the test. Or you may be advised to drink several glasses of water in the time leading up to the test and refrain from using the bathroom to ensure that your bladder is full.
You should wear comfortable clothing that is easy to remove or partially remove. In some cases, you may need to disrobe or wear a gown, but often an ultrasound technician can easily access the area of the body that is being screened without your having to take off your clothes.
The technician will apply a water-based gel to the area. This is so the transducer can easily glide across your skin without any air in between. He or she may be looking for specific markers and may make measurements or notes while the test is in progress.
A typical ultrasound takes between 30 minutes and an hour. Ultrasounds usually are not uncomfortable, and you are awake and alert during the procedure. Often a technician will discuss what he or she is seeing during the test, but in some instances, you may need to wait to discuss the findings with your doctor.