What is an ultrasound?
An ultrasound (US) is a radiology test that makes pictures of internal organs through the use of sound waves. A probe is used against the skin and waves are created. As the waves return to the probe, an attached computer interprets the pattern. The computer then transforms the pattern to create an image that can be interpreted by a radiologist. US waves work well in parts of the body made up of tissue or water.
US is most often used to look at a growing baby but can also be used to look at organs in the belly (liver, kidney, gallbladder) as well as the heart and blood vessels (arteries and veins) and the lymph nodes. An ultrasound can also be done during a biopsy to better see a mass that needs to be tested.
Ultrasounds can be used in emergency situations, looking for blood in the abdomen, a blood clot in the leg or looking at the heart. Most often ultrasounds are performed non-emergently and scheduled as an outpatient procedure. They can be used with a physical exam and lab work to diagnose a medical problem.
How do I prepare for an ultrasound?
How you prepare for an ultrasound depends on the part of your body that needs testing. In some cases you don’t need to prepare. You may need to refrain from eating and drinking for up to 12 hours prior to the test, or you may need to drink up to six glasses of water two hours prior to the test.
If the US will be placed rectally for a prostate biopsy, you may need to clear the bowel of stool. If the scope will be inserted either endoscopically (through the mouth and esophagus) or bronchoscopically (into the lungs), you will be asked to fast to prepare for the sedation medications that will be used.
Your provider will give you instructions as to how to prepare for your US.
How is this test performed?
You may be asked to put on a hospital gown. The position you are asked to be in depends on the part of your body being looked at. A gel will be applied to the skin to allow the probe to make better contact with the skin. The technician will then place a transducer or probe on the skin above the area being looked at. The probe produces sound waves that travel into the tissue and then reflect off tissues within the body and return to the probe.
The test is non-invasive and usually painless.It only takes 15-30 minutes to complete, depending on the size and complexity of the area being looked at.
Picture of an US machine
How do you receive the results of your ultrasound?
The radiologist writes a report for the provider who ordered the ultrasound. The report provides information about the patient and the reason for the test. The report will detail both normal and abnormal findings. Your provider will be able to discuss your results with you.