Ultrasound imaging, also called ultrasound scanning or sonography, involves exposing part of the body to high-frequency sound waves to produce pictures of the inside of the body.
Ultrasound exams do not use ionizing radiation (as used in x-rays). Because ultrasound images are captured in real-time, they can show the structure and movement of the body’s internal organs, as well as blood flowing through blood vessels. Ultrasound imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions.
Doppler ultrasound images can help the physician to see and evaluate:
• blockages to blood flow (such as clots).
• narrowing of vessels (which may be caused by plaque).
• tumors and congenital malformation.
Preparation for ultrasound is minimal. Generally, if internal organs such as the gallbladder are to be examined, patients are requested to avoid eating and drinking with the exception of water for six to eight hours prior to the examination. This is because food causes gallbladder contraction, minimizing the size, which would be visible during the ultrasound.
What to expect
Before the exam, you may be asked to change into a robe or gown. You will most likely be lying down on a table with a section of your body exposed for the test. An ultrasound technician will apply a special lubricating gel to the area under examination, ultrasound exams are painless, however, there may be varying degrees of pressure as the technologist guides the transducer over your body, especially if you are required to undergo the exam on a full bladder. This gel will prevent friction so that the technician can move the ultrasound transducer back and forth to image the area. The transducer has a similar appearance to a microphone and the gel that is applied will help transmit sound waves. Depending on the area being examined, you may need to change positions so that the technician has better access. After the procedure, the gel will be cleaned off your skin. You will be free to go about your normal activities after the procedure has finished.