What is ultrasound imaging?

Ultrasound imaging (also called ultrasound scanning or sonography)  is a procedure that produces pictures of the inside of the body using high frequency sound waves. These pictures are shown on a monitor in real time. The monitor displays the internal body structure and its movement. The ultrasound can show the blood moving through the veins. Ultrasound imaging may be used to examine internal organs and body parts to detect physical abnormalities or functional abnormalities. Ultrasound imaging is most commonly known for its use in pregnancy, where it is used to evaluate the fetus. Other common uses of ultrasound imaging include evaluation of blood flow through the veins and arteries and the detection of blood clots. 

What equipment is used?

A special machine called an ultrasound scanner is the only equipment needed to perform an ultrasound imaging test. The machine consists of a console which contains all the electronics, a computer, a monitor that shows the display in real time. Attached to the console is a transducer which is placed on the patient's skin over the area to be evaluated.Traditionally the ultrasound scanner are quite large bulky machines, however with the new computerized technology the ultrasound scanner may be as small and portable as a laptop computer.

How does ultrasound work?

Ultrasound imaging works by using high frequency sound waves introduced into the body and measuring the echo of the sound waves as they bounce off internal body structures. This is the same principle that is used of ships when using sonar. High frequency sound waves are produced by the ultrasound scanner and transmitted into the body through the transducer. The transducer also detects the same waves after they bounce off an object.  By measuring these sound waves the scanner determines how far away the object is, its size, and its shape. It will also determine whether the object is solid or hollow and whether or not it contains fluid.  The measurements of the returning sound waves are sent to a computer which in turn sends a real time display to the monitor where a live picture is displayed and recorded.

Explain the procedure.

The patient lies on an examination table usually on their back. The area to be examined is exposed and a cool clear gel is applied to the area. This is to prevent any air pockets between the transducer and the patient’s skin. The transducer is placed firmly on the skin overlying the area to be examined. The transducer is swiped back and forth or may be pressed harder until the correct image is acquired.A duplex (Doppler) ultrasound is performed through the same transducer at the same time. The examination is completed and the images are reviewed for quality and completeness. The patient is then free to go and may return to normal functions.

What will I experience during the procedure?

Ultrasound imaging is a completely painless procedure. Patients will feel the coolness of the gel when applied to their skin. Some may experience a small amount of discomfort if the area being examined is sore or tender. No anesthetics or medications are needed to tolerate the exam.Most examinations are completed within 30 minutes.

When will I get the results?

This depends on where you have the imaging and who is performing it. Results of an ultrasound imaging exam must be interpreted by a qualified physician. If a qualified physician performs the exam or is available, the patient may receive the results immediately. If not, a record of the exam will be sent to the physician to be interpreted and a report will be sent to the physician who requested the exam.

What are the risks and benefits of the test?

Benefits of the ultrasound imaging exam are numerous. They include painless, widely available, easy to perform, less expensive and gives a clear picture of tissues that will not show up on x-rays. Ultrasound may be repeated as often as necessary because it causes no ill affects to the patient.There are no known harmful effects of ultrasound on humans.