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What is Ultrasound?
Ultrasound or sonography is the practice of sending of sound waves through the body. When the waves strike the internal structures, some of the energy is reflected back to the surface and some continues on and strikes deeper structures. The reflected sound waves are detected by the instrument and used to create an image of anatomic parts. No ionizing radiation (x-ray) is involved in ultrasound imaging.
How does the procedure work?
Ultrasound imaging is based on the same principles involved in many
familiar devices, such as a depth sounder used by fisherman. The sound
wave is focused and is directed towards objects, and the reflected waves
can be used to determine how far away the structure is, its size, shape
and its internal consistency (fluid, solid or mixed). Importantly, for
vascular purposes, a special processing of the sound waves called
Doppler, can be used to evaluate moving things, such as its direction,
speed, and character. This is very similar to sonar used by bats, who
are the undeniable masters at this technique.
The ultrasound transducer functions as both a loudspeaker (to create the sounds) and a microphone (to record them). When the transducer is pressed against the skin, it directs a stream of inaudible, high-frequency sound waves into the body. As the sound waves echo from the body's fluids and tissues, the sensitive microphone in the transducer records tiny changes in the sound's pitch and direction. These signature waves are instantly measured and displayed by a computer, which in turn creates a real-time picture on the monitor. The live images of the examination can be recorded on videotape. In addition, still frames of the moving picture are usually "frozen" to capture a series of images. Blood flow changes the pitch of the sound beam; this Doppler effect can be heard or detected on the image as color or displayed graphically. Often, the patient is able to see it as well. Blood flow also produces sound that can be heard with Doppler ultrasound. You may also hear the sounds.
How is the procedure performed?
The patient is positioned on an examination table. A clear gel is applied to the area that will be examined. The gel helps the transducer make a secure contact and eliminates air pockets between the transducer and the skin, since the sound waves cannot penetrate air. The vascular technologist then presses the transducer firmly against the skin and sweeps along the area of interest, reviewing the images on the monitor and capturing "snapshots" as required.
How should I prepare for the procedure?
You should wear comfortable, loose-fitting clothing for your ultrasound exam. Depending upon the part of the body being examined, some disrobing may be necessary. For many of the examinations, there is no preparation required. If your abdominal vessels are being studied, you will need to fast before the procedure in order to minimize the motion of the intestine. We will notify you if this is necessary.
What will I experience during the procedure?
Most ultrasound studies are fast and easy usually taking less than 30". However depending upon the body part being evaluated and any disease that may be present, testing could run an hour or more. Do not assume that there is any problem if your exam takes longer.
Who interprets the results and how do I get them?
Because your personal physician knows your entire history, they are best suited to discuss the results with you and specifically what they mean to you. After the testing is completed and you are released, the vascular technologist's work is only half finished. They will then sort through all the images obtained during your exam. A large number of additional measurements are obtained and organized into a report format. This report, the images, and other data is then reviewed by your physician or one designated by them. QVI has a panel of qualified physicians from which to chose. This final report is forwarded to your personal physician who is best suited to explain what the findings mean to you. This typically happens within 1-2 days.
If there are any urgent findings, we will call your physician immediately.
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