Imaging

Ultrasound

Introduction

Ultrasound imaging is the method of obtaining images of the internal parts of the human body. Ultrasound has been used to take images of organs such as heart, liver, gallbladder, spleen, pancreas, kidneys, and bladder. Ultrasound actually takes images in real time, and they extensively show blood flow and heart valve function. Unlike an X-Ray, ultrasound imaging does not use ionizing radiation (radiation with enough energy to make atoms or molecules electrically charged).

Ultrasound imaging uses sonar technology, which is also utilized by bats and ships at sea. The ultrasound machine, the transducer, functions as both a generator of the sound as well as a detector.

Transducer

The transducer sends out high frequency, inaudible, sound waves through the body. The waves reflect off the object being scanned, and echoes are produced. These echoes are then used to figure out the size and consistency of the object being scanned as well as how far away it is. The transducer takes the echoes and also creates a real-time computer image/video which is capable of freeze-framing so the doctor can examine a still image.

A specialized version of ultrasound is Doppler ultrasound, which is used to examine blood flow. It allows the physician to observe blood flow blockages, blood clots, narrowing of vessels, plaque, tumors and congenital malformations. The Doppler ultrasound shows blood as blue or red, depending on the direction the blood is flowing (the velocity of the blood).

Echocardiogram is a specialized term used for ultrasound tests of the heart using Doppler Ultrasound. Ultrasound is a very useful way of examining the human heart as well as many of its many surrounding arteries and veins. It is a safe, painless, noninvasive way to look at the vital organs of the human body.

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In the lab...

Safety Precautions: There are generally no safety precautions related to getting an ultrasound scan. Often when the doctor is examining something other than the heart they instruct you to do something specific.

Orientation of Patient: The patient is generally positioned lying down on an examination table. A clear gel is then applied to the patient’s chest (the area being scanned). The gel is applied, because it helps the transducer make proper contact with the skin. Also the waves emitted by the transducer cannot penetrate air, and the gel eliminates any air pockets in between the transducer and the skin. Once the gel is applied, the radiologist will firmly press the transducer against the skin and sweep back and forth over the chest area.

Length of Scan: However long the physician needs to observe the real-time video produced. Usually the patient is allowed to leave immediately after. Top

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