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Ultrasound Imagery
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Ultrasound imaging is a technique
used mainly to obtain accuracy in medical diagnosis and for
certain medical treatments also. It has other non-medical uses
too. The images obtained by using ultrasound rays help doctors
in 'seeing' many of the organs inside the body. Ultrasound
waves - sound waves of a very high frequency are used for this
purpose. Using machinery specially designed for the purpose,
these ultrasound waves are directed into the part of the body
which needs to be examined. When the tissues in our body come
in contact with these waves they reflect them back. The
resultant reflected waves are processed to produce a moving
image that can be seen on a computer screen. Ultrasound
imaging is used for the diagnosis of many ailments. |
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The imaging process
Ultrasound waves are sound waves but are inaudible to the human
ears, as their frequency is very high. They are produced by the
electrical stimulation of a piezoelectric crystal. The electric
stimulation oscillates the crystal rapidly to produce these waves. A
device known as the transducer is used to transmit the sound waves
to the required area. When these waves travel through the human
body, they get reflected back whenever they encounter any change in
tissue density. The transducer then receives the reflected rays and
translates them into images. The transducer used for ultrasound
imagery gets ultrasound waves as input and it gives back the
reflected waves from our body as its output. |
The most popular use of ultrasound imaging is for examining
the fetus during pregnancy. |
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In order to be very effective the transducer needs to be as close to
the body as possible. So it is moved on the skin and for better
transmission of the sound waves and to improve its effectiveness, a
jelly-like substance is smeared on the skin.
Examination of the heart using ultrasound waves has become an
essential part of diagnosis for heart problems. This examination is
known as echocardiography. Another popular application of ultrasound
imagery is in surgical procedures. Ultrasound images are used for
guidance while conducting surgery. The Doppler motion study is
another popular application of ultrasonic waves in medicine. Joint
pains and certain types of tumors are treated using the localized
heating, that can be produced by ultrasound waves. These waves are
also used to eliminate stones from the kidney and the gall bladder.
The rays directed into our body are reflected back at different time
intervals and in varying proportions. The amount of reflection and
the time taken for reflection is analyzed and the analysis is used
to obtain relevant information.
Not all parts of our body can be 'seen' using ultrasound waves. The
bones and lungs absorb these waves and so no images can be formed.
Other uses
Ultrasound waves are used to speed up chemical processes like
oxidation, reduction, hydrolysis, polymerization, depolymerization,
etc. The ultrasound waves act as a catalyst and make these processes
faster and more efficient. The shape of the piezoelectric crystal is
chosen as per the application that the ultrasound imaging is
required for. Different shaped crystals produce different varieties
of ultrasound rays. |
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