Monday, March 9, 2009

Sonography

Sonography is used in a number of medical applications. Through the application of ultrasound technology, sonographers are able to obtain an image of the internal organs of a patient without any obtrusive procedures. Sonography has been used to spot tumors, abrasions in various tissues and is commonly used to check on the development of the fetus in pregnant women. Sonography depends on the frequency of sounds that are too high for the human ear to perceive, and the range of frequency has a direct affect on the quality of the picture a sonography machine picks up.








History of


The idea of using ultrasonic energy in the medical field, which ultimately led to the practice of sonography, was played around with every since the late 1930s and early 1940s. It was first applied as such in the United States Naval Medical Research Institute by Dr. George Ludwig. The technology was reported and tested further in Sweden by Inge Edler and Carl Hellmuth Hertz. In 1953, the duo achieved the first successful measurement of heart activity using sonography. At the same time, sonography technology was being practiced and researched in Scotland. Professor Ian Donald published one of the most important medical papers in the medical imaging field in 1958 on detecting abnormal body masses through sonography. His research continued into the 1960s to focus on fetal development. Research branched off from there to bring sonography to where it is in the medical field today.


Benefits


Sonography has a number of medical benefits attached to it. For one, it is a painless procedure that offers medical officials a wealth of information. They are able to use it to detect anomalies that could be related to a number of diseases, and also to detect fluid buildup in the body and measure it. Also, sonography helps doctors investigate the growth and health of the fetus in pregnant women without harming it.


Risk Factors


Even though sonography is considered to be a safe way of obtaining images of internal organs and body functions, there are some risks and side effects that have been observed. Studies done on mice at Yale University have shown that prolonged exposure to the ultrasound used in sonography has caused abnormalities in the neurons. While most medical officials agree that this may be only a slight risk, it is widely known that there have not been enough studies looking into this.


Type








There are four types, or modes, of ultrasound that is used in sonography. The first is A-mode, which is simple in that is charts the echoes of high frequency sounds in the body onto a chart to reveal depth. It is also used to pinpoint specific things in the body, such as tumors. B-mode ultrasound is a bit more complicated and creates a two-dimensional image on the sonography screen. M-mode makes use of rapid B-mode scans and compiles them to create a picture that is in motion. Finally, Doppler mode uses the Doppler effect in order to create motion, direction and a three-dimensional image.


The Facts


Sonography makes use of a machine that has a computer screen attached to a probe that has one or more acoustic transducers. A coat of jelly is applied to the area of the skin near where a scan is going to be made. This helps the ultrasound waves travel easier into the body. The transducers send pulses of sound into the body, which is reflected off objects of a different density. This reflection is noted as an echo, and the time it takes for an echo to reach the transducers is measured and from that the depth of the object can be determined. These echos are put together to form an image of varying quality, depending on the mode and duration of the ultrasound pulses.

Tags: fetus pregnant, fetus pregnant women, frequency sounds, have been, internal organs, into body