I'm sorry, but we cannot write answers that long on this site. It is recommended that we give answers of about 90 words. Hopefully you can use this answer to write your own longer answer.
Ultrasound is used in medicine for imaging various things within the human body.
Perhaps the most common and well-known use is in obstetrics. Ultrasound images of a developing fetus can be used to determine the size of the fetus so as to ensure that it is developing properly. It can be used to determine the sex of the fetus as well.
Ultrasound is also used in cardiology to look inside the heart and at the blood vessels surrounding the heart.
Finally, in urology, it is used to evaluate kidney function and to help detect prostate cancer.
Ultrasound is a diagnostic tool. It was discovered in 1951 by Ian Donald, an English physician. It was used on a pregnant women after its discovery . Ultrasound creates sound waves that penetrate the human body and bounce back. It creates an image from the returning waves. The low energy sound waves are safer than other forms of imaging because it is not capable of changing cell structure.
In contrast, x-ray radiation, which is also called ionizing radiation, is capable of changing and damaging cell structure. Therefore, ultrasound is the preferred method of visualizing many parts of the body. For the nonpregnant person it can be used to assess diseases of the abdomen, pelvis, breast, thyroid, testicle and soft tissue.
The statement in the answer posted above that:
It is recommended that we give answers of about 90 words.
is not entirely correct. About 90 words is not the recommended length of answer, but the minimum expected from editors. The maximum limit of answer is 3500 characters, which should easily accommodate 500 words. I hope editors will not give excuses of eNotes policy to justify answer that do not cover scope of question completely.
My answer below consists of 1630 characters or 258 words.
Ultrasound are sound waves with frequencies above the range of human hearings. Thus ultrasound may be defined as sound waves with frequencies exceeding 20,000 hertz. Ultrasound wavelength are shorter as compared to normal sound waves. Because of this the ultrasound waves are reflected back by obstacles in their path rather than bending round them and move forward. This quality of ultrasound makes it useful in many different fields including medical field.
Ultrasound is used passively in medical field to obtain information about the condition of health of patient being treated. It is also used actively to treat the patient. The medical use of ultrasound was pioneered by a obstetrician named Ian Donald, who used it to generate and study the image of a foetus in the womb. Now Ultrasound is used to obtain images of many internal organs such as kidney, heart and lever, for which x-ray does not work. Ultrasound images enable studying size shape and other dimensional characteristic of such organs, including existence of tumors and presence of other abnormalities such as internal eruptions. In this way Ultrasound is very useful in detecting tumors and gall stones. A special technique using ultrasound called echocardiography enables cardiologist to study the functioning of the heart including flow of blood through heart valves. The ultrasound techniques score over the x-ray techniques for obtaining images of internal organ in that these are safer.
Active use of ultrasound in medical field includes destruction of brain tumors and kidney stones. Ultrasound is also used to collect eggs for producing test tube babies.