Ultrasound is a form of high energy sound wave which frequency is higher than the upper limit of the hearing capacity of humans. It lies somewhere around 20,000 kilohertz. Ultrasound scanning is the most sought after form of scanning in medicinal science today, thanks to its ability to produce high quality images which help physicians diagnose the body condition of the patient. In medicinal terms, the procedure is called ultrasonography. It is done by passing high frequency sound waves through the body of the patient to get visual images of the internal organs, tissues, and blood flow. These images help physicians analyze the body condition of the patient and come up with an idea of the abnormality which might be causing the problem. This procedure is commonly called as ultrasound scan.
An ultrasound scan is done by passing through sound waves which have frequency higher than 20,000 kilohertz. It ranges from 3 to 15 megahertz, as high frequencies produce high resolution images. While frequencies lower than the one mentioned here might produce low resolution images, they images deeper into the body. Superficial organs such as muscles, tendons, breasts, and genitals don't require great penetration by the sound waves and are scanned in very high frequency (7-15 megahertz) to get high resolution images. Deeper organs such as liver, kidney, and pancreas cannot be reached with very high frequency waves and are imaged using a lower frequency (1-6 megahertz) to get low resolution images with greater penetration. So, it's the choice of the sonographers at the end of the day as to choose which frequency to get the scan done, depending on the need of the physician.
Ultrasound is used in various branches of medicine such as cardiology, endocrinology, gastroenterology, gynecology, obstetrics, urology, musculoskeletal, and ophthalmology. Specialty images can be produced in case of different branches of medicine by using a specialty transducer. An important and most common usage of ultrasound scan is to check the development of fetus during pregnancy. An ultrasound scan should be done only by qualified sonographers who have professional training. It requires a deeper understanding of anatomy, physiology, equipment usage, instrumentation techniques, and patient care. Also, the sonographer must be able to arrive at decisions during the scan regarding matters such as the frequency that should be used and other related things. An ultrasound scan usually has three stages. Production of the sound wave, reception of the echo, and interpretation of the echo received. A qualified sonographer should be able to interpret the echoes received and should be able to explain the physician. Apart from the usual diagnostic purposes, ultrasound can also be used for various other purposes. It can be used in the field of dentistry, to clean the teeth. It can be used to generate heat in the softer tissues of the body during occupational therapy, physical therapy, and in treating some forms of cancer. Focused ultrasound may also be used to treat both benign and malignant tumors. It can also be used to break kidney stones or renal calculi.