Ultrasound is sound waves which have a frequency above the human hearing range. The highest frequency that the human ear can detect is approximately 20,000 Hertz. Beyond this frequency, our human ear cannot hear. Ultrasound is used in electronic, navigational, industrial, security, and medical applications.
Ultrasound imaging is a common diagnostic medical procedure that uses high frequency sound waves to produce dynamic images (sonograms) of organs, tissues, or blood flow inside the body. Prenatal ultrasound examinations are performed by trained professionals, such as sonographers, radiologists, and obstetricians.
Ultrasound is increasingly being used in the detection and treatment of heart disease, heart attacks and vascular disease that can lead to stroke. It is also used to guide fine-needle tissue biopsy to assist in taking a sample of cells from an organ for lab testing (for example, a test for cancer in breast tissue).
The intensity level of ultrasound used for imaging is regarded as non-thermal and non-destructive. It is preferred over other imaging methods because it is noninvasive, involves no radiation, and avoids the possible hazards such as bleeding, infection, or reactions to chemicals of other diagnostic methods.
Ultrasound for pain relief
Ultrasound therapy is often used to decrease joint stiffness, to reduce pain and muscle spasms and to improve mobility. Ultrasound treatment is done by a physical or occupational therapist who guides the waves into the body from the head of a ultrasound machine.
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In recent years, High Intensity Focused Ultrasound (HIFU) has been used for the treatment of prostate cancer. This procedure uses ultrasound to destroy deep-seated tissue without affecting the surrounding healthy tissue. The results have been very encouraging.
Use of ultrasound in prostate cancer treatment
There has been quite a lot of research on bones and fractures using ultrasound. For instance, in one study carried out at the University of Texas Health Science Center in San Antonio, researchers used ultrasound to treat patients for 20 minutes a day and came to the conclusion that “Pulsed low-intensity ultrasound therapy can speed the healing of shinbone (tibia) fractures and dramatically lower health care costs.”
In a paper entitled “The use of ultrasound to accelerate the healing of fractures” published in the February 2001 issue of The Journal of Bone and Joint Surgery, the authors reviewed a series of studies that were carried out over a few decades and concluded that “A large repository of basic-science and clinical work suggests means of which fracture-healing can be augmented by low-intensity ultrasound”. The authors also revealed a study that suggests that the use of ultrasound in such patients could result in cost-savings of between US$13,000—$15,000 per case.
