Ultrasound energy

As stated above, properties of ultrasound energy traveling through biological tissues has been extensively studied in recent years. The attenuation due to scattering of energy in different tissues can be measured by a device called a transducer. Recorded information from transducers such as the relationship to the site of origin and intensity of the signal can then be put together to form images of what lies inside the target tissues. Higher frequency ultrasound waves generally produce higher resolution images, but attenuation also increases as frequency increases which restricts imaging depth. Consequently, the best frequency has been determined for each type of diagnostic test and body tissue. Some of the more common ultrasound tests include A-scans, M-scans, B-scans, and Doppler techniques. These test produce images ranging from one-dimensional images to moving, real-time two –dimensional images that can often be seen immediately on a screen. The advent of ultrasound technology has completely changed the medical diagnostic field due to its non-invasive characteristic. Medical professionals can now observe tissues within the body without having to physically enter the body. This reduces the amount of invasive and risky diagnostic procedures and increases the chances of a correct diagnosis. Some common medical imaging procedures include: One characteristic of ultrasound previously discussed is that of attenuation of an ultrasound signal partly due to the conversion of mechanical wave energy to thermal energy. Researchers and doctors have made medical applications to harness this heat conversion and use it in successful medical procedures. Ultrasound energy is a form of therapy being studied as an anticancer treatment. Intensified ultrasound energy can be directed at cancer cells to heat them and kill them. Recent testing has shown that ultrasound can increase the effectiveness of cancer treatments such as chemotherapy and radiation therapy. This procedure is known as heat or hyperthermia therapy. By using the converted heat energy that ultrasound provides, specific diseased tissues can be heated often to temperatures around 41° to 45°C. This increase in temperature has been linked to improved effectiveness of cancer treatment due to dilation of blood vessels and increased oxygen presence in affected tissues.Another new treatment called HIFU (High Intensity Focused Ultrasound) takes advantage of the thermal energy characteristics of ultrasound. HIFU uses an ultrasound device that is able to precisely focus ultrasound waves at a target tissue or specific group of cells. At the focus of this ultrasound energy, the temperature can reach excesses of 80°C which results in nearly spontaneous coagulative necrosis or cell death without harming neighboring cells. This treatment greatly expands the ability of doctors to be able to destroy cancer cells noninvasively. Currently, many test are being carried out to determine the effectiveness of the treatment on different tissues, but testing has already shown promising results in the field of prostate cancer.  This article incorporates public domain material from the U.S. National Cancer Institute document 'Dictionary of Cancer Terms'.