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Ultrasound energy, simply known as ultrasound, is a type of mechanical energy called sound characterized by vibrating or moving particles within a medium. Ultrasound is distinguished by vibrations with a frequency greater than 20,000 Hz, compared to audible sounds that humans typically hear with frequencies between 20 and 20,000 Hz.
A contrast agent (or contrast medium) is a substance used to increase the contrast of structures or fluids within the body in medical imaging. [1] Contrast agents absorb or alter external electromagnetism or ultrasound, which is different from radiopharmaceuticals, which emit radiation themselves.
The penetrating power of x-ray, gamma, beta, and positron radiation is used for medical imaging, nondestructive testing, and a variety of industrial gauges. Radioactive tracers are used in medical and industrial applications, as well as biological and radiation chemistry. Alpha radiation is used in static eliminators and smoke detectors.
Medical ultrasound includes diagnostic techniques (mainly imaging techniques) using ultrasound, as well as therapeutic applications of ultrasound. In diagnosis, it is used to create an image of internal body structures such as tendons, muscles, joints, blood vessels, and internal organs, to measure some characteristics (e.g., distances and velocities) or to generate an informative audible sound.
Contrast-enhanced ultrasound (CEUS) is the application of ultrasound contrast medium to traditional medical sonography. Ultrasound contrast agents rely on the different ways in which sound waves are reflected from interfaces between substances. This may be the surface of a small air bubble or a more complex structure.
Iodinated contrast contains iodine.It is the main type of radiocontrast used for intravenous administration.Iodine has a particular advantage as a contrast agent for radiography because its innermost electron ("k-shell") binding energy is 33.2 keV, similar to the average energy of x-rays used in diagnostic radiography.
Ultrasound is used in many different fields. Ultrasonic devices are used to detect objects and measure distances. Ultrasound imaging or sonography is often used in medicine. In the nondestructive testing of products and structures, ultrasound is used to detect invisible flaws. Industrially, ultrasound is used for cleaning, mixing, and ...
Gamma rays, at the high-frequency end of the spectrum, have the highest photon energies and the shortest wavelengths—much smaller than an atomic nucleus. Gamma rays, X-rays, and extreme ultraviolet rays are called ionizing radiation because their high photon energy is able to ionize atoms, causing chemical reactions. Longer-wavelength ...