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Attenuation in ultrasound is the reduction in amplitude of the ultrasound beam as a function of distance through the imaging medium. Accounting for attenuation effects in ultrasound is important because a reduced signal amplitude can affect the quality of the image produced.
ultrasound attenuation, where it is denoted α and measured in dB⋅cm −1 ⋅MHz −1; [4] [5] acoustics for characterizing particle size distribution, where it is denoted α and measured in m −1. The attenuation coefficient is called the "extinction coefficient" in the context of
Ultrasound attenuation spectroscopy is a method for characterizing properties of fluids and dispersed particles. It is also known as acoustic spectroscopy. There is an international standard for this method. [1] [2] Measurement of attenuation coefficient versus ultrasound frequency yields
Acoustic attenuation in water is frequency-squared dependent, namely =. Acoustic attenuation in many metals and crystalline materials is frequency-independent, namely =. [10] In contrast, it is widely noted that the of viscoelastic materials is between 0 and 2.
The figure provided in [30] provides an estimation of the attenuation that the ultrasound would suffer as it propagated through air. The figures from this graph correspond to completely linear propagation, and the exact effect of the nonlinear demodulation phenomena on the attenuation of the ultrasonic carrier waves in air was not considered.
In acoustics, Stokes's law of sound attenuation is a formula for the attenuation of sound in a Newtonian fluid, such as water or air, due to the fluid's viscosity.It states that the amplitude of a plane wave decreases exponentially with distance traveled, at a rate α given by = where η is the dynamic viscosity coefficient of the fluid, ω is the sound's angular frequency, ρ is the fluid ...
Time gain compensation (TGC) is a setting applied in diagnostic ultrasound imaging to account for tissue attenuation. [1] By increasing the received signal intensity with depth, the artifacts in the uniformity of a B-mode image intensity are reduced.
There are two methods of receiving the ultrasound waveform: reflection and attenuation. In reflection (or pulse-echo) mode, the transducer performs both the sending and the receiving of the pulsed waves as the "sound" is reflected back to the device.