attenuation coefficient


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attenuation coefficient

in radiography or ultrasound, the difference between the energy that enters a body part and the energy that is not detected. The difference is caused by the absorption and scattering of energy within the body tissues.

attenuation coefficient

A measure of the attenuation of energy waves or particles caused by absorption of energy as they pass through a particular medium (e.g., air, tissue, lead).

attenuation coefficient

The calculated remainder of the x-ray beam that is received by the detectors in a computed tomography (CT) unit. This value is used to determine the CT (Hounsfield) number.
See also: coefficient
References in periodicals archive ?
The slope of the lines represents the ratio of attenuation coefficients for each spectral band (Figure 4 and Figure 5).
T] = average temperature v = velocity p = Pressure P = perimeter of the shaft Pr = Prandtl number W = thickness of the shaft wall x = height of interests Greek symbols a = temperature attenuation coefficient [DELTA] = difference [epsilon] = roughness [eta] = normalized temperature rise in the fire floor due to fire [theta] = normalized temperature [lambda] = thermal conductivity [mu] = dynamic viscosity v = kinematic viscosity [?
The effective attenuation coefficient was then estimated according to
Attenuation coefficient ([alpha]) of ethyl acetate at 27 [degrees]C (Expt.
For V101 transmitter, using Pico or [micro]30 receiver, we found the attenuation coefficient (damping factor), [alpha], to be as below in Np/m:
Therefore, aerosol or Mie scattering dominates the total attenuation coefficient [8].
1]) of [gamma]-rays with energy E per disintegration of the gamma emitter, [mu]a[epsilon] is the linear attenuation coefficient in air ([cm.
However, rather essential conclusions may be drawn also on the basis of a certain group of in situ measurements: quite often the complex of data, containing the concentrations of optically significant substances (phytoplankton, coloured dissolved organic matter (CDOM) and suspended matter) as well as the incoming irradiance and diffuse attenuation coefficient, has been collected.