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 sound velocity c and the sound attenuation coefficient [alpha] are substance-specific pressure- and temperature-dependent parameters.
Measurements of the effective attenuation coefficient were reported by Davis [18] in his extensive study of the dosimetry of these sources.
We used the results of the underwater quantum irradiance for estimating the widely used diffuse attenuation coefficient, [K.
Estimating the diffuse attenuation coefficient from optically active constituents in UK marine waters.
6 presents the values of the longitudinal sound wave attenuation coefficient separately for fibreglass and foam polystyrene.
With these results a multiple regression is performed to obtain a equation relating amplitude of signal (A), reflection coefficient (Rc), attenuation coefficient (Ac) and RMS of the reflected waveform (Rs) with surface roughness (Ra).
Although the mass attenuation coefficient should theoretically be a constant material property, the calibrations yielded slightly different values for each radiation source.
The correlation between TU and the linear attenuation coefficient of the different materials utilised for the CT calibration showed that a linear regression ([r.
Along these ray-paths the reflection/transmission coefficients encountered at various interfaces and the effective attenuation coefficient are calculated, using conductive-dissipative electromagnetic propagation theory (Jackson 1977).