attenuation coefficient

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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).
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.

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
Medical Dictionary, © 2009 Farlex and Partners
References in periodicals archive ?
In the verification experiment [18], the materials with approximately linear attenuation coefficients in the reconstructed images could be significantly distinguished.
The mass attenuation coefficient ([[mu].sub.m]/[rho]) can be obtained by dividing the linear attenuation coefficient of the material ([[mu].sub.m]) by its density ([rho]).
The correlation between TU and the linear attenuation coefficient of the different materials utilised for the CT calibration showed that a linear regression ([r.sup.2] coefficient 0.999) represented a very good adjustment for the data obtained experimentally.
In both cases, the relative probability of Ti x-ray emission ([approximately equal to]0.008) was estimated such that the measured apparent linear attenuation coefficient would be close to the Loftus measured value of 0.0015 c[m.sup.-1].
As the linear attenuation coefficient [[mu].sub.m]H[rho]H remains constant in different beam paths, from Equation [3] it is possible to calculate a value [t.sub.c] that corresponds to the equivalent distance traversed by the beam, based on the following relationship derived from Equation [1]:
The (greylevel) intensity at each voxel in the final 3-D image corresponds to the linear attenuation coefficient of the material contained in that voxel.