X-ray energy optimisation in computed microtomography.
Expressions describing the absorbed dose and the number of incident photons necessary for the detection of a contrasting detail in x-ray transmission CT imaging of a circular phantom are derived as functions of the linear attenuation coefficients of the materials comprising the object and the detail. A shell of a different material can be included to allow simulation of CT imaging of the skulls of small laboratory animals. The equations are used to estimate the optimum photon energy in x-ray transmission computed microtomography. The optimum energy depends on whether the number of incident photons or the absorbed dose at a point in the object is minimised. For a water object of 300 mm diameter the two optimisation criteria yield optimum photon energies differing by an order of magnitude.
Spanne
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Atomic and Applied Physics Division, Brookhaven National Laboratory, Upton, NY 11973.
D006801:Humans; D008961:Models, Structural; D014057:Tomography, X-Ray Computed / Q000379:methods*