Summary
The measurement of the effective atomic number of a piece of material in vivo can be achieved using computed tomography. The precision of measurement of this parameter depends on the precision of measurement of the X-ray absorption coefficient at two energies and the separation of these energies. With the assumption of a fixed photon flux, it is shown that two optimum energies exist for the measurement of effective atomic number. The analysis indicates that if energies of 40 keV and 80 keV are employed, a precision of at least 1 part in 400 in the measurement of effective atomic number may be achieved.
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Rutherford, R. A., Pullan, B. R., Isherwood, I.: Measurement of Effective Atomic Number and Electron Density using an EMI Scanner. Neuroradiology 11, 15–21 (1976)
Hubbell, J. H.: Photon cross sections, attenuation coefficients, and energy absorption coefficients from 10 keV to 100 GeV. NSRDS-NBS 29, Washington: U. S. Government Printing Office 1969
EMI Ltd., Hayes, Middlesex: Personal Communication
Bracewell, R. N., Riddle, A. C.: Inversion of fan-beam scans in Radio Astronomy. Astrophysical J. 150, 427–434 (1967)
Crowther, R. A., Derosier, D. J., Klug, A.: The reconstruction of a three-dimensional structure from projections and its application to electron microscopy. Proc. Roy. Soc. Lond. A. 317, 319–340 (1970)
Ramachandran, G. N., Lakshminarayanan, A. V.: Three-dimensional reconstruction from radiographs and electron micrographs: application of convolutions instead of Fourier transforms. Proc. Nat. Acad. Sci. U.S.A. 68, 2236–2240 (1971)
Gilbert, P. F. C.: The reconstruction of a three-dimensional structure from projections and its application to electron microscopy II. Direct methods. Proc. Roy. Soc. Lond. B. 182, 89–102 (1972)
Hoffman, E. J., Phelps, M. E.: Production of monoenergetic X-rays from 8 to 87 keV. Phys. Med. Biol. 19, 19–35 (1974)
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Rutherford, R.A., Pullan, B.R. & Isherwood, I. X-ray energies for effective atomic number determination. Neuroradiology 11, 23–28 (1976). https://doi.org/10.1007/BF00327254
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DOI: https://doi.org/10.1007/BF00327254