, Volume 11, Issue 1, pp 15–21

Measurement of effective atomic number and electron density using an EMI scanner

  • R. A. Rutherford
  • B. R. Pullan
  • I. Isherwood


Computed tomography, employing an EMI scanner at two beam energies, can be used to obtain information about the electron density and the effective atomic number of materials. The theory which is discussed has been verified experimentally and then applied in the investigation of some brain tumours in vivo. It is anticipated that, as techniques improve, the ability to carry out chemical and physical analysis of pathological processes in vivo will be an important application of computed tomography.

Key words

Computed tomography EMI scanner Electron density Effective atomic number Brain tumour diagnosis 


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    Rutherford, R. A., Pullan, B. R., Isherwood, I.: Calibration and response of an EMI scanner. Neuroradiology 11, 7–13 (1976)Google Scholar
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    Veigele, W. J.: Photon cross-sections from 0.1 ke V to 1 Me V for elements Z=1 to Z=94. Atomic Data Tables 5, 51–111 (1973)Google Scholar
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    Spiers, F. W.: Effective atomic number and energy absorption in tissues. Brit. J. Radiol. 19, 52–63 (1946)Google Scholar
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    Weber, J., van den Berge, D. J.: The effective atomic number and the calculation of the composition of phantom material. Brit. J. Radiol. 42, 378–383 (1969)Google Scholar

Copyright information

© Springer-Verlag 1976

Authors and Affiliations

  • R. A. Rutherford
    • 1
  • B. R. Pullan
    • 1
  • I. Isherwood
    • 2
  1. 1.Department of Medical BiophysicsUniversity of ManchesterEngland
  2. 2.Department of Diagnostic RadiologyUniversity of ManchesterEngland

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