Effective atomic numbers for low-energy total photon interactions in human tissues

Journal Article · Tue Sep 01 00:00:00 EDT 1987 · Med. Phys.; (United States)

DOI:https://doi.org/10.1118/1.596000· OSTI ID:5650289

Yang, N C; Leichner, P K; Hawkins, W G

A new method is introduced in which the total photon interaction cross sections per electron of human tissues are used to define effective atomic numbers for blood, bone, brain, fat, heart, kidney, liver, lung, muscle, ovary, pancreas, spleen, and water. These effective atomic numbers are equal within 4% from 10 to 200 keV in each soft tissue, whereas for bones of different chemical compositions the variation ranges from 2.86% to 5.03%. This effective atomic number definition is less energy dependent than a previous definition based on the total photon interaction cross section per atom averaged over all elements in the tissue, from which the computed effective atomic numbers varied by as much as 50% (in bone) as a function of photon energy over the energy range from 10 to 200 keV.

• Research Organization: Johns Hopkins Hospital, Baltimore, MD
• OSTI ID: 5650289
• Journal Information: Med. Phys.; (United States), Vol. 14:5
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL TISSUES
CHEMICAL COMPOSITION
PHOTONS
ATOMIC NUMBER
ADIPOSE TISSUE
BLOOD
BRAIN
KEV RANGE
LIVER
MAN
MUSCLES
PANCREAS
RADIATION DOSES
SPLEEN
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ANIMALS
BIOLOGICAL MATERIALS
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CENTRAL NERVOUS SYSTEM
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ENERGY RANGE
GLANDS
HYDROGEN COMPOUNDS
MAMMALS
MASSLESS PARTICLES
MATERIALS
NERVOUS SYSTEM
ORGANS
OXYGEN COMPOUNDS
PRIMATES
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560151* - Radiation Effects on Animals- Man