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Author Ma, R. ♦ Zhao, X. ♦ Rarback, H. M. ♦ Yasumura, S. ♦ Dilmanian, F. A. ♦ Moore, R. I. ♦ Lo Monte, A. F. ♦ Vodopia, K. A. ♦ Liu, H. B. ♦ Economos, C. D. ♦ Nelson, M. E. ♦ Aloia, J. F. ♦ Vaswani, A. N. ♦ Weber, D. A. ♦ Pierson, R. N. (Jr.) ♦ Joel, D. D.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword BIOLOGY AND MEDICINE, APPLIED STUDIES ♦ NEUTRON ACTIVATION ANALYZERS ♦ CALIBRATION ♦ ACCURACY ♦ CALCIUM ♦ DELAYED GAMMA RADIATION ♦ DELAYED NEUTRON ANALYSIS ♦ MONTE CARLO METHOD ♦ PHANTOMS ♦ SIMULATION ♦ SKELETON ♦ TISSUE-EQUIVALENT MATERIALS
Abstract The delayed-gamma neutron activation facility at Brookhaven National Laboratory was originally calibrated using an anthropomorphic hollow phantom filled with solutions containing predetermined amounts of Ca. However, 99{percent} of the total Ca in the human body is not homogeneously distributed but contained within the skeleton. Recently, an artificial skeleton was designed, constructed, and placed in a bottle phantom to better represent the Ca distribution in the human body. Neutron activation measurements of an anthropomorphic and a bottle (with no skeleton) phantom demonstrate that the difference in size and shape between the two phantoms changes the total body calcium results by less than 1{percent}. To test the artificial skeleton, two small polyethylene jerry-can phantoms were made, one with a femur from a cadaver and one with an artificial bone in exactly the same geometry. The femur was ashed following the neutron activation measurements for chemical analysis of Ca. Results indicate that the artificial bone closely simulates the real bone in neutron activation analysis and provides accurate calibration for Ca measurements. Therefore, the calibration of the delayed-gamma neutron activation system is now based on the new bottle phantom containing an artificial skeleton. This change has improved the accuracy of measurement for total body calcium. Also, the simple geometry of this phantom and the artificial skeleton allows us to simulate the neutron activation process using a Monte Carlo code, which enables us to calibrate the system for human subjects larger and smaller than the phantoms used as standards. {copyright} {ital 1996 American Association of Physicists in Medicine.}
ISSN 00942405
Educational Use Research
Learning Resource Type Article
Publisher Date 1996-02-01
Publisher Department Brookhaven National Lab. (BNL), Upton, NY (United States)
Publisher Place United States
Journal Medical Physics
Volume Number 23
Issue Number 2
Organization Brookhaven National Lab. (BNL), Upton, NY (United States)


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