Measurement Principles & Theory
2021.5B
RTI Scatter Probe User's Manual
26
4.2 Mean Energy and Ambient Dose Equivalent
Relevant parameters to be measured with the RTI Scatter Probe are Air Kerma, Ambient Dose Equivalent (H*(10)), HVL and
Mean Energy. The RTI Scatter Probe algorithms are built upon a database for spectrum-specific values with the database being
structured in terms of kVp and filtration.
The Air Kerma algorithm is based on reference measurements with the RTI Dose Probe and several reference ion chambers.
Measurements for Air Kerma were performed at RTI’s accredited calibration laboratory for radiography and mammography at
RTI Headquarters in Sweden.
HVL and spectral Mean Energy are acquainted from spectrum calculations with SpekCalc and Siemens Spectrum Analyser
where set values of kVp and filtration are used as input parameters for producing spectral changes in radiography and
mammography, respectively.
SpekCalc is a software program for the calculation of x-ray spectra from tungsten anode x-ray tubes and is based on research
articles [1] - [3]. Siemens Spectrum Analyser is a web-based service hosted by Siemens Healthcare Deutschland [4] where
spectrum calculations are based on research articles [5] - [8].
Furthermore, the spectral Mean Energy is used to obtain a conversion coefficient to calculate Ambient Dose Equivalent (H*(10))
from Air Kerma by using the relationship found from [9], cf. Figure 1.
Figure 1: Conversion coefficient for calculation of Ambient Dose Equivalent, H*(10), at given photon energy.
[1] Poludniowski G, Landry G, DeBlois F, Evans PM, Verhaegen F. SpekCalc: a program to calculate photon spectra from
tungsten anode x-ray tubes. Phys Med Biol. 2009 Oct 7;54(19):N433-8. doi: 10.1088/0031-9155/54/19/N01. Epub 2009 Sep
1. PMID: 19724100.
[2] Poludniowski GG, Evans PM. Calculation of x-ray spectra emerging from an x-ray tube. Part I. electron penetration
characteristics in x-ray targets. Med Phys. 2007 Jun;34(6):2164-74. doi: 10.1118/1.2734725. PMID: 17654919.
[3] Poludniowski GG. Calculation of x-ray spectra emerging from an x-ray tube. Part II. X-ray production and filtration in x-ray
targets. Med Phys. 2007 Jun;34(6):2175-86. doi: 10.1118/1.2734726. PMID: 17654920.
[4] health.siemens.com/booneweb/
[5] John M. Boone, Thomas R. Fewell, Robert J. Jennings: Molybdenum, rhodium, and tungsten anode spectral models using
interpolating polynomials with application to mammography; Medical Physics 24(12), 1883 - 1874, 1997
[6] John M. Boone, J. Anthony Seibert: An accurate method for computer-generating tungsten anode x-ray spectra from 30 to
140 kV; Medical Physics 24(11), 1661 - 1670, 1997
[7] T.R. Fewell, R.E. Shuping: Handbook of Mammographic X-ray Spectra; HEW Publication (FDA) 79-8071; Rockville, MD (1978)
[8] T.R. Fewell, R.E. Shuping, K. Healy: Handbook of Computed Tomography X-ray Spectra; HHS Publication (FDA) 81-8162;
Rockville, MD (1981)
[9] Report 57, Journal of the International Commission on Radiation Units and Measurements, Volume os29, Issue 2, 1 August
1998
Содержание Scatter Probe
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Страница 3: ...RTI Scatter Probe...
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Страница 8: ...2021 5B RTI Scatter Probe User s Manual...
Страница 9: ...Chapter 1 Introduction...
Страница 11: ...Chapter 2 Product Overview...
Страница 15: ...Chapter 3 Measure...
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Страница 23: ...Chapter 4 Measurement Principles Theory...
Страница 27: ...Chapter 5 Hardware and Specifications...
Страница 33: ...Chapter 6 Maintenance...