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Radiation Exposure and Image Quality in X-Ray Diagnostic Radiology
Physical Principles and Clinical Applications
Contents of the CD-ROM
The book “Radiation Exposure and Image Quality in X-Ray Diagnostic Radiology - Physical
Principles and Clinical Applications” enclose this CD-ROM with a comprehensive database
as Excel-files which may be used in the readers own programs: X-ray spectra for conventional
diagnostics and mammography, interaction coefficients of nearly all chemical elements, for
compounds and mixtures, used in X-ray diagnostics, characteristics of the primary and the
imaging radiation field, backscatter factors, scatter fractions at image receptor with various
anti-scatter grids and dosimetric data, which are needed for the evaluation of patient dose.
1_X-ray spectra
QM_RS.xls: The data file contains X-ray spectra measured with the help of a special
reference X-ray tube assembly, which had a Be-window. Spectra are given
without and with an additional filtration of 2.5 mm Al. The target angle was
12°. The energy of the X-radiation was measured (s. section II.1.2) with an
energy gradation of 0.2 keV. Spectra for X-ray tube voltages from 10 kV to
125 kV are listed in the data file, normalized to the maximum of the quantum
numbers. To receive absolute photon numbers each numerical value must be
multiplied by the normalization factor.
QM_RD.xls: Diagnostic X-ray spectra measured with an energy gradation of 0.2 keV at
target angles of 16°, 10° and 6°. The normalization factor is given for each
spectrum.
QS_RD.xls:
Diagnostic X-ray spectra with an energy gradation of 1 keV at target angles of
16°, 10° and 6° and interpolated for 12° and 8°. The photon numbers are listed
in absolute values, normalized to a tube current-time product of 1 mAs and a
solid angle of 1 steradian (sr). The spectra are derived from that of file
QM_RD.xls, summing up five channels to 1 keV gradation (s. section II.1.2.4).
Conversion of the photon numbers with respect to an area element of 1cm² in a
focus distance of 1 m can be made by multiplication of the numerical values
with a factor of 10-4.
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QS_MD.xls: X-ray spectra applied in mammography are given for 8 anode-filter
combinations (Mo/40 µm Nb; Mo/30 µm Mo; Mo/25 µm Rh; Rh/25 µm Rh;
W/80 µm Nb; W/60 µm Mo; W/50 µm Rh; W 50 µm Pd) with an energy
gradation of 0.1 keV. Quantum numbers are listed in absolute values,
normalized to a tube current-time product of 1 mAs and a solid angle of
1 steradian (sr).
2_Interaction coefficients
MYR_NIST_Elements.xls:
Mass attenuation and mass energy absorption coefficients of
the most important elements in a logarithmic scale (NIST
2001)
MYR_NIST_Compounds.xls: Mass attenuation and mass energy absorption coefficients of
compounds and mixtures important in radiology in a
logarithmic scale (NIST 2001)
MYR151.xls:
Photon to kerma conversion coefficients (s. section II.3.1 equation
II.3.5), mass attenuation and mass energy absorption coefficients with an
energy gradation in 1 keV steps from 1 keV to 150 keV, suitable
especially for calculations in combination with spectra given in the data
file QS_RD.
MYR150_2.xls:
Photon to kerma conversion coefficients (s. section II.3.1 equation
II.3.5), mass attenuation and mass energy absorption coefficients with an
energy gradation in 0.2 keV steps from 1 keV to 150 keV, suitable
especially for calculations in combination with spectra given in the data
file QM_RD.
MYR_50_1.xls:
Photon to kerma conversion coefficients (s. section II.3.1 equation
II.3.5), mass attenuation and mass energy absorption coefficients with an
energy gradation in 0.1 keV steps from 1 keV to 50 keV, suitable
especially for calculations in combination with spectra given in the data
file QS_MD (Mammography).
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3_Primary beam Characteristics
RD_Tabs.xls:
The physical quantities (HVL, <E>, Φ/It, Ψ/It, Ka/It), which describe the
X-radiation field (without scatter) following the path from the production
of the X-rays in the focal spot to the image receptor are given. These
quantities can be used as source material within the process of optimising
image quality and reducing simultaneously patient dose. The quantities
are given for various additional filtration. The relative energy absorption
in different detector materials is considered (s. file Book_CD_Contents
MD_Tabs.xls:
The corresponding physical quantities as in RD_Tabs.xls with respect to
mammography for 8 anode filter combinations are listed (s. file
Book_CD_Contents). As phantom (absorber) material PMMA is used.
MD_Tabs_SB.xls: The corresponding quantities as in MD_Tabs.xls are listed whereby
“Standard breast” is considered as phantom (absorber) material.
4_Scatter
Scafrac.xls:
Scatter fraction at image receptor without and with anti-scatter grids (Pb 8/40,
Pb 12/40, Pb15/80 and Pb 17/70) and with air gap in dependence on water
thickness, image field size and X-ray tube voltage.
BSF.xls:
Backscatter factors in dependence on radiation quality for water, PMMA and
ICRU-tissue and various image field sizes (Petoussi et al. 1998
5_Image quality figure
SN_CsI.xls:
Data for a CsI-screen (coverage 180 mg/cm²) are listed, which can be
used for the calculation of the voltage response of an image intensifier or
the IQF in dependence on phantom thickness for different X-ray tube
voltages. Data with an additional filtration by 0 mm, 0.1 mm Cu, 0.2 mm
Cu and 0.3 mm Cu are given. As signal the contrast of 1 mg/cm² iodine
step is used (s. section III.3.2, supplement IV.5.2 and IV.5.3).
SN_GOS.xls:
Data for a Gd2O2S:Tb-screen (coverage 118 mg/cm²) are listed, which
can be used for the calculation of its voltage response or the IQF in
dependence on phantom thickness for different X-ray tube voltages. As
signal the contrast of 0.3 mm Al step is used (s. supplement IV.5.2 and
IV.5.3).
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SN_MDGOS.xls:
The data listed are equivalent to those given in the data file SN_GOS.xls
and applicable to mammography. The coverage of the Gd2O2S:Tb-screen
is assumed to be 34 mg/cm² and the signal is created by a 0.1 mm
microcalcification step (s. section III.3.3, supplement IV.5.2 and IV.5.3).
All data are calculated with reference to the absorbed energy Wsys in the
screen which is obtained at a system dose Ksys = 70 µGy when using a
Mo-anode/30 µm Mo-filter system at a X-ray tube voltage of 28 kV and
a phantom thickness of 45 mm (standard breast).
SN_M_GOS.xls:
The data listed are equivalent to SN_MDGOS.xls, whereby in contrast to
SN_MDGOS.xls the reference energy Wsys is calculated separately for
each anode-filter system.
6_Dosimetric data
KT_PMMA.xls:
Air kerma and primary radiation transmission without scatter for
diagnostik X-rays with 2.5 mm Al inherent filtration in dependence on
PMMA-phantom thickness for various additional filtration (0 mm,
0.5 mm Al, 1.5 mm Al, 2.5 mm Al, 0.1 mm Cu, 0.2 mm Cu and
0.3 mm Cu)
KT_water.xls:
Air kerma and primary radiation transmission without scatter for
diagnostik X-rays with 2.5 mm Al inherent filtration in dependence on
water-phantom thickness for various additional filtration (0 mm, 0.5 mm
Al, 1.5 mm Al, 2.5 mm Al, 0.1 mm Cu, 0.2 mm Cu and 0.3 mm Cu)
Mamm_HVL_Y60.xls:
Half value layer and dose output Y60 for the anode-filter
combinations considered in QS_MD.xls including a
compression plate thickness of 1 mm to 3mm polycarbonate.
Mamm_HVL_Y60_2PC.xls: Diagrams including 2mm polycarbonate corresponding to data
file Mamm_HVL_Y60.xls.
QKD_Mamm.xls:
Dose output and HVL-diagrams corresponding to data file
Mamm_HVL_Y60.xls.
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Signs and symbols
HVL
Half value layer in mm Al
<E>
mean energy of the X-ray spectrum under consideration in keV
Φ/It
photon fluence per tube current time product in 1/(cm²⋅As)
Ψ/It
energy fluence per tube current time product in J/(cm²⋅As)
Ka/It
air kerma per tube current time product in mGy/As
Φ/Ka
photon fluence per air kerma in 1/(cm²⋅µGy)
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