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
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needed for the evaluation of patient dose. The data base was also used for the
determination of all X-ray spectra and graphs shown within the book, especially in the
supplement. Cross references between book and CD-ROM are given in the
data file “book_CD_contents”.
1_X-ray spectra
The measurements on the diagnostic X-ray tubes - independent of the target angle - were
made in the direction of the central axis. All mammography X-ray tubes (with the
exception of the Rh-tube) had a target angle of 22°, the measurements were always made
in the direction (emission angle 16°) that corresponds to a point of the breast support
which lies about 6 cm from the chest wall edge.
2
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 Xradiation 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.
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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.
4
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).
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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.
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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.
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MD_Tabs_SB.xls:
The corresponding quantities as in MD_Tabs.xls are listed whereby “Standard breast” is
considered as phantom (absorber) material.
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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. Because Tp is affected not much by the X-ray tube voltage
(< 10%) in the voltage range from 60 kV to 125 kV, the value at 100 kV (IEC 60627,
IEC 1978) is used for calculation.
BSF.xls:
Backscatter factors in dependence on radiation quality for water, PMMA and ICRUtissue and various image field sizes (Petoussi et al. 1998).
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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).
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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.
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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).
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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)
Ksys
system dose
Wsys
absorbed energy in a screen at system dose Ksys
GOS
Gd2O2S
SPF
storage phosphor BaFBrI