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IEC TR 60522-2
Edition 1.0 2020-10
TECHNICAL
REPORT
colour
inside
Medical electrical equipment – Diagnostic X-rays –
Part 2: Guidance and rationale on quality equivalent filtration and permanent
filtration
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IEC TR 60522-2
Edition 1.0 2020-10
TECHNICAL
REPORT
colour
inside
Medical electrical equipment – Diagnostic X-rays –
Part 2: Guidance and rationale on quality equivalent filtration and permanent
filtration
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 11.040.50 ISBN 978-2-8322-8880-1
– 2 – IEC TR 60522-2:2020 IEC 2020
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 8
4 Technical issues in IEC 60522:1999 . 9
4.1 General . 9
4.2 Subclause 4.1, second dash, of IEC 60522:1999 . 9
4.3 Subclause 4.3, first paragraph, of IEC 60522:1999 . 9
4.4 Subclause 4.3, item a) of IEC 60522:1999 . 9
4.5 Subclause 4.3, item d), last phrase, of IEC 60522:1999 . 9
4.6 Subclause 4.3, last paragraph, of IEC 60522:1999 . 9
4.7 Subclause 4.6, second paragraph, second phrase of IEC 60522:1999 . 10
5 Influence of HIGH VOLTAGE and of atomic number of FILTER MATERIAL . 10
5.1 General . 10
5.2 RADIOGRAPHY – Atomic number of FILTERS ≤30 . 11
5.3 RADIOGRAPHY – Atomic number of FILTERS >30 . 19
5.4 Mammography . 20
5.5 Additivity . 21
5.5.1 General . 21
5.5.2 RADIOGRAPHY . 21
5.5.3 Mammography . 24
5.5.4 Decision process for the indirect determination of the permanent
FILTRATION . 24
6 Alignment of the REFERENCE AXES . 25
6.1 General . 25
6.2 RADIOGRAPHY – Atomic number ≤30 . 25
6.3 RADIOGRAPHY – Atomic number >30 . 26
6.4 Mammography . 26
7 Requirements on the HIGH VOLTAGE . 27
7.1 General . 27
7.2 RADIOGRAPHY – Determination at the K-edge – Requirement on constancy . 27
7.3 Mammography – Requirement on constancy . 28
7.4 Ripple . 28
7.5 Choice of HIGH VOLTAGE . 29
8 FILTERING MATERIAL – Representative TARGET ANGLE . 30
8.1 General . 30
8.2 RADIOGRAPHY – Atomic number ≤30 . 30
8.3 RADIOGRAPHY – Atomic number >30 . 30
8.4 Mammography . 31
9 RADIATION BEAM simulations . 32
9.1 Simulation tool . 32
9.2 Validation . 32
10 Statement of QUALITY EQUIVALENT FILTRATION. 33
10.1 Accuracy . 33
10.2 PERMANENT FILTRATION . 33
Bibliography . 34
Figure 1 – Typical FILTER materials for mammography and RADIOGRAPHY . 11
Figure 2 – QUALITY EQUIVALENT FILTRATION of elements as a function of HIGH VOLTAGE . 12
Data adapted from reference [4]. Axes logarithmic . 13
Figure 3 – Mass X-ray attenuation coefficients (μ/ρ) vs. photon energy . 13
Figure 4 – Energetic location of discontinuities of the absorption coefficients (vertical
axis) of elements vs. their atomic number, characteristic lines, L- and K-edge energies . 14
Figure 5 – QEF of 0,1 mm Cu FILTER vs. thickness of an additional Al FILTER (at HIGH
of 75 kV) . 15
VOLTAGE
Figure 6 – QUALITY EQUIVALENT FILTRATION of elements with 1,0 mm Al pre-FILTRATION
as a function of HIGH VOLTAGE (W TARGET with TARGET ANGLE 10°, thickness according
to Figure 2) . 16
Figure 7 – QEF of 0,1 mm Cu as determined with various pre-FILTRATION materials as a
function of HIGH VOLTAGE . 17
Figure 8 – X-RAY spectra (12 ° W TARGET, 100 kV HIGH VOLTAGE) for FILTER materials
Cu and Al with the same QEF . 18
Figure 9 – X-RAY spectra from a 12° W TARGET with 1,0 mm additional FILTRATION . 19
Figure 10 – QEF of a 0,025 mm W FILTER as a function of HIGH VOLTAGE . 20
Figure 11 – Four typical examples of PERMANENT FILTRATION of mammographic X-RAY
TUBE ASSEMBLIES as a function of HIGH VOLTAGE . 21
Figure 12 – Inconsistent results from addition of the qefs according to IEC 60522:1999. . 23
Figure 13 – Example of failing additivity concept of IEC 60522:1999 in mammography . 24
Figure 14 – Indirect determination of PERMANENT FILTRATION . 25
Figure 15 – Dependency of the QEF of a 0,025 mm W FILTER on the TARGET ANGLE. 31
Figure 16 – QEF for a range of practical TARGET ANGLES in mammography . 32
Table 1 – QEF-variation of 0,1 mm Cu FILTER with Al pre-FILTRATION . 16
Table 2 – Representative combinations of mammography TARGETS and FILTERS. 20
Table 3 – Sample comparison of concepts of addition: IEC 60522:1999 . 22
Table 4 – Sample comparison of concepts of addition: IEC 60522-1 . 22
Table 5 – PERMANENT FILTRATION per order of the FILTERS – comparison of concepts . 23
Table 6 – Impact of angular misalignment on PERMANENT FILTRATION . 26
Table 7 – Impact of angular misalignment on PERMANENT FILTRATION . 26
Table 8 – Impact of angular misalignment on PERMANENT FILTRATION . 26
Table 9 – Impact of HIGH VOLTAGE shift (close to K-edge) on PERMANENT FILTRATION . 27
Table 10 – Impact of HIGH VOLTAGE shift (distant from K-edge) on PERMANENT
............................................................................................................................. 27
FILTRATION
Table 11 – Impact of shift of HIGH VOLTAGE on PERMANENT FILTRATION . 28
Table 12 – Sensitivity for VOLTAGE RIPPLE . 29
Table 13 – Influence on QEF of low-Z FILTRATION and of TARGET ANGLE . 30
Table 14 – Comparison of simulated and measured PERMANENT FILTRATION . 33
– 4 – IEC TR 60522-2:2020 IEC 2020
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
MEDICAL ELECTRICAL EQUIPMENT – DIAGNOSTIC X-RAYS –
Part 2: Guidance and rationale on quality equivalent
filtration and permanent filtration
FOREWORD
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