This standard applies to optoelectronic X-ray image intensifiers as components of medical diagnostic X-ray equipment and describes the method for determining image distortion of X-ray image intensifiers. YY/T 0457.4-2003 Characteristics of optoelectronic X-ray image intensifiers for medical electrical equipment Part 4: Determination of image distortion YY/T0457.4-2003 Standard download decompression password: www.bzxz.net

YY/T 0457.4—2003/IEC 61262-4:1994 YY/T0457 "Characteristics of optoelectronic X-ray image intensifiers for medical electrical equipment" is divided into seven parts: Part 1: Determination of human radiation field, Part 2: Determination of conversion coefficient; Part 3: Determination of brightness distribution and brightness non-uniformity; - Part 4: Determination of image distortion; Part 5: Determination of detection quantum efficiency; - Part 6: Determination of contrast and glare coefficient; Part 7: Determination of modulation transfer function. This part is the 4th part of YY/T0457. The consistency of this part is equivalent to IEC61262-4:1994 "Medical electrical equipment - Characteristics of photoelectric X-ray image intensifiers - Part 4: Determination of image distortion" (English version). The main differences are as follows: some formatting formats have been modified according to Chinese conventions; some expressions applicable to international standards have been changed to expressions applicable to Chinese standards; the preface of international standards has been deleted;
-IEC788 has been changed to IEC60788.
Appendix A of this part is an informative appendix.
This part is proposed by the State Food and Drug Administration. This part is under the jurisdiction of the National Standardization Technical Committee for Medical X-ray Equipment and Appliances. The drafting unit of this part: Liaoning Medical Device Product Quality Supervision and Inspection Institute. The main drafters of this part: Liu Baishi and Mu Li. 1
YY/T0457.4—2003/IEC61262-4：1994Introduction
Image distortion is a functional characteristic that describes the deviation between the image of the human field and the output image of an optoelectronic X-ray image intensifier. Since the X-ray image intensifier itself is an axisymmetric structure, we assume that angular distortion can be reduced by using adequate magnetic shielding, just like the S-shaped distortion of a straight line through the center of the human field. Therefore, this part will be limited to radial distortion. Although there seems to be a slight S-shaped distortion in the case of magnetic shielding, its effect on the magnification measurement is negligible.
1 Scope
Medical electrical equipment
YY/T 0457.4—2003/IEC 61262-4:1994 Characteristics of optoelectronic X-ray image intensifiers
Part 4: Determination of image distortion
This part of YY/T0457 applies to optoelectronic X-ray image intensifiers as components of medical diagnostic X-ray equipment. This part describes the method for determining image distortion of X-ray image intensifiers. 2 Normative references
The clauses in the following documents become clauses of this part through reference in this part of YY/T0457. For any dated referenced document, all subsequent amendments (excluding errata) or revisions are not applicable to this part, however, parties to an agreement based on this part are encouraged to study whether the latest versions of these documents can be used. For any undated referenced document, the latest version of the document applies to this part.
IEC60788:1984 Medical radiology - Terminology 3 Terms
3.1 Definitions
For the purpose of this standard, the terms and definitions defined in IEC60788 and the following apply. In case of any ambiguity, the following definitions shall prevail.
English abbreviation for electro-optical X-ray image intensifier. 3.1.2
entrance plane
The plane perpendicular to the axis of symmetry of the XRII and tangent to the most protruding part of the XRII in the direction of the radiation source (including the protective shell of the XRII).
Not used.
entrance field sizeFor an XRII, the diameter of the area in the entrance plane that can be used for the X-ray image transmission at a specified source distance (SED). For an XRII with more than one magnification mode, the output image diameter corresponding to the human field size of each magnification mode shall be consistent with the output image diameter of the XRII at the maximum human field size. 3.1.5
source to entrance plane distance (SED) YY/T 0457.4—2003/IEC 61262-4:1994 The distance between the focus of the X-ray tube and the entrance plane of the XRII. 3.1.6
centre of the output imagecentre of the smallest circle circumscribing the output image.
centre of the entrance fieldcentre of the point on the entrance plane imaged at the centre of the output image. 3.1.8
central axiscentral axis
The line passing through the centre of the entrance field and perpendicular to the entrance plane. 3.1.9
central magnification
a characteristic of XRI1, the ratio of the length of the output image to the actual length of a small object placed symmetrically about the central axis on the entrance plane. 3.1.10
imagedistortion
A characteristic of XRII that represents the change in magnification of the image of an object. Image distortion is expressed in terms of the reference magnification (central magnification) and is a function of the object's position (local radial image distortion) or size (integral image distortion). 3.1.11
differential radial image distortion is the image distortion of a radially small, fixed-length radially positioned test device placed anywhere in the emissive plane. The local radial image distortion is a function of the position of the test device in the emissive plane. 3.1.12
integral image distortion is the image distortion of a circular test device placed symmetrically about its central axis in the emissive plane. The integral image distortion is a function of the radius of the circular test device.
local radial magnificationXRII is a property of the XRII that is the ratio of the output image length of a small test device placed radially relative to the central axis in the emissive plane, symmetrically about a given point, to the actual length.
Local radial magnification is a function of the location of the test device in the emissive plane. 3.1.14
Integral magnification1) Integral magnificationXRII is a property of the XRII that is the ratio of the output image diameter of a circular test device placed in the emissive plane, symmetrically about the central axis, to the actual diameter. The integral magnification is a function of the radius of the circular test device. 1) For off-axis points, the local radial magnification is usually not equal to the local tangential magnification. Since the local radial magnification (in combination with the central magnification) is used to determine local radial distortion, the adjective "radial" must be included in the definitions of 3.1.11 and 3.1.13. For overall magnification (3.1.14) and overall image distortion (3.1.12), the distinction between radial and tangential is unnecessary, since they are identical in the radial and tangential directions.
3.2 Degree of requirements
Auxiliary verbs in this standard:
— "shall" indicates that compliance with a requirement is necessary. YY/T0457.4--2003/IEC61262-4:1994 "should" indicates that compliance with a requirement is strongly recommended but not mandatory. - "may" indicates that compliance with a requirement is permitted in a particular way in order to comply with this standard. The following words have the following meanings:
- "specific" when used with parameter or condition: refers to a particular value or standardized arrangement, usually those required by IEC standards or by law; see IEC 60788, RM-74-01. ——“specified” when used with parameter or condition: a value or arrangement usually indicated in the accompanying documents or selected for the purpose under consideration; see IEC60788, rm-74-02. ——“designed for” when used in the standard to describe the characteristics of equipment, components, parts or arrangements: indicates the intended and usually obvious application purpose or use of the product. 4 Requirements
4.1 Test setup
a) SED shall be 100 cm ± 1 cm;
b) The focus of the X-ray tube shall be on the central axis; c) The test device shall be placed parallel in a plane not more than 10 mm apart as close as possible to the front of the human field. For the determination of local radial magnification, the scale line on the test device shall pass through the center of the human field. For the determination of central magnification, the placement of the test device shall be symmetrical to the center of the human field, and the symmetry deviation relative to the center of the human field shall not exceed 2% of the size of the human field.
4.2 X-ray image intensifier - operating conditions a) XRII shall operate under the normal use conditions specified by the manufacturer; b) Not used;
c) For multi-field XRII, measurements shall be made at the specified maximum human field size, and measurements of other field sizes are optional.
4.3 Input Radiation
The combination of the attenuation equivalent of the device under test and the quality of the radiation used to determine the magnification value should give a high contrast image of the device under test and the radiation intensity should be sufficient to obtain a low noise image. 4.4 Test Device
The test device should consist of an X-ray transparent sheet with markings made of X-ray radiation absorbers on it, from which distance measurements can be made. Transverse and longitudinal equidistant scale marks should be used to measure central and local radial magnification. Circular markings should be used to measure global magnification: this avoids measurement difficulties caused by severe S-shaped distortion (see Introduction). The distance between the scales should be checked by measuring the spacing between the scale marks on an X-ray photograph taken close to the device under test. The distance between the scale marks should not be greater than 10 mm or 10% of the human field size, whichever is the smaller. A recommended test device is shown in Figure 1.
4.5 Measuring Equipment
The length of the image of the test device should be measured by optical means, preferably with the help of a crosshair combined with a micrometer. The total uncertainty in the result shall be less than 2% of the absolute value of the overall image distortion and less than 3% of the absolute value of the local radial image distortion. 3
YY/T0457.4-2003/IEC61262-4:199415
5 Determination of image distortion
5. 1 Not applicable.
5. 2 Not applicable.
5.3 Not applicable.
5.4 Determination
Figure 1 Recommended test device for determination of chromatic image distortion 5.4.1 Determination of local radial image distortion
The local radial image distortion V.(r) as a function of radius r shall be determined as follows: V.(r) = [A,(r)/AJ - 1,
Where:
A.(r)—the average value of the local radial magnification of two points on the same diameter at a distance r from the center of the human field of view; A. --—Center magnification.
Note: By sign convention, Va corresponds to pincushion distortion with positive values ​​and barrel distortion with negative values. 5.4.2 Determination of overall image distortion
As a function of radius r, the overall image distortion V(r) shall be determined by the following formula: Vi(r) - [A(r)/A.」- 1,
Here A;(r) is the overall magnification, measured with a circular test device of radius r. Note: As in 5.4.1, V corresponds to pincushion distortion with positive values ​​and barrel distortion with negative values. 4
6 Indication of image distortion
The indication of image distortion shall include:
Identification of the XRII, such as type, model or serial number; YY/T0457.4--2003/IEC61262-4:1994 The local radial image distortion V(r) is expressed as a curve or diagram as a function of the distance r in absolute or relative units, the distance r extending from the center of the human field to at least 90% of the diameter of the corresponding human field. Optional:
——The overall image distortion V(r) is expressed as a curve or diagram as a function of the radius of the test device, the radius r is expressed in absolute or relative units, extending to at least 90% of the incident field. b) Unless otherwise specified, the distortion data corresponds to the maximum incident field size. 7 Declaration of conformity
If it is to be stated that the determination of image distortion of an X-ray image intensifier complies with this standard, the following statement shall be made: Local radial image distortion: YY/T0457.4--2003. Optional:
Overall image distortion: YY/T0457.4—2003. YY/T 0457.4--2003/1EC 61262-4: 1994IEC 60788
Unit names in the International System of Units
Undefined derived terms
Undefined terms
Early unit names
Abbreviations·
3.1 in YY/T0457.4
Accompanying documents
Attenuation equivalent
accompanying documents
attenuation equivalent
central axis
Central axis
Central magnificationcentre of entrance fieldAppendix A
(Informative Appendix)
Term index
Centre of the output imagecentre of the output imagedifferential radial image distortion imagedistortionelectro-optical X-ray image intensifierentrance field size.entrance field size
focal spot
image distortionimage distortion
integral image distortionintegral magnificationlocal radial magnificationnormal use
output image
output image
radiation quality…
source to entrance plane distance,SEDtest device
X-ray radiationX-radiation
X-rayequipmen
X-ray image intensifierX-ray pattern
X-ray image
X-ray tubeX-ray tube
Photoelectric X-ray image intensifier
rm-82-01
rm-13-37
rm-32-40
rm-20-13s
... 3.1.12
: 3.1.14
rm-82-04
rm-32-49
rm-13-28
rm-71 -04
rm-11-01
rm-20-20
rm-32-39
rm-32-01
rm-22-035 Measuring equipment
The image length of the test device shall be measured by optical methods, preferably with the aid of a crosshair combined with a micrometer. The total uncertainty in the result shall be less than 2% of the absolute value of the overall image distortion and less than 3% of the absolute value of the local radial image distortion. 3
YY/T0457.4-2003/IEC61262-4:199415
5 Determination of image distortion
5. 1 Not applicable.
5. 2 Not applicable.
5.3 Not applicable.
5.4 Determination
Figure 1 Recommended test device for determining chromatic image distortion 5.4.1 Determination of local radial image distortion
Local radial image distortion V. (r) as a function of radius r shall be determined by the following formula: V.(r) = [A.(r)/A.] - 1,
where:
A.(r)—the average value of the local radial magnification of two points on the same diameter at a distance r from the center of the human field of view; A. --—central magnification.
Note: According to the sign convention, Va corresponds to pincushion distortion with positive values ​​and barrel distortion with negative values. 5.4.2 Determination of overall image distortion
As a function of radius r, the overall image distortion V(r) shall be determined by the following formula: Vi(r) - [A(r)/A.] - 1,
where A.(r) is the overall magnification, measured with a circular test device of radius r. Note: As in 5.4.1, V corresponds to pincushion distortion with positive values ​​and barrel distortion with negative values. 4
6 Indication of image distortion
The indication of image distortion shall include:
Identification of the XRII, such as type, model or serial number; YY/T0457.4--2003/IEC61262-4:1994 The local radial image distortion V(r) is expressed as a curve or diagram as a function of the distance r in absolute or relative units, the distance r extending from the center of the human field to at least 90% of the diameter of the corresponding human field. Optional:
——The overall image distortion V(r) is expressed as a curve or diagram as a function of the radius of the test device, the radius r is expressed in absolute or relative units, extending to at least 90% of the incident field. b) Unless otherwise specified, the distortion data corresponds to the maximum incident field size. 7 Declaration of conformity
If it is to be stated that the determination of image distortion of an X-ray image intensifier complies with this standard, the following statement shall be made: Local radial image distortion: YY/T0457.4--2003. Optional:
Overall image distortion: YY/T0457.4—2003. YY/T 0457.4--2003/1EC 61262-4: 1994IEC 60788
Unit names in the International System of Units
Undefined derived terms
Undefined terms
Early unit names
Abbreviations·
3.1 in YY/T0457.4
Accompanying documents
Attenuation equivalent
accompanying documents
attenuation equivalent
central axis
Central axis
Central magnificationcentre of entrance fieldAppendix A
(Informative Appendix)
Term index
Centre of the output imagecentre of the output imagedifferential radial image distortion imagedistortionelectro-optical X-ray image intensifierentrance field size.entrance field size
focal spot
image distortionimage distortion
integral image distortionintegral magnificationlocal radial magnificationnormal use
output image
output image
radiation quality…
source to entrance plane distance,SEDtest device
X-ray radiationX-radiation
X-rayequipmen
X-ray image intensifierX-ray pattern
X-ray image
X-ray tubeX-ray tube
Photoelectric X-ray image intensifier
rm-82-01
rm-13-37
rm-32-40
rm-20-13s
... 3.1.12
: 3.1.14
rm-82-04
rm-32-49
rm-13-28
rm-71 -04
rm-11-01
rm-20-20
rm-32-39
rm-32-01bzxz.net
rm-22-035 Measuring equipment
The image length of the test device shall be measured by optical methods, preferably with the aid of a crosshair combined with a micrometer. The total uncertainty in the result shall be less than 2% of the absolute value of the overall image distortion and less than 3% of the absolute value of the local radial image distortion. 3
YY/T0457.4-2003/IEC61262-4:199415
5 Determination of image distortion
5. 1 Not applicable.
5. 2 Not applicable.
5.3 Not applicable.
5.4 Determination
Figure 1 Recommended test device for determining chromatic image distortion 5.4.1 Determination of local radial image distortion
Local radial image distortion V. (r) as a function of radius r shall be determined by the following formula: V.(r) = [A.(r)/A.] - 1,
where:
A.(r)—the average value of the local radial magnification of two points on the same diameter at a distance r from the center of the human field of view; A. --—central magnification.
Note: According to the sign convention, Va corresponds to pincushion distortion with positive values ​​and barrel distortion with negative values. 5.4.2 Determination of overall image distortion
As a function of radius r, the overall image distortion V(r) shall be determined by the following formula: Vi(r) - [A(r)/A.] - 1,
where A.(r) is the overall magnification, measured with a circular test device of radius r. Note: As in 5.4.1, V corresponds to pincushion distortion with positive values ​​and barrel distortion with negative values. 4
6 Indication of image distortion
The indication of image distortion shall include:
Identification of the XRII, such as type, model or serial number; YY/T0457.4--2003/IEC61262-4:1994 The local radial image distortion V(r) is expressed as a curve or diagram as a function of the distance r in absolute or relative units, the distance r extending from the center of the human field to at least 90% of the diameter of the corresponding human field. Optional:
——The overall image distortion V(r) is expressed as a curve or diagram as a function of the radius of the test device, the radius r is expressed in absolute or relative units, extending to at least 90% of the incident field. b) Unless otherwise specified, the distortion data corresponds to the maximum incident field size. 7 Declaration of conformity
If it is to be stated that the determination of image distortion of an X-ray image intensifier complies with this standard, the following statement shall be made: Local radial image distortion: YY/T0457.4--2003. Optional:
Overall image distortion: YY/T0457.4—2003. YY/T 0457.4--2003/1EC 61262-4: 1994IEC 60788
Unit names in the International System of Units
Undefined derived terms
Undefined terms
Early unit names
Abbreviations·
3.1 in YY/T0457.4
Accompanying documents
Attenuation equivalent
accompanying documents
attenuation equivalent
central axis
Central axis
Central magnificationcentre of entrance fieldAppendix A
(Informative Appendix)
Term index
Centre of the output imagecentre of the output imagedifferential radial image distortion imagedistortionelectro-optical X-ray image intensifierentrance field size.entrance field size
focal spot
image distortionimage distortion
integral image distortionintegral magnificationlocal radial magnificationnormal use
output image
output image
radiation quality…
source to entrance plane distance,SEDtest device
X-ray radiationX-radiation
X-rayequipmen
X-ray image intensifierX-ray pattern
X-ray image
X-ray tubeX-ray tube
Photoelectric X-ray image intensifier
rm-82-01
rm-13-37
rm-32-40
rm-20-13s
... 3.1.12
: 3.1.14
rm-82-04
rm-32-49
rm-13-28
rm-71 -04
rm-11-01
rm-20-20
rm-32-39
rm-32-01
rm-22-031994IEC 60788
Unit names in the International System of Units
Undefined derived terms
Undefined terms
Early unit names
Abbreviations·
3.1 in YY/T0457.4
Accompanying documents
attenuation equivalent
accompanying documents
attenuation equivalent
central axis
Central axis
Central magnificationcentral magnificationcentre of entrance fieldAppendix A
(Informative Appendix)
Term index
centre of the output imagecentre of the output imagedifferential radial image distortionelectro-optical X-ray image intensifierentrance field size.entrance field size
focal spot
image distortion
integral image distortionintegral magnificationlocal radial magnificationnormal use
output image
output image
radiation quality…
source to entrance plane distance,SEDtest device
X-radiation
X-ray equipment
X-ray image intensifierX-ray pattern
X-ray image
X-ray tubeX-ray tube
Photoelectric X-ray image intensifier
rm-82-01
rm-13-37
rm-32-40
rm-20-13s
... 3.1.12
: 3.1.14
rm-82-04
rm-32-49
rm-13-28
rm-71 -04
rm-11-01
rm-20-20
rm-32-39
rm-32-01
rm-22-031994IEC 60788
Unit names in the International System of Units
Undefined derived terms
Undefined terms
Early unit names
Abbreviations·
3.1 in YY/T0457.4
Accompanying documents
attenuation equivalent
accompanying documents
attenuation equivalent
central axis
Central axis
Central magnificationcentral magnificationcentre of entrance fieldAppendix A
(Informative Appendix)
Term index
centre of the output imagecentre of the output imagedifferential radial image distortionelectro-optical X-ray image intensifierentrance field size.entrance field size
focal spot
image distortion
integral image distortionintegral magnificationlocal radial magnificationnormal use
output image
output image
radiation quality…
source to entrance plane distance,SEDtest device
X-radiation
X-ray equipment
X-ray image intensifierX-ray pattern
X-ray image
X-ray tubeX-ray tube
Photoelectric X-ray image intensifier
rm-82-01
rm-13-37
rm-32-40
rm-20-13s
... 3.1.12
: 3.1.14
rm-82-04
rm-32-49
rm-13-28
rm-71 -04
rm-11-01
rm-20-20
rm-32-39
rm-32-01
rm-22-03
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