ASTM E2002-98
(Practice)Standard Practice for Determining Total Image Unsharpness in Radiology
Standard Practice for Determining Total Image Unsharpness in Radiology
SCOPE
1.1 This practice covers the design and basic use of a gage used to determine the total image unsharpness of radiographs and radioscopic systems.
1.2 This practice is applicable to radiographic and radioscopic imaging systems utilizing X-ray and gamma ray radiation sources.
1.3 The values stated in SI units are to be regarded as standard.
1.4 The gage described can be used effectively with radiation energies up to 400 kv. When using energies in the megavolt range the results may not be completely satisfactory.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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Designation: E 2002 – 98
Standard Practice for
Determining Total Image Unsharpness in Radiology
This standard is issued under the fixed designation E 2002; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope 3. Terminology
1.1 This practice covers the design and basic use of a gage 3.1 Definitions—Definitions of terms applicable to this
used to determine the total image unsharpness of radiographs practice may be found in Terminology E 1316.
and radioscopic systems.
4. Summary of Practice
1.2 This practice is applicable to radiographic and radio-
scopic imaging systems utilizing X-ray and gamma ray radia- 4.1 When it is determined necessary to evaluate and mea-
tion sources. sure the Total Image Unsharpness (Spatial Resolution) of a
imaging system separately and apart from contrast sensitivity
1.3 The values stated in SI units are to be regarded as
standard. measurements, a tool or gage as described in this practice can
be used. Conventional IQIs described in Practices E 747 and
1.4 The gage described can be used effectively with radia-
tion energies up to 400 kv. When using energies in the E 1025 combine the contrast sensitivity and resolution mea-
surements into an overall figure of merit. Such figures of merit
megavolt range the results may not be completely satisfactory.
1.5 This standard does not purport to address all of the may not be adequate to detect subtle changes in the imaging
systems performance. For example, in a high-contrast image,
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- spatial resolution can degrade with almost no noticeable effect
upon the overall image quality. Similarly, in an application in
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use. which the imaging system provides a very sharp image,
contrast can fade with little noticeable effect upon the overall
2. Referenced Documents
image quality, as determined using conventional IQIs. These
2.1 ASTM Standards: situations often develop and may go undetected until the
E 747 Practice for Design, Manufacture and Material system performance deteriorates below acceptable image qual-
Grouping Classification of Wire Image Quality Indicators ity limits.
(IQI) Used for Radiology
5. Significance and Use
E 1025 Practice for Design, Manufacture and Material
5.1 The gage is intended to provide a means for measuring
Grouping Classification of Hole-Type Image Quality Indi-
cators (IOI) used for Radiology total image unsharpness as independently as practicable from
E 1316 Terminology for Nondestructive Examinations the imaging system contrast sensitivity limitations. Further
description and details of the gage are provided in EN-462-5.
E 1647 Practice for Determining Contrast Sensitivity in
Radioscopy 5.2 The gage can be used in conjunction with a contrast
sensitivity measuring gage, as described in Practice E 1647.
2.2 EN Standard:
EN-462-5:1994 Nondestructive Testing—Image Quality of
6. Gage Construction
Radiographs—Part 5: Image Quality Indicators (Duplex
6.1 The gage shall be fabricated in accordance with Fig. 1,
Wire Type)—Determination of Total Image Unsharpness
using the tolerances given in Table 1. This gage is identical to
Value
the gage described in EN-462-5 and if necessary, EN-462-5
should be reviewed for additional detailed information.
This practice is under the jurisdiction of ASTM Committee E-07 on Nonde-
6.2 The gage shall consist of 13 elements. Each element
structive Testing and is the direct responsibility of Subcommittee E07.01 on
shall consist of a pair of wires with circular cross-section.
Radiology (X and Gamma) Method.
Elements 1 through 3 are of tungsten material and elements 4
Current edition approved Dec. 10, 1998. Published February 1999.
Annual Book of ASTM Standards, Vol 03.03.
through 13 are of platinum material. The 13 elements are
Available from British Standards Institution, British Standards House, 389
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