ASTM E1647-03

Standard Practice for Determining Contrast Sensitivity in Radioscopy

SIGNIFICANCE AND USE
The contrast sensitivity gage measures contrast sensitivity independent of the imaging system spatial resolution limitations. The thickness recess dimensions of the contrast sensitivity gage are large with respect to the spatial resolution limitations of most imaging systems. Four levels of contrast sensitivity are measured: 4 %, 3 %, 2 %, and 1 %.
The contrast sensitivity gage is intended for use in conjunction with a high-contrast resolution measuring gage, such as the EN 462 – 5 Duplex Wire Image Quality Indicator. Such gages measure spatial resolution essentially independent of the imaging system’contrast sensitivity. Such measurements are appropriate for the qualification and performance monitoring of radiographic and radioscopic imaging systems.
Radioscopic/radiographic system performance may be specified by combining the measured contrast sensitivity expressed as a percentage with the spatial resolution expressed in millimeters of unsharpness. For the EN 462 – 5 spatial resolution gage, the unsharpness is equal to twice the wire diameter. For the line pair gage, the unsharpness is equal to the reciprocal of the line-pair/mm value. As an example, an imaging system that exhibits 2 % contrast sensitivity and images the 0.1 mm EN 462 – 5 paired wires (equivalent to imaging 5 line-pairs/millimeter resolution on a line-pair gage) performs at a 2 %–0.2 mm sensitivity level. A standard method of evaluating overall radioscopic system performance is given in Practice E 1411 and in EN 13068–1.
SCOPE
1.1 This practice covers the design and material selection of a contrast sensitivity measuring gage used to determine the minimum change in material thickness or density that may be imaged without regard to spatial resolution limitations.
1.2 This practice is applicable to transmitted-beam radiographic and radioscopic imaging systems utilizing X-ray and gamma ray radiation sources.
1.3 The values stated in inch-pound units are to be regarded as standard.
1.4 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. For specific safety statements, see NIST/ANSI Handbook 114 Section 8, Code of Federal Regulations 21 CFR 1020.40 and 29 CFR 1910.96.

General Information

• Status: Historical
• Publication Date: 09-Aug-2003
• ICS: 11.040.50 - Radiographic equipment
• Technical Committee: E07 - Nondestructive Testing
• Drafting Committee: E07.01 - Radiology (X and Gamma) Method

Relations

• Replaces: ASTM E1647-98a - Standard Practice for Determining Contrast Sensitivity in Radioscopy
• Effective Date: 10-Aug-2003
• Replaced By: ASTM E1647-09 - Standard Practice for Determining Contrast Sensitivity in Radioscopy
• Effective Date: 01-Jul-2009
• Referred By: ASTM E1416-23 - Standard Practice for Radioscopic Examination of Weldments
• Effective Date: 10-Aug-2003
• Referred By: ASTM E2033-17 - Standard Practice for Radiographic Examination Using Computed Radiography (Photostimulable Luminescence Method)
• Effective Date: 10-Aug-2003
• Referred By: ASTM E1931-16(2022) - Standard Guide for Non-computed X-Ray Compton Scatter Tomography
• Effective Date: 10-Aug-2003
• Referred By: ASTM E2445/E2445M-20 - Standard Practice for Performance Evaluation and Long-Term Stability of Computed Radiography Systems
• Effective Date: 10-Aug-2003
• Referred By: ASTM E3398-23 - Standard Guide for Digital Neutron Radiography
• Effective Date: 10-Aug-2003
• Referred By: ASTM E2533-21 - Standard Guide for Nondestructive Examination of Polymer Matrix Composites Used in Aerospace Applications
• Effective Date: 10-Aug-2003
• Referred By: ASTM E1411-16 - Standard Practice for Qualification of Radioscopic Systems
• Effective Date: 10-Aug-2003

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:E1647–03
Standard Practice for
1
Determining Contrast Sensitivity in Radiology
This standard is issued under the fixed designation E1647; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope E1025 Practice for Hole-Type Image Quality Indicators
4
Used for Radiography
1.1 Thispracticecoversthedesignandmaterialselectionof
4
E1316 Terminology for Nondestructive Examination
a contrast sensitivity measuring gage used to determine the
4
E1411 Practice for Qualification of Radioscopic Systems
minimum change in material thickness or density that may be
E2002 Practice for Determining Total Image Unsharpness
imaged without regard to spatial resolution limitations.
4
in Radiology
1.2 This practice is applicable to transmitted-beam radio-
2.2 Federal Standards:
graphic and radioscopic imaging systems utilizing X-ray and
21 CFR 1020.40 Safety Requirements for Cabinet X-ray
gamma ray radiation sources.
5
Systems
1.3 Thevaluesstatedininch-poundunitsaretoberegarded
5
29 CFR 1910.96 Ionizing Radiation
as standard.
2.3 NIST/ANSI Standards:
1.4 This standard does not purport to address all of the
NIST/ANSI Handbook 114 General Safety Standard for
safety concerns, if any, associated with its use. It is the
Installations Using Non-Medical X-ray and Sealed
responsibility of the user of this standard to establish appro-
6
Gamma Ray Sources, Energies to 10 MeV
priate safety and health practices and determine the applica-
7
2.4 Other Standard:
bility of regulatory limitations prior to use. For specific safety
EN462–5 Duplex Wire Image Quality Indicator
statements, see NIST/ANSI Handbook 114 Section 8, Code of
EN13068–1 Radioscopic Testing-Part 1: Qualitative Mea-
Federal Regulations 21 CFR 1020.40 and 29 CFR 1910.96.
surement of Imaging Properties
2. Referenced Documents
3. Terminology
2.1 ASTM Standards:
3.1 Definitions—Definitions of terms applicable to this test
B139 Specification for Phosphor Bronze Rod, Bar, and
2 method may be found in Terminology E1316.
Shapes
B150 Specification for Aluminum Bronze Rod, Bar, and
4. Summary of Practice
2
Shapes
3 4.1 It is often useful to evaluate the contrast sensitivity of a
B161 Specification for Nickel Seamless Pipe and Tube
penetrating radiation imaging system separate and apart from
B164 Specification for Nickel-CopperAlloy Rod, Bar, and
3 spatial resolution measurements. Conventional image quality
Wire
indicators(IQI’s),suchasTestMethodE747wireandPractice
B 166 Specification for Nickel-Chromium-Iron Alloys
E1025 plaque IQIs, combine the contrast sensitivity and
(UNS N06600, N06601, and N06690) and Nickel-
resolution measurements into an overall performance figure of
Chromium-Cobalt-Molybdenum Alloy (UNS N06617)
3 merit, other methods such as included in Practice E2002 do
Rod, Bar, and Wire
4 notaddresscontrastspecifically.Suchfiguresofmeritareoften
E94 Guide for Radiographic Examination
not adequate to detect subtle changes in imaging system
E747 Practice for the Design Manufacture and Material
performance. For example, in a high contrast image, spatial
Grouping Classification of Wire Image Quality Indicators
4 resolution can degrade with almost no noticeable effect upon
(IQI) Used For Radiology
overall image quality. Similarly, in an application in which the
imagingsystemprovidesaverysharpimage,contrastcanfade
1
This practice is under the jurisdiction of ASTM Committee E07 on Nonde-
structive Testing and is the direct responsibility of Subcommittee E07.01 on
5
Radiology (X and Gamma) Method. Available from the Superintendent of Documents, U.S. Government Printing
Current edition approved August 10, 2003. Published October 2003. Originally Office, Washington, DC 20402.
6
approved in 1994. Last previous edition approved in 1998 as E1647–98a. Available from American Society for Nondestructive Testing, 1711 Arlingate
2
Annual Book of ASTM Standards, Vol 02.01. Plaza, P.O. Box 28518, Columbus, OH 43228-0518.
3 7
Annual Book of ASTM Standards, Vol 02.04. Available from British Standards Institute, 2 Park Street, London, England
4
Annual Book of ASTM Standards, Vol 03.03. W1A2B5.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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E1647–03
TABLE 1 Design of the Contrast Sensitivity Gage
with little noticeable effect upon the overall image quality.
These situations often develop and may go unnoticed until the Gage Thickness J Recess K Recess L Recess M Recess
T 1%ofT 2%ofT 3%ofT 4%ofT
systemperformancedeterioratesbelowacceptableimagequal-
ity limits.
TABLE 2 Co
...