1、BSI Standards PublicationBS ISO 18939:2013Imaging materials Digitalhard copy for medical imaging Methods of measuringpermanenceBS ISO 18939:2013 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 18939:2013.The UK participation in its preparation was entrusted to
2、TechnicalCommittee CPW/42, Photography.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Inst
3、itution 2013. Published by BSI StandardsLimited 2013ISBN 978 0 580 79979 2ICS 37.100.01Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 30 November 2013.Amendments
4、issued since publicationDate Text affectedBS ISO 18939:2013 ISO 2013Imaging materials Digital hard copy for medical imaging Methods of measuring permanenceMatriaux pour limage Photocopie numrique pour imagerie mdicale Mthodes de mesure de la permanenceINTERNATIONAL STANDARDISO18939First edition2013-
5、11-01Reference numberISO 18939:2013(E)BS ISO 18939:2013ISO 18939:2013(E)ii ISO 2013 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2013All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or
6、mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCase postale 56 CH-1211 Geneva 20Tel. + 41 22 749
7、01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in SwitzerlandBS ISO 18939:2013ISO 18939:2013(E) ISO 2013 All rights reserved iiiContents PageForeword ivIntroduction v1 Scope . 12 Normative references 13 Terms and definitions . 14 Physical test methods 44.1 General . 44.2 L
8、ayer adhesion 44.3 Binder stability test . 64.4 Blocking test and image interaction test 75 Test methods for image stability . 95.1 General . 95.2 Thermal-ageing test (dark stability) 95.3 Light chamber test 135.4 Image spread test .16Annex A (informative) Light stability test conversion of units .1
9、9Annex B (informative) Effect of residual compounds on thermally processed radiographic images 20Annex C (informative) Simulated thermal ageing tests .21Annex D (informative) Greyscale evaluation based on just noticeable differences (JNDs) defined DICOM standard display function (SDF) .22Annex E (in
10、formative) CIE colour space parameters for evaluation of discolouration 26Bibliography .27BS ISO 18939:2013ISO 18939:2013(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International
11、 Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, a
12、lso take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1.
13、 In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).Attention is drawn to the possibility that some of the eleme
14、nts of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received
15、 (see www.iso.org/patents).Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adheren
16、ce to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information.The committee responsible for this document is ISO/TC 42, Photography.iv ISO 2013 All rights reservedBS ISO 18939:2013ISO 18939:2013(E)IntroductionThis International Standard
17、 prepared by ISO TC 42, WG 5 provides information for measuring the image stability and other relevant properties of medical dry hard copy films with greyscale images made with photothermographic, thermographic, and microcapsule type materials or with inkjet printing. Medical colour images and print
18、s on reflective material for referral purposes are not covered.Medical dry hard copy films are employed widely for digitally recording medical images in general radiography and mammography, because of the systems simplicity, flexibility, ease of use, and attendant environmental advantages. First rea
19、lizations of medical dry hardcopy systems entered the market together with CR and DR modalities in the 1990s, starting with photothermographic, thermographic, and microcapsule type materials. Recently, also inkjet based systems were also available. Dry hard copy systems gained through its one-step d
20、ry processing method which obviates the need for film processing equipment and liquid processing solutions and provides a significant saving in capital and labour costs.Thermally processed dry hard copy films use osynthetic polymers, e.g. poly (vinylbutyral), poly (vinyl alcohol), and poly (styrene
21、butadiene) as binders for image forming silver clusters, instead of gelatine being used in wet processed AgX films. This renders the binder more inert to moisture and its deleterious effects, including oxidation. The support for thermally processed dry hard copy films is normal, photographic grade P
22、ET poly (ethylene terephthalate) safety film.123456A disadvantage of thermally processed dry hard copy images is their greater potential instability caused by the presence of unused chemicals after image formation; these are not removed by liquid processing solutions as with conventional silver hali
23、de films. Consequently, the potential for formation of excessive fog exists throughout the life of the thermally processed dry hard copy film. Such degradation of image quality has occasionally been observed in the course of prolonged exposure to ambient illumination or storage under high temperatur
24、e or, most frequently, due to unintended over-exposure to light and heat in a reader-printer (view box). Also, in case of a fire in the storage area or near a vault or safe, the temperature sometimes increase sufficiently high to cause image degradation, even though the temperature used for generati
25、ng thermally processed dry hard copy images range well above 100 C. These images are considerably stable under normal user and storage conditions as well as on accelerated ageing studies789). Hence, thermally processed dry hard copy films do not fall within the provisions of ISO 18901 that apply to
26、chemical fixation.Inkjet based dry hard copy images may also be susceptible to temperature, humidity and light depending on the details of the technical details of the inkjet printing system, its type of ink (e.g. aqueous, solvent or wax based), the colorants (dye or pigment) and the type of ink rec
27、eiver layers (porous, swellable, etc.) of the hard copy film.General radiographs are normally viewed on light boxes at a luminance level of 2 000 to 4 000 cd/m2, whereas according to American College of Radiology (ACR) recommended practices,2425mammograms and clinical quality reviews are viewed at a
28、 luminance of at least 3 000 cd/m2or higher depending on the modality. In addition, all mammograms and mammogram test images are required to be masked completely during diagnostic inspection, so that no light directly emitted by the light box surface can reach the observers eyes. The recommended lev
29、el of intensity of surrounding illumination in that viewing situation is below 10 cd/m2. In practice, light box outputs and surrounding illumination conditions do vary considerably and, therefore, this standard requires use of a light chamber which permits close control of all illumination parameter
30、s, temperature, relative humidity and duration of exposure.Everyone concerned with the preservation of records on radiographic film understands that specifying the chemical and physical characteristics of the material does not, by itself, ensure that the records will not deteriorate. It is also reco
31、gnized that enclosure materials used to make radiographic envelopes effects the preservation quality of records It is also essential to provide the correct storage temperature and humidity, and protection from the hazards of fire, water, fungus, and certain atmospheric pollutants. These aspects are
32、considered in pertinent International Standards for storage of films, for example, ISO 1890216and ISO 18911.17 ISO 2013 All rights reserved vBS ISO 18939:2013BS ISO 18939:2013Imaging materials Digital hard copy for medical imaging Methods of measuring permanence1 ScopeThis International Standard est
33、ablishes test methods for measuring the stability of photographic films intended for storage of medical records. It is applicable to greyscale images on films for use in transmission mode that are based on thermally processed materials (photothermography, thermography, microcapsule) or created by in
34、kjet printing. Thermally processed materials have a base of safety polyester poly (ethylene terephthalate) and work predominantly with silver behenate salts dispersed in non-gelatinous emulsions or dye-based microcapsule emulsions that are thermally processed to produce a black-and-white image. In i
35、nkjet printing ink droplets are jetted onto a film with an ink-receiving layer to produce a greyscale image.This International Standard does not cover wet-processed black-and-white films or black-and-white paper. It is not applicable to medical colour images or colour prints created by colour inkjet
36、 or dye diffusion thermal transfer (D2T2). Neither does it cover medical greyscale images printed on reflective materials for referral purposes or filmless systems such as picture archiving and communication systems (PACS) in medical imaging.This International Standard requires the arbitrary choice
37、of “illustrative end points” for changes in colour and perceived contrast to depict quantifiable changes due to physical ageing. Extrapolations based on illustrative end points do not have any proven diagnostic or clinical relevance due to the lack of corresponding statistically significant scoring
38、by radiologists.2 Normative referencesThe following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (incl
39、uding any amendments) applies.ISO 5-2, Photography and graphic technology Density measurements Part 2: Geometric conditions for transmittance densityISO 5-3, Photography and graphic technology Density measurements Part 3: Spectral conditionsISO 18907, Imaging materials Photographic films and papers
40、Wedge test for brittlenessISO 18924, Imaging materials Test method for Arrhenius-type predictions3 Terms and definitionsFor the purposes of this document, the following terms and definitions apply.3.1adherographyimaging technology utilizing a high intensity laser beam to form a positive carbon image
41、 through differential thermal adhesionNote 1 to entry: This process involves fusion of a laser sensitive, carbon-containing layer with the final imaging layer in exposed areas, followed by controlled peeling, which removes the unexposed portion. The positive image is then made durable and permanent
42、by the application of a transfer coat.INTERNATIONAL STANDARD ISO 18939:2013(E) ISO 2013 All rights reserved 1BS ISO 18939:2013ISO 18939:2013(E)3.2microcapsuleimaging technology in which heat-responsive microcapsules containing dye precursors are thermally rendered to develop a dye imageNote 1 to ent
43、ry: Heat-responsive microcapsules containing dye precursors are dispersed together with a development emulsion on a polyester support. Application of computer-modulated heat that matches the density pattern of a digital image renders the walls of the microcapsules differently permeable. The varying
44、amounts of developer, which penetrate the capsule walls, produce corresponding differences in dye image density. The capsule walls revert to their impermeable state on cooling and provide protection against dye formation and dye degradation under normal storage conditions.3.3phase change solid inkje
45、timaging technology based on modulated deposition of micro-droplets of non-aqueous, waxy inks on a microcellular surface of a layer coated on a polyester supportNote 1 to entry: Four shades of neutral ink are used to obtain the wide grey scale density range required for medical images. The melting p
46、oint of the ink is considerably above ambient temperature, ensuring image stability under normal storage conditions.3.4photothermographyimaging technology based on thermal development of a light-induced latent image in dispersed silver saltsNote 1 to entry: The process involves a polymeric layer con
47、taining light sensitive silver halide crystals, light insensitive silver behenate crystallites, silver soaps and a reducing agent coated on a polyester support. A latent image formed by light exposure of the silver halide crystals catalyses an oxidation-reduction reaction between the silver behenate
48、 and the reducing agent upon heating above 120 C. This yields a metallic silver image by physical development.3.5thermographyimaging technology based on image-wise thermal modulation and development of dispersed silver saltsNote 1 to entry: The process utilizes a polymeric layer containing a light-i
49、nsensitive organic silver salt, a reducing agent and a stabilizer, coated on a polyester support. Reduction of the organic silver salt by the reducing agent accelerated by heat (100 C200 C) yields a metallic silver image whose densities are controlled by the adjustable temperature of print head elements. The integrity of the silver image under normal storage conditions is secured by stabilization of the unused silver salt.3.6aqueous inkjetimaging technology involving image formation with an aqueous
