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1、BRITISH STANDARD BS 7555:1992 Guide to Miniaturization of medical diagnostic images on film Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 10:26:11 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7555:1992 This British Standard, having been prepared under the dir
2、ection of the Information and Documentation Standards Policy Committee was published under the authority of the Standards Board and comes into effect on 31 March 1992 BSI 09-1999 The following BSI references relate to the work on this standard: Committee reference DOT/16 Draft for comment 90/96351 D
3、C ISBN 0 580 20524 X Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Information and Documentation Standards Policy Committee (DOT/-) to Technical Committee DOT/16, upon which the following bodies were represented: British Computer Socie
4、ty British Library British Office Technology Manufacturers Alliance British Photographic Association Her Majestys Stationery Office London Borough of Bromley National Centre for Information Media and Technology (Cimtech) United Kingdom Association for Information and Image Management The following b
5、odies were also represented in the drafting of the standard, through subcommittees and panels: British Institute of Radiology College of Radiographers Department of Health Institute of Administrative Management Royal College of Radiologists Amendments issued since publication Amd. No.DateComments Li
6、censed Copy: London South Bank University, London South Bank University, Fri Dec 08 10:26:11 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7555:1992 BSI 09-1999i Contents Page Committees responsibleInside front cover Forewordii 1Scope1 2Definitions1 3General1 4Image polarity1 5Film and filming2 6Met
7、hods of production, processing and storage2 7Retrieval, viewing and duplication2 8Staffing and studio management3 Appendix A Test films5 Appendix B Quality management system8 Figure 1 Flowchart: studio management4 Figure 2 Resolution test grids6 Figure 3 Test object, with sensitometric strip7 Figure
8、 4 Flowchart: miniaturization10 Figure 5 Flowchart: retrieval and viewing11 Figure 6 Flowchart: monitoring performance13 Publication(s) referred toInside back cover Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 10:26:11 GMT+00:00 2006, Uncontrolled Copy, (c) B
9、SI BS 7555:1992 ii BSI 09-1999 Foreword This British Standard guide has been prepared under the direction of the Information and Documentation Standards Policy Committee. Hospitals and other organizations that are required to keep medical diagnostic images for many years frequently find that they la
10、ck space to store them. Miniaturization offers a solution. This guide has been prepared to help organizations that are considering miniaturization to decide whether it will meet their needs and, if so, to help them to establish a suitable programme. Medical diagnostic images tend to be consulted fre
11、quently in the first two years after they are made. Most of them have to be kept for several more years, some for the life of the patient, in case they have to be consulted for medical, legal or social services purposes. They should therefore be stored in a form that will be of a quality to provide
12、the information required if the need to consult them should arise. Straightforward photographic copies are unlikely to be satisfactory because the range of the densities will usually be less than the range of densities on the original and information may be lost in copying. Electronic scanning and a
13、djustment will be needed if all the information is to be retained. New techniques, e.g. picture archiving and communication systems (PACS), are being developed and any organization that considers using miniaturization should take specialist advice about the range of methods currently available. Appe
14、ndix A describes methods of checking the quality of the output of a system for miniaturizing medical diagnostic images. Appendix B gives advice on the operation (or installation) of a quality management system. A British Standard does not purport to include all the necessary provisions of a contract
15、. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 14, an inside back cover
16、 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 10:26:11 GMT+00:00 2006, Unc
17、ontrolled Copy, (c) BSI BS 7555:1992 BSI 09-19991 1 Scope This British Standard gives guidance on matters to be taken into account when an organization is considering whether to set up a programme for the miniaturization of medical diagnostic images on film and on procedures to be followed if a mini
18、aturization programme is adopted. The standard applies to the 35 mm microfilming of medical diagnostic images of good quality that are recorded on film and form part of a patients medical record. General guidance on setting up a micrographics unit is given in BS 6660. NOTEThe titles of the publicati
19、ons referred to in this standard are listed on the inside back cover. 2 Definitions For the purposes of this British Standard the definitions given in BS 6054-1 apply, together with the following: 2.1 frame that area of the film on which radiant energy can fall during a single exposure 2.2 microform
20、 generic term for any form, usually film, that contains microimages 2.3 microimage an image too small to be read without magnification 2.4 noise granularity, quantum or screen mottle, processing and other blemishes found on film 3 General 3.1 Advantages The advantages of miniaturizing medical diagno
21、stic images are: a) miniaturized images require considerably less storage space than the originals; b) originals are released sooner for silver recovery; c) individual images will be easier to retrieve if the miniaturization programme includes the introduction of a simple retrieval system (see 7.1).
22、 3.2 Disadvantages The disadvantages of miniaturizing medical diagnostic images are: a) staff who are reluctant to use miniaturized images may take time to accept the new system; b) for reading images on 35 mm microfilm some form of optical aid will be required; c) some detail can be lost in the min
23、iaturized image; d) duplicates of individual images are inconvenient to make and will require a trained operator. 3.3 Suitability of images When a miniaturization programme is established, the organization concerned should consider whether all categories of diagnostic image are suitable for miniatur
24、ization or whether certain categories should be excluded. 3.4 Choice of in-house or bureau systems A miniaturization programme may be undertaken in-house or contracted to a bureau. Capital costs of setting up an in-house system will include the provision of suitable accommodation and equipment for f
25、ilming, viewing, retrieval and duplication. Additional members of staff may be required (see 8.1). If the likely volume of work is not large enough to justify such expense, it may be more cost- effective to employ a bureau. In all cases detailed quality requirements should be specified. Appendix A d
26、escribes methods of checking the quality of output of a system. (See also BS 6660.) 3.5 Quality management In the processes of miniaturization, retrieval and viewing, something of the original will be lost because of variations in the performance of the equipment or the characteristics of the consum
27、ables, or, more commonly, because of human error. To ensure that the programme operates in compliance with established criteria, the organization should consider setting up a quality management system as described in Appendix B. 4 Image polarity Miniaturized medical diagnostic images should be prese
28、nted in the same polarity as the original white-bone images, unless black-bone images are specifically requested. The production of images of the same polarity as the original usually requires reversal processing (see 6.2). Licensed Copy: London South Bank University, London South Bank University, F
29、ri Dec 08 10:26:11 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7555:1992 2 BSI 09-1999 5 Film and filming 5.1 Film width: reasons for choosing 35 mm Although images on 35 mm film cannot be read without magnification and their quality is more likely to be impaired by dust, 35 mm film is widely used
30、 for conventional microfilming and much of the equipment needed for miniaturizing is readily available, at a lower cost than that used for 105 mm film. Images on 35 mm film also require less storage space. This standard has therefore been written for programmes that use 35 mm film. NOTEIf the same e
31、mulsion and the same technique, e.g. electronic scanning, are used when exposing both 105 mm and 35 mm film, the larger format provided by 105 mm film should give better results. Miniaturized images on 105 mm film are the smallest that can be viewed without magnification, but the equipment needed to
32、 produce and store 105 mm film costs more than that for 35 mm film, and the costs of film and chemicals for processing it are higher. 5.2 Tonal range The film should be capable of recording an acceptable tonal range without distortion of intermediate density differences. The range required may be ac
33、hieved by processing or exposure techniques. 5.3 Density The maximum visual diffuse transmission density of the film should be not less than 2.0. 5.4 Speed Film exposed by electronic scanning usually requires a higher film speed than film exposed by photographic methods. The manufacturer should be a
34、sked to advise. 5.5 Resolution The film should be of high resolution, typical of film designed for microfilming. 5.6 Reduction ratio Medical diagnostic images should normally be miniaturized at a reduction ratio of approximately 1 : 14, regardless of the size of the original. The use of a single red
35、uction ratio simplifies procedures for filming and enlarging. 5.7 Duplicates and enlargements All duplicates and enlargements should be made on silver halide film. 6 Methods of production, processing and storage 6.1 Choice of microform The choice of microform will depend on cost and projected use. F
36、or the purposes of storage, roll film is the simplest and cheapest to produce, but is more likely than other forms to suffer degradation in storage, particularly if the atmosphere is dusty. Individual frames may be difficult to duplicate. If roll film is used, it should comply with BS 1371. Microfil
37、m jackets provide a convenient way to store the diagnostic images and, if necessary, other microfilmed medical records of a patient in one package. Jackets are simple to use and can be duplicated on 105 mm microfilm, although inserting film in jackets is time-consuming and adds to the cost. If micro
38、film jackets are used for storage, they should comply with BS 5632. 6.2 Processing Processing can be negative or reversal (positive). Negative processing is comparatively simple. If reversal processing is required, extra processing chemicals, a more complicated machine and greater understanding of t
39、he process will be needed. (See also clause 4.) 6.3 Storage conditions The miniaturized images should be stored, in accordance with the manufacturers instructions, in plastics jackets or in rolls in their original containers, depending on the users requirements. The relative humidity of the storage
40、area should be not more than 60 % and temperature within the range 15 C to 25 C. (See also BS 1153.) 6.4 Control of accuracy The miniaturization programme should include provision for controlling and monitoring the accuracy of the process to ensure that the miniaturized image, when magnified to the
41、size of the original, is an acceptable reproduction of the original. Methods of test are described in Appendix A. 7 Retrieval, viewing and duplication 7.1 Retrieval 7.1.1 Introduction The complexity and, to some extent, the cost of a microform retrieval system depends on: a) the number of microforms
42、 in store; b) the number of frames per microform; c) the frequency of access; d) the number of users who access the store; e) the degree of randomness of enquiry; Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 10:26:11 GMT+00:00 2006, Uncontrolled Copy, (c) BSI
43、 BS 7555:1992 BSI 09-19993 f) the need for protection against loss; g) the need to ensure the integrity of the record (see BS 6498). 7.1.2 Choice of system Systems available include: a) manual (written) index/manual retrieval; b) computerized index/manual retrieval; c) computerized index/automated m
44、icroform retrieval/manual frame access; d) computerized index/manual microform retrieval/automated frame access; e) computerized index/automated microform retrieval/automated frame access. Although a system that relies on a manual index and manual retrieval may be adequate at the outset, when the st
45、ore being accessed is small, it should be designed to allow for some degree of automation as the store becomes larger and more complex. For example, a data retrieval and indexing system and relational database manager for use with a personal computer would enable a user to identify a microform unit
46、number and a frame number within that unit according to generally used data fields such as patients name, patients number, date, or any other character string by which the captured data image is identified. The cost of a complex system is likely to be justified only in a store containing large volum
47、es of data that are frequently accessed, e.g. more than 250 000 frames. 7.2 Viewing 7.2.1 General Most microform readers are designed to enable the user to view line images, e.g. text and drawings. It is essential that the reader selected: a) has a carrier that will accept all the kinds of microform
48、 that are to be viewed; b) is capable of making all useful information legible, generally by magnifying the microimage to the size of the original from which it was reduced. The reader will be easier to use if it has the following additional characteristics. 1) Screen materials that minimize specula
49、r reflectance. 2) Illuminance that is controllable in relation to levels of ambient light. 3) Screens angled from the perpendicular to facilitate reading for long periods, although they may give poorer contrast if levels of ambient light are high. NOTEFor further information, see ISO 6198 and ISO 7565. 7.2.2 Reader for medical diagnostic images A reader for medical diagnostic images should conform to ISO 6198 and ISO 7565. In addition, it should have controllable luminance, preferably blue or neutral (grey). If magnification to the size of the original is requi