BS EN 60627:2015
$167.15
Diagnostic X-ray imaging equipment. Characteristics of general purpose and mammographic anti-scatter grids
| Published By | Publication Date | Number of Pages |
| BSI | 2015 | 42 |
IEC 60627:2013 is applicable to anti-scatter grids used in medical diagnostic X-ray imaging equipment. Anti-Scatter Grids are used to reduce the incidence of scattered radiation, produced particularly in the body of the patient, upon the image reception area and thus to improve the contrast of the X-ray pattern. This International Standard specifies the definitions, determination and indication of characteristics of anti-scatter grids. In this standard only linear grids are considered. Since at present only focused grids are used in mammography, this standard is restricted to focused grids where mammographic anti-scatter grids are concerned. This standard is not intended to be applied for acceptance tests. This standard does not cover the homogeneity of performance over the area of a grid. This standard is intended to be applied for the determination of the characteristics of anti-scatter grids under test conditions. These conditions are not usually available at the site of the responsible organization. This third edition cancels and replaces the second edition published in 2001, and constitutes a technical revision. In this revision calcium tungstate phosphor fluorescent screens, which are no longer available, have been replaced by gadolinium oxysulphide (GOS) fluorescent screens. Further, a new quality parameter is introduced: the Image Improvement Factor or Q-factor, which better describes the properties of the anti-scatter grid, especially for digital detector applications. Further differences between this third edition and the previous second edition are: – new instrumentation is prescribed for measurements of the transmission of primary radiation, the transmission of scattered radiation and the transmission of total radiation, because fluorescent screens made of calcium tungstate phosphors are outdated and are no longer available; – the definition of the phantom used for measurements of the transmission of primary radiation, the transmission of scattered radiation and the transmission of total radiation is modified and references to IEC 61267 are omitted; – and the radiation conditions used for the measurements have been adapted and are now the RQR and RQR-M conditions specified in IEC 61267:2005.
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 7 | English CONTENTS |
| 9 | FOREWORD |
| 12 | INTRODUCTION |
| 13 | 1 Scope 2 Normative references 3 Terms and definitions |
| 14 | 3.1 Grid definitions |
| 15 | 3.2 Geometric characteristics 3.3 Physical characteristics |
| 16 | 3.4 Other terms |
| 17 | 4 Structure of anti-scatter grids 5 Measurement and determination of physical characteristics 5.1 Method and arrangement for measurement 5.1.1 Determination of physical characteristics |
| 18 | 5.1.2 Instrumentation |
| 19 | 5.1.3 Phantoms 5.1.4 Arrangements |
| 21 | 5.1.5 Radiation conditions 5.1.6 Constancy of source 5.2 Physical characteristics 5.2.1 Measurements for the transmission of primary radiation (Tp) 5.2.2 Measurements for the transmission of scattered radiation (Ts) |
| 22 | 5.2.3 Measurements for the transmission of total radiation (Tt) 5.2.4 Calculation of the grid selectivity (Σ) 5.2.5 Calculation of the contrast improvement ratio (K) 5.2.6 Calculation of the grid exposure factor (B) 5.2.7 Calculation of the image improvement factor (Q) 5.2.8 Accuracy of measurements |
| 23 | 6 Requirements for anti-scatter grids 6.1 Manufacturing tolerances 6.2 Determination of the application limits 6.3 Accuracy of characteristics 6.3.1 Grid selectivity 6.3.2 Contrast Improvement Ratio 6.3.3 Grid Exposure Factor |
| 24 | 6.3.4 Image Improvement Ratio 6.4 Markings and accompanying documents 6.4.1 Data in accompanying documents 6.4.2 Mandatory markings and indications for linear grids 6.4.3 Mandatory markings and indications for focused grids 6.4.4 Additional mandatory markings and indications |
| 25 | 6.4.5 Further requirements |
| 26 | Figures Figure 1 – Structure of anti-scatter grids |
| 27 | Figure 2 – Radiation detector |
| 28 | Figure 3 – Measurement arrangement for general purpose anti-scatter grids with narrow-beam condition (determination of the transmission of primary radiation) |
| 29 | Figure 4 – Measurement arrangement for general-purpose anti-scatter grids with broad beam condition (determination of the transmission of scattered radiation) |
| 30 | Figure 5 – Measurement arrangement for mammographic anti-scatter grids withnarrow-beam condition (determination of the transmission of primary radiation) |
| 31 | Figure 6 – Measurement arrangement for mammographic anti-scatter grids withbroad beam condition (determination of the transmission of scattered radiation) |
| 32 | Annex A (normative) Calculation of the application limits |
| 35 | Annex B (informative) Influence of scatter fraction on the physical characteristics |
| 36 | Figure B.1 – Physical characteristics as function of scatter fraction: selectivity Σ (dash-dotted line), contrast improvement ratio K (dotted line), grid exposure factor B (dashed line), and image improvement factor Q (solid line) |
| 37 | Bibliography |
| 38 | Index of defined terms used in this standard |
