Fluke 07-611 User Manual

Nuclear Associates

Radiographic and Mammographic

Focal Spot Measurements Products

March 2005
Manual No. 38659 Rev. 2
©2004, 2005 Fluke Corporation, All rights reserved. Printed in U.S.A.
All product names are trademarks of their respective companies

Users Manual

Fluke Biomedical

Radiation Management Services

6045 Cochran Road
Cleveland, Ohio 44139

440.498.2564

www.flukebiomedical.com/rms

Table of Contents

Section 1: Introduction................................................................................................ 1-1

1.1 Introduction .................................................................................................. 1-1

Section 2: Operation.................................................................................................... 2-1

2.1 X-Ray Tube Focal Spot Measurements....................................................... 2-1

2.1.1 Purpose .................................................................................................. 2-1

2.1.2 Equipment Needed/Recommended for X-Ray Tube Focal Spot

Measurement............................................................................................... 2-1

2.1.3 Equipment Needed/Recommended for Mammographic X-Ray Tube

Focal Spot Measurements...................................................................... 2-2

2.1.4 Procedure for Over-Table X-Ray Tube Focal Spot Test Stand

Alignment..................................................................................................... 2-2

2.1.5 Procedure for Under-Table X-Ray Tube Focal Spot Test Stand

Alignment..................................................................................................... 2-4

2.1.6 Procedure for Slit Measurement or Mammographic X-Ray Tube Focal

Spot Measurement ................................................................................. 2-4

2.1.7 Procedure – Slit Measurement of Focal Spots ....................................... 2-7

2.1.8 Procedure – Pinhole Measurement Technique ...................................... 2-8

2.2 Star Measurement Technique...................................................................... 2-9

2.2.1 Physical Description of Star Test Pattern ............................................... 2-9

2.2.2 Instructions for Use................................................................................. 2-9

2.3 Procedure – Star Measurement Technique ............................................... 2-10

2.4 Procedure – Half-Value Layer Measurements ........................................... 2-12

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Introduction

Introduction

1

Section 1

Introduction

1.1 Introduction

This manual is to be used for the following models:

07-624, 07-624-1000, 07-624-2222 - Slit Cameras

07-622 - Multipurpose Focal Spot/HVL Test Stand

07-623 - Mammography Focal Spot Measurement Test Stand

07-503, 07-509, 07-510, 07-542, 07-543, 07-550 - Star X-Ray Test Patterns for Measuring Focal Spot
Size

07-611, 07-613, 07-617 and 07-633 - X-Ray Pinhole Assemblies

Focal spot size and intensity distribution play a significant role in mammographic image quality. It is
particularly important to verify the size of the focal spot during acceptance testing of new mammographic
equipment or when a new x-ray tube is installed.

The National Electrical Manufacturers Association (NEMA) has developed a standard of describing a
technique for measuring the focal spot size. Some of the aspects of the standard are difficult, if not
impossible, to meet in the clinical setting. This manual follows as closely as possible, the present NEMA
standard.

Additional information regarding focal spot measurement techniques is available in the references cited
on page 2-12. Data is available that indicates that detail screen-film systems can be used in place of
direct x-ray exposure film, with a considerable reduction in x-ray tube loading
the slit measurement technique, the recommended NEMA technique, is a repeatable method for
acceptance testing, but that the star measurement technique can also be used as a repeatable method
for obtaining quality control measurements

The American College of Radiology has published a document regarding quality control in
mammography. This document, which has separate sections for the radiologist, medical physicist, and
technologist, describes tests that will help assure quality mammographic imaging. The Mammography
Focal Spot Test Stand (Figure 1-1) can be used as one of the tools in the ACR Mammographic Quality

Control Program.

Figure 1-1. Mammography Focal Spot Test Stand (Model 07-623)

1

.

1

. Studies also indicate that

1-1

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