chapter 19:quality management - international … chapter 19 table of contents 19.1. introduction...

IAEAInternational Atomic Energy Agency

Slide set of 118 slides based on the chapter authored by

P. Hiles, D. McLean and S. Christofides

of the IAEA publication (ISBN 978-92-0-131010-1):

Diagnostic Radiology Physics:

A Handbook for Teachers and Students

Objective:

To introduce the principles and definitions of Quality

Management Systems for radiology facilities and provide a

framework for setting up such systems.

Chapter 19: Quality Management

Slide set prepared

by E. Berry (Leeds, UK and

The Open University in

London)

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CHAPTER 19 TABLE OF CONTENTS

19.1. Introduction

19.2. Definitions

19.3. Quality Management System requirements

19.4. Quality Assurance programme for equipment

19.5. Example of a Quality Control programme

19.6. Data management

Diagnostic Radiology Physics: A Handbook for Teachers and Students – 19. Slide 1 (02/118)

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19.1 INTRODUCTION19.1

Diagnostic Radiology Physics: A Handbook for Teachers and Students – 19.1 Slide 1 (03/118)

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19.1 INTRODUCTION19.1

Introduction

� Effective management of radiation medicine services

demands a quality culture

� Systematic approach

• all elements that govern delivery of the service

• factors that affect the intended outcome – a clinical diagnosis

� Overall Quality Management System includes a role for

the medical physicist

• especially with respect to equipment performance

• role is illustrated in section 19.5


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19.2 DEFINITIONS19.2


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Definitions

� Only the most relevant definitions included here, in the

context of radiology

� For a more comprehensive list see

• INTERNATIONAL ORGANIZATION FOR STANDARDS, Quality

Management Systems – Fundamentals and vocabulary Rep.

ISO9000:2000 (2000)

• HOYLE, D., ISO 9000 Quality Systems Handbook, 4th edn,

Butterworth Heinemann, Oxford (2001)


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Definitions

� 19.2.1 Quality Management System

� 19.2.2 Quality Assurance

� 19.2.3 Quality Control

� 19.2.4 Quality Standards and Good Practice


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19.2 DEFINITIONS19.2.1 QUALITY MANAGEMENT SYSTEM

Diagnostic Radiology Physics: A Handbook for Teachers and Students – 19.2.1 Slide 1 (8/118)

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Definitions






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19.2 DEFINITIONS19.2.1 Quality Management System

Quality Management System

� A Quality Management System (QMS) is a framework to

support the operation of a facility’s service, with the

objective of continuous quality improvement

� A quality system involves:

• the organisation’s objectives and policies

• documented procedures consistent with these objectives and

policies

• written practice instructions for staff

• monitoring, recording and auditing of practice


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Quality Management System – customising

� Framework may suggest that a QMS is simply a collection

of procedures, tasks and documents

� But customisation is required

� Each QMS must be designed specifically for each

individual radiology facility

• all the components need to fit together

• the inputs and outputs need to be defined and connected

• system monitors need to feed information to processes that

cause changes in the performance of the facility

• all parts need to work together to achieve the common

purposes of the facility.


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QMS – Definition

� A set of interrelated and interacting processes that achieve

• the quality policy of the radiology facility

• quality objectives of the radiology facility

� The processes in turn

• form an integral part of the hospital’s management system

• focus on the achievement of the many aspects of service provision

and quality objectives


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19.2 DEFINITIONS19.2.2 QUALITY ASSURANCE


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Definitions






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19.2 DEFINITIONS19.2.2 Quality Assurance

Quality Assurance (QA)

� Those planned and systematic actions necessary to

provide adequate confidence that an item, process or

service will satisfy given requirements for quality

� QA is wide ranging, covering all relevant

• procedures

• activities

• actions

• and hence all groups of staff involved in the process under

consideration


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Quality Assurance (QA) Programme

� Part of a QMS

� Focused on providing confidence that the quality needs or

expectations are fulfilled

• applies whether quality needs are stated, generally implied or

obligatory

� In diagnostic radiology is an organized effort by the staff

operating a facility to reach the correct diagnosis by

• performing the most appropriate examination

• producing images of sufficiently high quality and consistency

• using the lowest possible dose


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QA Programme in diagnostic radiology

� World Health Organisation

• “satisfactory performance in service implies the optimum quality of

the entire process, i.e., the consistent production of adequate

diagnostic information with minimum exposure of both patient and

personnel”

� A comprehensive QA programme should, therefore,

embrace the entire process of radiology


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19.2 DEFINITIONS19.2.3 QUALITY CONTROL


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Definitions






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19.2 DEFINITIONS19.2.3 Quality Control

Quality Control (QC)

� Quality Control is one part of overall quality assurance

• intended to verify that structures, systems and components

correspond to predetermined requirements

� It is concerned with operational techniques and activities

used

� QC is the process through which

• the actual quality performance is measured and compared with

existing standards to check that quality requirements are met

• if the requirements are found not to have been met, actions are

taken to adjust and correct performance in order to keep or regain

conformance with the standards


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19.2 DEFINITIONS19.2.4 QUALITY STANDARDS AND GOOD PRACTICE


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Definitions






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19.2 DEFINITIONS19.2.4 Quality Standards and Good Practice

Quality Standards

� A set of accepted criteria against which the quality of

particular activities can be assessed

� Recommendations for quality standards for diagnostic

radiology have been issued by

• IAEA, WHO and PAHO

• European Commission (EC), the American Association of

Physicists in Medicine (AAPM) and the Institute of Physics and

Engineering in Medicine (IPEM)

� Where recommended standards are not available, local

standards need to be developed, based on a local

assessment of requirements


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19.2 DEFINITIONS19.2.4 Quality Standards and Good Practice

Good Practice

� The practice which can be recommended based on the

most recent considerations on the necessary structure,

process and outcome using

• evidence based data

• long term experience

• knowledge gained

� Quality standards and good practice form a basis for

clinical audit


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19.3 QUALITY MANAGEMENT

SYSTEM REQUIREMENTS 19.3


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SYSTEM REQUIREMENTS 19.3.1 GENERAL REQUIREMENTS


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19.3 QUALITY MANAGEMENT SYSTEM REQUIREMENTS 19.3.1 General requirements

General requirements for an effective QMS

� See

• INTERNATIONAL ORGANIZATION FOR STANDARDS, Quality

Management Systems – Requirements Rep. ISO9001:2000 (2000)

� The Organisation is required to establish, document,

implement and maintain a QMS and continually improve its

effectiveness in accordance with a list of requirements

� Following list includes key activities

• not intended as a sequence

• can be represented as a cycle


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General requirements for an effective QMS (ISO 9001)

� The Organisation shall:

• Identify the processes needed for the quality management system

and their application throughout the organisation

• Determine the sequence and interaction of these processes

• Determine criteria and methods needed to ensure that both the

operation and control of these processes are effective

• Ensure the availability of resources and information necessary to

support the operation and monitoring of these processes

• Monitor, measure and analyse these processes

• Implement actions necessary to achieve planned results and

continual improvements of these processes


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QMS cycle (1 of 3)

� In planning to meet organizational objectives

• processes are identified

• their sequence and interaction are determined

� Once the relationship between the processes is known

• criteria and methods for effective operation and control developed

and documented

� For effective communication compile the process

descriptions into a quality manual

• references the associated procedures and records

• shows how the processes interact.


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QMS cycle (2 of 3)

� Before implementation

• processes need to be resourced

• information necessary to operate and control the processes

deployed and brought under document control

� Once operational

• processes monitored to ensure they are functioning as planned

• measurements taken to verify that the processes are delivering the

required output

• actions taken to achieve the planned results documented


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QMS cycle (3 of 3)

� Data obtained from monitoring and measurement captured

on controlled records

• data analysed

• opportunities for continual improvement identified

• agreed actions implemented

See ISO 9001 for more detail on italicised words in the cycle


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SYSTEM REQUIREMENTS 19.3.2 THE ROLE OF THE MEDICAL PHYSICIST


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19.3 QUALITY MANAGEMENT SYSTEM REQUIREMENTS 19.3.2 The role of the Medical Physicist

The role of the Medical Physicist

� Image quality

� Ionising radiation dose

• IAEA - International Basic Safety Standard (BSS) for protection

against ionising radiation and for the safety of radiation sources

• requires registrants and licensees to establish a comprehensive

programme of quality assurance for medical exposures; by, or

under the oversight of or with the advice of, a medical physicist

specialised in the relevant field

� Measurement, recording and analysis of QA data,

especially for complex equipment


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19.4 QUALITY ASSURANCE

PROGRAMME FOR EQUIPMENT 19.4


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19.4 QUALITY ASSURANCE PROGRAMME FOR

EQUIPMENT 19.4

Background

� A QA programme for equipment

• is essential as much of the complexity of modern radiological

imaging comes from the equipment and associated technical

processes

• should cover the entire process from the initial decision to adopt a

particular procedure through to the interpretation and recording of

results

• should include a systematic control methodology

� To be effective, a strong commitment from the facility and

institutional leadership is needed, to provide

• time, personnel, budget


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EQUIPMENT 19.4

Elements of QA Programme for equipment (1 of 3)

� Measurements of the physical parameters of medical

radiological equipment

• at the time of acceptance and commissioning prior to clinical use

on patients

• periodically thereafter

• after any major maintenance that could affect patient safety

� Implementation of corrective actions if measured values of

the physical parameters are outside control limits

� Verification of the appropriate physical and clinical factors

used in patient diagnosis


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EQUIPMENT 19.4


� Records of relevant procedures and results, including a

manual that

• defines clear lines of responsibility

• outlines the individual quality control (QC) tests performed

• gives the test frequencies

• is useful for staff training

• facilitates audit of a service

• helps to keep information within the service

� Verification of the appropriate calibration and conditions of

the operation of dosimetry and monitoring equipment


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EQUIPMENT 19.4


� Optimisation of clinical protocols and equipment operation

to achieve the aims of quality assurance

� Regular and independent audits of the programme of

quality assurance for medical exposures


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EQUIPMENT 19.4

QA Programme for equipment

� 19.4.1 Multidisciplinary team

� 19.4.2 Structure of an equipment quality assurance

programme

� 19.4.3 Outline of quality control tests

� 19.4.4 Specification for test equipment


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PROGRAMME FOR EQUIPMENT19.4.1 MULTIDISCIPLINARY TEAM


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EQUIPMENT 19.4




programme




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EQUIPMENT 19.4.1 Multidisciplinary team

Multidisciplinary team

� Many elements contribute to the imaging process

• experience of personnel, whether directly or indirectly involved, is

crucial to the final outcome

� Each discipline has an important role in the output of the

entire process

• roles are interdependent and require close cooperation

• responsibilities shared between disciplines must be clearly defined

� Each staff member must have

• appropriate qualifications (education, training and experience)

• access to appropriate opportunities for continuing education and

development


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EQUIPMENT 19.4.1 Multidisciplinary team

Multidisciplinary team

� Multidisciplinary teams have important roles when working

with quality systems, to:

• lead

• develop

• maintain

• manage

• improve

� Well-directed team work is equally, if not more, important

than individual work in delivering systematic improvement

for a quality assurance programme


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PROGRAMME FOR EQUIPMENT 19.4.2 STRUCTURE


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EQUIPMENT 19.4




programme




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EQUIPMENT 19.4.2 Structure

Life cycle of an imaging system

� Sometimes referred to as equipment QA cycle

• begins with the decision to acquire equipment, whether new or

used, to fulfil a need at the facility

• completed with the disposal of the equipment

• maintenance is a vital part of the cycle

� The stages of the life cycle are important for all pieces of

radiological equipment

• special attention should be paid to equipment designed for

paediatrics, health screening and those which may produce high

doses


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Example of the life cycle of an imaging system


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Five stages applicable to imaging equipment QA

� Equipment specification and tendering process

� Critical examination

� Acceptance

� Commissioning

� Routine performance testing

� All are part of the life cycle of imaging equipment


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Equipment specification

� An agreed need for equipment

� Translated into an equipment specification

� Formal tender or option appraisal process

� A critical part of the cycle

� Team that draws up the specifications

• the facility medical physicist responsible for diagnostic radiology

• engineering professionals


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Equipment specification

� Team should consider

• the construction of the installations site, power supply and air

conditioning.

• radiation shielding for X-ray equipment

• environmental shielding, for example magnetic and radio frequency

shielding, for other equipment such as MRI scanners

� Involvement continues after a contract is awarded

• during construction the medical physicist should ensure that

• architectural plans are being correctly followed

• shielding requirements are correctly installed


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Critical examination – what?

� Takes place after installation is complete

� The safety features and warning devices incorporated into

the equipment are inspected

• to assure correct operation

• to check that there is sufficient protection of the staff, visitors and

patients against exposure to ionising radiation


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Critical examination – who?

� Undertaken by medical physicist, in conjunction with other

appropriate personnel

• representative of the equipment supplier

• regulatory inspector

� Facility should not allow equipment to be used for medical

exposures unless the results of the critical examination are

satisfactory so

• medical physicist present should ideally represent the radiology

facility

• a medical physicist representing the installer may be agreed

instead, preferably at the contract stage


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Critical examination – when?

� Appropriate when there could be radiation protection

implications associated with an incorrect installation

• failure of the safety features or warning devices to operate

correctly

• poor siting

• inadequate shielding - especially important if it has not been

possible to confirm that the correct shielding has been installed

during construction


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Critical examination – method?

� Concentrates on ‘critical’ features most likely to affect

safety

� Achieved by selective examination of those features

• depending on results obtained may then probe more deeply

� Does not involve a long list of prescriptive tests on every

part of the system


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Acceptance testing

� Verification of equipment specifications and features

• performed by representatives of the installer and the facility

medical physicist

� Completion of a checklist

� Any significant discrepancy should be notified formally to

the contractor, who should be required to undertake

corrective action

� During acceptance testing a qualified person should check

the electrical and mechanical safety of any new installation


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Commissioning

� Carried out after acceptance

• performed by the facility representative, usually a medical physicist

specializing in radiology physics

• sometimes undertaken jointly with the installer

� Aim is

• to ensure that the equipment is ready for clinical use

• to establish baseline values against which the results of

subsequent routine performance tests can be compared

• to optimize performance of the imaging system


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Commissioning tests

� Testing should include all parameters and conditions of

use that are expected in clinical use

� A check should be made that all relevant testing for the

unit has been completed and that no tests have been

omitted during either the critical examination or

acceptance

� After major work on the equipment, the relevant

commissioning tests may have to be repeated to establish

new baseline values, for example

• after an X-ray tube is replaced

• after new software is installed


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Critical examination, acceptance and commissioning

� Purpose of the tests should remain distinct

� Even if carried out by same personnel and at the same

time


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Commissioning – completion

� Commissioning tests described above are not the end

point

� Radiology personnel and users of equipment should check

• clinical protocol settings

• image processing

• ergonomics

• positioning of equipment

� May be done during, or after, training from the product

specialist


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Routine performance testing

� Or constancy testing

� Or quality control (QC) testing

� Those tests that are undertaken either regularly or after

maintenance or repairs, to detect whether any change in

the performance of the equipment has occurred that would

require corrective action

� Such tests are a sub-set of the commissioning tests


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Routine performance testing – who?

� A collaborative, multidisciplinary approach to routine

performance testing is essential

� Involves staff with different levels of expertise, some of

whom may be external to the radiology facility

• for example, when a regional medical physics unit undertakes the

quality assurance programmes for a number of hospitals with

expert staff making periodic visits to a department

� Frequent tests, which are quick to perform, are usually

undertaken locally with advice from a medical physicist

� More complex and time-consuming tests may require

special expertise and instrumentation

� Diagnostic Radiology Physics: A Handbook for Teachers and Students – 19.4.2 Slide 18 (61/118)

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Reject analysis (1 of 2)

� Reject analysis of images from appropriate systems

should be performed in addition to routine QC testing

• to ensure optimal image quality

• to identify faults or long-term deterioration

� Rejects can be due to, for example

• poor film processing

• positioning errors or patient movement

• incorrect exposure

• faulty X-ray equipment


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Reject analysis (2 of 2)

� Rejects can be reduced or prevented

• with adequate training for staff on all appropriate pieces of

equipment

• careful maintenance of equipment

• reject analysis should be undertaken on a regular basis, with

results fed back to staff and action undertaken as appropriate

� Applies to digital imaging as well as film

• there should be a simple procedure for rejecting images that does

not result in the image disappearing from the system.

• ideally, the rejected images should be categorised and stored


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Maintenance programme

� Maintenance and routine performance testing are

complementary

• maintenance ensures that any malfunction of equipment, revealed

by quality control testing, is rectified

• important in order for a QA programme to be effective

• tests need to be performed after maintenance or repairs that may

affect imaging and/or radiation characteristics of equipment

� Mechanical and electrical safety checks should be

described in the maintenance contract

• users of X ray equipment have a duty of care to be on the lookout

for obvious signs of mechanical or electrical deterioration


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Maintenance – aims

� To ensure that equipment is safe to use

� To ensure that equipment is working properly

� To allow the detailed performance specification,

demonstrated at commissioning, to continue to be

achieved during the working life of the equipment

� Additional critical examination or partial commissioning

tests may be necessary when the machine has been

subject to modification, maintenance, reinstallation or

repair


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Maintenance and performance against the specification

� Service contractors should demonstrate that they

undertake appropriate tests to check performance against

specification

• service engineers should feed back results

• particularly if these could affect the clinical image quality and

radiation dose

� Departments can use the results of their own routine

performance testing programme to audit the service

contract


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Disposal or alternative use

� When imaging equipment no longer meets the required

performance specifications, it should be withdrawn from

use and may be disposed of and replaced

� Alternatively, it may be used for less demanding imaging

tasks for which a lower specification of performance may

be acceptable


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PROGRAMME FOR EQUIPMENT 19.4.3 OUTLINE OF QUALITY CONTROL TESTS


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EQUIPMENT 19.4




programme




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EQUIPMENT 19.4.3 Outline of quality control tests

Outline of quality control tests

� These tests are intended to verify the stability in the

operation of the equipment or elements used to acquire

the image

� Described in terms of

• frequency

• priority

• performance standards

• test types


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Frequency

� The recommended frequency of a routine performance test varies from

daily to three yearly

• often given as a range, e.g. three to six monthly

• frequency selected should depend on the equipment characteristics (e.g.

age, reliability) and the clinical workload to which the equipment is

subjected

� A lower frequency of tests may be appropriate for simple imaging

equipment that is used less frequently

• e.g. in community hospitals or for equipment where experience shows that

parameters are unlikely to change.

� The frequency of tests may also be designated as essential and

desirable

• e.g. a test may be essential every year but desirable every six months


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Priority

� The priorities for whether a routine performance test is

recommended may be denoted as:

Essential: Represents the recommended minimum standard

• conformance to this standard of testing would be regarded as

good practice

Desirable: The inclusion of this level of testing would be regarded as

best practice

• it is recognised that the implementation of desirable tests may

be constrained by test equipment costs, manpower availability,

equipment characteristics, clinical workload or other factors


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Performance standards

� Quality control tests help maintain equipment performance

through the use of tolerance criteria that are applied to QC

test results. These performance standards can be

characterised as:

Acceptable: Performance must be within these tolerances

• if it is not, the equipment should not be used

Achievable: This level of performance should be attained under

favourable circumstances

• this is the level at which a facility should work if it is feasible


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Test types

� Many quality control tests are designed to measure

equipment performance consistency over time. These

performance standards can be characterised as:

• Repeatability: performance must be within given tolerances of self

consistency for a set of measurements taken at one time

• Consistency / reproducibility: performance parameters are not

changing over the period between QC tests

• achieved through comparison with an established baseline

measurement

• in cases where the baseline values are fixed to nominal values

it is known as accuracy testing


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PROGRAMME FOR EQUIPMENT19.4.4 SPECIFICATION FOR TEST EQUIPMENT


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EQUIPMENT 19.4




programme




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EQUIPMENT 19.4.4 Specification for test equipment

Test equipment

� Equipment testers at radiology facilities should have

access to the necessary test equipment for the required

tests within the QA programme

� Instruments which measure physical parameters should be

calibrated to an appropriate standard prior to use and at

suitable intervals

� A range of phantoms may be needed


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EQUIPMENT 19.4.4 Specification for test equipment

Phantoms: real and virtual

� Phantoms may be needed for

• dosimetry measurements especially under automatic exposure

control modes

• image quality assessment

• the evaluation of digital images requires access to image data sets

and the use of a computer and appropriate software

� The evaluation of image display monitors further requires

specific test patterns


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19.5 EXAMPLE OF A QUALITY

CONTROL PROGRAMME 19.5


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19.5 EXAMPLE OF A QUALITY CONTROL PROGRAMME 19.5

Introduction to examples (1 of 2)

� Provided as illustrations

� For various X-ray modalities in a radiology facility

• X-ray tubes and generators

• Screen-Film radiography

• Digital radiography

� Many factors influence the selection of QC tests

• e.g. age, condition and level of use of the equipment, equipment

performance and departmental resources

� So, flexibility needed in the programme

• avoid being too prescriptive about the detail of test types,

frequencies, priorities and tolerances


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Introduction to examples (2 of 2)

� Avoid testing for its own sake

• particularly with the increasing reliability of modern X-ray systems,

which have advanced considerably in the last decade

� Resources for quality assurance should match

• need to produce images of sufficiently high quality and consistency

• use of lowest dose needed to provide the required diagnostic

information

� QC programme may have to be more extensive and/or

frequent for

• equipment used for medical exposure of children, health screening

programmes or high dose procedures


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Examples

� 19.5.1 X-ray Tubes and Generators

� 19.5.2 Screen-Film Radiography

� 19.5.3 Digital radiography


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CONTROL PROGRAMME 19.5.1 QC PROGRAMME FOR X-RAY TUBES AND

GENERATORS


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Examples





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19.5 EXAMPLE OF A QUALITY CONTROL PROGRAMME 19.5.1 QC programme for x-ray tubes and generators

X-ray tubes and generators

� All equipment used for medical radiography requires

routine performance testing, including

• fixed installations (both radiographic and fluoroscopic)

• mobile radiography units

• mobile image intensifiers

� Table lists physical parameters to be assessed on each

item of equipment


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19.5 EXAMPLE OF A QUALITY CONTROL PROGRAMME 19.5.1 QC programme for x-ray tubes and generators

Outline quality control programme for X ray tubes and

generators


Parameter Frequency Priority

X ray/light beam alignment 1 to 2 monthly Essential

X ray/light beam centring 1 to 2 monthly Essential

Light beam/Bucky centring 1to 2 monthly Essential

Distance & scales 1 to 2 monthly Desirable

Image receptor alignment & collimation 3 to 6 monthly Desirable

Radiation output index: repeatability and

consistency

1 to 2 monthly Essential

Radiation output: repeatability and consistency 1 to 2 yearly Essential

Exposure time repeatability and accuracy 1 to 2 yearly Essential

Tube potential repeatability and accuracy 1 to 2 yearly Essential

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CONTROL PROGRAMME 19.5.2 QC PROGRAMME FOR SCREEN-FILM

RADIOGRAPHY


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Examples





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19.5 EXAMPLE OF A QUALITY CONTROL PROGRAMME 19.5.2 QC programme for screen-film radiography

Screen-film radiography

� Screen-film AEC systems

• use of AEC will reduce the number of repeated films, provided that

the AEC system is correctly set up for optimal operation

• optimal set up of AEC system established during commissioning

• QC tests are continued at regular intervals to ensure continuing

optimal performance

� Film processor and darkroom

� Light boxes and viewing conditions


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Outline quality control programme for screen-film radiography

systems



AEC backup timer operation 12 monthly Essential

Resultant film density under AEC 1 to 3 monthly Essential

Consistency between AEC chambers 12 monthly Essential

AEC Repeatability and consistency 12 monthly Essential

AEC Image receptor dose 12 monthly Essential

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• 50% of the rejected films attributable to poorly controlled automatic

film processing systems

• essential to monitor through sensitometric control



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Sensitometry (1 of 2)

� One box of film, of the type used clinically, is set aside for

daily sensitometric measurement

� Standardised light source: sensitometer

• exposes X ray film with logarithmically increasing intensity

• each intensity step typically √2, so intensity is doubled every two

steps

� Calibrated densitometer used to measure the resulting

optical density (OD) on the processed control film

• OD for a specified step is recorded as the ‘speed index’ on a trend

chart

• accepted tolerances identified on the chart


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Sensitometry (2 of 2)

� Action should be taken to correct the film processing when

OD is outside of tolerance

� Similar indices for

• film contrast

• base + fog value

� In combination on a trend chart indices can assist in

determining the corrective action needed


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Sample film

processor

QC chart


Note that the

measurement

on the 6th of

April was

repeated

because the

initial value of

the contrast

index DD was

outside action

level.

Dashed lines

indicate upper and

lower tolerance

limits

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Outline quality control programme for film processor and

darkroom



Developer temperature Daily to weekly Essential

Gross fog Daily to weekly Essential

Film speed: speed index Daily to weekly Essential

Film contrast: contrast index Daily to weekly Essential

Replenishment rates 1 -3 monthly Desirable

Fixer pH 1 -3 monthly Desirable

Silver content of fixer 1 -3 monthly Desirable

Condition of cassettes and screens 6 to 12 monthly Essential

Relative speed of intensifying screens 12 monthly Desirable

Film fogging 12 monthly Desirable

Darkroom lightproofing 12 monthly Desirable

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• optimal film viewing is critical for the successful reading of

radiographic films

• once identified poor viewing conditions can often be quite easily

rectified

• care must be taken that

• view boxes have uniform luminance and colour temperature

• ambient lighting illumination levels are low


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Outline quality control programme for lightboxes and viewing

conditions



Film viewer condition 6 monthly Essential

Film viewer luminance 6 to 12 monthly Essential

Film viewer uniformity 6 to 12 monthly Essential

Variation between adjacent film viewers 6 to 12 monthly Desirable

Room illumination 6 to 12 monthly Essential

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CONTROL PROGRAMME 19.5.3 QC PROGRAMME FOR DIGITAL RADIOGRAPHY


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Examples





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19.5 EXAMPLE OF A QUALITY CONTROL PROGRAMME 19.5.3 QC programme for digital radiography

Digital radiography

� Image acquisition, processing and display

• Computed Radiography (CR): cassette and image processor

combination

• Digital radiography (DR): direct digital detector and processor

� Automatic Exposure Control (AEC) involved in both


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Digital radiography

� Separation of acquisition, processing and display functions

• wide dynamic range, so images of varying exposure level can be

displayed optimally

• but removes link between image brightness and image receptor /

patient exposure

• not obvious to users if exposure levels are changing, so QC

important

� Exposure index (EI)

• indicates detector response to radiation


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Optimization

� Digital systems may appear to be fully automatic, but

• functions of acquisition, processing and display can be altered for

different examination types

• to gain optimal image quality for diagnosis at acceptable dose to

the patient

� Once optimization is achieved, quality control testing

should be undertaken to maintain equipment performance

� QC testing should use consistent image processing


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Picture Archiving and Communication System (PACS)

� QC includes:

� Setup and performance maintenance of image display

devices

� Use of DICOM structures to record equipment-generated

dose related data

• data is increasingly available to patients, is stored in records

• important for medical physicists to verify recorded dose accuracy

• verification of DICOM dose indicators during the commissioning

of new equipment

• routine calibration of KAP meters and other dose indicators

such as those used in CT etc.


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Digital radiography

� Tables show outline quality control programmes for

• General

• Computed Radiography (CR)

• Digital Radiography (DR)


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Outline quality control programme for digital radiography

systems – general tests



EI monitoring 1 to 3 monthly Essential

Image uniformity (visual check) 1 to 3 monthly Essential

Threshold contrast visibility 4 to 6 monthly Desirable

Limiting spatial resolution 4 to 6 monthly Desirable

EI repeatabilitya and consistencyb 12 monthly Essential

Image uniformity 12 monthly Essential

Threshold contrast detail detectability 12 monthly Essential

Limiting spatial resolution 12 monthly Desirable

Scaling errors 12 monthly Desirable

Dark noise 12 monthly Desirable

AEC sensitivity 1 to 3 monthly Essential

AEC backup timer operation 12 monthly Essential

AEC Consistency between chambers 12 monthly Essential

AEC Repeatability and consistency 12 monthly Essential

AEC Image receptor dose 12 monthly Essential

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systems – CR specific tests


systems – DR specific tests



Condition of cassettes and image plates 1 to 3 monthly Essential

Erasure cycle efficiency 12 monthly Essential


Sensitivity reproducibility between DR

detectors connected to the same generator

12 monthly Essential

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19.6 DATA MANAGEMENT 19.6


IAEA


Data management

� Quality management will lead to the accumulation of a

significant volume of data

• requires a suitable repository for storage and retrieval

� The data can also be used in an active way to help

manage the quality control system

• requires the development of a suitable data management system,

which could be either paper based or computer based


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Elements of a data management system ( 1 of 2)

� Policy and control manuals that determine

• the nature of the quality assurance programmes

• the details of the QC testing procedures

� The results from QC tests need to recorded and compared

to the required performance criteria

• some tests involve performance constancy and comparison to

baseline data - graphical representation, such as a trend chart is

very useful for review


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Elements of a data management system ( 2 of 2)

� A test report is often required to

• document the test results

• initiate action if needed for equipment adjustment

� Trend analysis is an important tool that can be used to

• assess drifts in performance

• highlight tests which consistently fail

• enable comparisons of similar types of equipment


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Example of a test report

Sample film

processor

QC chart


Note that the

measurement on the

6th of April was

repeated because the

initial value of the

contrast index DD

was outside action

level.

Dashed lines

indicate upper and

lower tolerance

limits

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Additional functionality (1 of 2)

� Ability to perform auditing of the data to help determine

• suitability of tests

• optimum test frequency

� Automation using database software

• replaces use of spreadsheet software

• more likely to accomplish a satisfactory set of outcomes

• can include test scheduling, trend analysis, automated report

generation and auditing of performance

� A medical physicist who is involved in the establishment

and maintenance of the data management system


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Additional functionality (2 of 2)

� System that enables

quality control to be a

dynamic process

� Continued analysis of

results feeds back into

an on-going QC

programme review

• suitability and relevance

of tests performed

• frequency of testing

Example data management structure



IAEA

19. BIBLIOGRAPHY19.

Diagnostic Radiology Physics: A Handbook for Teachers and Students – 19. Bibliography Slide 1 (114/118)

IAEA Diagnostic Radiology Physics: A Handbook for Teachers and Students – 19. Bibliography Slide 2 (115/118)

19. BIBLIOGRAPHY19.

� AMERICAN ASSOCIATION OF PHYSICISTS IN MEDICINE, An Exposure

Indicator for Digital Radiography: Report of AAPM Task Group 116, AAPM

Rep. 116, New York (2009). http://www.aapm.org/pubs/reports/RPT_116.pdf

� AMERICAN ASSOCIATION OF PHYSICISTS IN MEDICINE, Quality control in

diagnostic radiology AAPM Rep. 74, New York (2002).

http://www.aapm.org/pubs/reports/rpt_74.PDF

� AMERICAN ASSOCIATION OF PHYSICISTS IN MEDICINE, Quality control in

diagnostic radiology, Report of AAPM Diagnostic X-ray Imaging Committee,

Task Group 12, AAPM Report 74 (2002)

� EUROPEAN COMMISSION, Radiation Protection 91: Criteria for acceptability

of radiological (including radiotherapy) and nuclear medicine installations, EC,

Luxembourg (1997)

� HAUS, A.G., Advances in Film Processing Systems Technology and Quality

Control in Medical Imaging, (2001)


19. BIBLIOGRAPHY19.

� HEALTH AND SAFETY EXECUTIVE, Equipment used in connection with

medical exposure, Guidance Note PM77.

http://www.hse.gov.uk/pubns/guidance/pm77.pdf

� HOYLE, D., ISO 9000 Quality Systems Handbook, 4th edn, Butterworth

Heinemann, Oxford (2001)

� INSTITUTE OF PHYSICS AND ENGINEERING IN MEDICINE, Quality Control

in Magnetic Resonance Imaging, IPEM Rep. 80, York (2002)

� INSTITUTE OF PHYSICS AND ENGINEERING IN MEDICINE, Measurement

of the Performance Characteristics of Diagnostic X-ray Systems used in

Medicine. Report No 32, second edition, Part III: Computed Tomography X-ray

Scanners IPEM York (2003)

� INSTITUTE OF PHYSICS AND ENGINEERING IN MEDICINE,

Recommended standards for the routine performance testing of diagnostic x-

ray imaging systems, IPEM Report 91, IPEM, York (2005)


19. BIBLIOGRAPHY19.

� INSTITUTE OF PHYSICS AND ENGINEERING IN MEDICINE, The critical

examination of X-ray generating equipment in diagnostic radiology, IPEM

Report 79, IPEM, York (1998)

� INTERNATIONAL ATOMIC ENERGY AGENCY, Quality Assurance

Programme for Screen–Film Mammography, Human Health Series, 2, IAEA,

Vienna (2009). http://www-

pub.iaea.org/MTCD/publications/PDF/Pub1381_web.pdf

� INTERNATIONAL ORGANIZATION FOR STANDARDIZATION, Quality

Management and Quality Assurance Standards — Part I. Guidelines for

Selection and Use, ISO 9000, ISO, Geneva (1994)

� INTERNATIONAL ORGANIZATION FOR STANDARDS, Quality Management

Systems – Fundamentals and vocabulary Rep. ISO9000:2000 (2000)


19. BIBLIOGRAPHY19.

� INTERNATIONAL ORGANIZATION FOR STANDARDS, Quality Management

Systems – Requirements Rep. ISO9001:2000 (2000)

� PAN AMERICAN HEALTH ORGANISATION, WORLD HEALTH

ORGANISATION, Organisation development, quality assurance and radiation

protection in radiology service: Imaging and radiation therapy (Borras, C., Ed.),

PAHO, Washington, DC (1997)

chapter 19:quality management - international … chapter 19 table of contents 19.1. introduction...

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