Unit IV Analyzing the Image Chapter 33 Quality Management

Unit IV

Analyzing the Image

Chapter 33

Quality Management

Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 4

Objectives

• Define quality assurance and quality control and discuss their relationship to excellence in radiography

• Describe process of identifying imaging requirements, selecting equipment, specifications, and training


Objectives

• Describe objectives and responsibilities of monitoring equipment performance

• Discuss primary automatic film processor quality control monitoring and maintenance procedures


Objectives

• Discuss primary quality control tests for:– External radiation beam monitoring of

diagnostic radiographic systems– Fluoroscopic systems– Tomographic systems– Automatic exposure controls


Objectives

• List primary quality control tests for miscellaneous ancillary equipment, including cassettes and view boxes

• Explain rationale behind data collection process and basic analysis of a radiographic repeat-rate study


Objectives

• Describe a basic troubleshooting procedure


Quality Assurance and Quality Control

• Regulation and accreditation

• Quality assurance

• Quality control


Regulation and Accreditation

• 1968 - Radiation Control and Safety Act

• 1981- Consumer-Patient Radiation Health and Safety Act

• 1990 - Safe Medical Devices Act

• 1992 - Mammography Quality Standards Act


Regulation and Accreditation

• Enforced by Center for Devices and Radiological Health (CDRH)– Branch of the Food and Drug

Administration (FDA)

• Joint Commission on the Accreditation of Healthcare Organizations (JCAHO)– State and federal reimbursement


Accreditation Agencies

• Establish quality standards

• Assess them

• Provide certification that individual facilities have met quality standards


Quality Assurance

• Evolutionary process that provides quality images and services

• Medical, technical, or managerial in nature

• Identifies, monitors, and resolves problems


Monitoring Problems

• Establish criteria

• Monitor performance

• Collect data

• Analyze data

• Evaluate data


Quality Control

• Aspect of QA that is concerned with the equipment’s technical standards


Purchasing Equipment

• Identification of imaging requirements

• Development of equipment specifications

• Selection of equipment

• Installation and testing of equipment

• Continuing education


Identification of Imaging Requirements

• Team input– Radiologists, administrators, supervisors,

and staff technologists


Development of Equipment Specifications

• Person determining specifications must have technical background

• Once specifications have been selected, send to vendors for bidding


Selection of Equipment

• Compare bids for:– Ability to meet required specifications– Cost– Service


Installation and Acceptance Testing of Equipment

• Responsibility of vendor/manufacturer

• QC must verify that acceptance testing specification has been met

• Include full disclosure of exact evaluation methods in specifications– Provides baseline to reference with future

QC testing


Continuing Education

• Applications– QC and education coordinators– Should include orientation and periodic

updates


Monitoring Equipment Performance

• Monitor quality of image processing systems

• Measure quality of external radiation beam

• Specify faults within these systems to allow corrective measures to be taken


Responsibility

• Professional service personnel or medical physicists not required

• Radiographers can perform necessary daily testing– Initial cost to purchase test equipment– Time must be allotted in technologists work

day to complete tests


Processor Monitoring

• Ensures that the processor is operating within proper limits

• Can be performed by anyone trained on the equipment used


Processor Monitoring

• Tests include safelight test and processor sensitometry to monitor speed, contrast, and base fog of film

• Corrective actions should be made by radiographer or processor maintenance person


External Beam Evaluation

• Tests should be performed by a radiographer

• Corrective action by authorized service person


Diagnostic Radiographic Systems

• Semi-annual schedule

• Focal spot size estimation

• Half-value layer

• Angulator or protractor accuracy

• Kilovoltage accuracy• Timer accuracy


Diagnostic Radiographic Systems

• Collimator, central ray, and Bucky tray accuracy

• Distance and centering indicators’ accuracy

• mR/mAs and milliamperage linearity

• Exposure reproducibility


Focal Spot Size Estimation

• Important for proper recorded detail

• Three types of focal spot test tools:– Line pair resolution tools– Star test patterns– Pinhole cameras


Half-Value Layer

• Measured by using dosimetry equipment to determine amount of filtration that will reduce beam intensity to one-half of its original value


Collimator, Central Ray, and Bucky Tray Accuracy

• Light field and x-ray beam congruence crucial

+/- 2% of SID allowance

• Central ray1% allowance


Distance and Centering Indicators

• Distance indicator+/- 10%

• Centering indicator+/- 2%


Angulator or Protractor Accuracy

• Can be evaluated using a large protractor– +/- 1%


Kilovoltage Accuracy

• Computerized dosimeter– +/- 5%


Timer Accuracy

• Computerized dosimeters

• Spinning top– Single phase

• Motorized spinning top– Three phase

• +/- 5%


mR/mAs and Milliamperage Linearity

• mA station accuracy is confirmed by mR/mAs measurement

• Computerized dosimeter

• +/- 10% between mA stations

• +/- 10% between high and low mA stations


Exposure Reproducibility

• Computerized dosimeter

• +/- 5%


Fluoroscopic Systems


• Exposure rate

• Field size accuracy and beam alignment

• Source-to-skin distance limits


Fluoroscopic Systems

• Intensifier viewing system resolution

• Intensifier viewing system contrast

• TV monitors and recorders

• Automatic brightness control


Tomographic Systems

• Uniformity and completeness of motion

• Section depth indicator accuracy

• Section thickness accuracy

• Resolution


Automatic Exposure Controls


• Ion chamber sensitivity

• Density variation control accuracy

• Response capability

• Backup timer verification


Ancillary Equipment

• Cassette cleaning and inspection– Film/screen contact

• View Box Uniformity

• Display monitors


PACS Systems

• Accuracy of interface between PACS and EMR, HIS, and RIS

• Fix-queue


Repeat Image Studies

• Obtaining data

• Analysis of data


Troubleshooting

• Diagnostic process

• Beginning with assessment of symptoms

• Radiographer works through problem-solving process to determine the cause

Documents

Unit IV Analyzing the Image Chapter 33 Quality Management