Copyright 2006 by Thomson Delmar Learning ALL RIGHTS
Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED.
Unit IV Analyzing the Image Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED.
Chapter 33 Quality Management Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED.
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 Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 4
Objectives • Describe objectives and responsibilities of monitoring equipment performance • Discuss primary automatic film processor quality control monitoring and maintenance procedures Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 5
Objectives • Discuss primary quality control tests for: – External radiation beam monitoring of diagnostic radiographic systems – Fluoroscopic systems – Tomographic systems – Automatic exposure controls Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 6
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 Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 7
Objectives • Describe a basic troubleshooting procedure Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 8
Quality Assurance and Quality Control • Regulation and accreditation • Quality assurance • Quality control Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 9
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 Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 10
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 Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 11
Accreditation Agencies • Establish quality standards • Assess them • Provide certification that individual facilities have met quality standards Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 12
Quality Assurance • Evolutionary process that provides quality images and services • Medical, technical, or managerial in nature • Identifies, monitors, and resolves problems Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 13
Monitoring Problems • • • Establish criteria Monitor performance Collect data Analyze data Evaluate data Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 14
Quality Control • Aspect of QA that is concerned with the equipment’s technical standards Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 15
Purchasing Equipment • Identification of imaging requirements • Development of equipment specifications • Selection of equipment • Installation and testing of equipment • Continuing education Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 16
Identification of Imaging Requirements • Team input – Radiologists, administrators, supervisors, and staff technologists Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 17
Development of Equipment Specifications • Person determining specifications must have technical background • Once specifications have been selected, send to vendors for bidding Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 18
Selection of Equipment • Compare bids for: – Ability to meet required specifications – Cost – Service Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 19
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 Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 20
Continuing Education • Applications – QC and education coordinators – Should include orientation and periodic updates Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 21
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 Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 22
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 Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 23
Processor Monitoring • Ensures that the processor is operating within proper limits • Can be performed by anyone trained on the equipment used Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 24
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 Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 25
External Beam Evaluation • Tests should be performed by a radiographer • Corrective action by authorized service person Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 26
Diagnostic Radiographic Systems • Semi-annual schedule • Focal spot size estimation • Half-value layer • Angulator or protractor accuracy • Kilovoltage accuracy • Timer accuracy Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 27
Diagnostic Radiographic Systems • Collimator, central ray, and Bucky tray accuracy • Distance and centering indicators’ accuracy • m. R/m. As and milliamperage linearity • Exposure reproducibility Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 28
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 Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 29
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 Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 30
Collimator, Central Ray, and Bucky Tray Accuracy • Light field and x-ray beam congruence crucial +/- 2% of SID allowance • Central ray 1% allowance Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 31
Distance and Centering Indicators • Distance indicator +/- 10% • Centering indicator +/- 2% Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 32
Angulator or Protractor Accuracy • Can be evaluated using a large protractor – +/- 1% Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 33
Kilovoltage Accuracy • Computerized dosimeter – +/- 5% Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 34
Timer Accuracy • Computerized dosimeters • Spinning top – Single phase • Motorized spinning top – Three phase • +/- 5% Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 35
m. R/m. As and Milliamperage Linearity • m. A station accuracy is confirmed by m. R/m. As measurement • Computerized dosimeter • +/- 10% between m. A stations • +/- 10% between high and low m. A stations Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 36
Exposure Reproducibility • Computerized dosimeter • +/- 5% Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 37
Fluoroscopic Systems • • Exposure reproducibility Exposure rate Field size accuracy and beam alignment Source-to-skin distance limits Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 38
Fluoroscopic Systems • • Intensifier viewing system resolution Intensifier viewing system contrast TV monitors and recorders Automatic brightness control Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 39
Tomographic Systems • • Uniformity and completeness of motion Section depth indicator accuracy Section thickness accuracy Resolution Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 40
Automatic Exposure Controls • • • Exposure reproducibility Ion chamber sensitivity Density variation control accuracy Response capability Backup timer verification Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 41
Ancillary Equipment • Cassette cleaning and inspection – Film/screen contact • View Box Uniformity • Display monitors Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 42
PACS Systems • Accuracy of interface between PACS and EMR, HIS, and RIS • Fix-queue Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 43
Repeat Image Studies • Obtaining data • Analysis of data Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 44
Troubleshooting • Diagnostic process • Beginning with assessment of symptoms • Radiographer works through problemsolving process to determine the cause Copyright © 2006 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 45
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