Quality assurance

Quality Assurance ProgramChest X-ray & Fluoroscopy Machine

_Ramzee Small

Outline Brief Definition of Terms Quality Assurance Program

Quality Control Administrative Procedure Preventive Maintenance Procedure Training

Quality Assurance Committee Chest X-ray Technology Quality Control Test for Chest X-ray Equipment Fluoroscopy Technology Quality Control Test For Fluoroscopy Equipment Quality Assurance Program Review Test Integration of Quality Control Test into Multimodality System Quality Assurance Drawback Health and Safety Conclusion References Group Members

Definitions

Diagnostic Facility

A diagnostic radiology facility is any facility in which an x-ray system(s) is used in any procedure that involves irradiation of any part of the human for the purpose of diagnosis or visualization.

Radiology Department Organization Chart

Radiology Information System (RIS)

A RIS is an information system where; Patients are registered, Examinations are scheduled and Radiologists’ reports are recorded, Stored and distributed.

The RIS can also provide management information and may hold information that is important for revenue generation

Picture Archiving and Communication System (PACS)

PACS is a healthcare technology use for; The short- and long-term storage, Retrieval, Management, Distribution and Presentation of medical images.

PACS and a RIS need to work seamlessly together

PACS Workflow

Teleradiology

Teleradiology is considered to be the transmission of a full set of full integrity images to a Centre distant from where the images were generated. Purposes of teleradiology includes; Primary diagnostic interpretation Expert secondary consultation Preoperative surgical planning

Teleradiology

Benefits of Teleradiology Provide access to medical image reporting for underserviced centers. Support patient consultations and inform patient treatment decisions Provide access to image interpretation for remote regions Provide reporting in shifts to provide timely interpretation after normal

working hours

Teleradiology Workflow

PACS and Teleradiology

Quality Assurance Program


What is a Quality Assurance Program ?An organized effort by the staff operating a facility to ensure that the diagnostic images produced are of a sufficiently high quality so that they consistently provide adequate diagnostic information at the lowest possible cost and with the least possible exposure of the patient to radiation.

_World Health Organization (WHO)


Objectives of QA Program to maintain optimal quality of diagnostic images; to reduce unnecessary radiation exposure to patient and staff; and to be cost effective

The primary goal of a radiology QA program is to ensure the consistent provision of prompt and accurate diagnosis of patients


This program has many facets, including, 1. Quality Control tests, 2. Administrative procedures, 3. Preventive maintenance procedures and 4. Training.


1. Quality Control

Quality control (QC) is an integral part of quality assurance

It involves specific actions designed to keep measurable aspects of the process involved in manufacturing a product (image) or providing a service within specified limits.


QC is summarized in four principal steps.I. Acceptance testing to detect defects in equipment that is newly

installed or has undergone major repairII. Establishment of baseline performance of the equipment

(commissioning test)III. Detection and diagnosis of changes in equipment performance before

they become apparent in imagesIV. Verification that the causes of deterioration in equipment performance

have been corrected


The frequency of any QC test depends on the following variables; The inherent variability of the process or equipment The age, reliability, and frequency of use of the equipment The criticality of the element in the imaging chain


2. Administrative Procedure

These procedures are design to verify that QC testing is effective, i.e., the tests are performed regularly and correctly, the results evaluated promptly and accurately, and the necessary action taken.

They include recommendations regarding the responsibility for quality assurance action, staff training, equipment standards, and the selection of the appropriate equipment for each examination

Summary Of Administrative Procedure

Quality Assurance Program3. Preventive Maintenance Procedure

These are performed on a regularly scheduled basis with the goal of preventing breakdowns due to equipment failing without warning signs detectable by monitoring. These procedures includes;

Visual inspection of the mechanical and electrical characteristics of the x-ray system Assuring cleanliness with respect to spilling of contaminants in the examination room.

Following the manufacturer’s recommended procedures for cleaning and maintenance of the equipment

Regular inspection and replacement of switches and parts that routinely wear out or fail


4. TrainingThe QA program include the means to provide appropriate training for all personnel with QA responsibilities (especially those directly involved with QC testing) to ensure each meet a minimum level of competency to perform QC test correctly and consistently.

Companies whose sole purpose is training as well as service and repair companies and the facility’s medical physicist can provide seminars and training courses on the how to perform Quality Control tests.

Quality Assurance Committee


What is the Quality Assurance Committee ?Personnel in the QA program who are responsibility for oversight of the QA program, setting the goals and direction, determining policies, and assessing the effectiveness of QA activities.

They have an overall documented strategy with clearly defined work plans to achieve the goals and objectives of the radiology department.


QA committee members includes; Medical Physicist Radiologist Biomedical engineer Medical Imaging Technologist (MIT) and Radiographer Information Technology (IT) Technician

Quality Assurance CommitteeMedical PhysicistAn individual who is competent to independently practice in one or more of the subfields in medical physics. Advising the facility on radiation protection of the patient, staff and members of the

public. Conducting tests to ensure the safety and proper performance of imaging equipment

used. Assignment of Bio-medical engineering service staff for corrective maintenance or

preventive actions. Training of personnel utilized for quality control Develop and implement a radiation protection program


RadiologistA medical doctor who specializes in the diagnosis and treatment of disease and injury by using medical imaging technologies.

Determine the overall quality of the output image Select the technologist to be the primary QC technologist, performing the prescribed

QC tests. Ensure that appropriate test equipment and materials are available to perform the QC

tests. Ensuring that medical physicists and radiographers have adequate training and

continuous education


Biomedical EngineerBiomedical engineers use their knowledge of modern biological principles in their engineering principle to design and develop devices and procedures that solve medical and health-related problems.

Biomedical engineer are involve in; Corrective and preventative maintenance Fault Reporting

Quality Assurance CommitteeMedical Imaging Technologist (MIT) and Radiographer Ensuring that the appropriate protocol and technique factors are used for

the requested examination. Ensuring that the QC tests are performed, interpreted and recorded

appropriately. Perform all the checks for the daily, monthly and quarterly QC testing of

equipment Report faults immediately any deviation in trend of equipment

performance to QA manager Undertaking additional continuous education courses

Quality Assurance CommitteeInformation Technology (IT) TechnicianIT is a key element of any digital radiology facility that intends to store, review and distribute images electronically or using hard copy. There responsibility includes;

Maintenance of the integrity of system databases to ensure continuous and accurate operation of the information systemsPlanning, Deployment, Testing

Chest X-ray

X-ray Tube

Chest X-ray TechnologyThe technology use for chest examination is similar to that of any other x-ray examination,however it is perform with the patient in an upright position against a tube stand.

Chest X-ray TechnologyThe x-ray tube emits x-rays directed towards the patient, which interacts with the patient's anatomy.

The computed radiography (CR) image receptor records the altered x-ray distribution to form the image.

CR system firstly converts the incoming x-ray photons to light then converts light into an electronic signal.

The images are read by a reader device where it is scanned by a laser beam and the final image appearing on the computer screen.

Quality Control TestAcceptance Test

Equipment Visual Check Test Control Panel Collimator/Indicator/Locks Upright Bucky General

Commissioning Test System assembly evaluation

Collimation assessment

kVp accuracy and reproducibility

Exposure reproducibility and beam quantity (mR/mAs)

Radiographic AEC system performance assessment

Focal Spot Size

Beam quality assessment (HVL)

Equipment warm-up test

View boxes and viewing conditions

Phantom image quality evaluation

Laser Film Printer Quality Control Test

Protective Shielding Test

Quality Control Test

Quality Control TestFocal Spot testObjective

To determine effective focal spot size, the magnification factor must be known (image size/object size)

Frequency

Initially and after tube replacement

Equipment required

Star test Pattern- e.g. 9 - 2,0°; 9 - 1, 5°-360 (A disk with radiating bars is used to produce a radiographic image).

Cassette 35cm×35cm

Quality Control TestProcedure1. Mount the star test plate so that the radiographic central ray is perpendicular to the star pattern and

passes through the center of the star.

2. Place a image plate at about the same distance from the test plate as the plate is from the focal spot, and align it so that the central ray strikes the center of the film.

3. If the blur pattern is too small, magnification can be increased by moving the film further from the test plate. If the blur pattern is too large, magnification can be decreased by moving the film closer to the tube.

4. The kV and mA should be comparable to that used clinically, to get the true focal size which is somewhat dependent upon the electrical factors. Recommended technique should be one half the maximum mA at 75 kVp. The density of the image should be about 1.5.

Quality Control Test5. Process the CR cassette. Determine the magnification (M) by dividing the diameter

of the radiographic image of the star pattern by the true star test pattern diameter (45 mm).

6. Scan the star pattern on the radiograph inward from the periphery to find the outermost region in which the image of the sectors disappears. This is the region of zero contrast. Measure the diameter of this region across its greatest extent and also in the perpendicular dimension. Let these diameters be called D1 and D2.

7. The focal spot size corresponding to the individual diameter dimensions can be determined by the following formula:

Where:F - Focal spot size in mmN - Angle of the star pattern line D - Diameter of the zero contrast region in mm M - Magnification


8. Several regions of zero contrast may be found on a single film. It is extremely important that the largest one be used.

Analysis

Measurements of the radiographic image of the star are taken lengthwise and crosswise. Along with the magnification factor, the measurements are put into the formula.

N=2Magnification (M - 1) = 0.18


For the Anode-Cathode Diameter:

D u- d =2 mm

For the Transverse Diameter:

D a- c = 28 mm

Therefore

The focal spot is 5.4 mm x 6.6 mm at the kVp and mA setting used.

Fluoroscopy

Fluoroscopy TechnologyFluoroscopy refers to the continuous acquisition of a sequence of x-ray images over time.

A standard fluoroscopic imaging system contains an x-ray tube, filters, and collimation similar to the technologies used in radiography

The principal component of the imaging system that distinguishes fluoroscopy from radiography is the image intensifier

Fluoroscopy TechnologyAn x-ray beam is passed through the patient body

The antiscatter grid removes contrast degrading scattered radiation from the x ray beam

The intensifying screen converts the low intensity x ray photon fluence exiting the patient into a high fluence of visible photons by using multiple conversion layers and a series of electrodes inside a vacuum container.

The distribution of the visible photons are capture by the video camera to form the image seen on the monitor.


Acceptance Test

Equipment Visual Checklist Table Fluoroscopy Image Intensifier Assembly Monitor General

Commissioning Test System assembly evaluation Fluoroscopy System high and low contrast resolution test Laser Film Printer Test Fluoroscopy Collimation field size Test kVp accuracy and reproducibility mAs Linearity Test Spot film AEC system performance Entrance skin air kerma and air kerma rate Maximum air kerma (exposure) rate Beam quality assessment (HVL) Equipment warm-up test

Artifact evaluation Phantom image quality evaluation CR Cassette Integrity Check View Box Protective Shielding integrity check

Quality Control TestkVp Reproducibility TestObjective

To measures the ability of the x-ray generator to faithfully deliver the same output when the same exposure factors are used.

Suggested performance criteria

Limit (±5%)

Frequency

Initially, annually

Equipment required

Multifunction meter


Procedure1. Take 5 consecutive measurements at the same SID (~150cm for the

chest detector and 110cm for the table detector) 2. Use any combination of operating loading factors (kVp and mAs), while

kVp is kept fixed.3. From the recorded output readings, the maximum and minimum

readings are plugged into the following formula;


Example

A test of reproducibility using 70kVp, 100 mA and 0.10 seconds resulted in the following readings;

The control limit for reproducibility is no more than 5%. In this case, a variance of 8.4% is clearly unacceptable and corrective action is needed.

Exposure 1 Exposure 2 Exposure 3 Exposure 4 Exposure 5

0.45 0.38 0.45 0.44 0.40

Quality Assurance Program Review TestObjective

The Quality Assurance Program must be reviewed in its entirety to ensure that all information is current and accurate.

Frequency

Annually, After any equipment or personnel change

Procedure

1. Review and update as necessary the following information QA personnel

QC measures Policies and procedure Corrective action Record keeping

QA Program Drawback

CostlyThe QA program is based on, planning, delegating responsibility, training and purchasing the proper equipment, then establishing a high standard of quality and maintaining it.

Personnel Unclear responsibility Lack of qualification Lack of commitment to perform QC test

Any program lacking genuine interest from its staff and initiated only to satisfy a regulatory requirement is unlikely to produce optimal results.

Health And SafetyHealth and safety issues in any work environment are very important

All heads of department are responsible for ensuring that injury or sickness, due to working conditions, is kept to a minimum

To make the environment as safe as possible, make certain the following; Regular maintenance inspections are carried out Safety procedures are followed Adequate staff instruction is given Safety equipment is readily available

ConclusionQA promote the effective use of radiation for a diagnostic outcome through achieving and maintaining appropriate image quality and reduction of patient dose.

An established QA program monitor the imaging process from start to finish and reveal potential problems that may otherwise go unrecognized, through a sequences of QC tests

QA in medical imaging is a rapidly evolving concept and each facility is encouraged to continually pursue ways to improve and expand its program.

ReferencesQuality Assurance Programme for Computed Tomography; Diagnostic and Therapy Application, International Atomic Energy Agency IAEA, Human Health Series No. 19, 2012, ISBN 978–92–0–128910–0

Worldwide Implementation of Digital Imaging in Radiology, Atomic Energy Agency IAEA, Human Health Series 28, 2015, ISBN 978–92–0–102114–4

Radiation Protection in Diagnostic and Interventional Radiology, International Atomic Energy Agency, Part 15.1: Optimization of protection in radiography Practical exercise

Quality Assurance Programme for Digital Mammography, Atomic Energy Agency IAEA, Human Health Series 17, 2011, ISBN 978–92–0–111410–5

Quality assurance workbook for radiographers & radiological technologists, World Health Organization, 2001, ISBN 9241546425

X-ray equipment maintenance and repairs workbook for radiographers & radiologic technologists, World Health Organization, 2004, ISBN 9241591633

Quality Control Recommendations for Diagnostic Radiography Conference of Radiation Control Program Directors Inc. CRCPD, Volume 2, 2001

Quality Control Recommendations for Diagnostic Radiography, Volume 3: Radiographic or Fluoroscopic Machines, Conference of Radiation Control Program Director Inc. CRCPD Publication 01-6 (July 2001)..

Quality Control in Diagnostic Radiology, American Association of Physicist in Medicine AAPM, Report No. 74. ISBN 1-888340-33-9

Basic Quality Control in Diagnostic Radiology, American Association of Physicist in Medicine AAPM, Report No. 4, 1981

Compliance Guidance for Fluoroscopic Quality Control, New Jersey Department of Environmental Protection, Bureau of Radiological Health

ReferencesQuality Control Program Department of Radiology, X-Ray Equipment Procedure manual, Mary Hitchcock Memorial Hospital Dartmouth-Hitchcock Medical Center Lebanon, new Hampshire, June 2009

A. Dimov, J. Vassileva, Quality Control Of The X-Ray Fluoroscopy Equipment In The Period Of Their Clinical Use - Methods And First Results, National Centre of Radiobiology and Radiation Protection, Sofia, Bulgaria

Charles R. Wilson, Ph.D., F.A.C.R., American College of Radiology ACR Radiography and Fluoroscopy Accreditation.

https://www.inlandimaging.com/what-is-a-radiologist

M.A. Périard and P. Chaloner, Diagnostic X-Ray Imaging Quality Assurance: An Overview, X-Ray Section, Consumer And Clinical Radiation Hazards Division Radiation Protection Bureau, Environmental Health Directorate Health Protection Branch, Health Canada

Quality Control Programme for Radiodiagnostic Equipment: Acceptance tests, the radiation protection and nuclear safety authorities in Denmark, 1999 ISSN: 0804-5038

https://www.acr.org/Quality-Safety/Radiology-Safety/Patient-Resources/About-Radiology

Phillip W. Ballinger, Eugene D. Frank, volume 3: Merrill's Atlas of Radiographic Positions and Radiologic Procedures, Edition 10, ISBN (Set) 0-323-01604-9

Jerrold T. Bushberg, J. Anthony Seibert, Edwin M. Leidholdt Jr., John N. Boone, The Essential Physic of Medical Imaging, second edition, ISBN 0-683-30118-7

Magnetic Resonance Imaging, Quality Control manual, American College of Radiology ACR

Manual on quality assurance in diagnostic radiology - Part1 Radiographic equipment July 2001

Kamarul Aminbin Abdullah, QC Test For Fluoroscopic Equipment chapter 6 Abu Bakar School of Medical Imaging KLMUC.

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Quality assurance

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