Quality Assurance in Clinical Settings

Quality Assurance

• Quality Assurance (QA) is a crucial process for ensuring safe X-ray equipment performance.
• Standardised tests are used to check alignment and X-ray beam parameters, ensuring safe operation.
• Testing is performed by Radiographers and Medical Physics staff.

Fundamentals of Radiation and Radiation Safety Module Timeline 2024-2025

• The module timeline outlines key dates for lectures, seminars, virtual simulations, on-campus simulations, a mock assessment, and exams.
• The schedule includes lectures, seminars, and virtual and on-campus simulations spread across September, October, November, and December.
• A mock assessment and MCQ exam are scheduled.
• Holidays are also included in the timeline.

Module Learning Objectives

• Students need to understand the significance of ionising radiation regulations and radiographers' responsibilities.
• Students should demonstrate radiation protection methods within diagnostic imaging.

Today's Learning Outcomes

• Understanding the importance of Quality Assurance (QA).
• Familiarity with the types of QA tests required.
• Introduction to remedial and suspension performance levels.

Quality Assurance Requirements

• This section likely covers the regulatory and operational requirements for maintaining quality in radiology equipment and procedures.

QA - we HAVE to do it

• Regulations (IRR 17, Reg 33) require employers to implement suitable QA programs to ensure equipment can restrict exposure according to intended use.

When must we do QA?

• QA is required before new equipment is used, even before training.
• Routine QA checks are needed at set intervals.
• Particular attention is needed after major maintenance, even if parts not directly related to patient protection are touched.

Acceptance / Commissioning

• Acceptance/Commissioning tests are performed by the purchaser's representative (usually Medical Physics) to ensure proper equipment functioning according to specifications.
• It ensures equipment is ready for clinical use and establishes baselines.
• Confirming that requirements of IRR Reg 33 are met is also included in this process.

Baseline Values

• Baseline values are established during commissioning, used to compare subsequent performance tests.
• Baseline values are set for each routinely performed test.

Routine Testing

• Regular performance (constancy) testing is used to detect any changes in system performance.
• Results are compared to baseline values.
• Radiographers and medical physicists perform routine testing.

Major Maintenance

• Major maintenance involves changes or replacement of components like X-ray tubes or software.
• QA is crucial after major maintenance.
• QA should be performed after each engineer visit.

Routine QA Tests

• IPEM Report 91 (Published 2005) lists routines QA tests and tolerances, but it is currently being revised.

Two Levels of Testing

• Level A testing includes more frequent, simple pass/fail tests, usually performed by Radiographers.
• Level B testing involves less frequent but more detailed checks requiring more equipment, and are performed by Medical Physics staff.
• There are different priorities assigned to the levels of testing.

The Recipe Book

• IPEM Report 32 provides detailed information and guidance on performing various radiation protection tests and justifying their necessity.

Which Exposure Parameters?

• To compare results, use the same acquisition parameters (kV, mA, exposure time, focus to detector distance, and collimation) across different tests.

Documentation

• Comprehensive documentation of QA results is vital.
• CQC inspectors require evidence of QA procedures and that results fall within tolerance limits.

X-ray and Light Beam Alignment

• Proper alignment of the light beam and X-ray beam is essential to ensure accurate patient positioning and exposure.
• Matching the centers of the beams ensures the X-ray field covers the indicated area on the patient.

X-ray to Light Beam Alignment - Testing

• Place the alignment plate on the detector, set the distance to 100 cm, adjust the light field, and make an exposure at low kV/mAs.
• Results should be evaluated for alignment and any misalignment should be corrected.

X-ray to Light Beam Alignment - Results

• Remedial level is reached when misalignment is greater than +/- 1 cm.
• Suspension level occurs at misalignment of greater than +/- 3 cm.

X-ray to Light Beam Centring - Testing

• Use the same procedure as alignment testing, but with a Perspex cylinder containing ball bearings.
• Evaluate the results to assess the beam centring.

X-ray to Light Beam Centring - Results

• The remedial level for misalignment is > +/- 1 cm.

Light Beam Field Size - Testing

• In most cases, light beam field size testing is combined with other tests.

Distances and Scales

• Accurate distances are crucial for proper imaging and to control the radiation dose to the patients.
• Specific distances and settings are required for specific examinations.

Distances and Scales - Testing

• Measure the actual source-to-detector distance with a tape measure.
• Compare the measured value with the indicated value.

Quality Assurance Tests- X-ray Tube Output

• Testing X-ray tube output ensures consistent radiation dose and effective image quality.

X-ray Tube Output - Testing

• Place the dose detector in the centre of the light field and collimate well.
• Set the appropriate source-to-detector distance.
• Obtain measurements across specific parameters.

X-ray Tube Output - Testing - Repeatability

• Repeatability checks the consistency of output for similar exposures at the same settings.

X-ray Tube Output - Testing - Reproducibility

• Reproducibility monitors how parameters (kV, mA, s) impact measured output.
• Check that the trend of the kV measurement stays the same as its starting baseline.

Additional Level B Tests - Exposure Time, Tube Potential, Half-Value Layer

• These additional Level B tests provide further comprehensive evaluation of X-ray parameters.

Exposure Time & Tube Potential

• Establish appropriate ranges for kV and time settings.
• Evaluate exposure time parameters to ensure they meet the required safety standards and intended patient dose.

Half Value Layer - Testing

• Set constant kV and mAs, using increasingly thick aluminium absorbers to evaluate how much radiation is being absorbed.
• This step helps find the half-value layer.

Further Comparisons

• Evaluate system performance based on its previous initial performance levels.
• Compare among different systems using the same tools (and parameters).

Comparing Systems

• Use consistent testing equipment (e.g., dose meters, test tools) and parameters (kV, mA, exposure time).

Summary

• Quality Assurance is required to ensure the safety and performance of X-ray equipment and testing.
• The procedures involve standardised tests, and testing by radiographers and medical physicists.

This quiz focuses on key regulations concerning quality assurance in clinical environments, specifically referencing IRR 17 and IRMER 17. Participants will explore essential requirements, responsibilities of employers regarding equipment, and the broader implications of quality assurance practices. Test your understanding of these vital aspects of healthcare compliance.