Radiographic Quality Control: Equipment Tests, Tolerances, and Frequencies

What is Quality Assurance (QA)?

Focuses on PEOPLE and the overall quality of health care.

What is another name for QA?

Continuous Quality Improvement (CQI).

What is the primary goal of QA?

Provide an accurate and timely diagnosis.

What is the secondary goal of QA?

Minimize radiation exposure to the patient.

What is Quality Control (QC)?

Focuses on EQUIPMENT and the actual testing of imaging equipment.

What is another name for QC?

Total Quality Management (TQM).

What is the purpose of QC?

Evaluate imaging equipment to ensure safe and reliable operation.

What are the types of QC testing listed?

Acceptance testing, preventive maintenance (PM) testing, and error testing.

What is the total filtration formula?

Total filtration = inherent filtration + added filtration.

What is the minimum total filtration above 70 kVp?

At least 2.5 mm aluminum equivalent.

What is the frequency of filtration or beam quality tests?

Annually.

What is the half-value layer (HVL)?

Amount of filtration that reduces x-ray beam intensity or air kerma to 50% of its original value.

How does HVL relate to beam hardness?

Higher HVL = harder beam with higher average energy. Lower HVL = softer beam.

What is the collimation light field to radiation field alignment tolerance?

Within 2% of the source-to-image receptor distance (SID).

What is the frequency of collimation alignment tests?

Semi-annually (every 6 months).

What is the Positive Beam Limitation (PBL) tolerance?

Automatic collimators must be within 2% of SID.

What is the SID accuracy tolerance?

Actual SID must be within ±2% of the indicated SID.

What is the frequency of SID accuracy tests?

Annually.

What is the centering tolerance?

The x-ray beam center must align with the centering indicator within 1% of SID.

What is the frequency of centering tests?

Annually.

What is the effective focal spot size tolerance?

Within 50% of the size stated in the equipment specifications.

What is the frequency of effective focal spot tests?

Annually.

What is the kVp calibration tolerance?

Actual kVp must be within 5% of the indicated kVp.

What is the frequency of kVp calibration tests?

Annually.

What is the timer accuracy tolerance?

Exposure time must be within 5% of the indicated exposure time.

What is the timer test method and frequency?

Spinning top test; performed annually.

What is exposure linearity?

Exposure per mAs should not change more than 10% between different mA stations.

What is the frequency of exposure linearity tests?

Annually.

What is exposure reproducibility?

Exposure values produced using identical technical parameters should be within 5%.

What is the frequency of exposure reproducibility tests?

Annually.

What is the line focus principle?

Explains the relationship between the actual focal spot on the anode and the effective focal spot size