QUALITY CONTROL AND ASSURANCE Flashcards
What are the two main areas of activity for quality control in radiology?
Quality Assurance (QA) and Quality Control (QC)
What organization promotes the “Ten-Step Monitoring and Evaluation Process”?
The Joint Commission (TJC)
What is the main focus of Quality Assurance (QA)?
People, including patient scheduling, reception, and preparation
Who is responsible for a QA program?
The radiologist
What does Quality Control (QC) primarily focus on?
Instrumentation and equipment
Who is responsible for a QC program?
Medical physicist
What is the first step in the TJC’s Quality Assurance Program?
Assign responsibility
What is the purpose of routine performance monitoring in QC?
To ensure optimal image quality with minimal patient radiation exposure
What is Acceptance Testing in QC?
Testing new radiologic equipment before clinical use
What does preventive maintenance in QC aim to do?
Make repairs unnecessary by regular maintenance
What is the minimum total filtration required for x-ray beams?
2.5 mm Al
How often should collimation be checked?
Semiannually
What should the focal-spot size accuracy be within?
± 50%
What is the tolerance for kVp calibration accuracy?
± 10%
What devices are used to measure kVp calibration?
Filtered ion chamber and photodiodes
What is the frequency of exposure timer accuracy testing?
Annually
What is the acceptable accuracy for exposure times greater than 10 ms?
± 5%
How often should exposure linearity be tested?
Annually
What should exposure reproducibility be within?
± 5%
What is the function of Positive Beam-Limiting (PBL) collimators?
Automatically adjust the x-ray field size to the image receptor size
What is used to measure focal-spot size?
Pinhole camera, star pattern, and slit camera
What is a limitation of the star pattern method for focal-spot size measurement?
Ineffective for sizes less than 3 mm
What does kVp calibration ensure?
The x-ray generator produces the correct energy levels
What happens if the kVp varies by 4%?
It affects image optical density and contrast
What is the purpose of Automatic Exposure Control (AEC)?
To provide a constant image density regardless of tissue differences
How is exposure linearity determined?
Using a precision radiation dosimeter
What should the accuracy of section level in tomographic QC be within?
± 2 mm
What is the required minimum half-value layer (HVL) for a single-phase x-ray unit at 70 kVp?
1.6 mm Al
What should processor cleaning frequency be?
Weekly
How is screen-film contact evaluated?
Using a wire mesh pattern and analyzing for blur
How often should protective apparel be checked?
Annually
What is used to measure film illuminator intensity?
Photometer
What is the minimum intensity for film illuminators?
1500 cd/m²
What is the tolerance for film illuminator uniformity?
± 10% across the surface
What is the typical entrance skin exposure (ESE) rate for fluoroscopy in normal operation?
≤ 10 R/min (100 mGya/min)
What is the entrance skin exposure (ESE) rate limit for interventional procedures?
20 R/min (200 mGya)
How is automatic brightness stabilization (ABS) system adequacy tested?
Using Lucite, aluminum, copper, and lead filters
What is the purpose of cassette spot-film in fluoroscopy?
To record images based on kVp and mAs settings
What is the input exposure rate range for automatic brightness control systems?
10-40 μR/s
What is the dry-to-dry processing time for a double-capacity processor?
3 minutes
What is the processing rate for a fast-access system?
500 films per hour
What temperature should a high development processor be maintained at?
35°C (95°F)
What is the consequence of nonscheduled maintenance?
System failures and unscheduled repair
How often should developer temperature be checked in a processor QC program?
Daily
What kind of maintenance involves routine lubrication and observation of parts?
Scheduled maintenance
What does preventive maintenance require?
Parts replacement at regular intervals
What are the characteristics checked in tomographic QC?
Section uniformity and level accuracy
What should be done if screen-film contact blur appears?
Replace the felt or foam pressure pad
What method is used for ensuring uniform optical density (OD) in images?
Sensitometric strip evaluation
How often should film illuminators be photometrically analyzed?
Annually
What type of device measures radiographic exposure reproducibility?
Precision radiation dosimeter
What should exposure reproducibility be consistent across?
A series of at least three exposures
How is the function of backup timers in AEC evaluated?
Using a lead filter to terminate exposure
What is necessary for processor crossover rack cleaning?
Removing and washing with manufacturer-provided fluids
What system component needs adjustment if kVp calibration fails?
The high-voltage generator
What does a precision dosimeter measure in exposure linearity tests?
Radiation intensity at various mA and exposure time combinations
What is the function of automatic exposure control (AEC) systems in radiography?
To maintain consistent image optical density
How is focal-spot size tested when a new x-ray tube is installed?
Using a pinhole camera, star pattern, or slit camera
How frequently should exposure timer accuracy be checked after repairs?
More frequently than annually
What defines the uniformity in film illuminators?
No more than ± 10% variance over the surface
What QC evaluation tool is used for measuring focal-spot size?
Slit camera
What is the purpose of radiographic intensifying screens?
To reduce patient radiation dose
What is the accuracy tolerance for collimation in radiography?
± 2% of the source-to-image distance (SI
What QC evaluation ensures x-ray beam quality?
Measuring half-value layer (HVL)
What is the maximum exposure rate for cineradiography?
Unlimited
How is tomographic section level accuracy checked?
Imaging a hole in a lead sheet
What QC measure ensures minimal patient radiation exposure in fluoroscopy?
Monitoring entrance skin exposure (ESE) rates
What tool measures light intensity in film illuminators?
Photometer
How often should radiographic intensifying screens be cleaned?
Every other month, at minimum
What must the measured kVp be within for QC compliance?
± 10% of the indicated kVp
What must a film illuminator’s intensity exceed?
1500 cd/m²
How is automatic exposure rate in fluoroscopy verified?
Using Lucite, aluminum, or other filters
How often should film cassettes be tested for quality?
Once or twice a year
What is checked during weekly processor maintenance?
Observation of moving parts and lubrication
