UTC Quality Assurance & Standards 3 — Questions and Answers
Question 1: Which material property of a tissue-mimicking phantom most closely approximates soft tissue for ultrasound QA testing?
- Speed of sound approximately 1540 m/s and attenuation of 0.5 dB/cm/MHz (Correct answer)
- Speed of sound approximately 1800 m/s and attenuation of 1.5 dB/cm/MHz
- Speed of sound approximately 1000 m/s and attenuation of 0.1 dB/cm/MHz
- Speed of sound approximately 2000 m/s and attenuation of 2.0 dB/cm/MHz
Correct answer: Speed of sound approximately 1540 m/s and attenuation of 0.5 dB/cm/MHz
Tissue-mimicking phantoms are designed with a speed of sound near 1540 m/s and attenuation around 0.5 dB/cm/MHz to simulate soft tissue.
Question 2: In color Doppler QA, a flow phantom is used primarily to evaluate:
- Axial and lateral resolution of B-mode imaging
- Velocity accuracy, color fill, and aliasing thresholds (Correct answer)
- Penetration depth and sensitivity
- Transducer frequency output
Correct answer: Velocity accuracy, color fill, and aliasing thresholds
A Doppler flow phantom allows assessment of velocity accuracy, color fill uniformity, and the velocity at which aliasing occurs.
Question 3: What is the purpose of the AIUM 100 mm test object in ultrasound quality assurance?
- Testing only axial resolution with pins at 1 mm increments
- Providing a standardized target for evaluating multiple performance parameters including distance accuracy and resolution (Correct answer)
- Measuring Doppler sensitivity exclusively
- Testing transducer center frequency
Correct answer: Providing a standardized target for evaluating multiple performance parameters including distance accuracy and resolution
The AIUM 100 mm test object contains multiple pin groups that allow evaluation of distance accuracy, axial/lateral resolution, and dead zone.
Question 4: When should a baseline QA assessment be performed on a new ultrasound system?
- After the first month of clinical use
- After the system passes manufacturer warranty inspection
- Before or immediately upon clinical commissioning (Correct answer)
- During the first scheduled annual review
Correct answer: Before or immediately upon clinical commissioning
A baseline QA assessment must be performed before or immediately upon commissioning a new system to establish reference performance values.
Question 5: The ALARA principle in diagnostic ultrasound QA primarily directs sonographers to:
- Achieve maximum image quality regardless of output settings
- Keep acoustic output as low as reasonably achievable while maintaining diagnostic image quality (Correct answer)
- Maintain the highest possible frame rate during scanning
- Use the lowest frequency transducer available for all exams
Correct answer: Keep acoustic output as low as reasonably achievable while maintaining diagnostic image quality
ALARA (As Low As Reasonably Achievable) means minimizing patient exposure to acoustic energy while still obtaining clinically adequate diagnostic images.
Question 6: Which index displayed on the ultrasound monitor is used to assess the potential for thermal bioeffects in tissue?
- Mechanical Index (MI)
- Thermal Index (TI) (Correct answer)
- Dynamic Range Index (DRI)
- Acoustic Power Index (API)
Correct answer: Thermal Index (TI)
The Thermal Index (TI) estimates the potential for temperature rise in tissue and is the primary indicator of thermal bioeffects.
Question 7: A quality assurance log for ultrasound equipment should include which of the following?
- Patient demographics and diagnosis codes
- Date, technologist performing QA, findings, and corrective actions taken (Correct answer)
- Insurance billing codes and equipment purchase price
- Staff scheduling and room assignments
Correct answer: Date, technologist performing QA, findings, and corrective actions taken
QA logs must document the date, performing technologist, measured parameters, any deviations found, and corrective actions taken to provide an auditable record.
UTC Quality Assurance & Standards 3
Which material property of a tissue-mimicking phantom most closely approximates soft tissue for ultrasound QA testing?