ARDMS SPI Quality Assurance and Phantoms 5 — Questions and Answers
Question 1: Which organization publishes widely used guidelines for ultrasound equipment performance testing in the United States?
- FDA Center for Devices and Radiological Health only
- AIUM (American Institute of Ultrasound in Medicine) (Correct answer)
- Joint Commission on Accreditation only
- NEMA (National Electrical Manufacturers Association)
Correct answer: AIUM (American Institute of Ultrasound in Medicine)
The AIUM publishes equipment performance testing standards widely adopted by clinical facilities and accreditation bodies in the United States.
Question 2: During QA testing, a phantom image shows a persistent bright horizontal line at 3 cm depth across the full width of the image. What artifact does this most likely represent?
- Acoustic enhancement from a cystic structure
- Reverberation artifact from a highly reflective internal phantom structure or transducer face (Correct answer)
- Grating lobe artifact from the array
- Refraction artifact at a tissue interface
Correct answer: Reverberation artifact from a highly reflective internal phantom structure or transducer face
A horizontal bright line spanning the full image width at a fixed depth is characteristic of reverberation between parallel reflective surfaces such as the transducer face and a reflective phantom layer.
Question 3: What is the primary reason ultrasound QA records should be kept for a minimum of several years?
- To comply with Medicare reimbursement rules for technical components
- To document trending of performance changes and support accreditation reviews (Correct answer)
- To satisfy state radiation safety officer requirements
- To track phantom consumable replacement schedules
Correct answer: To document trending of performance changes and support accreditation reviews
Long-term QA records enable trending of gradual performance changes and are required by accreditation bodies such as the ACR and ICAVL during site reviews.
Question 4: A flow phantom is used to assess color Doppler. If the pump speed is set to produce a known flow velocity but the system reads a significantly higher velocity, what is the most likely technical explanation?
- The color gain is set too high
- The Doppler angle correction is set incorrectly to a smaller angle than actual (Correct answer)
- The wall filter is set too low
- The ensemble length is too short
Correct answer: The Doppler angle correction is set incorrectly to a smaller angle than actual
An angle correction set smaller than the true beam-to-flow angle causes cosine correction to overestimate velocity, since cosine of a smaller angle is larger.
Question 5: Which QA parameter specifically evaluates the system's ability to display echoes from structures located very close to the transducer surface?
- Maximum depth of penetration
- Dead zone measurement (Correct answer)
- Slice thickness assessment
- Axial resolution at focus
Correct answer: Dead zone measurement
Dead zone measurement quantifies the region nearest the transducer where ring-down from the transmitted pulse masks true returning echoes.
Question 6: When a tissue-mimicking phantom is scanned with a transducer at a frequency significantly higher than the phantom's design frequency, how does this typically affect the penetration depth result?
- Penetration depth increases because resolution improves
- Penetration depth decreases because higher-frequency sound attenuates faster (Correct answer)
- Penetration depth is unchanged because the phantom speed of sound is fixed
- Penetration depth doubles due to improved axial resolution
Correct answer: Penetration depth decreases because higher-frequency sound attenuates faster
Acoustic attenuation increases with frequency, so scanning at a higher frequency than the phantom's design frequency results in greater signal loss per centimeter and shallower penetration.
Question 7: Which of the following best describes the role of the physics QA physicist or qualified medical physicist in an ultrasound department?
- Performing all clinical scans requiring QA phantom images
- Overseeing and validating the QA program, interpreting results, and recommending corrective actions (Correct answer)
- Calibrating DICOM network connections between scanners
- Writing billing codes for ultrasound examinations
Correct answer: Overseeing and validating the QA program, interpreting results, and recommending corrective actions
The medical physicist oversees the QA program, interprets performance data, identifies equipment deficiencies, and recommends or validates corrective actions before systems return to clinical use.
ARDMS SPI Quality Assurance and Phantoms 5
Which organization publishes widely used guidelines for ultrasound equipment performance testing in the United States?