ARDMS SPI Quality Assurance and Phantoms 3

Question 1

A tissue-mimicking phantom contains hyperechoic spherical masses. These targets are primarily used to test which system performance parameter?

Accepted Answer

Contrast resolution for high-reflectivity lesions

Answer

Hyperechoic spherical targets surrounded by uniform background material test the system's ability to detect and resolve high-amplitude echoes against background speckle.

Question 2

Which QA measurement describes the shortest distance from the transducer face at which the system can display accurate image information?

Accepted Answer

Dead zone

Answer

The dead zone is the region immediately adjacent to the transducer face where the system cannot detect echoes due to the ring-down artifact from the transmitted pulse.

Question 3

In a QA protocol for Doppler systems, a string phantom or flow phantom is used. What specific parameter does a string phantom test?

Accepted Answer

Velocity accuracy and angle dependence of Doppler measurements

Answer

A string phantom moves a target at a known velocity, allowing the sonographer to verify that the system accurately reports Doppler-derived velocity at various beam-to-target angles.

Question 4

When assessing depth of penetration during QA, what endpoint is typically used to define maximum usable depth?

Accepted Answer

The deepest depth at which a uniform speckle pattern is still visible

Answer

Penetration depth is defined as the greatest depth at which the speckle pattern from the tissue-mimicking material is still discernible above noise.

Question 5

A QA test finds that the dead zone has increased significantly from the baseline value. Which clinical implication is most important?

Accepted Answer

Superficial structures may not be visualized accurately

Answer

An enlarged dead zone means structures immediately beneath the transducer face may be missed or misrepresented, which is critical for superficial examinations.

ARDMS SPI - ARDMS Sonography Principles and Instrumentation Practice Test

ARDMS SPI - ARDMS Sonography Principles and Instrumentation Practice Test

ARDMS SPI Quality Assurance and Phantoms 3