Comprehensive and Detailed Explanation From Exact Extract:
Temporal resolution refers to the system's ability to accurately track moving structures over time (i.e., frame rate). Temporal resolution improves when:
The number of focal zones is reduced (fewer focal zones = faster frame rate).
The imaging depth is reduced (shallower depth = faster frame rate).
According to sonography instrumentation references:
“Fewer focal zones and shallow imaging depth optimize temporal resolution by decreasing the time required for each frame, resulting in a higher frame rate.”
Therefore, the correct answer is C: Fewer focal zones and shallower depth.
55
Which region of this image from a sector phantom is evaluating the dead zone?
A close-up of a ultrasound
Description automatically generated
A. Region A
B. Region B
C. Region C
D. Region D
Answer: A
Comprehensive and Detailed Explanation From Exact Extract:
The dead zone in ultrasound refers to the shallow area immediately beneath the transducer where no useful data can be collected due to the transducer's ring-down and the time required for the system to switch from transmit to receive mode.
In a sector phantom image, the area closest to the transducer (superficial portion) is used to evaluate the dead zone. In this image, Region A is located at the top of the image, closest to the transducer surface.
According to sonography instrumentation reference:
“The dead zone is assessed by evaluating the area immediately beneath the transducer. This area is used to test the system's near-field performance and transducer surface integrity.”
Therefore, the correct answer is A: Region A.
—
Submit