URR part 4 Flashcards
The strength of the received echo determines the _____ on the display
brightness of the pixel
The use of multiple focal zones will improve _____, but degrade ______
lateral resolution
temporal resolution
What system control adjusts the number of gray levels in the image to maintain the gray scale within the range of human vision?
compression
Which of the following console settings should be lower in superficial imaging and higher in deep imaging?
a. focal zone
b. transmit frequency
c. PRF
d. gain
d
You are scanning with a transducer that maintains a constant of 2 scan lines per sector degree. Which of the following statements is true regarding changing a 45 degree sector angle to a 90 degree sector angle?
a. the PRF will increase
b. the number of scan lines will decrease
c. the elevational resolution will degrade
d. the temporal resolution will degrade
d
Which of the following imaging parameters is responsible for the ability to resolve the AP wall thickness of an artery?
a. lateral resolution
b. dynamic range
c. axial resolution
d. contrast resolution
c
Which of the following imaging parameters is responsible for the ability to resolve the AP wall thickness of an artery?
a. lateral resolution
b. dynamic range
c. axial resolution
d. contrast resolution
c
When Harmonic imaging is turned on, it primarily improves ______ resolution
lateral
To increase the amplitude of the ultrasound pulse produced by the transducer:
a. the voltage amplitude from the pulser must decrease
b. the number of piezoelectric elements must increase
c. the voltage amplitude from the pulser must increase
d. the size of the piezoelectric element must increase
c
If the entire image is too dark, what console adjustment should you make first?
a. adjust the far field TGC
b. adjust the near field TGC
c. increase the overall gain
d. increase the output power
c
_______ removes low amplitude signals and noise from the image.
increasing rejection
Increased damping improves axial resolution, but decreases ______
sensitivity
When you activate Harmonic imaging and add a focal zone to the field of view, which type of resolution improves the most?
a. axial
b. contrast
c. elevational
d. lateral
d
If the input power is 2mW and the ouput power is 1mW, what is the gain?
3dB
Which of the following correctly describes an amplifier?
a. sonographer controls this by using the compression control
b. only useful signals are amplified
c. each returning reflection is made stronger/larger for additional processing and storage
d. the signal to noise ratio improves with amplification
c
While scanning an echo, you change the gray map to a new choice and continue to scan. This be termed a changed in ______
preprocessing
______ is the percentage of time the transducer is transmitting soundwaves
duty factor
What effect does frequency compounding have on the image?
reduce speckle artifact
increasing scan line density leads to improved _______ resolution
spatial
Which of the following types of resolution varies with different depths on the image?
a. axial resolution
b. lateral resolution
c. contrast resolution
d. temporal resolution
b
The amount of compensation necessary for different echoes varies with reflector:
depth
Axial resolution varies directly with:
a. spatial pulse length
b. beam intensity
c. output power
d. beam diameter
a
A linear transducer providing a trapezoidal image demonstrates degraded _____ resolution in the far field of the image.
lateral
Decreasing the number of cycles in a pulse will:
a. increase the frequency of the wave
b. degrade the axial resolution of the system
c. increase the wavelength
d. improve the axial resolution of the system
d