1-5
The ultrasound system in your lab has multiple transducers that exhibit different axial resolutions. For the following axial resolution measurements, which offers the finest detail?
0.31 mm
0.15 mm
0.44 mm
0.77 mm
0.15 mm
What defines the best axial resolution?
Spatial pulse length/4
Spatial pulse length/2
Spatial pulse length x 4
Spatial pulse length x 2
Spatial pulse length/2
Which of the following transducers will have the poorest axial resolution?
2.9 MHz & 5 cycles per pulse
2.9 MHz & 4 cycles per pulse
3.6 MHz & 3 cycles per pulse
3.6 MHz & 2 cycles per pulse
2.9 MHz & 5 cycles per pulse
Which statement is not true regarding lateral resolution?
It is determined as the minimum separation required to define two structures perpendicular to the beam axis.
It remains constant throughout scanning depth
It is improved by focusing
It is equal to beam width
It remains constant throughout scanning depth
Which of the following will not improve axial resolution?
Increased PZT vibrations
Decreased spatial pulse length
Decreased pulse duration
Increased transducer frequency
Increased PZT vibrations
In which region of a sound beam is focusing most effective?
At the focus
The ultrasound sound beam's width is 4 mm. Two structures are separated by 3 mm and lie side by side in relation to the sound beam's main axis. What will most likely appear on the system's display?
One echo
Two ultrasound systems produce acoustic pulses with the same beam width. One pulse is 0.4 μsec in duration, and the other is 0.2 μsec. Which pulse will most likely provide the best lateral resolution?
0.2 μsec
0.4 μsec
Cannot be determined
They are the same
They are the same
What should you do to obtain the best lateral resolution for a given transducer?
Use the maximum number of focal zones
Which display mode has the sound beam depth on the x-axis and echo amplitude on the y-axis?
A mode
With B mode on, which axis is the strength of the reflection input?
Z axis
What type of resolution is affected most by pulse duration?
Axial resolution
The mode that produces a line related to the changing position of reflectors in the body with respect to time is called:
M mode
The lateral resolution of an ultrasound system is primarily determined by the:
Beam diameter
What is the display mode technique illustrated in this image? (Image)
A mode
Which of the following display modes is the basis for real-time imaging?
A mode
B mode
M mode
B mode
Which of the following focusing techniques is different from the others?
Lens
Curved PZT
Fixed
Phased
Phased
In a motion mode display, the y-axis represents the:
Penetration depth
Using a fixed focusing technique, a greater lens arc is associated with a(n):
Greater degree of focusing
The ultrasound systems have near zone lengths of 8 cm. At the focus, system G's lateral resolution is 3.0 mm, whereas system P's is 5.0 mm. Which system will produce higher quality pictures at their foci?
System G
Which of the following techniques is internal focusing?
Lens
Curved backing material
Curved array
Electronic
Curved array
Resolution is a machine's ability to:
Create accurate images
The focus of a sound beam is the location where the:
Frequency is the highest
In soft tissue, a 3-cycle, 4 MHz pulse has a spatial pulse length equal to 8.5 mm. What is the axial resolution?
4.25 mm
All of the following occur when a beam is focused except:
Smaller beam diameter at the end of the near zone
More compact focal zone
Shorter near zone length
Lower intensity at the focus
Lower intensity at the focus