EDELMAN ULTRASOUND PHYSICS PART 2 | THE SMART
WAY TO PASS | REAL TESTS, REAL RESULTS!
As sound travels deeply into the far zone, the beam diverges, or spreads out. Which will
result in the greatest beam divergence deep in the far zone? - Answer: Low frequency, small
diameter.
Two ultrasound systems are identical except for the pulse repetition period of the emitted
pulse. What system will have the deeper focus? - Answer: Their foci will be at the same
depth. Changes in PRP do not affect the depth of the focus.
All of the following terms describe the shape of a sound wave created by a tiny fragment of
PZY except:
A.Spherical
B.Huygens' wavelet
C.V-shaped
D.Hourglass shaped - Answer: Hourglass shaped. The waves are not hourglass in shape.
What explains the difference in sound beam shape created by disc-shaped crystal from
that of a small chip of PZT? - Answer: Huygen's Principle. This explains the difference
between the beam shape from the tiny chips of PZT and disc crystals of a larger dimension
Huygen's principle is based on __ - Answer: Interference
The focus of an ultrasound beam is the location where the __ - Answer: optimum transverse
resolution is. The focus of an ultrasound beam is the location where the beam is most
narrow.
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1
,The lateral resolution of an ultrasound system is primarily determined by the__ - Answer:
Width of the sound pulse. The lateral resolution achieved by an imaging system is
approximately equal to the width of the ultrasound pulse.
Two ultrasound systems produce acoustic pulses. One pulse is 0.4 microseconds in
duration and the other is 0.2 microseconds. Which pulse will most likely provide the best
lateral resolution?
A) 0.4 microsecond pulse
B) 0.2 microsecond pulse
C) they are the same
D) cannot be determined - Answer: D. Duration of a pulse is unrelated to the lateral
resolution.
The pulse duration does not profoundly influence the lateral resolution? True or false? -
Answer: True.
Two 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? - Answer: System G . It has a narrower beam and will produce
higher quality images at that depth.
When using the standard ultrasonic imaging instrumentation, the lateral resolution has a
higher numerical value than the axial resolution. True or false? - Answer: True. Most imaging
systems have better axial resolution than lateral resolution.
Two ultrasound systems have near zone lengths of 8 cm. At their foci, System Q's lateral
resolution is 3.0 mm and system H's is 5.0 mm Which system will correctly display two
small structures at a depth of 8 cm? The objects are side by side and are 0.4 cm apart. -
Answer: System Q.
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2
,The lateral resolution of an ultrasound system is 4 mm. Two structures are seperated 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? - Answer: One echo.
True or false? When using an instrument typical of today's imaging devices, a higher
frequency transducer is likely to mildly improve the system's lateral resolution. - Answer:
True.
True or false? When using an instrument typical of today's diagnostic imaging devices, a
higher frequency transducer is likely to improve the axial resolution. - Answer: True. Higher
frequency pulses have shorter pulse lengths.
What will lower the value of an ultrasound system's lateral resolution?
A. decrease the # of cycles in the pulse
B. increase the effective damping material
C. increase the PRP
D. use an acoustic lens - Answer: D
What technique is internal focusing? - Answer: Curved crystal.
What technique is external focusing? - Answer: Lens.
What means adjustable focusing or multi focusing? - Answer: Phased array
What technique is consistent with variable or multi-focusing? - Answer: Electronic. (it is
adjusted by the sonographer)
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3
, What does not occur with focusing? - Answer: Lower intensity at the focus. Focusing does
not lower the beam's intensity at the focus.
In which region of a sound beam is focusing most effective? - Answer: The end of the near
zone. (this area is called the focal zone)
True or false? In comparison to other locations along the length of an ultrasound beam,
focusing is generally ineffective in the far zone? - Answer: True. Focusing narrows the width
of the sound beam to improve image quality.
Two ultrasound systems have near zone lengths of 8 cm. At the focus, System S's lateral
resolution is 3.0 mm, whereas System C's is 5.0 mm. Which system is most likely to
appropriately display two small body structures that lie, one in front of the other, at depths
of 8.6 and 9.0 mm? - Answer: Cannot be determined. No information on axial resolution.
The diameter of a disc-shaped, unfocused piezoelectric crystal is 1 cm. What is the best
estimate for the minimum lateral resolution of the ultrasound system? - Answer: 5 mm.
The diameter of a disc-shaped, unfocused piezoelectric crystal is 1.2 cm. The near zone
length is 8 cm. What is the best estimate for the lateral resolution at a depth of 16 cm? -
Answer: 1.2 cm.
Which imaging modality places time-of-flight information on the x-axis and echo amplitude
on the y-axis? - Answer: A-Mode.
Which imaging mode accurately displays reflector depth? - Answer: A-Mode
Which imaging technique usually displays a single jagged line of varying heights? - Answer:
A-Mode
APPHIA – Crafted with Care and Precision for Academic Excellence.
4
WAY TO PASS | REAL TESTS, REAL RESULTS!
As sound travels deeply into the far zone, the beam diverges, or spreads out. Which will
result in the greatest beam divergence deep in the far zone? - Answer: Low frequency, small
diameter.
Two ultrasound systems are identical except for the pulse repetition period of the emitted
pulse. What system will have the deeper focus? - Answer: Their foci will be at the same
depth. Changes in PRP do not affect the depth of the focus.
All of the following terms describe the shape of a sound wave created by a tiny fragment of
PZY except:
A.Spherical
B.Huygens' wavelet
C.V-shaped
D.Hourglass shaped - Answer: Hourglass shaped. The waves are not hourglass in shape.
What explains the difference in sound beam shape created by disc-shaped crystal from
that of a small chip of PZT? - Answer: Huygen's Principle. This explains the difference
between the beam shape from the tiny chips of PZT and disc crystals of a larger dimension
Huygen's principle is based on __ - Answer: Interference
The focus of an ultrasound beam is the location where the __ - Answer: optimum transverse
resolution is. The focus of an ultrasound beam is the location where the beam is most
narrow.
APPHIA – Crafted with Care and Precision for Academic Excellence.
1
,The lateral resolution of an ultrasound system is primarily determined by the__ - Answer:
Width of the sound pulse. The lateral resolution achieved by an imaging system is
approximately equal to the width of the ultrasound pulse.
Two ultrasound systems produce acoustic pulses. One pulse is 0.4 microseconds in
duration and the other is 0.2 microseconds. Which pulse will most likely provide the best
lateral resolution?
A) 0.4 microsecond pulse
B) 0.2 microsecond pulse
C) they are the same
D) cannot be determined - Answer: D. Duration of a pulse is unrelated to the lateral
resolution.
The pulse duration does not profoundly influence the lateral resolution? True or false? -
Answer: True.
Two 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? - Answer: System G . It has a narrower beam and will produce
higher quality images at that depth.
When using the standard ultrasonic imaging instrumentation, the lateral resolution has a
higher numerical value than the axial resolution. True or false? - Answer: True. Most imaging
systems have better axial resolution than lateral resolution.
Two ultrasound systems have near zone lengths of 8 cm. At their foci, System Q's lateral
resolution is 3.0 mm and system H's is 5.0 mm Which system will correctly display two
small structures at a depth of 8 cm? The objects are side by side and are 0.4 cm apart. -
Answer: System Q.
APPHIA – Crafted with Care and Precision for Academic Excellence.
2
,The lateral resolution of an ultrasound system is 4 mm. Two structures are seperated 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? - Answer: One echo.
True or false? When using an instrument typical of today's imaging devices, a higher
frequency transducer is likely to mildly improve the system's lateral resolution. - Answer:
True.
True or false? When using an instrument typical of today's diagnostic imaging devices, a
higher frequency transducer is likely to improve the axial resolution. - Answer: True. Higher
frequency pulses have shorter pulse lengths.
What will lower the value of an ultrasound system's lateral resolution?
A. decrease the # of cycles in the pulse
B. increase the effective damping material
C. increase the PRP
D. use an acoustic lens - Answer: D
What technique is internal focusing? - Answer: Curved crystal.
What technique is external focusing? - Answer: Lens.
What means adjustable focusing or multi focusing? - Answer: Phased array
What technique is consistent with variable or multi-focusing? - Answer: Electronic. (it is
adjusted by the sonographer)
APPHIA – Crafted with Care and Precision for Academic Excellence.
3
, What does not occur with focusing? - Answer: Lower intensity at the focus. Focusing does
not lower the beam's intensity at the focus.
In which region of a sound beam is focusing most effective? - Answer: The end of the near
zone. (this area is called the focal zone)
True or false? In comparison to other locations along the length of an ultrasound beam,
focusing is generally ineffective in the far zone? - Answer: True. Focusing narrows the width
of the sound beam to improve image quality.
Two ultrasound systems have near zone lengths of 8 cm. At the focus, System S's lateral
resolution is 3.0 mm, whereas System C's is 5.0 mm. Which system is most likely to
appropriately display two small body structures that lie, one in front of the other, at depths
of 8.6 and 9.0 mm? - Answer: Cannot be determined. No information on axial resolution.
The diameter of a disc-shaped, unfocused piezoelectric crystal is 1 cm. What is the best
estimate for the minimum lateral resolution of the ultrasound system? - Answer: 5 mm.
The diameter of a disc-shaped, unfocused piezoelectric crystal is 1.2 cm. The near zone
length is 8 cm. What is the best estimate for the lateral resolution at a depth of 16 cm? -
Answer: 1.2 cm.
Which imaging modality places time-of-flight information on the x-axis and echo amplitude
on the y-axis? - Answer: A-Mode.
Which imaging mode accurately displays reflector depth? - Answer: A-Mode
Which imaging technique usually displays a single jagged line of varying heights? - Answer:
A-Mode
APPHIA – Crafted with Care and Precision for Academic Excellence.
4
