Chapter 12 2d Imaging
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- 1.What characteristics of sound make it difficult to create two dimensional images?
- A.
Sound travels only in a straight line
- B.
Sound beams must be narrow to opitmize lateral resolution
- C.
Multiple pulses
- D.
Less pulses
- 2.What overcomes the difficulties of two dimensional images?
- A.
A straight line
- B.
Few pulses
- C.
One pulse at a time
- D.
Multiple pulses
- 3.The mechanical transducer has what kind of shape?
- A.
Disc shaped
- B.
Rectangular shaped
- 4.How many crystals does the mechanical transducer hold?
- A.
1
- B.
2
- C.
3
- D.
10
- 5.The image created by by a mechanical transducer is fan or sector shaped
- A.
True
- B.
False
- 6.The 2 dimensionalimage is built up by rotating the crystal with a .
- 7.In mechanical beam steering the scan plane is created through?
- A.
Electronic steering
- B.
Mechanical steering
- 8.Mechanical transducers have a fixed focal depth
- A.
True
- B.
False
- 9.Mechanical transducers use 2 methods of fixed focusing which are:
- A.
Internal focusing
- B.
External focusing
- C.
Both internal and external focusing
- D.
None
- 10.With a mechanical transducer, the pzt crystal is physically moved to create the image.
- A.
True
- B.
False
- 11.With the mechanical transuder, if the PZT crystal is damaged. What happens to the image?
- A.
Entire image is lost
- B.
Portion of the image is lost
- C.
Nothing happens
- D.
Turns black and grey
- 12.Arrays contain only one element
- A.
True
- B.
False
- 13.An array comprises a single slab of PZT cut into a collectoinof seperate pieces called:
- A.
Elements
- B.
Slopes
- C.
Waves
- D.
Pulses
- 14.A channel is a combnation of?
- A.
Active element, wire, and system electronics
- B.
Crystal,backing material, gel
- C.
System electronics,pzt,skin
- 15.There are several types of array transuders which are:
- A.
Linear
- B.
Vector
- C.
Annular
- D.
Convex
- 16.The face of a linear phased array is about what size?
- A.
1cm on each side
- B.
2cm on each side
- C.
1.5cm on each side
- D.
.1cm on each side
- 17.The beam is steered and focused using an electrical technique called phasing
- A.
True
- B.
False
- 18.How many crystals does the linear phased array contain?
- A.
100-300
- B.
100-200
- C.
100
- D.
100-400
- 19.Each element on the the linear phased array is rectangular and narrow
- A.
True
- B.
False
- 20.The linear phased array has elements with a width of?
- A.
1/4 to 1/2 of the sounds wavelength
- B.
1/3/ to 1/2 of the sounds wavelength
- C.
1/5 to1/3 of the sounds wavelength
- 21.The image created by a phased array transducer is:
- A.
Fan or sector shaped
- B.
Rectangular
- C.
Circular
- 22.With linear phased array transudcers, sound beams are focused mechanically
- A.
True
- B.
False
- 23.Phased array always means "adjustable" or "multi focus"
- A.
True
- B.
False
- 24.Damaged PZT crystals in linear phased array result in :
- A.
Inconsistant or erratic beam steering
- B.
No image
- 25.All active elements in a linear phased array probe are fired to create each sound beam.
- A.
True
- B.
False
- 26.When the spike line is straight, an unfocused sound beam is created in a linear phased array
- A.
True
- B.
False
- 27.In linear phased array the curved pattern creates a foucused sound beam.
- A.
True
- B.
False
- 28.The sound beam is focused if the spike line in linear phased array is curved
- A.
True
- B.
False
- 29.The active elements of annular array transducers appear as shaped.
- A.
Rectangular
- B.
Square
- C.
Disc
- D.
Trapizoid
- 30.The annular phased array contains how many crystals?
- A.
More than one
- B.
Less than one
- C.
One
- D.
None of the above
- 31.Annular phased array transducers use steering
- A.
Mechanical
- B.
Electronic
- 32.The annular phased array transducer collects informatiom only from the shallowest depths;all other information is ignored.
- A.
True
- B.
False
- 33.The annular phased arrays image is
- 34.When one ring of an annular phased array is damaged what can be said?
- A.
Only a portion of the image is lost
- B.
Whole image is lost
- C.
Its irratic
- 35.How many crystals does the linear seq. array carry?
- A.
120-250
- B.
100-300
- C.
125-300
- 36.All is true about the linear seq. array but one:
- A.
Rectangular-shaped
- B.
Elements are arranged side by side
- C.
Each crystal is about 2 wavelength in width
- D.
Is up to 10cm long
- 37.With linear seq. arrays,some but not all of the crystals are fired simultaneously to create each sound beam
- A.
True
- B.
False
- 38.The linear sequential transducer has what kinda of shape image?
- A.
Disc shaped
- B.
Circular shaped
- C.
Rectangular
- 39.Although a linear sequential array with a 10cm footprint may produce an 8 cm wide image, it cannot produce an image that is wider than 10cm
- A.
True
- B.
False
- 40.When one element in a linear sequential array is damaged,only the portionof the image extending directly below the damaged element is affected.
- A.
True
- B.
False
- 41.Can linear sequential array transducers steer sound beams electronically?
- A.
Yes
- B.
No
- 42.Curvilinear array transducers is also known as :
- A.
Convex
- B.
Curved
- C.
Vector
- D.
Linear
- 43.A convex array has up to how many crystals?
- A.
120-250
- B.
120-140
- C.
140-200
- D.
100-300
- 44.In a convex array each crystal is about what width?
- A.
1 wavelength
- B.
2 wavelength
- 45.In convex sequential array, some but not all crysatls are fired.
- A.
True
- B.
False
- 46.In convex array transducers focusing is achieved :
- A.
Mechanically
- B.
Electronically
- 47.The image shape of the convex array transucer is:
- A.
Blunted sector shaped
- B.
Sector shaped
- C.
Disc shaped
- 48.The curvilinear array is damaged, only the portion of the image is affected
- A.
True
- B.
False
- 49.A vector array is a combination of what?
- A.
Linear sequential and linear phased array
- B.
Linear phased array and convex array
- 50.The vector array has how many crystals?
- A.
120-250
- B.
100-300
- C.
150-300
- 51.The vector array has a trapzoidal image
- A.
True
- B.
False
- 52.What shape of the active element creates the best elevational resolution?
- 53.Which transducer types have the best elevational resoltuion?
- 54.A technique called can be used to make a sound beam narrow over a greater range of depths and optimize lateral resolution
- 55.Reducing the strength of the side and grating lobes can be achieved by a process called
- 56.Mechanical scanning produces pictures that are similar in shape to linear phased array images
- A.
True
- B.
False
- 57.Many active elements fire at almost the same time in a mechanical scanner.
- A.
True
- B.
False
- 58.Many active elements are fired at almost the same time in a phased array scanner.
- A.
True
- B.
False
- 59.A linear sequential array transducer has 128 crystals.how many of these crystals are fired to create a single sound beam
- A.
1
- B.
A small group
- C.
A large group
- D.
128
- 60.How are the piezoelectric crystals excited when using an ultrasound system with a sequential linear array transducer?
- A.
Singly and in order
- B.
In pairs
- C.
In a specific order
- D.
In a random sequence
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