DAVIES SPI REVIEW QUESTIONS & ANSWERS
Artifact based on the interface patterns of scattered echoes - answers - acoustic
speckle
Impedance increases with what two things? - answers - increased tissue density &
increased propagation speed
Main advantage of using an intracavitary (transvag) probe? - answers - probe is closer
to the area of interest, so a higher frequency can be used, resulting in superior spatial
reso
Varying the excitation voltage to each element in the group used to form the ultrasound
pulse is called? - answers - apodization
A digital scan converter is another name for what system component? - answers -
image memory
Propagation speed is lowest in what biological tissue? - answers - fat
List the order of biological tissue sound travels through by lowest to highest propagation
speed: - answers - fat (lowest)
Liver
Blood
Muscle
Bone (highest)
When increasing the number of transmit focal zones to improve spatial reso, the trade-
off is: - answers - lateral reso vs temporal reso
Each transmit focus requires a pulse/listen cycle. As more focal zones are added, the
frame rate is decreased. Temporal reso is related to frame rate
The speed of sound is defined as the speed at which the: - answers - sound wave
propagates through the medium
The ability to distinguish similar structures with varying grey scale is termed: - answers -
contrast reso
Resolution of two structures at different depths along the path of the sound beam is
termed: - answers - axial reso
You have increased the output power by 10db. This effects the signal intensity how? -
answers - increases by a factor of 10.
Increasing a control by 3db corresponds to a ______ of the setting.
, If it is increased by 10db, it has been increased by a factor of ____. - answers - doubling
10
How is reflector depth determined with pulse-echo us? - answers - by the echo arrival
time
A ____ _____ transducer creates a rectangular image shape - answers - linear array
This kind of resolution is:
-equal to beam width
-improved by focusing
-is defined as the minimum separation required to resolve two structures perpendicular
to the beam axis
-aka azimuthal reso
It does not remain constant throughout scanning depth - answers - lateral resolution
Lateral resolution is best at the _____ _____ and _____ on either side - answers - focal
point ,
Degrades
If you wish to increase the frame rate, you should.... - answers - decrease the sector
width
When you change the transmit frequency, what else is altered? - answers - the number
of cycles per second
Increasing the number of acoustic scan lines in one frame improves what? - answers -
lateral reso
As the number of lines in one frame increases, the distance between lines decreases.
Reducing this distance improves the lateral reso
____ imaging would be most helpful to obtain an accurate anatomic volume
measurement - answers - 3d
What technique would be most helpful in reducing grating lobes in your image? -
answers - tissue harmonic imaging
Electronic focusing in the transmit mode is accomplished using.... - answers - time
delays to excite transducer elements
The audible frequency range of sound is: - answers - 20 hz to 20,000 hz
Artifact based on the interface patterns of scattered echoes - answers - acoustic
speckle
Impedance increases with what two things? - answers - increased tissue density &
increased propagation speed
Main advantage of using an intracavitary (transvag) probe? - answers - probe is closer
to the area of interest, so a higher frequency can be used, resulting in superior spatial
reso
Varying the excitation voltage to each element in the group used to form the ultrasound
pulse is called? - answers - apodization
A digital scan converter is another name for what system component? - answers -
image memory
Propagation speed is lowest in what biological tissue? - answers - fat
List the order of biological tissue sound travels through by lowest to highest propagation
speed: - answers - fat (lowest)
Liver
Blood
Muscle
Bone (highest)
When increasing the number of transmit focal zones to improve spatial reso, the trade-
off is: - answers - lateral reso vs temporal reso
Each transmit focus requires a pulse/listen cycle. As more focal zones are added, the
frame rate is decreased. Temporal reso is related to frame rate
The speed of sound is defined as the speed at which the: - answers - sound wave
propagates through the medium
The ability to distinguish similar structures with varying grey scale is termed: - answers -
contrast reso
Resolution of two structures at different depths along the path of the sound beam is
termed: - answers - axial reso
You have increased the output power by 10db. This effects the signal intensity how? -
answers - increases by a factor of 10.
Increasing a control by 3db corresponds to a ______ of the setting.
, If it is increased by 10db, it has been increased by a factor of ____. - answers - doubling
10
How is reflector depth determined with pulse-echo us? - answers - by the echo arrival
time
A ____ _____ transducer creates a rectangular image shape - answers - linear array
This kind of resolution is:
-equal to beam width
-improved by focusing
-is defined as the minimum separation required to resolve two structures perpendicular
to the beam axis
-aka azimuthal reso
It does not remain constant throughout scanning depth - answers - lateral resolution
Lateral resolution is best at the _____ _____ and _____ on either side - answers - focal
point ,
Degrades
If you wish to increase the frame rate, you should.... - answers - decrease the sector
width
When you change the transmit frequency, what else is altered? - answers - the number
of cycles per second
Increasing the number of acoustic scan lines in one frame improves what? - answers -
lateral reso
As the number of lines in one frame increases, the distance between lines decreases.
Reducing this distance improves the lateral reso
____ imaging would be most helpful to obtain an accurate anatomic volume
measurement - answers - 3d
What technique would be most helpful in reducing grating lobes in your image? -
answers - tissue harmonic imaging
Electronic focusing in the transmit mode is accomplished using.... - answers - time
delays to excite transducer elements
The audible frequency range of sound is: - answers - 20 hz to 20,000 hz
