CH 2 - Physics - Ultrasound Transducers - (Textbook Questions)
Which of the following is not a true statement?
A larger aperture results in a shorter near-zone length
Which of the following is not a synonym for axial resolution?
Angular
Which of the following is not a characteristic of an unfocused single-element transducer?
At the face of the transducer, the beam diameter is twice the size of the element thickness
Which of the following shortens the length of the pulse by decreasing the number of cycles in the pulse?
Backing material
Which of the following describes the range of frequencies presented within the beam?
Bandwidth
Which of the following is not a method of creating 3D images?
Bradband technology
How are ultrasound transducers typically sterilized?
Cold-sterilization methods
Which type of interference results in a higher-amplitude sound wave?
Constructive interference
Which of the following transducers is not used for imaging?
Continuous-wave transducers
Which transducer has no range resolution?
Continuous-wave transducers
Which of the following electrical patterns producers electronic focusing of the ultrasound beam?
Curved
Which of the following would be best utilized for imaging of deep structues in the abdomen?
Curved sequence
Which of the following is the part of the transducer that stops the ringing of the element?
Damping material
Which of the following is not true of damping?
Damping worsens axial resolution
Which of the following is the resolution in the third dimension of the beam?
Elevational resolution
Which of the following best describes the components of the damping material?
Epoxy resin loaded with tungsten
Which of the following would be considered the narrowest part of a sound beam?
Focal Zone
Temporal resolution relates to which of the following?
Frame rate
Which of the following ins not a component of spatial resolution?
Frame resolution
Which of the following may also be referred to as the far zone?
Fraunhofer zone
Along with crystal diameter (aperture), the divergence in the far field is also determined by which of the following?
Frequency
What states that waves are the result of the interference of many wavelets produced at the face of the transducer?
Huygen's principle
Which of the following would cause an increase in frame rate?
Increased PRF
Damping material produces all of the following except:
Increased SPL
Which of the following would cause a decrease in temporal resolution?
Increased line density
Which of the following is true of the diameter of the sound beam in the fresnel zone?
It decreases with distance from the transducer
What does heat sterilization do to an ultrasound transducer?
Kills pathogens and destroys the transducer
Which of the following would most likely decrease beam divergence in the far field?
Large crystal diameter, high frequency
Which of the following would most likely increase the near-zone length?
Large crystal diameter, high frequency
Which resolution typically has the lowest number in clinical imaging?
Longitudinal
Imaging transducers typically have:
Low-quality factors, wide bandwidths
The portion of the transducer that comes in contact with the patient is the?
Matching layer
Which of the following facilitates the transmission of sound from the element into the patient's skin?
Matching layer
Along with image depth, which of the following also determines frame rate?
Number of lines per frame
In an unfocused, single-element transducer, the width at the focal point of the sound beam measures how much compared to the beam width at the face of the transducer?
One-half
Which of the following produces a pie-shaped image?
Phased array
Which of the following transducers is also referred to as a sector or vector transducer?
Phased array
Which of the following is defined as changing the timing of the shocking of the elements in order to shape and steer the beam?
Phasing
Which of the following is defined as the minimum distance two reflectors can be parallel to the beam, and still appear on the screen as two dots?
Range resolution
Which of the following transducers can be described as having the scan lines originate from a common point of origin?
Sector array
Which of the following will not affect temporal resolution?
Spatial pulse length
Which of the following is represented as time, or the ability to display structures in real tiem?
Temporal resolution
Which type of resolution is an accurate representation of moving structures?
Temporal resolution
Which of the following is not true of the linear sequenced array transducer?
The elements are arranged in a ring
Which of the following best describes the frame rate?
The frame rate is equal to the pulse repetition frequency divided by the lines per frame
Which of the following is true concerning the frequency and the near-zone length, assuming a single-element, unfocused transducer?
The higher the frequency, the longer the near-zone length
If the depth is increased and the frame rate is unchanged, what else must have decreased?
The number of lines per frame
Which of the following describes the result of destructive interference?
The resulting wave is smaller than the original waves
Which of the following is not a true statement about a mechanical transducer?
There are no moving parts
To produce a transducer with a higher frequency one should?
use a thin a thinner piezoelectric element
