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46 Cards in this Set
- Front
- Back
widening of the sound beam is demonstrated in the
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fraunhofer zone
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weak beams emitted from a linear sequenced array transducer are termed
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grating lobes
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the resonant frequency of a pulse wave is determined by the
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thickness and propagation speed of the element
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heat sterilization is not recommended for diagnostic transducers because
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the piezoelectric properties will be lost
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which of the following compontnts is unnecessary in the construction of a continuous wave transducer |
damping layer
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lateral resolution is determined by the |
beam width
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what is the axial resolution in soft tissue when using a 5 MHz frequency with a two cycle pulse and an element thickness of 0.5mm
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0.3 mm
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what is the operating frequency of a two cycle pulse with an element thickness of 0.2 mm and a propagation speed of 4 mm / us
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10 MHz
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which of the following principles do diagnostic ultrasound transducers operate? snell's law ALARA principle Hugens principle piezoelectric effect |
piezoelectric effect
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reducing the impedance difference between the crystal and the skin is the primary function of what transducer component |
matching layer
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a sound beam demonstrates the most uniform intensity in the |
far field
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what is the near zone length of a 6 mm 5MHz transducer
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30mm
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which of the following changes will improve temporal resolution increase the beam width increase focal zone depth decrease the depth decrease in dynamic range |
decrease the depth
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The near zone length of a 3 mm 10 MHz transducer is |
15mm
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which of the following transducers elements has the longest focal length 7mm, 2.5 MHz 2mm, 7.5 MHz 5mm, 10 MHz 3mm, 15 MHz |
5mm, 10MHz
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the distance from the face of a focused transducer to the point of spatial peak intensity is termed the
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focal length |
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Irregular excitation of the elements in an array to reduce grating lobes describes
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apodization
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diameter of the transducer describes the
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diameter of the focus
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the impedance of the damping layer is
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similar to the element's
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the purpose of backing material in the transducer is to
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reduce the number of cycles in a pulse
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vector array is a type of transducer
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operation
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focusing of the sound beam is directly related to
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lateral resolution
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steering of the sound beam is accomplished by
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altering the excitation of the active elements
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exceeding the curie point of a transducer wll result in
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loss of all piezoelectric properties
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an active element with a thickness of 0.8 mm and a propagation speed of 4 mm/us will have an operating frequency of
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2.5MHz
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what is the thickness of the crystal with an operating frequency of 5 MHz and a propagation speed of 4 mm/us? |
0.4 mm
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what is the axial resolution in soft tissue when using a 15 MHz frequency with a two cycle pulse |
0.1 mm
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which of the following transducers operates by applying voltage pulses to groups of linear elements in succession |
linear sequenced array
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focusing of the sound beam is only accomplished within the
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near field
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what is the diameter of the sound beam at one near zone length when using a 6mm 2.5 MHz transducer
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3mm
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the ability to distinguish two structures in a path perpendicular to the sound beam describes
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azimuthal resolution
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the most common piezoelectric material used in diagnostic ultrasound transducers is
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lead zirconate titanate
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subdicing the elements in diagnostic ultrasound transducers is used to |
reduce grating lobes
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diagnostic frequencies range between
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2 and 20 MHz
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which of the following changes will improve axial resolution
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increase in transducer frequency
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during transmission diagnostic ultrasound transducers convert
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electrical energy into thermal energy
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which of the following states "some materials produce a voltage when distorted by an applied pressure"
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piezoelectric principle
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which of the following is a negative effect of using a damping material in the transducer assembly
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reduced sensitivity
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how many cycles pre pulse are typically used in doppler imaging
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5-30
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the sonographer can determine the depth of the focal zone when using a transducer with an
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electronic focus
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the impedance of the matching layer is
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less than the impedance of the crystal
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which of the following transducers displays a trapezoidal image? convex vector annular curvilinear |
vector |
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which of the following differentiates similar or dissimilar tissues? axial resolution lateral resolution contrast resolution temporal resolution |
contrast resolution
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section thickness is related to the
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beam width
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operating frequency of a transducer is directly related to the
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propagation speed of the element
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a focused 10 mm 15 MHz transducer will demonstrate a focal diameter of
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5 mm
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