Chapter 2 Questions

If the depth is increased and the frame rate is unchanged, what else must have decreased?

# of lines per frame

Along with image depth, which of the following also determines the frame rate?

# of lines per frame, line density, # of focal zones, and imaging depth (PRF)

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?

1/2

which of the following is the part of the transducer that stops the ringing of the element

Damping material

Which of the following would be considered the narrowest part of the sound beam?

Focal zone

which of the following electrical patterns produces electronic focusing of the ultrasound beam

curved

which of the following is true of the diameter of the sound beam in the fresnel zone( near zone)

decreases with distance from the transducer

along with crystal diameter, the divergence in the far field is also determined by what

frequency so frequency and crystal diameter determine divergence in far field

which of the following would cause an increase in frame rate

increased PRF decreasing the depth which is the same as increasing PRF, would increase the frame rate

Damping material produces all of the following except

increased SPL supposed to decrease the spa by decreasing # of cycles in a pulse

which of the following would cause a decrease in temporal resolution

increased line density

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

imaging transducers typically have

low Q factors, wide bandwidths

which resolution typically has the lowest # in clinical imaging

lower is better, axial is better than longitudinal, axial=LARD so answer is longitudinal

which of the following facilitates the transmission of sound from the element into the patients skin

matching layer

which of the following transducers can be described as having scan lines originate from a common point of origin

sector array comes to a point at the top, bc all of scan lines come from a point of origin

which type of resolution is an accurate representation of moving structures

temporal resolution, also known as frame rate, has ability to display moving structures in real time

which of the following is not a true statement about a mechanical transducer

there are no moving parts mechanical transducers DO have moving parts