Transducer review questions

What would cause a decrease in temporal resolution

An increase in line density

Most transducers usually have better

Axial resolution than lateral resolution

The range of frequencies present within the beam

Bandwidth

What type of interference results in a higher Amplitude sound wave

Constructive interference

What determines the divergence in the far field

Crystal diameter( aperture) And frequency

What electrical patterns produce electronic focusing in the ultrasound beam

Curved

What would improve temporal resolution( frame )

Decrease in the sector size, single transmit zone, and an increased pulse repetition frequency

Damping material produces

Decreased spatial pulse length, decreased sensitivity, wide bandwith, low quality factors

What would increase frame rate

Decreasing the imaging death which is the same as increasing the pulse repetition frequency

If the depth is increased what happens to frame rate

It decreases

What is true of the diameter of the sound beam in the Fresnel zone?

It decreases with distance from the Transducer

What happens to the diameter of the sound beam in the Fresnal zone

It decreases with distance from the transducer

What are synonyms for lateral resolution

LATA lateral, angular, transverse, azimuthal

What would most likely decreased beam Divergence in the far Field

Large Crystal diameter high frequency

What would most likely increase the near zone length-

Large crystal diameter and high frequency

What affects temporal resolution

Line density, image depth PRF and number of focal zones

Which resolution typically has the lowest number in clinical imaging

Longitudinal

What are synonym for Axial resolution

Longitudinal Axial radial range and depth(larrd)

Imaging Transducers typically have

Low Qfactors and wide bandwidths

What facilitates the transmission of sound from the element to the patient's skin

Matching layer

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 transducer can be described as having the scan lines originate from a comment point of origin

Sector array

What part of the transducer stops ringing of the element

The damping material

What is considered the narrowest part of the sound beam

The focal zone

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

The number of lines per frame

Mechanical transducers

can be curved or linear in shape. They have a single circular disc-shaped active element. It uses a motor to steer the beam, most transducers are no longer mechanical, and may be focused with a lens or phased focused

Which type of resolution is an accurate representation of moving structures In real time

temporal resolution otherwise known as frame rate

Frame rate is determined by

the number of lines per frame/line density, number of focal zones, and the imaging depth(PRF)

Sector arrays are useful for imaging what areas?

those limited by ribs, gas filled-bowels, or lungs. The narrow near field and wide far field enable the transducer scan plane to be postitioned between or around these structures.

Large Crystal diameter and high frequency

what will decrease beam divergence in the far field