Ch 2 Ultrasound Transducers

Number of lines per frame

Along with image depth, which of the following also determines the frame rate? a. axial resolution b. damping c. number of lines per frame d. lateral resolution

increased SPL

Damping material produces all of the following except: a. decreased sensitivity b. increased SPL c. wide bandwidths d. low-quality factors

Cold-sterilization methods

How are ultrasound transducers typically sterilized?

the number of lines per frame

If the depth is increased and the frame rate is unchanged, what else must have decreased? a. The PRP b. the number of lines per frame c. the DF d. the output power

Low-quality factors, wide bandwidths

Imaging transducers typically have: a. low-quality factors, wide bandwidths b. high-quality factors, narrow bandwidths c. low-quality factors, narrow bandwidths d. high-quality factors, wide bandwidths

Frame Rate

Temporal resolution relates to which of the following? a. lateral resolution b. Frame Rate c. Range ambiguity d. element diameter

Matching Layer

The portion of the transducer that comes in contact with the patient is the _________________.

Kills pathogens and destroys

What does HEAT sterilization do to an ultrasound transducer ______________________ & ______________________ the transducer.

Frame Rate = PRF / lines per frame

What is the equation for frame rate

Huygen's Principle

What states that waves are the result of the interference of many wavelets produced at the face of the transducer? a. Curie's Point b. Snell's Law c. Bernoulli's Law d. Huygen's Principle

epoxy resin loaded with tungsten

Which of the following best describes the components of the damping material? a. epoxy resin loaded w/ tungsten b. resin made with lead zirconate titanate c. polyvinylidene fluoride d. tungsten impregnated with lead

Bandwidth

Which of the following describes the range of frequencies present within the beam? a. matching layer b. bandwidth c. array d. wavefront

The resulting wave is smaller than original

Which of the following describes the result of destructive interference? a. resulting wave is much larger than original b. resulting wave is a little larger than original c. resulting wave is smaller than original

curved

Which of the following electrical patterns produces electronic focusing of the ultrasound beam? a. curved b. sloped c. spiral d. circular

Damping worsens axial resolution

Which of the following is NOT true of damping? a. damping decreases the number of cycles in a pulse b. damping decreases spatial pulse length c. damping worsens axial resolution d. damping decreases the sensitivity of the transducer

Phasing

Which of the following is defined as changing the timing of the shocking of the elements in order to shape and steer the beam? a. angulation b. focusing c. phasing d. bundling

Range resolution

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? a. range resolution b. angular resolution c. contrast resolution d. transverse resolution

Frame resolution

Which of the following is not a component of spatial resolution? a. frame resolution b. contrast resolution c. axial resolution d. elevational resolution

Broadband technology

Which of the following is not a method of creating 3D images? a. broadband technology b. 2d array technology c. freehand technique d. mechanical technique

Angular

Which of the following is not a synonym for axial resolution? a. angular b. range c. depth d. radial

a larger aperture results in a shorter near-zone length

Which of the following is not a true statement ? a. lateral resolution varies with depth b. a larger aperture results in a shorter near-zone length c. a larger aperture produces less divergence in the far field d. lateral resolution may also be referred to as azimuthal resolution

There are no moving parts

Which of the following is not true about a mechanical transducer? a. it uses a motor to steer the beam b. most transducers are no longer mechanical c. may be focused with a lens or phased focused d. there no moving parts

the elements are arranged in a ring

Which of the following is not true of the linear sequenced array transducer? a. rectangular shape image b. firing is sequential c. electronically focused d. the elements are arranged in a ring

Damping Material

Which of the following is part of the transducer that stops the ringing of the element? a. matching layer b. housing c. damping material d. insulator

Temporal resolution

Which of the following is represented as time, or the ability to display structures in real time? a. Temporal resolution b. Axial resolution c. Longitudinal resolution d. Contrast resolution

Elevational resolution

Which of the following is the resolution in the third dimension of the beam? a. Lateral resolution b. Elevational resolution c. Contrast resolution d. Longitudinal resolution

The higher the frequency, the longer the near-zone length

Which of the following is true concerning the frequency and the near zone length, assuming a single-element, unfocused transducer? a. the higher the frequency, the longer the near-zone length b. the lower the frequency, the longer the near-zone length c. frequency and near-zone length are not related d. increasing the frequency causes divergence in the near field

it decreases with distance from the transducer

Which of the following is true of the diameter of the sound beam in the Fresnel zone? a. it increases with distance from the transducer b. it decreases with distance from the transducer c. it does not change with distance from the transducer d. it is unpredictable

Fraunhofer Zone

Which of the following may also be referred to as the far zone? a. Frame zone b. Fresnel zone c. Fraunhofer zone d. Frankincense zone

Phased Array

Which of the following produces a pie-shaped image? a. linear sequenced array b. phased array c. curved sequenced array d. convex transducer

Backing Material

Which of the following shortens the length of the pulse by decreasing the number of cycles in the pulse? a. Matching material b. Piezoelectric element c. backing material d. PZT

Phased array

Which of the following transducers is also referred to as a sector or vector transducer? a. linear sequential array b. phased array c. continuous wave transducers d. curved sequential array transducer

continuous wave transducers

Which of the following transducers is not used for imaging? a. continuous wave transducers b. curved sequenced array transducers c. linear sequenced array transducers d. phased array transducers

Spatial Pulse Length

Which of the following will not affect temporal resolution? a. line density b. image depth c. spatial pulse length d. number of focal zones

Curved sequenced array transducer

Which of the following would be best utilized for imaging of deep structures in the abdomen? a. endocavity transducer b. linear sequenced array transducer c. curved sequenced array trasnducer d. continuous-wave transducer

Focal Zone

Which of the following would be considered the narrowest part of a sound beam? a. Far zone b. near zone c. Fresnel zone d. focal zone

Increased line density

Which of the following would cause a decrease in temporal resolution? a. increased line density b. decreased sector size c. single transmit zone d. increased PRF

increased PRF

Which of the following would caused an increase in frame rate? a. multifocusing b. increased line density c. increased imaging depth d. increased PRF

Large crystal diameter, high frequency

Which of the following would most likely decrease beam divergence in the far field? a. large crystal diameter, low frequency b. small crystal diameter, low frequency c. large crystal diameter, high frequency d. small crystal diameter, high frequency

Large crystal diameter, high frequency

Which of the following would most likely increase the near-zone length? a. large crystal diameter, low frequency b. small crystal diameter, low frequency c. large crystal diameter, high frequency d. small crystal diameter, high frequency

Longitudinal

Which resolution typically has the lowest number in clinical imaging? a. longitudinal b. lateral c. transverse d. azimuthal

continuous wave transducers

Which transducer has no range resolution? a. continuous wave transducer b. curved sequenced array transducers d. linear sequenced array transducers d. phased array transducers

Constructive interference

Which type of interference results in a higher-amplitude sound wave? a. constructive interference b. destructive interference c. true interference d. false interference

temporal resolution

Which type of resolution is an accurate representation of moving structures? a. lateral b. azimuthal c. spatial d. temporal

frequency

along with crystal diameter (aperture), the divergence in the far field is also determined by which of the following? a. SPL b. frequency c. propagation speed d. line density

one-half

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? a. one-fourth b. one-third c. one-half d. equal

Thinner piezoelectric element

to produce a transducer with a higher frequency one should use a ____________________________________________________.

matching layer

which of the following facilitates the transmission of sound from the element into the patients skin? a. damping material b. matching layer c. tungsten covering d. focusing material

sector array

which of the following transducers can be described as having the scan lines originate from a common point of origin? a. sector array b. vector array c. curvilinear array d. linear sequenced array