Ch. 3 Flashcards
Coupling medium is applied to the transducer-tissue boundary to increase _______ of the sound wave.
a. reflection
b. scattering
c. refraction
d. transmission
d. transmission
Arrays are operated in two ways, called _____ and _____.
a. linear; convex
b. sequencing; phasing
c. pulse wave; continuous wave
d. spatial; angular
b. sequencing; phasing
The transducer element converts _____ to ______ and vice versa.
a. voltage; electricity
b. pulses; ultrasound
c. ultrasound; voltage
d. electricity; ultrasound
d. electricity; ultrasound
Which of the following frequencies is operated by the thinnest element?
a. 2.5 MHz
b. 3.5 MHz
c. 7.5 MHz
d. 10.0 MHz
d. 10.0 MHz
At a distance of two near-zone lengths, the beam diameter is _____ the diameter of the transducer element.
a. one half of
b. double
c. equal to
d. triple
c. equal to
The transducer has an impedance ______ times that of the tissue
a. 4
b. 10
c. 20
d. 6
c. 20
The linear image consists of ____ scan lines.
a. vertical
b. oblique
c. horizontal
d. perpindicular
a. vertical
Another name for the Fresnel zone is _________.
a. near zone
b. far zone
c. field length
d. near path length
a. near zone
In a single-element transducer, additonal beams are not included in the ultrasound beam are called _______.
a. grating lobes
b. side lobes
c. slice thickness
d. scattering
b. side lobes
Lateral resolution is equal to _____.
a. wavelength/2
b. beam width
c. spatial pulse length/2
d. operating frequency/2
b. beam width
The useful frequency range for most diagnostic applications is _____ MHz.
a. 1 - 15 MHz
b. 2 - 20 MHz
c. 2 - 15 MHz
d. 1 - 50 MHz
b. 2 - 20 MHz
Factors determining axial resolution are the ______.
a. frequency and wavelength
b. beam diameter and element thickness
c. number of cycles in the pulse and wavelength
d. propagation speed and number of cycles in a pulse
c. number of cycles in the pulse and wavelength
The matching layer _________.
a. reduces reflection of ultrasound at element
b. reduces transmission of ultrasound at element
c. increases reflection of the ultrasound element
d. increases the spatial pulse length
a. reduces reflection of ultrasound at element
What principle states that some materials produce a voltage when deformed by an applied pressure?
a. ALARA (as low as reasonably achievable) principle
b. Piezoelectric principle
c. Snell’s principle
d. Huygens’ principle
b. Piezoelectric principle
Electric _____ applied to a transducer are converted to ultrasound.
a. pulses
b. waves
c. echoes
d. voltages
d. voltages
Sequenced, phased, and vector are types of ______.
a. transducer
b. operations
c. focusing
d. construction
b. operations
Which resolution relates more directly to the transducers?
a. Temporal
b. Contrast
c. Vectoral
d. Detail
d. Detail
If the propagation speed of the transducer element material is 6 mm/us, the operating frequency for a thickness of .2 mm is ____ MHz.
a. 15
b. 30
c. 12
d. 7.5
a. 15
The critical temperature an ultrasound transducer cannot exceed is called the _____.
a. Curie point
b. quality factor
c. critical point
d. piezoelectric point
a. Curie point
Which of the following is attached to the rear face of the transducer element?
a. Damping
b. Ceramics
c. mathcing layer
d. puling media
a. damping