REVIEW QUESTIONS |
GUARANTEED ACCURATE
ANSWERS |VERIFIED
SPL - ACCURATE ANSWERS✔✔ wavelength x # of cycles
With phased array transducers, the transmitted sound beam is steered by
- ACCURATE ANSWERS✔✔ Varying the timing of pulses to the
individual piezoelectric elements.
What type of wave is sound? - ACCURATE ANSWERS✔✔ mechanical
and longitudinal.
The Frequency ranges for Ultrasound are: - ACCURATE
ANSWERS✔✔ > 20,000 Hz (20kHz).
The speed of sound in soft tissue is: - ACCURATE ANSWERS✔✔
1540 m/s.
Linear sequence Array - ACCURATE ANSWERS✔✔ transducer that
fires the elements in groups
,Unit for Wavelength - ACCURATE ANSWERS✔✔ is millimeters
Enhancement is caused by - ACCURATE ANSWERS✔✔ weakly
attenuating structures (such as a cyst)
The wavelength in a material having a propagation speed of 1.5 mm/us
employing a transducer frequency of 5.0 MHz is: - ACCURATE
ANSWERS✔✔ 0.3 mm Wavelength= c/f = 1.5mm/us ÷ 5MHz = 0.3mm
An ultrasound transducer converts: - ACCURATE ANSWERS✔✔
electrical energy into mechanical energy and vice versa
The order of attenuation, from the lowest attenuation to highest: -
ACCURATE ANSWERS✔✔ fat, muscle, bone, air
Propagation Speed from the lowest to highest: - ACCURATE
ANSWERS✔✔ air, fat, muscle, bone
If the frequency doubled, what to wavelength? - ACCURATE
ANSWERS✔✔ Decrease by one half/ Frequency and wavelength are
inversely related
What happened to intensity if the amplitude of a signal is halve? -
ACCURATE ANSWERS✔✔ Quarted/ Intensity is proportional to the
, amplitude squared, so if the amplitude is halved, the resulting intensity is
one fourth the original intensity
Duty factor - ACCURATE ANSWERS✔✔ is the percentage of the time
the sound is being transmitted
A 3dB gain would indicated in intensity by: - ACCURATE
ANSWERS✔✔ 2 times (A gain of 3dB results in doubling of intensity
(or power))
Ignoring the effects of attenuation, the intensity of ultrasound beam is
usually greater at the focal zone because of: - ACCURATE
ANSWERS✔✔ The smaller beam diameter (Intensity equals power
divided by area. The area is smallest in the focal zone; therefore, the
intensity is highest)
Attenuation denotes: - ACCURATE ANSWERS✔✔ is the weakening of
the strength of the beam, typically from absorption, reflection, or
scattering
SATA - ACCURATE ANSWERS✔✔ is the lowest of the intensities
Beam Uniformity Ratio - ACCURATE ANSWERS✔✔ BUR= SP/SA