SPI ULTRASOUND REGISTRY REVIEW
EXAM QUESTIONS & VERIFIED
CORRECT ANSWERS
SPL CORRECT ANSWER - wavelength x # of cycles
With phased array transducers, the transmitted sound beam is steered by CORRECT ANSWER -
Varying the timing of pulses to the individual piezoelectric elements
What type of wave is sound? CORRECT ANSWER - mechanical and longitudinal
The Frequency ranges for Ultrasound are: CORRECT ANSWER - > 20,000 Hz (20kHz)
The speed of sound in soft tissue is: CORRECT ANSWER - 1540 m/s
Linear sequence Array CORRECT ANSWER - transducer that fires the elements in groups
Unit for Wavelength CORRECT ANSWER - is millimeters
Enhancement is caused by CORRECT ANSWER - 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: CORRECT ANSWER - 0.3 mm Wavelength= c/f = 1.5mm/us ÷ 5MHz =
0.3mm
, An ultrasound transducer converts: CORRECT ANSWER - electrical energy into mechanical
energy and vice versa
The order of attenuation, from the lowest attenuation to highest: CORRECT ANSWER - fat,
muscle, bone, air
Propagation Speed from the lowest to highest: CORRECT ANSWER - air, fat, muscle, bone
If the frequency doubled, what to wavelength? CORRECT ANSWER - Decrease by one half/
Frequency and wavelength are inversely related
What happened to intensity if the amplitude of a signal is halve? CORRECT ANSWER - 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 CORRECT ANSWER - is the percentage of the time the sound is being transmitted
A 3dB gain would indicated in intensity by: CORRECT ANSWER - 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: CORRECT ANSWER - 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: CORRECT ANSWER - is the weakening of the strength of the beam,
typically from absorption, reflection, or scattering
SATA CORRECT ANSWER - is the lowest of the intensities
EXAM QUESTIONS & VERIFIED
CORRECT ANSWERS
SPL CORRECT ANSWER - wavelength x # of cycles
With phased array transducers, the transmitted sound beam is steered by CORRECT ANSWER -
Varying the timing of pulses to the individual piezoelectric elements
What type of wave is sound? CORRECT ANSWER - mechanical and longitudinal
The Frequency ranges for Ultrasound are: CORRECT ANSWER - > 20,000 Hz (20kHz)
The speed of sound in soft tissue is: CORRECT ANSWER - 1540 m/s
Linear sequence Array CORRECT ANSWER - transducer that fires the elements in groups
Unit for Wavelength CORRECT ANSWER - is millimeters
Enhancement is caused by CORRECT ANSWER - 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: CORRECT ANSWER - 0.3 mm Wavelength= c/f = 1.5mm/us ÷ 5MHz =
0.3mm
, An ultrasound transducer converts: CORRECT ANSWER - electrical energy into mechanical
energy and vice versa
The order of attenuation, from the lowest attenuation to highest: CORRECT ANSWER - fat,
muscle, bone, air
Propagation Speed from the lowest to highest: CORRECT ANSWER - air, fat, muscle, bone
If the frequency doubled, what to wavelength? CORRECT ANSWER - Decrease by one half/
Frequency and wavelength are inversely related
What happened to intensity if the amplitude of a signal is halve? CORRECT ANSWER - 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 CORRECT ANSWER - is the percentage of the time the sound is being transmitted
A 3dB gain would indicated in intensity by: CORRECT ANSWER - 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: CORRECT ANSWER - 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: CORRECT ANSWER - is the weakening of the strength of the beam,
typically from absorption, reflection, or scattering
SATA CORRECT ANSWER - is the lowest of the intensities
