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SPI PRACTICE TEST QUESTIONS AND
APPROVED ANSWERS.
Which of the following do the source and the medium determine? a. duty factor b. frequency c. propagation speed d. axial resolution - Correct Answer-d. Axial resolution is affected by all of the following EXCEPT a. frequency b. damping c. spatial pulse length d. focusing - Correct Answer-d. Damping in a transducer a. reduces the number of cycles in a pulse and increases the quality factor b. increases the number of cycles in a pulse and increases penetration c. causes poor axial and lateral resolution d. reduces the duty factor and increases the range of transmitted frequencies - Correct Answer-d. Far zone beam divergence can be reduced on a single-element transducer by using a. a transducer with a smaller element diameter b. a higher frequency transducer c. a lower frequency transducer or a smaller element diameter d. adjustable focusing - Correct Answer-b. The area between the face of an unfocused single-element transducer and the point where the beam starts to diverge is the
a. Fraunhofer zone b. refraction zone c. focal zone d. near zone - Correct Answer-d. Assuming a fixed frequency, what happens if the diameter of an unfocused transducer is increased? a. the far zone divergence increases b. the penetration decreases c. the length of the near zone increases d. the length of the near zone decreases - Correct Answer-c. Which of the following does NOT affect lateral resolution? a. focusing b. element diameter c. frequency d. bandwidth - Correct Answer-d. Higher frequency transducers provide a. improved lateral resolution b. smaller Doppler shifts c. improved axial resolution and reduced attenuation d. increased penetration - Correct Answer-a. Ultrasound waves that are traveling through a medium consist of a. electromagnetic and radio frequencies b. compressions and refractions c. electromagnetic and ionizing frequencies d. compressions and rarefactions - Correct Answer-d. What is the difference between audible sound and ultrasound? a. audible sound waves can travel through a vacuum b. audible sound has a higher frequency c. ultrasound has a higher frequency d. ultrasound waves are ionizing - Correct Answer-c.
If the number of cycles in a pulse is reduced, a. the pulse repetition frequency is automatically reduced b. the spatial pulse length increases c. the pulse duration is reduced which results in a lower duty factor d. the bandwidth is decreased and the quality factor is increased - Correct Answer-c. The minimum reflector separation required to produce separate echoes is a. the spatial resolution of the ultrasound system b. the temporal resolution c. the attenuation coefficient d. the total attenuation - Correct Answer-a. As the frequency of sound increases, a. the amount of scatter is increased b. the attenuation decreases c. the amount of scatter decreases d. the penetration increases - Correct Answer-a. Which of the following transducers provides the maximum penetration? a. 10.0 MHz b. 7.5 MHz c. 2.25 MHz d. 3.5 MHz - Correct Answer-c. The average attenuation of ultrasound energy in the patient is approximately a. 2.0 dB per cm per MHz b. 10.0 dB per cm per MHz c. 5. dB per cm per MHz d. 0.7 dB per cm per MHz - Correct Answer-d. If sound from a 3 MHz transducer has 3 dB of attenuation after traveling through 2 cm of tissue, what is the amount of attenuation of sound from a 5 MHz transducer after traveling through 1 cm of the same tissue?
a. 5 dB b. 1 dB c. 2 dB d. 2.5 dB - Correct Answer-d. The half-value layer or the half-intensity-depth a. is the depth where the intensity is 50% of the originally transmitted intensity b. increases as the frequency of the transmitter increases c. is the range of frequencies contained in an ultrasound pulse d. is the attenuation coefficient in tissue - Correct Answer-a. The speed of ultrasound in soft tissue is closest to a. 1.54 mm/sec b. 1540 km/sec c. 1540 mm/sec d. 1540 m/s - Correct Answer-d. Ultrasound energy is traveling through the same medium. If the frequency is doubled, the propagation speed is a. quartered b. doubled c. halved d. unchanged - Correct Answer-d. The reason most ultrasound systems are calibrated at 1540 meters per second is because a. 1540 meters per second is the average speed of sound encountered in the patient b. 1540 meters per second is the maximum speed of sound encountered in a patient c. 1540 meters per second is the speed of sound in muscle d. 1540 meters per second is the maximum speed of sound in a patient - Correct Answer-a.
d. equal to the acoustic impedance of the piezoelectric element - Correct Answer-a. The prefix micro- represents the mathematical value a. 10 to the 6th power b. 10 to the negative 6th power c. 10 to the third power d. 10 to the negative third power - Correct Answer-b. The representation for volume is a. m b. cm c. cm squared d. cm cubed - Correct Answer-d. If the amplitude is decreased by 50%, what is the corresponding change in power? a. -6 dB b. 3 dB c. -3 dB d. 0 dB - Correct Answer-a. If the relative output power of an ultrasound instrument is calibrated in decibels and the operator increases the output by 20 dB. the beam intensity is increased by a. twenty times b. fiver percent c. one hundred times d. one million times - Correct Answer-c. A decrease in power or intensity by a factor of 2 represents a change of a. -3 dB b. -50 dB c. -6 dB d. 3 B - Correct Answer-a.
The Power control on an ultrasound system is set at maximum. The display indicates PWR= 0 dB. If this Power control is used to reduce the intensity by one-half, the display will indicate PWR= a. 2 dB b. 0 dB c. -3 dB d. -6 dB - Correct Answer-c. Sound power is measured in units of a. dB/cm b. mW/cm c. Watts d. W/dB - Correct Answer-c. Which one of the following statements is true about a single pulse of ultrasound from a transducer? a. It contains a range of frequencies b. It contains sound at the resonant frequency of the transducer only c. The shorter the pulse, the narrower the bandwidth d. Sound energy is continuously transmitted - Correct Answer-a. Lateral resolution is determined mainly by a. damping b. beam diameter c. pulse duration d. spatial pulse length - Correct Answer-b. Which one of the following describes Snell's Law? a. Law that describes the angle of transmitted beam b. Law that describes the impedance of two media c. Law that describes the intensity of a reflected beam d. Law that says you have to buckle up - Correct Answer-a.
What principles states that sound is generated from the transducer as wavelets? a. Snell's b. Huygen's c. Kremkau's d. Bernoulli's - Correct Answer-b. What control should be used to correct the image to the right? a. Increase the spectral gain b. Raise the baseline c. Lower the baseline d. Increase the PRF - Correct Answer-d. Which transducer produces the image shape shown to the right? a. flat linear array b. phased array c. curvilinear array d. linear array - Correct Answer-c. Dynamic focusing is possible a. only with transducers with frequencies above 5 MHz b. only with transducer arrays c. the two-element CW Doppler probes d. with single piezoelectric elements - Correct Answer-b. With phased array transducers, the transmitted sound beam is swept by a. mechanically sweeping the piezoelectric elements b. mechanically rotating the piezoelectric elements c. varying the timing of pulses to the individual piezoelectric elements d. varying the frequency of pulses to the individual piezoelectric elements - Correct Answer-c. Which pulsing pattern provides a non-steered beam that is focused?
a. A b. B c. C d. D e. E - Correct Answer-a. A 1.5D transducer has what ability? a. Electronically focus in the elevational plane b. Produce a 3D image c. Dynamic aperture d. Color Doppler imaging - Correct Answer-a. Parenchyma appears on ultrasound as a pattern of gray dots. This interference pattern is a result of a. specular reflectors b. harmonic signals c. acoustic speckle d. large border reflectors - Correct Answer-c. Which of the following frequencies is in the "ultrasound" range? a. 15 MHz b. 15 kHz c. 15 MHz d. 17,000 MHz - Correct Answer-c. Which of the following has the highest relative attenuation? a. bone b. air c. liver d. blood - Correct Answer-b. A small (relative to the wavelength) reflector is said to ______________ an incident sound beam a. focus b. speculate
a. period b. impedance c. beam width d. wavelength - Correct Answer-d. The attenuation of 5 MHz ultrasound in 4 cm of soft tissue is: a. 2.5 dB/cm b. 10 dB c. 2.5 MHz/cm d. 2 cm - Correct Answer-b. Which of the following quantities vary most with distance from the transducer? a. axial resolution b. lateral resolution c. frequency d. period - Correct Answer-b. The lateral resolution of an ultrasound system depends on: a. the aperture b. the transducer frequency c. both a and b d. none of the above - Correct Answer-c. Which of the following is a characteristic of the medium through which a sound is propagating? a. impedance b. intensity c. amplitude d. frequency - Correct Answer-a. Attenuation along a sound path is a decrease in: a. frequency b. amplitude c. wavelength
d. propagation speed - Correct Answer-b. An unfocused, single-element disc transducer that is 13mm in diameter has a diameter at the focal zone of: a. 13 mm b. 6.5 mm c. 26 mm d. cannot be determined - Correct Answer-b. Which of the following has time represented on the X-axis? a. B-mode b. X-mode c. M mode d. A mode - Correct Answer-c. Which of the following produces a rectangular format? a. curvilinear sequenced array b. convex array c. phased array d. linear sequenced array - Correct Answer-d. The piezoelectric effect describes how __________ is converted into ___________ by a ___________. a. electricity; image; display b. ultrasound; heat; tissue c. incident sound; reflected sound; boundary d. ultrasound; electricity; transducer - Correct Answer-d. As frequency is increased: a. a three-cycle ultrasound pulse decreases in length b. wavelength increases c. attenuation decreases d. propagation speed increases - Correct Answer-a. Focusing
b. decibel c. Hertz d. Curie - Correct Answer-b. Pulsed-wave operation is necessary for B-mode imaging because: a. the transducer becomes too hot to handle if continuous wave is used b. the crystal would break with continuously produced sound waves c. the depth to the reflector can be determined d. improved temporal resolution - Correct Answer-c. Which Doppler function controls how many waveforms are displayed on the image at one time? a. sweep speed b. gate size c. scale d. spectral gain - Correct Answer-a. If the number of lines per frame is kept constant, but the pulse repetition frequency is doubled, what is the effect on the maximum frame rate? a. doubled b. halved c. quadrupled d. unchanged - Correct Answer-a. Looking at the image to the right, what type of image mode was used? a. A-mode b. B-mode c. M-mode d. Amplitude mode - Correct Answer-c. Which of the following terms does not belong with the others? a. Increased depth of view b. Decreased duty factor c. Increased pulse repetition period d. Decreased spatial pulse length - Correct Answer-d.
If the power of a wave is halved, the intensity ___________ its original value. a. Is reduced to one-half its original value b. Is reduced to one-fourth its original value c. Is the same as the original intensity and does not change d. Is double its original value - Correct Answer-a. Which of the following will create the fastest speed of sound? a. High density, high stiffness b. Low density, high stiffness c. High density, low stiffness d. Low density, low stiffness - Correct Answer-b. Longitudinal resolution is also called a. Axial b. Azimuthal c. Lateral d. Transverse - Correct Answer-a. Which of the following is the best lateral resolution? a. 15 mm b. 6 mm c. 6 cm d. 2 cm - Correct Answer-b. An increase in the diameter of a transducer results in a(n) ______________ of the near zone length a. increase b. decrease c. no change - Correct Answer-a. To create a transducer with less divergence in the far field, you would use a. a transducer with a larger diameter b. a transducer with a small diameter
d. static B-scanner - Correct Answer-a. Which of the following is true about PRF? a. PRF increases as depth increases b. PRF increases as pulse repetition period increases c. PRF increases as pulse duration increases d. PRF increases as depth decreases - Correct Answer-d. What is the component of an ultrasound system that is made rout of lead zirconate titanate? a. Transducer's matching layer b. Transducer's active element c. Transducer's damping material d. Insulation - Correct Answer-b. Two ultrasound systems produce pulses. One pulse is 0.4 microseconds in duration and the other is 0.2 microseconds. Which pulse is most likely to produce the best radial resolution? a. 0.4 microsecond system b. 0.2 microsecond system c. They are not the same d. Cannot be determined - Correct Answer-b. Which of the following is proportional to the square of the amplitude? a. Period b. Impedance c. Power d. Frequency - Correct Answer-c. Which of the following will produce a transducer with a high Q-factor? a. Heavily damped transducer b. Pulsed-wave operation c. Wide bandwidth transducer d. Continuous-wave transducer - Correct Answer-d.
For perpendicular incidence, if the impedances of the media are the same, there will be no a. Reflection b. Refraction c. Inflection d. Transmission - Correct Answer-a. The output gain of an ultrasound pulser determines the __________ of the acoustic pulse. a. Imaging depth b. Intensity c. Duration d. Pulse repetition period - Correct Answer-b. What is the term for adjusting the attenuation related to path length? a. Compression b. Compensation c. Confirmation d. Condensation - Correct Answer-b. With an oblique incidence, if the propagation speeds of two media are equal, incidence angle equals a. Reflection angle b. Transmission angle c. A and B d. None of the above - Correct Answer-c. Which of the following tasks is incorporated in the process of demodulation? a. Compression b. Rectification c. Amplification d. Rejection - Correct Answer-b. Which of the following is true about digital signals?
