Free SPI (Physics) Practice Test

10 Free SPI (Physics) Practice Questions

1. In an ultrasonic wave traveling through soft tissue, the particles vibrate in the same direction as the wave's movement. What is the most accurate way to characterize this type of wave?

   1. Mechanical and Longitudinal
   2. Mechanical and Transverse
   3. Electromagnetic and Longitudinal
   4. Electromagnetic and Transverse
   Show Answer & Explanation

   Correct answer: Mechanical and Longitudinal

   The correct answer is Mechanical and Longitudinal. A mechanical wave is a wave that requires a medium to propagate, such as soft tissue. A longitudinal wave is a wave in which the particles of the medium vibrate parallel to the direction of the wave's propagation. An example of a longitudinal wave is sound. A transverse wave is a wave in which the particles of the medium vibrate perpendicular to the direction of the wave's propagation. An example of a transverse wave is light. An electromagnetic wave is a wave that does not require a medium to propagate, such as light or radio waves.

2. What is the main disadvantage of using persistence in sonographic imaging of rapidly moving structures?

   1. Relevant abnormalities may be concealed
   2. Increased noise in the image
   3. Reduced image quality
   4. Increased image distortion
   Show Answer & Explanation

   Correct answer: Relevant abnormalities may be concealed

   When using persistence with rapidly moving structures, relevant abnormalities can be concealed, and a low persistence must be selected.

3. What is the primary advantage of using autocorrelation in color flow Doppler imaging over Fast Fourier Transform (FFT)?

   1. Greater depth penetration
   2. Higher accuracy in velocity estimation
   3. Faster processing of Doppler shift information
   4. Better visualization of blood flow
   Show Answer & Explanation

   Correct answer: Faster processing of Doppler shift information

   Autocorrelation allows for faster processing of Doppler shift information in color flow Doppler imaging compared to Fast Fourier Transform (FFT).

4. What can cause two closely spaced reflectors to appear as one reflector in ultrasound imaging?

   1. Refraction
   2. Reverberation
   3. Acoustic speckle
   4. Resolution artifacts
   Show Answer & Explanation

   Correct answer: Resolution artifacts

   Resolution artifacts (axial, lateral) can cause two closely spaced reflectors to appear as one reflector in ultrasound imaging.

5. Which artifact is caused by the beam not being extremely thin, leading to unintended echoes appearing in the image?

   1. Multipath
   2. Mirror Image Artifact
   3. Reverberation
   4. Slice Thickness Artifact
   Show Answer & Explanation

   Correct answer: Slice Thickness Artifact

   Slice Thickness Artifact occurs when the ultrasound beam is not extremely thin, causing echoes from structures located above or below the intended imaging plane to be included in the image. This leads to unintended echoes appearing in the image, which can affect diagnostic accuracy.

6. What is the primary factor affecting lateral resolution in ultrasound imaging?

   1. Pulse repetition frequency
   2. Receive focus
   3. Sector width
   4. Beam width
   Show Answer & Explanation

   Correct answer: Beam width

   Lateral resolution is affected by beam width and transducer frequency, with narrower beams and higher frequency transducers providing optimal lateral resolution.

7. Which of the following best describes how much resistance an ultrasound beam encounters as it passes through the medium?

   1. Reflection coefficient
   2. Attenuation coefficient
   3. Speed of sound
   4. Acoustic impedance
   Show Answer & Explanation

   Correct answer: Acoustic impedance

   Acoustic impedance is the measure of the resistance that an acoustic wave encounters as it travels through a medium. It is a product of the density of the medium and the speed of sound within that medium.

8. How does persistence affect the resulting live image in sonography?

   1. It appears smoother and less wobbly
   2. It appears with reduced clarity
   3. It appears more distorted
   4. It appears with more noise
   Show Answer & Explanation

   Correct answer: It appears smoother and less wobbly

   Persistence defines how much of the previous image is taken over into the current frame, making the resulting live image appear smoother and less wobbly.

9. What is used in Pulsed Wave Doppler to process Doppler shift information from a specific depth location?

   1. Doppler angle
   2. Output power
   3. Pulse length
   4. Range gating
   Show Answer & Explanation

   Correct answer: Range gating

   Pulsed Wave Doppler utilizes range gating to process Doppler shift information from a particular depth location chosen by the sonographer.

10. What can cause mirroring in Doppler spectral artifacts?

    1. Decreased sample gate size
    2. Decreased Doppler transmit gain
    3. Decreased sound beam diameter
    4. Excessive Doppler transmit gain or poor intercept angle
    Show Answer & Explanation

    Correct answer: Excessive Doppler transmit gain or poor intercept angle

    Mirroring can be caused by excessive Doppler transmit gain and/or a poor intercept angle.