UH
1. A sound wave is moving through the body and travel from muscle to blood. What percentage of the sound wave is most likely to be transmitted at the muscle-blood boundary?
a. 5%
b. 75%
c. 99%
d. 0.5%
d. 99%
2. Which of the following interfaces will produce the smallest amount of transmission?
a. Blood-muscle
b. Liver-air
c. Bone-tendon
d. Fat-liver
b. Liver-air
3. Which of the following is the best estimate for attenuation coefficient in soft tissue?
a. 1.0 dB/cm/MHz
b. 0.55 dB/cm/MHz
c. 1.54 dB/cm/MHz
d. 0.77 db/cm/MHz
b. 0.55 dB/cm/MHz
6. In which of the following media does ultrasound attenuate the least?
a. Blood
b. Bone
c. Lung
d. Water
d. Water
32. Which of the following is not a mechanism related to attenuation?
a. Tissue heating
b. Scattering
c. Transmission
d. Absorption
c. Transmission
34. Another way of describing a 90o incident angle of sound to a reflector is:
a. Acute angle
b. Obtuse angle
c. Right angle
d. Transmission angle
c. Right angle
25. If the angle of incidence is 30o and a reflection off a smooth boundary is made, what is the closest estimate of the angle of reflection?
a. 60o
b. 30o
c. Unable to determine
d. 45o
b. 30o
13. What does SPTA stand for?
a. Spatial peak thermal average
b. Spatial partial time average
c. Spatial peak temporal average
d. Spatial pulse thermal aperature
c. Spatial peak temporal average
8. A sound wave is traveling in the body and moves from muscle to air. What percentage of the sound wave is most likely to be transmitted at the muscle-air boundary?
a. 99%
b. 5%
c. 75%
d. 0.5%
d. 0.5%
22. Which of the following lists shows the correct order of increasing attenuation?
a. Water, blood, soft tissue, fat, muscle, bone, air
b. Water, blood, fat, muscle, soft tissue, bone, air
c. Water, fat, soft tissue, muscle, bone, air
d. Blood, fat, muscle, soft tissue, bone, air
c. Water, fat, soft tissue, muscle, bone, air
9. Impedance is associated with:
a. Medium and distance traveled
b. Medium and operating frequency
c. Speed x distance
d. Medium only
d. Medium only
38. As frequency increases, attenuation:
a. Decreases
b. Increases
c. Remains the same
d. Definitely something
b. Increases
4. A reflection is created when a 2 MHz wave travels from medium 1, with an impedance of 100 rayls into medium 2, with an impedance of 70 rayls. If the Sonographer uses a higher frequency transducer, how will the impedance mismatch of medium 1 and 2 be affected?
a. Decrease
b. Increase
c. Remains the same
d. Unable to be determined from given information
c. Remains the same
39. The term spatial refers to:
a. Space
b. Time
c. Intensity
d. Attenuation
a. Space
29. With rayleigh scattering, in which direction are the sound waves reflected?
a. Definitely somewhere
b. Back toward the transducer
c. In the forward direction of propagation
d. In all directions
d. In all directions
11. The attenuation coefficient in soft tissue is equal to:
a. The total decibels
b. Twice the operating frequency
c. Frequency x path length
d. 1/2 the operating frequency
d. 1/2 the operating frequency
15. In soft tissue, which of the following is the best estimate for the attenuation coefficient of a 4 MHz sound wave with a PRF of 10 kHz?
a. 10 dB/cm
b. 1.96 dB/cm
c. 40 dB
d. 1.96 dB
b. 1.96 dB/cm
36. Speed x density describes the formula for calculating a mediums:
a. IRC
b. ITC
c. Attenuation
d. Impedance
d. Impedance
21. What is the total attenuation of 6 MHz sound traveling a total of 3 cm?
a. 3 dB/cm
b. 9 dB/cm
c. 9 dB
d. 18 dB
c. 9 dB
Ac xx distance
(1/2f) xx distance
26. Snell's law describes which acoustic phenomenon?
a. Reflection
b. Transmission
c. Refraction
d. Impedance
c. Refraction
5. 10 MHz sound is traveling in a medium and strikes a boundary. If 1% of the wave's intensity is reflected back toward the transducer, what's the IRC and ITC?
a. IRC 0.1; ITC 0.9
b. IRC 0.11; ITC 0.99
c. IRC 1%; ITC 99%
d. IRC 99%; ITC 1%
c. IRC 1%; ITC 99%
27. The relative measurement of the strength of a sound beam may be reported in which of the following units?
a. Pascals
b. Hertz
c. Decibels
d. cm/s
c. Decibels
17. As frequency decreases, depth of penetration:
a. Increases
b. Decreases
c. Remains the same
d. They are unrelated
a. Increases
42. For a 12 MHz sound wave traveling in soft tissue to a depth of 5 cm, the Attenuation Coefficient (Ac) is:
a. 60 dB
b. 6 dB/cm
c. 30 dB
d. 12 cm/dB
b. 6 dB/cm
30. Which of the following reported intensities is used when referring to bioeffects?
a. SPTP
b. SPTA
c. SATP
d. SATA
b. SPTA
16. Which of the following reported intensities is the highest?
a. SPTP
b. SPTA
c. SATP
d. SATA
a. SPTP
43. A sound wave is traveling in the body and moves from muscle to air. What percentage of the sound wave is most likely to be reflected at the muscle-air boundary?
a. 99%
b. 5%
c. 75%
d. 0.5%
a. 99%
19. Which of the following conditions must be present for refraction to occur?
a. Different densities and normal incidence
b. Different impedances and different densities
c. Identical speeds and different densities
d. Different speeds and oblique incidence
d. Different speeds and oblique incidence
37. In soft tissue which of the following will result in the lowest amount of attenuation?
a. Frequency 4 MHz, path length 4 cm
b. Frequency 4 MHz, path length 8 cm
c. Frequency 2 MHz, path length 4 cm
d. Frequency 2 MHz, path length 9 cm
e. Frequency 8 MHz, path length 9 cm
c. Frequency 2MHz, path length 4 cm
35. A sound wave traveling in the body strikes a very smooth boundary. A portion of the acoustic energy is redirected back towards the skin surface. Which of the following terms best describes the redirected energy?
a. Rayleigh scattering
b. Specular reflection
c. Backscatter
d. Speckle
b. Specular reflection
10. The maximum imaging depth during an ultrasound exam is 3 cm. The Sonographer adjusts the imaging depth to 6 cm. What happens to the PRF?
a. Decreases
b. Remains the same
c. Increases
d. Increases by 1/2
a. Decreases
28. What is the total attenuation of 2 MHz sound that traveled a total distance of 8 cm?
a. 4 dB/cm
b. 8 dB
c. 16 dB
d. 24 dB
b. 8 dB
Ac xx d
(1/2f) xx d
14. Which of the following statements about decibels (dB) is not true?
a. +10 dB increases intensity 10 times
b. -3 dB decreases the intensity by a factor of 2
c. Two intensities are needed to report in dB
d. Decibels are an absolute scale of measurement
d. Decibels are an absolute scale of measurement
Which of the following has the lowest value?
a. SPTA
b. SATP
c. SATA
d. SAPA
c. SATA
What is Zach's favorite color?
Royal blue obvi
Come to the board and label the pulse, amplitude, and pulse repetition frequency.
Slay.
What is the most common type of attenuation?
a. Scattering
b. Absorption
c. Reflection
d. Definitely something else
b. Absorption
12. A sound beam strikes a boundary between two media. 70% of the sound beam's intensity is reflected at the boundary. The angle of incidence is 42o, what is the angle of the reflection?
a. 42o
b. 70o
c. 58o
d. 30o
a. 42o
33. Increases in Rayleigh scattering will occur with:
a. Increased frequency
b. Decreased PRF
c. Increased wavelength
d. Decreased duty factor
a. Increased frequency
23. If the impedance of medium 1 = 20 rayls and medium 2 = 100 rayls, is the IRC going to be larger using a 2 MHz or 10 MHz transducer?
a. The same
b. Increased
c. Decreased
d. A fourth option, idk lmao
a. The same
20. A sound wave with an intensity of 50 mW/cm2, strikes a boundary with normal incidence. Which of the following characteristics will determine whether reflection occurs at the interface?
a. Different stiffness of the media on either side of the boundary
b. Different impedances of the media on either side of the boundary
c. Different thermal indexes of the media on either side of the boundary
d. Different speeds of the media on either side of the boundary
b. Different impedances of the media on either side of the boundary
What are the two main factors that determine the amount of attenuation?
Path length (distance), Frequency
40. A sound wave traveling in the body strikes a boundary with slight degree of roughness. These irregularities have the same general dimensions as the wavelength of the sound beam. A portion of the acoustic energy is redirected back toward the surface of the skin. This best describes:
a. Specular reflection
b. Rayleigh scattering
c. Diffuse reflection
d. Huygen's principle
c. Diffuse reflection
18. In soft tissue, which of the following are most important with regard to attenuation?
a. Path length and PD
b. PD and PRP
c. Frequency and path length
d. PRF and frequency
e. DF and frequency
c. Frequency and path length
Ac xx d
(1/2f) xx d
24. A Sonographer is scanning a patient with a 3 MHz probe and then replaces it with a 6MHz probe. Which of the following statements is correct?
a. Both beams will travel the same speed
b. The 6 MHz sound beam will have a longer period than the 3 MHz beam
c. The 3 MHz sound beam will have a shorter wavelength than the 6 MHz
d. The 6 MHz sound will travel through the tissues twice the speed of the 3 MHz sound
a. Both beams will travel the same speed
7. A sound wave traveling in the body strikes a boundary with a slight degree of roughness. These irregularities are about the same size as the sound's wavelength. Part of the sound energy is redirected back towards he skin surface in an unorganized way. The redirected energy is best described as:
a. Specular reflection
b. Rayleigh scattering
c. Huygen's reflection
d. Speckle
e. Backscatter
e. Backscatter
31. A sound beam strikes a boundary between two media. The impedance of the first medium is 14 Mrayls. 70% of the sound beam's intensity is reflected at the boundary. The angle of incidence is 42o. What percentage of the sound beams intensity is transmitted?
a. 70%
b. 100%
c. 30%
d. 0%
c. 30%
What are the 7 acoustic parameters?
Frequency, Period, Wavelength, Speed, Amplitude, Power, Intensity