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Definition
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Term
| How much bigger is a billion than a million? |
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Definition
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Term
| How many milliliters are contained in a jar filled with 5 liters of fluid? |
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Definition
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| How many liters are in 80 ml of fluid? |
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Definition
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| What is 10 negative to 6 divided by 10 to negative 3? |
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Definition
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| What is 10 to negative 6 seconds divided by 10 to negative 3 seconds? |
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Definition
| 10 to negative 3 (note: subtract top from bottom and keep signs as they are the same) |
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Term
| What is 10 to the negative 6 times 10 to the negative 3? |
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Definition
| 10 to the negative 3 (note: add like signs when multiplying) |
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Term
| What are the units of wavelength? |
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Definition
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Term
| What are the units for frequency? |
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Definition
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Term
| What are the units for intensity? |
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Definition
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| What are the units for propagation speed? |
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Definition
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Term
| What are the units for period? |
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Definition
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| What are the units for power? |
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Definition
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| Does the medium or the sound source determine wavelength? |
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Definition
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Term
| Does the medium or the sound source determine frequency? |
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Definition
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Term
| Does the medium or the sound source determine intensity? |
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Definition
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Term
| Does the medium or the sound source determine propagation speed? |
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Definition
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Term
| Does the medium or the sound source determine period? |
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Definition
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Term
| Does the medium or the sound source determine power? |
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Definition
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Term
| Using a particular ultrasound system, whic of the following cannot be changed by the operator? |
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Definition
wavelength cannot
amplitude can
intensity can
propagation speed cannot
period cannot
power can |
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Term
| True or False: Sound is a transverse, mechanical wave. |
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Definition
| FALSE - it is a longitudinal, mechanical wave |
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Term
| True or False: A wave with a frequency of 15,000 MHz is ultrasonic. |
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Definition
| TRUE - Ultrasound is any wave greater than 20,000 HERTZ. |
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Term
| The power in a beam is one watt and the area is 5cm squared. What is the beam's intensity? |
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Definition
| Note: intensity is watts/cm squared, so 1/5 = .2 |
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Term
| If intensity remains the same while the power is double, what happens to intensity? |
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Definition
| Note: Power=Intensity, so Intensity also doubles |
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Term
A sound beam travels a total of 10cm in 2 seconds. What is the speed of the sound in this medium?
a) 10cm/sec
b) 2cm/sec
c) 5cm/sec
d) .2cm/sec |
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Definition
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| TRUE OR FALSE Speed increases as frequency increases. |
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Definition
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Term
What happens to the speed of sound when the bulk modulus increases?
a) faster
b) slower
c) remains the same |
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Definition
| C) faster. Note: bulk modulus is the same as stiffness (Speed up/Stiffness up) Speed down, Density down |
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Term
| The effects of ultrasound upon tissue is called? |
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Definition
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Term
Which of the following waves will have the shortest wavelength?
a) low freq traveling in a fast medium
b) low freq in a slow medium
c)high freq in a fast medium
d) high freq in a slow medium |
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Definition
| d) high freq in a slow medium |
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Term
Which of the following characteristics 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 |
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Definition
| b) low density, high stiffness |
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Term
Which of the following waves is ultrasonic and is LEAST useful in diagnostic imaging?
a) 8MHz
b) 2.5 MHz
c) 18,000 Hz
d) 24,000 Hz
e) 3,000,000 Hz |
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Definition
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Which of the following waves is ultrasonic and MOST useful in diagnostic imaging?
a)2,455,000 Hz
b) 100 MHz
c)2.4 kHz
d) 14,000 Hz |
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Definition
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Term
Which of the waves has the longest wavelength?
a) low freq
b) low amplitude
c) high freq
d) high intensity |
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Definition
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Term
TRUE OR FALSE
If the amplitude of a wave in increased to 3 times its original value, the intensity is increased by 6 times. |
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Definition
FALSE
note: amplitude squared! so 3 squared is 9, not 6 |
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Term
TRUE or FALSE
If the power of a wave is halved, the intensity is reduced to 1/4 its original value. |
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Definition
FALSE
note: Power=Intensity, so intensity is halved |
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Term
| If frequency of sound is doubled, what happens to wavelength? |
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Definition
wavelength is halved
Formula:
wavelength - Speed (C)/Frequency
so wavelength and speed are direct relationships while wavelength and frequency are inverse |
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Term
A sonographer adjusts the depth of view of an U/S scan from 8cm to 16 cm. What happens to each of the following parameters? Do they increase? decrease or remain the same?
a) period
b) frequency
c)wavelength
d) speed
e) amplitude
f) power
g) intensity
h) pulse duration
i) PRF
j) duty factor
k) spatial pulse length
l) pulse repetition period |
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Definition
All remain the same except:
PRF & Duty Factor DECREASE
PRP INCREASES |
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Term
A sonographer using a 3 MHz transducer switches to a 6MHz transducer. The imaging depth remains unchanged. What will happen to each of the following parameters? Increase, decrease or remain the same?
period
frequency
wavelength
speed
amplitude
power
intensity
PRF
PRP |
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Definition
period and wavelength decrease
frequency increases
rest remains the same |
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Term
A sonographer is using a 3MHz transducer and increases the output power in order to visualize structures deeper in the patient. No other controls are adjusted. What happens to each parameter, increase, decrease or remain the same?
a) period
b) frequency
c)wavelength
d) speed
e) amplitude
f) power
g) intensity
h) pulse duration
i) PRF
j) duty factor
k) spatial pulse length
l) pulse repetition period |
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Definition
All remain the same
except for amplitude, power and intensity increase (bigness parameters) |
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Term
| What is the duty factor of a 7MHz continuous wave sound beam at a depth of 10cm? |
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Definition
1.0
The duty factor of continuous wave sound is 1. |
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Term
| Name the three components of attenuation. Which of these 3 components is the dominant contributor to attenuation? |
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Definition
| Absorption, reflection and scattering. Absorption is the dominant contributor. |
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Term
| As the path length increases, attenuation in soft tissue ________. |
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Definition
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Term
| Total attentuation in soft tissue is related to _______ and _______. |
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Definition
path length (how far it travels)
and frequency |
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Term
| Attentuation in lung tissue is ________ (less than, greater than or same) in soft tissue. |
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Definition
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Term
| Attentuation in bone is _______ than soft tissue. |
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Definition
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| Attenuation in air is ________ than soft tissue. |
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Definition
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Term
| Attenuation in water is __________ than in soft tissue. |
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Definition
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Term
| What are the units of attenuation? |
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Definition
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Term
| What is the relationship between frequency and attenuation coefficient in soft tissue? |
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Definition
| In soft tissue the attenuation coefficient in DB per cm is about .5 times the u/s frequency in MHz. |
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Term
| Impedance is a characteristic of ______? |
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Definition
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Term
| As the path length increases. the attenuation coefficient of U/S in soft tissue ___________? |
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Definition
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Term
| Impedance is important in __________ at boundaries. |
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Definition
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Term
| Acoustic impedance = _______ x _______? |
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Definition
| density and propagation speed |
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Term
| Which is better to use while examining a carotid artery, 7.5 MHz or 3.0 MHz |
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Definition
| Because the structure is superficial, the 7.5MHz is best. |
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Term
| In soft tissue, attenuation coefficient is directly related to _______? |
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Definition
| frequency (If frequency doubles, Atten Coeff doubles) |
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Term
| Rayleigh scattering is related to ______? |
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Definition
frequency to the 4th
(if freq doubles, Rayleigh scattering increases by a factor of 16 - 2x2x2x2 = 16) |
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Term
| What does 100mW/cm squared stand for? |
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Definition
| THe incident intensity of the u/s beam. Units of W/cm squared should tell us this. |
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Term
| What does the 3.5dB/cm represent? |
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Definition
| Attenuation coefficient of the sound in the media, because the units are dB/cm. |
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Term
| If the media are soft tissue, what is an estimate of the U/S frequency? |
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Definition
| Approximately 7MHz, the attenuation coefficient multiplied by 2 approximates the frequency (3.5 x 2 = 7) |
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Term
| What property of units is Rayls? How is it determined? |
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Definition
| Impedance (impedance = density x propagation speed). Impedance is calculated. |
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Term
Which of these media have the greatest attentuation and the slowest speed?
a) bone
b) tendon
c) fat
d) air |
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Definition
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Term
Which of these media have the greatest attenuation and the fastest speed?
a) bone
b) tendon
c) lung
d) fat
e) air |
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Definition
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Term
Which of the following mathematically describes the physics of refraction?
a) Bernouille's principle
b) Snell's Law
c) Pouseille's Law
d) Murphy's Law
e) Bernouille's Law |
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Definition
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Term
Which of the following terms does not belong with the others?
a)oblique
b) normal
c) perpendicular
d) orthogonal
e) 90 degrees |
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Definition
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Term
Which of the following terms best describes a reflection arising from a rough boundary?
a) non-diffuse
b) absolute
c) Rayleigh
d) smooth
e) non-specular |
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Definition
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Term
A sound wave strikes a boundary between 2 media with different impedances. The angle of incidence is non-orthogonal. Which of he following statements is most correct?
a) all sound will be reflected
b) some of the sound will be reflected
c) some of the sound MAY be reflected
d) some of the sound will be refracted
e) some of the sound MAY be refracted |
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Definition
| c) some of the sound may be reflected |
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Term
When a transducer is covered with a sterile cover with gel on the inside, what can the transducer not come in contact with in order to produce an image?
a) gel
b) water
c)talcum powder
d) sterile liquid
e) lubricating gel |
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Definition
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Term
| T or F: If the frequency of the electrical excitation voltage of a oulsed wave transducer 6MHz, the main or center frequency of the transducer is 6MHz. |
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Definition
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Term
| T or F: If the PRF of a transducer is increased, the frequency of the transducer remains the same. |
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Definition
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Term
| T or F: The diameter of the active element of the transducer helps determines the frequency. |
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Definition
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Term
| T or F: If the frequency of the electrical excitation voltage of a continuous wave transducer is 6MHz, the main or center frequency of the transducer is 6MHz. |
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Definition
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Term
| T or F: Two piezoelectric crystals are made from the same material. The thicker crystal will make the transducer a higher frequency. |
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Definition
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Term
| For a pulsed wave transducer, if the PZT crystal thickness is doubled, the frequency of sound is halved. |
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Definition
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Term
| T or F: The normal propagation speed for piezoelectric material is approximately 3-5 times greater than soft tissue. |
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Definition
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Term
| T or F: The acoustic impedance of the matching layer equals the acoustic impedance of skin. |
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Definition
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Term
| T or F: A broadband transducer is more characteristic than a narrow bandwidth for imaging transducers. |
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Definition
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Term
| T or F: A very high "Q" factor transducer is more common than low "Q" factor for diagnostic imaging. |
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Definition
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Term
The impedance of a transducer active element is 1,900,000 rayls, and for bthe skin is 1,400,000 rayls. What is an acceptable impedance for the matching layer?
a) 1,200,000 rayls
b) 1,400,000 rayls
c) 1,726,000 rayls
D) 1,950,000 rayls |
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Definition
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Term
T or F for each:
The damping material in a transdcuer acts to:
a) increase the sensitivity
b) increase pulse length
c) decrease pulse duration
d) improve lateral resolution
e) improve longitudinal resolution
f) narrows bandwidth
g) decrease quality factor |
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Definition
| a)F b)F c)T d)F e)T f)F g)T |
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Term
With a pulsed wave transducer, which of the following occurs if the PZT is halved?
a) increase the pulse length
b)frequency is doubled
c) frequency is halved |
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Definition
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Term
With a pulsed wave transducerm which of the following occurs is the thickness of the PZT crystal is doubled?
a)increase in pulse length
b) frequency is doubled
c) frequency is halved |
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Definition
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Term
Which of the following does not fit with the others?
a) broadband
b) backing material
c) short pulse
d) good lateral resolution
e) low Q |
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Definition
| d) good lateral resolution |
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