Comprehensive Exam Flashcards
The speed of u/s in soft tissue is closest to: A. 1,540km/sec B. 1.54km/msec C. 1,500m/s D. 1,540mm/sec
C
Sound waves are: A. Electric B. mechanical, transverse C. Spectral D. Longitudinal, mechanical
D
The frequency closest to the lower limit of u/s is A. 19,000kHz B. 10,000MHz C. 20,000msec D. 15,000Hz
D
Which is not an acoustic variable? A. Density B. pressure C. Distance D. Intensity
D
The effects of soft tissue on u/s are called A. Acoustic proliferation properties B. dynamic effects C. Acoustic propagation properties D. Biological effects
C
All of the following are true except:
A. Two waves with identical freq must interfere constructively
B. constructive interference is associated with waves that are in-phase
C. Out-of-phase waves interfere destructively
D. Waves of different freq may exhibit both constructive and destructive interference at different times
A
Put in decreasing order A. Deca B. deci C. Micro D. Centi
A b d c
----- is the time to complete one cycle A. Pulse duration B. pulse period C. Period D. Duration period
C
Which of the following sound waves is ultrasonic and least useful in diagnostic imaging? A. 30 kHz B. 8 MHz C. 8,000 Hz D. 3,000 kHz E. 15 Hz
A
What is the freq of a wave with 1 msec period? A. 10,000 Hz B. 1,000 kHz C. 1 kHz D. 1 MHz
C
----- is the distance covered by one cycle. A. Pulse length B. wavelength C. Cycle distance D. Cycle duration
B
Which of the following is determined by the sound source and the medium? A. Frequency B. period C. Propagation speed D. Range resolution
D
Propagation speed =\_\_\_\_ x wavelength A. Pulse duration B. period C. Number of cycles in pulse D. Frequency
D
As a result of ____ the propagation speed increases.
A. Increasing stiffness and increasing density
B. increasing stiffness and increasing elasticity
C. Decreasing compressibility and decreasing density
D. Decreasing stiffness and decreasing density
C
Put in decreasing order of propagation speed
A. Gas
B. liquid
C. Solid
C b a
If the frequency of u/s is increased from 0.77MHz to 1.54MHz, what happens to the wavelength? A. Doubles B. halved C. Remains same D. 4 times greater
B
A sound wave's frequency is 10MHz. The wave is traveling in soft tissue. What is it's wavelength? A. 0.15 mm B. 1.54 mm C. 0.77 mm D. 10 MHz
A
If the frequency of an u/s wave is doubled, what happens to the period? A. Doubles B. halved C. Remains same D. 4 times greater
B
If the frequency of u/s is increased from 0.77 MHz to 1.54 MHz. What happens to the propagation speed? A. Doubles B. halved C. Remains same D. 4 times greater
C
The units of pulse repetition frequency are A. Per minute B. Msec C. mm/us D. MHz
A
The time from the beginning of a pulse until it's end is \_\_\_? A. Period B. pulse duration C. Pulse length D. PRF
B
What happens to the speed of sound in a medium when the bulk modulus of the medium increases?
A. Faster
B. slower
C. Unchanged
A
\_\_\_\_ resolution is determined by the spatial pulse length. A. Radial B. image C. Axial D. Angular
A or c
If a waves amplitude is doubled, what happens to the power? A. Nothing B. halved C. Doubled D. Quadrupled
D
Power of sound has units of A. dB B. dB/cm C. Watts D. Watts/cm2
C
If the intensity of a sound beam remains unchanged while the beam area is reduced in half, what has happened to the power? A. Quadrupled B. doubled C. Halved D. Unchanged
C
Which of these intensities is smallest?
A. SATP
B. SPTP
C. SATA
C
The duty factor for continuous wave u/s is A. 10.0 B. 1% C. 1.0 D. 0.0%
C
What is the minimum value of the duty factor? A. 10.0 B. 1% C. 1.0 D. 0.0
D
What are the units of intensity? A. Watts B. dB C. Watts/cm2 D. dB
C
What happens to the speed of sound in a medium when the bulk modulus of the medium decreases?
A. Faster
B. Slower
C. Unchanged
B
The units of attenuation are \_\_\_; this is a \_\_\_\_ scale. A. mm/cm, parametric B. dB/m, multiplicative C. None, relative D. dB, logarithmic
D
Sound intensity is decreased by 75%. How many decibels of attenuation is this? A. 6 dB B. 9 dB C. 5 dB D. 10 dB
A
The fundamental frequency of a transducer is 2.5 MHz. What is the second harmonic frequency? A. 1.25 MHz B. 4.5 MHz C. 5 MHz D. 5 cm
C
A pulse is emitted by a transducer and is traveling in soft tissue. The go-return time, or time of flight, of a sound pulse is 130 microseconds. What is the reflector depth? A. 10cm B. 10 mm C. 10 m D. 130 mm E. 13 cm
A
If a 5 MHz sound wave is traveling in the tissues listed below, which will have the longest wavelength? A. Fat B. Air C. Muscle D. Bone
D
If a 5 MHz sound wave is traveling in the tissues listed below, which will have the shortest wavelength? A. Fat B. Air C. Muscle D. Bone
B
What is the approximate attenuation coefficient of 1 MHz u/s in soft tissue? A. 0.5 dB/cm B. 1 cm C. 3 dB/cm D. 1 dB
A
The rayl is the unit of: A. Intensity B. Reflectance C. Density D. Impedance
D
Impedance is the \_\_\_\_ of \_\_\_\_ and \_\_\_. A. Product, propagation speed, density B. Sum, stiffness, density C. Quotient, stiffness, propagation speed D. Difference, attenuation, density
A
What are attenuations three components?
Scattering
Reflection
Absorption
For soft tissue, the approximate attenuation coefficient in dB/cm is equal to one-half \_\_\_\_ in \_\_\_\_. A. Wavelength, mm B. Frequency, Hz C. Frequency, MHz D. Impedance, Rayls
C
As the impedance of two media become vastly different, the A. Reflection increases B. Transmission increases C. Refraction increases D. Absorption increases
A
The angle between an u/s pulse and the boundary between two media is 90' . What is this called? A. Direct incidence B. Oblique incidence C. Indirect incidence D. Orthogonal incidence
D
The angle between an u/s pulse and the boundary between two media is 56'. What is this called? A. Direct incidence B. Oblique incidence C. Indirect incidence D. Orthogonal incidence
B
Refraction only occurs if there are:
A. Normal incidence & different impedances
B. Indirect intensity & different propagation speeds
C. Oblique incidence & different propagation speeds
D. Oblique frequency & identical impedances
C
With normal incidence, what factors affect refraction of u/s? A. Propagation speeds B. Frequencies C. Attenuation coefficients D. None of the above
D
(True or false) with right angle incidence, reflections are always generated at a boundary if the propagation speeds of the media are different
False
\_\_\_\_ is redirection of u/s in many directions as a result of rough boundary between two media. A. Refraction B. Rayleigh scattering C. Scattering D. Reflection
C
Which of the following tissues is most likely to create Rayleigh scattering? A. Red blood cells B. Muscle C. Fat D. Bone
A
(True or false) with normal incidence the angle is 180’
False
Under which of the following conditions is axial resolution improved? A. Decrease spatial pulse length B. Decrease pulse amplitude C. Decreased imaging depth D. Decrease pixel size E. Decrease beam diameter
A
Snell's law describes physics of \_\_\_\_\_. A. Ultrasound B. Reflection C. Refraction D. Transmission
C
The most likely amount of reflection at a boundary between soft tissues is: A. 1% B. 22% C. 34% D. 99%
A
The most typical amount of transmission at a boundary and biological media is: A. 1% B. 22% C. 34% D. 99%
D
Sound is traveling from medium 1 to medium 2. Propagation speeds of M1 and M2 are 1,600 m/s and 1,500 m/s, respectively. there is normal incidence.
A. angle of incidence > angle of reflection
B. angle of incidence = angle of reflection
C. angle of incidence
B
(true or false) Doppler shifts always occur if the sound source and receiver are in motion
False
The following is associated with power mode Doppler?
A. poor temporal resolution and flash artifact
B. lower sensitivity and good temporal resolution
C. high sensitivity and high frame rates
D. flash artifact and reduce sensitivity
E. good temporal resolution and flash artifact
A
The doppler shift is a measure of:
A. ratio of incident frequency to reflector frequency
B. sum of incident frequency and reflected frequency
C. difference between incident and reflected frequency
D. product of incident and reflected frequencies
C
(true or false) the sonographer cannot change, directly or indirectly, the duty factor of an u/s machine
False
(true or false) there have not been biological effects from u/s found in the laboratory
False
Depth calibration of the machine measures 100mm spaced wires to be 90mm apart. Scanning reflectors 50mm apart. what will the machine calculate the distance to be? A. 40 mm B. 45 mm C. 60 mm D. 65 mm
B
what has the correct order? Mega- milli- kilo- micro A. 10^6 10^-6 10^3 10^-3 B. 10^-6 10^6 10^2 10^-3 C. 10^6 10^-3 10^3 10^-6 D. 10^6 10^-6 10^3 10^-4
C
How many cm are 60 millimeters? A. 600 B. 6 C. 0.6 D. 0.06
B
(true or false) lateral resolution is also called axial
False
(true or false) lateral resolution is also called azimuthal
True
(true or false) lateral resolution is also called longitudinal
False
(true or false) lateral resolution is also called range
False
which has the correct units?
freq speed intens atten
A. Hz mm/s joules dB/cm
B. mHz m/sec W/cm2 dB
C. kHz mm/us W/cm3 dB/cmB
What increases patient exposure? A. exam time B. frequency C. video taping D. wavelength
A
(true or false) Shadowing may result from high amounts of reflection of u/s energy.
True
Where are harmonics created? A. in the receiver B. in the transducer C. in the tissues D. in the beam former
C
How is range ambiguity artifact eliminated? A. lower PRF B. raise PRF C. increase gain D. use lower frequency transducer
A
how is lateral resolution measured if this test object is scanned from the top
Pin Image
A * ____
B * __
C * ______
D * _________
E * ____________
A. measure the distance from A to E
B. measure the length of time of line C and divide by 2
C. measure the length of line B
C
