Physics tests Flashcards
1
Q
supine means that you are
A
Laying flat on your back
2
Q
True or False
Stenosis will have increased velocity within the stenosis
A
True
3
Q
Tissue vibration associated with turbulence is called a
A
Thrill
4
Q
Pressure energy is a form of _____________ energy
A
Potential
5
Q
Turbulent flow profiles may be seen __________ from a significant stenosis in a vessel
A
Downstream
6
Q
True or False
Plug flow is the velocity in the center of the lumen and gradually decreases to its minimum at the vessel wall
A
False
7
Q
The three basic forms of blood flow are
A
Pulsatile, phasic and steady
8
Q
If a patient is supine, what is the arterial pressure at the knee?
A
140 mmHg
9
Q
During inspiration, the diaphragm moves
A
Down
10
Q
What happens to venous flow in the legs during inspiration?
A
Decreases
11
Q
The law of conservation of energy states that the pressure is lowest at
A
the stenosis
12
Q
True or False
Viscosity describes the energy flow when heat is converted as one object rubs against another
A
False
13
Q
as blood flows through the circulation, energy is lost in what 3 ways
A
viscous, frictional, inertial
14
Q
True or False
The Reynolds number for turbulent flow is greater than 2,000
A
True
15
Q
What is the hydrostatic pressure at the waist if the person is standing?
A
50 mmHg
16
Q
What is the arterial pressure measured at this patients knee – the hydrostatic pressure is 140mmHg?
A
215mmHg
17
Q
Blood moving from regions of higher energy to lower energy is called
A
Energy gradient
18
Q
True or False
Phasic and steady flow are present in venous circulation
A
True
19
Q
The Reynolds number for laminar flow is less than
A
1500
20
Q
Flow increases when either
A
pressure gradient increases and resistance decreases
21
Q
What are the hydrostatic pressures while standing upright in a patient with a blood pressure of 140mmHg
A
ankle 100 knee 75 waist 50 Mid chest 0 top of head -30
22
Q
When color gain is set to an inappropriately high level, color appears throughout the color box. A term that describes this is called?
A
Color confetti
23
Q
Multiple ultrasound pulses that are used to accurately determine blood velocities are called
A
Ensemble
24
Q
True or False
a wall filter is used to eliminate high frequency Doppler shifts from moving anatomy rather than from moving blood cells
A
False
25
Which technique is used to perform spectral analysis on color Doppler data?
Autocorrelation
26
True or False
| velocity mode distinguishes laminar flow from turbulent flow
False
27
What re the 2 things that are correct about pulsed Doppler transducers?
at least 1 crystal and lower sensitivity
28
The _______ frequency is the highest Doppler frequency than can be measured without the appearance of aliasing
Nyquist limit
29
What is the most common error with Doppler ultrasound?
Aliasing
30
Simultaneous anatomic imaging and Doppler is called
Duplex imaging
31
True or False
| Doppler shift is inversely related to the frequency of the transmitted sound
False
32
When the bloos cells are moving _____ to the sound beam, the entire velocity is measured
Parallel
33
assume that a Doppler study is performed and the Doppler shift is 6KHz when the blood's velocity is 2m/s. If the blood velocity slows to 1m/s. What will the Doppler shift be?
3KHz
34
_____________ is defined by a magnitude and a direction
Velocity
35
This process extracts the low Doppler frequency from the transducer's carrier frequency
Demodulation
36
True or false
| The lumen of a horizontal vessel evaluated with a color Doppler, Sector shaped image contains a single color
False
37
Transducer frequencies of _________ Doppler shifts range are used since they are audible
20Hz-20000Hz
38
Cosine 0 degrees is 1 indicating flow __________ the transducer, whereas cosine 180 degrees is -1, indicating flow _______ from the transducer
Toward, away
39
all of the following occur during expiration except?
a. venous flow in the legs increases
b. the diaphragm rises into the thoracic cavity
c. venous return to the heart decreases
d. abdominal pressure increases
d. abdominal pressure increases
40
True or False
Velocity mode color Doppler and variance mode color Doppler will produce identical images when blood flow patterns are turbulent
False
41
True or False
Velocity mode color Doppler and variance mode color Doppler will produce identical images when blood flow patterns are laminar
True
42
True or False
| Absence of color on a color Doppler image always indicates a region of no blood flow
False
43
During a pulsed Doppler exam, aliasing is observed. All of the following may eliminate aliasing except
a. selection of another imaging view with a shallower sample volume
b. selection of another transducer with a lower frequency
c. selection of another imaging view that provides a greater pulse repetition period
d. use of a continuous wave system
C. selection of another imaging view that provides a greater pulse repetition period
44
The highest Doppler frequency without the appearance of aliasing is called the ________ and is equal to ______
Nyquist limit, half the emitted PRF
45
True or False
| The higher the pulse repetition frequency of a Doppler exam, the more likely aliasing is to occur
False
46
What happens to venous flow in the legs during inspiration?
Decreases
47
__________ in a fluid system is called voltage, similarly, _________ in a fluid system is called current
Pressure, flow
48
What is the arterial pressure measured at the patients knee who is standing and the hydrostatic blood pressure is 14mmHg?
215 mmHg
49
During expiration, the diaphragm moves
up
50
Gravitational energy is a form of ______ energy
stored
51
_______ energy loss in blood is determined by the hematocrit
Viscous
52
True or False
| Parabolic flow is the velocity in the center of the lumen and gradually decreases to its minimum at the vessel wall
True
53
An advantage to power mode Doppler is
it is unaffected by Doppler angles
54
True or False
| Ghosting artifact show up only on spectral Doppler
False
55
True or False
| Color Doppler will have crosstalk as an artifact
False
56
True or False
| Wall filters are used to eliminate low frequency Doppler shifts from moving anatomy
True
57
What is the current method of processing Doppler signals that can distinguish laminar and turbulent flow?
FFT
58
Which of the following terms is synonymous with spectral broadening?
a. parabolic flow
b. laminar flow
c. turbulent flow
d. plug flow
C. turbulent flow
59
when a vessel is colorless, what is the first thing to do?
Change the angle
60
Shadows appear then attenuation is too
High
61
Enhancement artifact appears as a
hyperechoic region
62
Structures with equal echo brightness are described as
isoechoic
63
Focal enhancement is a special form of enhancement in which a _________ region of an image appears brighter that tissues at other depths
Side to side
64
What are the characteristics of a medium the produces comet tail artifact?
strong reflectors, closely spaced, high propagation speed
65
When enhancement occurs, where does it appear on the image?
Deeper that a weak attenuator
66
What is the noise resulting from the constructive and destructive interference of small sound wavelets
Acoustic speckle
67
True or False
| Spatial resolution is related to the overall detain in the image
True
68
Portions of an image that are not as bright as surrounding tissues are
Hypoechoic
69
Characteristics of reverberation are
appear in multiples
70
Which artifact is created when closely spaced reverberations merge
comet tail
71
on a mirror image artifact, does the artifact appear Deeper or shallower than the true reflector?
Deeper
72
Focal banding has the same appearance as an?
incorrect TGC setting
73
True or False
| High pixel density declines spatial resolution
False
74
If an Ultrasoun pulse travels through a large mass in the body at a speed of 1.2 mm/us, what happens to the position of all echoes produced from reflectors shallower than the mass?
They are likely to be placed at the correct depth
75
What type of artifact causes a reflection to be placed at an incorrect depth?
Range ambiguity
76
Grating lobes are most commor with which type of transducer technology?
Linear arrays
77
Two small cysts, positioned perpendicular to the main axis of a sound beam, are 2.4 mm apart. What determines whether they appear as two distinct images of the system's display?
Beam width
78
True or False
Artifacts are likely to appear when the dimensions of the sound beam area are larger then the dimensions of the reflectors in the body
True
79
True or False
all artifacts are errors in imaging that do not represent the true anatomy of the image organ, therefore, they are all undesirable and should be eliminated if possible
False
80
What are the 6 assumptions incorporated into the design of every ultrasound system
1. sound travels in a straight line
2. sound travels directly to a reflector and back
3. sound travels in soft tissue at exactly 1,540 m/s
4. reflections arise only from structures positioned in the beam's main axis
5. the imaging plane is very thin
6. the strength of a reflection is related to the characteristics of the tissue creating the reflection
81
Who is responsible for implementing a quality assurance action plan?
Sonographer
82
True or False
| Flow phantoms are the devices of choice for evaluating soft tissue
False
83
Two forms of sensitivity are
normal and maximum
84
An acoustic standoff may be used to image
superficial structures
85
axial resolution is evaluated by scanning
sets of successively closer spaced pins
86
Quality assurance is the routine evaluation of an ultrasound system to guarantee optimal image quality. This should be performed
periodically
87
There are 4 requirements for quality assurance program, One of the requirements are:
a. minimize downtime
b. Doppler phantom
c. reduce number of repeat scans
d. repairs
d. repairs
88
a proper method for the quality assurance program is
image in an identical environment
89
The tissue equivalent phantom will contain which structures?
nylon strings, structures that mimic hollow cysts
90
True or False
| normal sensitivity should vary from one routine evaluation to the next
False
91
Which frequency transducers have a thinner dead zone?
Higher
92
The accuracy of reflector depth positioning in A-mode, M-mode, B-mode, and 2-D imaging is called
Depth calibration
93
The patient has the capacity to act intentionally, with understanding, and with free will is
Informed consent
94
informed consent generally includes the
risks, benefits, and uncertainties related to each alternative
95
When can a patient withdraw consent for the procedure?
at any time
96
What should the sonographer do when first meeting the patient?
introduce yourself
97
True or False
As a sonographer, you have the right to tell the patient what you think their exam findings are before the Dr. comes into the room
False
98
True or False
it is best to continue scanning the same type of studies all day and to also add as many patients into the schedule for the best ergonomics on the sonographer
False
99
True or False
Gloves should only be worn when you know that you will be handling blood from someone who has something like HIV. You will only need to wash your hands after you scan 5 patients or if you get them dirty
False
100
True or False
| Workers should nor engage in tasks or activities that will potentially put them at risk of exposure of being harmed
True
101
Give 4 ways that a tissue equivalent phantom is similar to soft tissue
attenuation
same speed 1540 m/s
scattering characteristics
echogenicity
102
True or False
| In vivo is performed within the living body
True
103
What is the primary mandate regarding clinical ultrasound?
benefits to the patient must outweigh the risks
104
What does a calorimeter do?
Measures the total power in a sound beam through the process of absorption
105
What is the science of identifying and measuring the characteristics of an ultrasound beam that are relevant to its potential for producing biological effects?
dosimetry
106
Which approach searches for relationship between exposure and response, empirical or mechanistic
Empirical
107
What degree in testicular temperature can cause infertility?
2-4 degrees
108
True or False
| Bone absorbs less acoustic energy than soft tissue
False
109
Core temperature is regulated at what degree?
37 degree
110
Bubble bursting is also known as
Transient cavitation
111
2 forms of cavitation are
stable and transient
112
What is a limitation of epidemiologic studies
Justification for the exam
113
True or False
| it is always fun to scan your friends for entertainment purposes when they are pregnant
False
114
True or False
| it is safe to scan with a cracked transducer housing
False
115
Which intensity is related most closely to tissue heating?
SPTA
116
True or False
| the transducer exposes a patient to the greatest risk
True
