問題一覧
1
Which of the following transducers uses a beam former
B) sector phased array
2
for an ultrasound system to produce a real time flicker free image the minimum frame rate required is
C) 15 Hz
3
diagnostic ultrasound is described as frequencies greater than
B) 2 MHz
4
____ compares each reflected echo to the same echo from a previous ultrasound pulse to determine if motion is present
B) autocorrelation
5
multiply density of the tissue by propagation speed in the tissue will provide a value for what tissue characteristic
B) acoustic impedance
6
blood flow volume changes in the body are mainly controlled by what two factors
A) cardiac function and peripheral resistance
7
Which of the following will be negatively affected by spatial compounding
A) temporal resolution
8
which of the following correctly describes how to avoid underestimation of peak velocity measurement on a faint Doppler wave form
D) increase the gain until speckle artifact is displayed across the screen, then reduce slightly
9
what change in system controls can reduce the appearance of color displayed over vessel walls
A) decreasing color priority
10
____ used to form the sector shaped field of view for a phased array transducer
D) electronic steering is
11
increasing ____ Will increase the ability of the system to display fine details on the image
C) pixel density
12
The acoustic impedance of the matching layer
C) is usually very low
13
increasing the number of bits per pixel in an image memory will improve the
C) contrast resolution
14
which of the pulses produced from a 7MHz transducer would have the best lateral and axial resolution
D) 2mm beam diameter, 3 pulses per cycle
15
____ is the predominant factor causing attenuation of the ultrasound beam and this can be counteracted by ____
A) sound absorption, increasing the TGC settings for the far field
16
If the entire image is too dark, what console adjustment should you make first?
A) increase the overall gain
17
which of the following sound/ tissue interactions does not cause redirection of the incident wave
A) absorption
18
resistance to blood flow is primarily controlled by
B) the radius of the vessel
19
____ is the process that is performed in the beam former where the output voltage is better to decrease the formation of lobe artifacts
A) apodization
20
if the dynamic range is 64 dB and there are 32 shades of gray what is the contrast resolution?
C) 2 dB/shade
21
____ artifact is caused by the refraction and results in subtle image degradation
D) multipath
22
tissue Doppler imaging uses ____ settings than PW doppler
D) lower filter
23
____ is defined as the time from onset of systole to the peak systole occurs
A) acceleration time
24
the acoustic power is changed by -3dB the beam intensity ___
C) decreases by half
25
which of the following will improve the lateral resolution on the image?
C) increase the focal zone number
26
increasing the number of pulses in a color packet will
D) increase frame rate
27
Assuming line density is constant at two lines per degree and you change from a 90° sector to a 45° sector how many lines will now be produced
B) 90
28
which of the following system controls would increase the color display on the image
A) image threshold settings
29
when you adjust the Doppler PRF you adjust the ___ control on the system
D) velocity scale
30
The ___ of a wave multiplied by the number of cycles in the pulse will calculate the pulse duration (PD)
D) period
31
if a renal Doppler exam demonstrates stenosis, but normal flow is identified on angiography evaluation the results are described as
C) false positive
32
What component of the beam former protects the sensitivity circuitry of the amplifier
B) transmit/ receive switch
33
Blood flow at a focal stenosis will demonstrate
B) increased resistance
34
What type of precautions is required for a patient with MRSA
D) contact precautions
35
what is the best way to increase beam penetration
A) decrease operating frequency
36
Which of the following is a primary factor in visualization of tissue boundaries that are not perpendicular to the incident beam such as tissue parenchyma and organ boundaries
B) backscatter
37
which of the following is a limitation of power Doppler
C) has slower frame rates than color doppler
38
what is the best way to reduce sliced thickness artifact that is causing false echoes in a superficial structure
A) use a standoff pad
39
which of the following is a limitation of analog Doppler?
D) unable to detect post stenotic turbulence and spectral broadening
40
diagnostic ultrasound is described as frequencies greater than
B) 2 MHz
41
what is the proper method used to assess the size of the dead zone?
B) measure from the top of the image to the depth that uniform tissue is identified
42
which of the following will reduce color flash artifact
A) decrease color priority
43
what determines the frequency of a captivated micromachined ultrasound transducer
D) frequency of the drive voltage
44
which of the following describes the effect on the frame rate when changing from duplex to triplex imaging
C) decreased
45
while imaging the thyroid you increase the number of focal zones from 1 to 3. How will this affect the image?
A) degraded temporal resolution
46
which of the following can change the image data displayed on an archived exam on the ultrasound system
A) change the gray map used to create the image
47
when harmonic imaging is turned on a primarily improves ____ resolution
D) lateral
48
The spatial pulse length is 4 mm. what is the minimum axial resolution?
B) 2 mm
49
if you increase the sector angle from 45 to 90°, and no other console changes are made what happens to the frame rate
B) it is reduced to 1/2 the original frame rate
50
review the image in the system, setting along the right side use your mouse and place over the setting that should be increased to improve the diagnostic quality of the color Doppler image
PRF & WF ( green )
51
Transesophageal and transvaginal transducers are considered ___ Devices that should be disinfected using ____
A) semi critical, high-level disinfectant
52
As the area of the beam increases _______
A) the intensity of the beam decreases
53
which of the following is related to an increase in the spatial pulse length of an ultrasound beam produced by the transducer
B) decease in probe frequency
54
Aliasing artifact does not occur with CW Doppler systems because
D) CW doppler transducers used two separate elements so they are not limited by pulse echo parameters like PRF and Nyquist limit
55
if two calcifications are located side-by-side in the liver with a 3 mm distance between them and a beam width of 6 mm how will the structure appear on the image?
A) as a single elongated horizontal reflection
56
The more bits per pixel the __ shades of gray on the image and ____ improves
B) more, contrast resolution
57
increasing the PRF will reduce the appearance of ___ while increasing the appearance of __ on Doppler evaluation
C) aliasing, range ambiguity
58
in order to assess low velocity flow which of the following operator adjustments should be made
D) decrease the rejection and wall filter setting
59
what acoustic artifact is demonstrated on the image below
A) posterior shadowing
60
what type of transducer produce the image?
A) sector phased array
61
which of the following adjustments would improve the appearance of ultrasound enhancing agents on the image
C) decrease output power
62
propagation speed, artifact reverberation artifact and the bayonet artifact are all acoustic artifacts seen with?
D) needles
63
imaging an adult should never be performed with a thermal index level at or above ___ and imaging A fetus should never be performed with a thermal index level at or above ___
B) 6,3
64
activating harmonic imaging will result in ____
C) improved contrast resolution
65
which of the following transducers would be most useful for imaging deeper structures?
A) 3 MHz long focus
66
as the frequency of the wave doubles the wavelength ___
A) deceased by half
67
according to the attached color map, what color would demonstrate for blood that is moving toward the probe at an average velocity of 100cm/s
B) white/ light blue
68
____ artifact appears as multiple parallel equidistant lines that look like steps on the ladder
C) reverbation
69
which of the following statements is true regarding the image produced by the transducer on the left?
D) the frame rate will be higher for the image
70
what is the cause of the vertical acoustic shadow seen on both images?
A) element damage
71
which of the following describes the best way to improve the doppler tracing of the internal carotid artery
D) increase the cursor angle to 60°
72
when working in a hospital setting what is the best way to verify a patient’s identity
D) check the hospital issued ID bracelet
73
What setting should be increased to improve the diagnostic quality of color doppler image
PRF & WF
74
you are performing real time imaging of a vessel adjacent to the tibia what acoustic artifact Will most likely be identified on the 2-D image
B) posterior shadowing
75
the best obtainable angle of insonation for vascular evaluation that is most commonly used to provide Doppler shift information is ___ degrees
C) 60
76
which of the following is considered the capacitive component of the circulatory system
D) veins
77
____ is defined as the range of frequencies contained in the U/S pulse
B) bandwidth
78
as a Doppler incident angle increases to 90° the detected Doppler shift varies and approaches what value
B) 0 kHz
79
in the electronically focused ultrasound beam then intensity is
B) greatest at the focal point
80
The ___ is defined as the time it take for one pulse to occur
B) pulse duration
81
which of the following is the best way to reduce the artifactual echoes on the image indicated by the red arrows
D) reduce TGC settings in the near field
82
if a 7 MHz wave is transmitted through the media listed below the shortest wavelength will be seen in the wave moving through ___
A) air
83
which of the following will lead to more color displayed in real time in the abdominal aorta
C) increase frame rate
84
what color Doppler artifact is demonstrated on the image
A) flash
85
what changes occurred to the ultrasound beam when time pulses are emitted from left to right from the elements of the phased transducer
D) the beam is steered to the right
86
which statement correctly describes a spectral wave form
D) the presence of a spectral window indicates laminar flow is present in the vessel being evaluated
87
The cine function on the ultrasound system
B) is a type of post processing
88
if the peak systolic velocity is 3 m/s what is the peak pressure gradient?
B) 36 mmHg
89
what artifact is demonstrated on the ultrasound image by the red arrows?
D) posterior enhancement
90
which of the following is displayed with spectral Doppler but not with color Doppler
A) peak flow velocity
91
Which of the following will maintain compliance with the ALARA principal
B) reducing the number of images taken in standard protocol
92
how do the microbubbles in an ultrasound contrast agent change the image
A) increase the reflectivity of flowing blood
93
in a resting patient the highest resistance in the arterial system is in the
A) arterioles
94
transducer can be electronically focused by
C) varying timing of the release of the pulses
95
how is the pulse repetition period reduced in Doppler imaging
B) decrease imaging depth
96
What should have been done to adjust and improve the color Doppler display on the image
A) decrease sample volume
97
what happens to the attenuation coefficient as the wave travels through soft tissue
A) remains constant
98
which of the following system adjustments would increase the size of the spectral window
D) changing from a 4mm to 2mm sample size
99
how is detail resolution limit documented on phantom testing?
D) two separate pins are displayed as a single reflector on the image
100
which of the following ultrasound techniques has the highest temporal resolution
A) M-mode