SPI: Principles & Instrumentation Flashcards
Increasing _________ removes low amplitude signals in noise from the image.
INCREASING REJECTION!
While scanning an echo, you change the gray map to a new choice and continue to scan. This would be termed a change in ___________
Pre or post processing?
PREPROCESSING -NEW -BEFORE
What correctly describes an amplifier?
Each returning reflection is made
_______/larger for additional processing and storage
STRONGER
2D image is composed of:
Pixels or bits?
PIXELS
3D image if composed of:
Voxels
An amplifier gain of 20dB=
100
What transducer component reduces the sensitivity and efficiency of the ultrasound system?
Matching layer or damping?
Damping material
What system control will simultaneously enhance FAR FIELD echoes in diminished Near field echoes?
Overall gain or TGC?
TGC = enhance far field
If you are performing an abdominal exam, but inadvertently select the carotid preset on the machine, how will this affect your exam?
Depth setting will be very ______
Depth settings will be very superficial, causing potential non-visualization of the abdominal structures
Harmonic frequencies are generated: as the sound travels through the _______
As the sound wave travels through the medium
List the parts of the beam former in the order they function to produce and receive sound waves:
Pulser, pulse delays, transmit/receive switch, amplifier, a-d converter, echo delays, summer
What part of the ultrasound system is responsible for changing the PRF with changes in the imaging depth?
PULSER
The gray scale map is adjusted to a new map just after freezing that image. This is an example of?
Applying post processing
Contrast resolution = dynamic range/# of shades
If the dynamic range is 64 dB and there are 32 shades, contrast resolution is:
Contrast resolution =
64dB/32 shades of gray= 2dB/shade
What part of the ultrasound system is responsible for changing the element function back-and-forth from transmit to receive?
Beam former
-back and forth
-Transmit/receive
When using virtual beamforming, the ultrasound beam is described as: ______-thin
Laser-thin
What system functions converts the receives signals from radio frequency from the amplitude form?
Demodulation or detection converts the received signal from radio frequency, form to amplitude form (video form)
What is the best way to increase beam penetration?
Decreasing transducer operating frequency, will increase beam penetration
The vertical axis on the M-mode display represents the
Depth of the reflector
The horizontal axis on the m-mode represents the ________
Time
What operator control can be used to adjust the image contrast?
Dynamic range/compression
Adjust the range of grays displayed on the image this changes, the contrast level of the image
What is the primary difference between virtual beamforming and traditional pulse Echo imaging?
Virtual beamforming does not use transmit, focusing like pulse Echo imaging
In radiology imaging department, what does PAC stand for?
Picture, archival and communication system
True or false? Reducing grading lobe and side lobe artifacts relates to tissue harmonic imaging.
True
If you increase the sector angle from 45 to 90° and reduce line density by 50%, what happens to frame rate?
Unchanged
Amplification of the received signal occurs in the
Beam former
What is the type of post processing that assigns shades of color, instead of gray, to create the image?
B color= post processing
When evaluating heavily calcified arteries, what system setting should be increased to improve the demonstration of flow in the vessels?
Persistence and sensitivity
As more reflections occur with reverberation, they each become _________ and are placed_____on the image.
Weaker , deeper on image
What portion of the TGC curve is the deepest region attenuation compensation can occur?
Knee
The cine function on ultrasound system:
Type of post processing
Focusing of the transmitted and received beam occurs in the:
Beam former
The imaging that is increased, and temporal resolution is degraded. Which of the following consul adjustments can improve the temporal resolution? Reduce_______ size
Reduce sector size
B-mode display is termed:
Brightness mode 🔅
When scanning using harmonic imaging, the second harmonic frequency is 10 MHZ. What is the fundamental frequency?
5MHz
The second harmonic frequency is 2X the fundamental frequency.
What system control should be turned off when attempting to demonstrate posterior shadowing from a renal or biliary stone?
Spatial compounding
-Reduces the appearance of posterior shadowing and enhancement.
When the image is frozen, an ellipses can be used to measure the ________ of structure
AREA of structure
Bandpass filtering is a function performed in the:
Signal processor
A 4 bit memory will be how many shades?
16 shades= 4 bits
2x2x2x2= 16
What is the correct a listing for the number 28 as a binary number?
011100
Explain
The amount of compensation necessary for different echoes varies with reflector:
Depth
Increasing the number of bits per pixel in an image of memory will improve the:
Contrast resolution
What instrument controls does the sonographer used to adjust the amplitude of a reflected, sound wave?
Receiver gain
-impacts amplitude
Increasing the frequency improves ______, _____, and ______
Axial, resolution, lateral resolution, and beam width
Even and odd harmonic frequencies are created by:
Non-linear sound waves
While scanning, soft tissue, the reflected wave return to the transducer in 0.05msec. How far away is the reflector?
0.4cm
What system components converge the scanline data into image format for display?
Image processor
Convert the scanline data into image format for display in storage
Apodization is a function of the:
Beam former or image former?
Beam former
Increasing the edge enhancement setting will :
Increase image contrast, or improve contrast resolution?
Increase image contrast
Edge enhancement , pixel, interpolation, persistence, and 3-D image acquisition are all types of: preprocessing or post processing?
PREPROCESSING
-before!
-edge enhancement
-pixel interpolation
-persistence
What dimension of the mass is being measured on this image?
Width
If the sonographer decreases the image death, how will affect the pulse repetition frequency?
Increase
PRF increase, depth decrease
What component of the Beam former protects the sensitivity circuitry of amplifier?
Transmit/receiver switch or transducer?
Transmit/receiver switch
Activation of B-color is used to improve:
Contrast resolution, or temporal resolution?
Contrast resolution
An amplifier gain of 3dB=
2
And advantage of virtual beamforming over traditional pulse Echo instrumentation is
No transmit focusing is needed
The grayscale map is adjusted to a new map just before to freezing the image. This is an example of?
Applying post processing, or pre-processing?
Before= preprocessing
Increasing __________ will improve detail resolution, the most on the lateral side of the image.
Line density or image death?
Line density
-By using more scanline= more detail
Increasing the sector size, increases:
The number of pulses per image or frame rate?
The number of pulses per image
Contrast resolution is calculated by dividing the dynamic range by the
Number of shades of gray
If an ellipses used to document the circumference of a structure, what unit is used?
Cm
In order to improve spatial resolution, and the signal to noise, ratio ________ uses frequency modulation to manipulate the transmitted beam
Coded excitation
What image controls is used to counteract beam attenuation?
TGC
If you increase the sector angle from 45 to 90° and no other consul changes are made, what happens to frame rate?
It is reduced to 1/2 the original frame rate
What is a primary factor in determining the frame rate of an ultrasound system?
Propagation speed in soft tissue or output power
Propagation, speed, and soft tissue
What system controls reduces noise and smooth the image using frame average?
Persistence
Low levels are necessary for fast moving structures
What techniques described as a graphic representation of motion of the structure over time?
B color or m-mode?
M-mode
What is the function of the signal processor?
Filtering and compression
Demodulation
What causes range ambiguity artifact?
Refraction or high PRF
High PRF
Range ambiguity is related with shallow depth settings. Decreasing the PRS and increasing imaging depth can reduce this artifact.
If the input power is 0.5mW and the output power is 500mW. What is the gain?
40dB
What system component is responsible for 3-D image acquisition, and presentation?
Beam former or image processor?
Image processor
-Responsible for pre-processing, post processing, storing images, grayscale maps, color, Maps, 3-D image acquisition, presentation, digital to analog conversion
To increase the amplitude of the ultrasound post produced by the transducer:
The voltage amplitude from the pulser increases
What best describes the difference between 3-D ultrasound imaging in 4D ultrasound imaging?
4D imaging provides real time display of 3-D images
What will improve contrast resolution?
Coded excitation or decreasing frequency?
Coded excitation
What technique can improve contrast resolution to aid in the visualization of an isoechoic mass?
Turn on harmonic imaging or decrease the number of focal zones?
Turn on harmonic imaging
Two Main reasons the reflected signals must undergo compression is:
Range of reflected signals exceeds the ability of the system to process and display that many signals, and it is important to maintain grayscale within range of human vision
What is the period for a 5MHZ transducer?
Period= 1/freq
1/5MHz= 0.2
Spatial compounding= can ______ the appearance of useful artifacts, such as enhancement and shadowing.
Can decrease the appearance of useful artifact, such as enhancement and shadowing.
If the sonographer increases the size of the field of view, the frame rate will:
Decrease
What can change the image data displayed on an archived exam?
Change the gray map used to create image
A disadvantage of increasing edge enhancement is:
Reduces beam penetration or amplifies echoes related to noise and spackle?
Amplifies echoes related to noise and speckle
The contrast resolution for system with 4 bit memory and 32 dynamic range?
2
What correctly describes m-mode?
Uses a very high sampling rate
What control affects the power of the beam?
Swept gain or transmit gain?
Transmit gain
_________ is the predominant factor causing attenuation of the beam, and this can be counteracted by ________.
sound absorption= predominant factor causing attenuation
Increasing the TGC settings for the far Field
_________ the process that is performed in a beam former where the output voltage is varied to decrease the formation of lobe artifacts
Apodization
The strength of the received, Echo determines the _________on the display
Brightness of the pixel= strength
When harmonic imaging is turned on, it primarily improves ________ resolution
Lateral resolution-harmonic imaging
What consul setting can be changed to adjust the propagation speed of a transverse wave?
Imaging depth, or none of the above
None
Demodulation is only necessary, when
A television monitors used to display the image
_________ can be used to reduce image, noise and clutter on the 2-D image
Spatial compounding
What correctly describes dynamic receive focusing?
A function of the pulser, or allows focusing at multiple depths on the image ?
Multiple depths = dynamic receive
If a reflector is 5cm from the transducer, how long will it take a post to reach it?
0.03msec
What system control, adjust the number of gray levels in the image to maintain the grayscale within the range of the human vision?
Compression
