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127 Cards in this Set

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What system control determines the amount of amplification that occurs in the receiver?
Gain
When you adjust the output power, you affect the following system component: Pulsar, Beam former, Scan converter, memory, or receiver?
Pulsar
What system control equalizes the differences in echo amplitudes received from similar structures situated at different depths?
TGC/DGC
Electronic noise is reduced in the US system by which of the followng methods: Demodulation, Compenstaion, Rectification, Amplification, or Rejection?
Rejection
You have chosen to enlarge an US image with read magnificaiton, Which of the following is NOT related to read magnification: pREPROCESSING, iNCREASED PIXEL SIZE, PERFORMANCE ON A FROZEN IMAGE, RESOLUTION LOSS?
Preprocessing - Read magnification is a postprocessing funtion.
Which of the following terms describes the rate at which the transmitter applies transmit pulses to the transducer: Period, PRF, DGC, Demodulation, Apodization?
PRF Pulse Repitition Frequnecy
A transmitted wave is necesary for real time imaging, why?
Because the depth of the interface from which the echo originated can be determined
What receiver function is responsible for decreasing the difference between the smallest and the largest reveived signal amplitudes?
Compression
What receiver function listed is not operator adjustable: Amplification, Compression, Demodulation, Rejection?
Demodulation and Compression are not receiver operator adjustable
While performing an US exam of the thyroid you have performed both preprocessing and post-processing functions, Which of the following functions is post processing: Write zoom, TGC, Gray scale map assignment, Scan line density, acoustic power?
Gray scale map assignment
You are scanning a patient with liver metastases and wish to improve contrast resolution to enhance the visibility of the lesion. You can accomplish this by: Increasing the acoustic output power, Decreasing the scan line density, Performing a read-zoom over the area of interest, Changing the gray-scale map assignment, Increasing the overall receiver gain
Changing the gray-scale map assignment
What part of the US instrument is responsible for apodization, beam stearing, focusing, and aperature control?
The beam former
What control should you adjust to account for the attenuation of sound as it propagates through tissue?
DGC/TGC
Which operator control adjusts the dynamic range of the displayed echoes?
Compression
The technique of frame averaging during real time acquisition is designed to do what?
Reduce random noise
Yoi are performing an abdominal US exam and select the tissue harmonics operating mode, what advantage will you abtain over conventional imaging?
Improved contrast resolution, and improved signal to noise ration
You have decreased the scan line density during a color doppler exam of the Kidney, what technique will be employed to fill in the empty data between the scan lines?
Interpolation
While performing an OB US exam, you decide to adjust the system parametes to improve the image. WHich of the following is not adjustable by operator control on the US system: fREQ, Power, Intensity, AMplitude, and Prop speed.
Prop speed
What control should you adjust to optimize the image if you are scanning a structure producing very bright echoes on the display: Rejection, TGC, Edge enhancement, Frame averaging, Freq
TGC/DGC
To generate an US image, what is the order of activation for these system components: Pulsar, receiver, video display, beam former, memory or Pulsar, beam former, receiver, memory, video display or Beam former, pulsar, memory, video display, receiver or Memory, beam former,pulsar, receiver video display, or beam former, memory, pulsar receiver, video display?
Pulsar, beam former, receiver, memory, video display
You have adjusted several system controls and notice that the frame rate has decreased to a level that makes scanning difficult. What is a typical fram rate for B-Mode real-time imaging?
10-50 Hz
Which of the following control should you adjust to improve the signal to noise ratio on the image: Dynamic range, Frame averaging, Gray scale map, Edge enhancement, receiver gain
Frame Averaging
The ratio of the largest to the smallest signal that a system can handle is termed what?
Dynamic range
What does the term duty factor describe?
The fraction of time the transducer is actively transmitting sound
If the pulse repitition frequency is increased, but no other paramenters are changes, what will occur?
Frame rate will increase
If the PRF is increased to a level too great for the depth of field, what will the result be?
Range ambiguity
You have adjusted the following controls during an abdominal US exam, which control increased patient exposure to US energy?
Output power
You have increased the reject level while performing a thyroid US exam, what effect will you see in the image?
Decreased low-level echoes
If sound sis not attenuate with increasing depth, what system control would no longer be needed?
TGC/DGC
What does the term signal to noise ratio denote?
The relative amplitude of the signal compared to the amplitude of the noise
What receiver function converts the negative portion of the RF signal to positive?
Rectification
Preprocessing functions may be defined as what?
A function that is performed before the echo data are stored in memory
Increasing the dynamic range setting will affect the US image how?
Decreasing the image contrast
When you adjust the TGC, what component of the US system implements the changes?
The receiver
What are the 5 functions of the receiver?
Gain, Compensation (TGC), Compression, Demodulation (Rectification, Sloping, Smoothing), Rejection
What is a typical value for the Duty factor in doagnostic US imaging?
0.1 - 1.0%
You have performed the folllowing function while scanning a gallbladder, which function is considered preprocessing: Edge enhancement, TGC, Dynamic range, Frame Averaging, All of them
All of them
Pulse repition period is the inverse of what?
Pulse repitition frequency
What system somponent determines the pulse repitition frequency?
Pulsar
In US sustems, the range equation is used to determine which of the following: Reflector amplitude, Relfector frequency, Reflector direction, Reflector depth, Reflector size?
Reflector depth (Range = Depth)
You have increased the output power by 10dB. How much have you increased the signal intensity?
It is increased by a factor of 10
What is the purpose of preamplification of the incoming signal that occurs in the transducer assembly?
To increase echo voltage before noise is induced through the cable.
Proper adjustment of the DGC is approx what?
1 dB/cm/MHz
What function of the receiver converts electrical signals from radiofrequency to video form?
Demodulation
What component of the US system converts the electric energy provided by the pulsar into acoustic pulses transmitted into the patient?
Transducer
The incoming raw echo signals must be compressed into smaller dynamic range because: A wide dynamic range results in increased display of electronic noise, A wide dynamic range does not allow differentiation between echoes arriving from different depths, The display cant accommodate the wide range of the incoming signals, The existing wide dynamic range significantly slows the frame rate. or A wide dynamic range compromise spatial resolution
The display cannot accommodate the wide dynamic range of the incoming signals
Which of the following is not a function of the receiver?
Dynamic aperature
What system function is limited by the speed of sound in tissue: Demodulation, Pulse Repitition Frequency, Voltage amplitude, Rectification, or TGC?
Pulse repitition frequency
What control should you adjust to modify the image if the attenuation coefficient of the tissue is very high: Dynamic range, Rejection, Threshold, Compensation, Compression
Compensation
Which of the following adjustments will increase the duty factor: Increasing receiver gain, Increasing output power, Increasing pulse repitition frequency, Increasing scanning time, or Increasing TGC?
Increasing PRF
What is the advantage of using Write Zoom instead of Read Zoom magnification?
Write Zoom provides better spatial resolution than Read Zoom
How is reflector depth determined with pulse wave US?
By the arrival times of the echoes
What effect eill you detect in the image if you increase the threshold control?
Decreased appearance of weak echo signals
You are performing a real time exam of the gall bladder. What mode of US display are you using?
B-Mode
During performance of an abdominal US exam you notice that the temporal resolution is poor. What can you do to improve the temporal resolution: Increasae the number of focal zones, Increase the depth, Increase the scan line density, decrease the acoustic power output?
Decrease scan line density
The number of images displayed per second in real time imaging is termed what?
Frame Rate
Which scanninc mode does not rely on the principle of echo ranging to determine the interface location?
A-Mode
Which display mode may be used to calculate distance measurement?
A, B, and M modes
M-mode scanning is characterized by which of the following: Presentation of reflector amplitudes along multiple lines of sight, 2D gray scale image, Movement of a single structure along multiple lines of sight, Depth of reflectors along a single lone of sight with respect to time, or Frequency shift of moving reflectors along a single line of sight?
The depth of reflectors along a single line of sight with respect to time
Which operator control affects time frame rate: Amplification, Transmit power, Scan depth, TGC, compression
Scan depth
While performing an OB US exam, you wish yo increase the frame rate to evaluate the fetal heart. What should u do: Increase scan line density, Increase the number of focal zones, Decrease the sector width, Decrease the system PRF?
Decrease the sector width
What information is present in the M-mode display
Time, Motion pattern, and Amplitude
You are scanning an interface with high acoustic impedance mismatch. How will this be displayed on the B mode image?
A bright dot
The computer parameter that limits the number of brightness levels (shades of gray) available for display of the image matrix is what?
The number of bits per pixel
Television frames are displayed at a rate of how many frames per second?
30
The ability to distinguish between adjacent structures producing echoes of similar amplitude is termed what?
Contrast Resolution
Which of the following digital scan converters would demonstrate the best contrast resolution: 8 bit, 7 bit, 6 bit, 5 bit, or 4 bit?
8 bit (equaks 256 shades of gray in standard US systems
What control converts the numbers stored in memory to proportional voltage that controls the brightness on the monitor?
Digital to Analog converter since the numbers are "Stored" they have been digitized
Where are images stored in the US system?
in the Scan converter
What is the maximum number of shades of gray in an 8-bit digital scan converter?
256
The spatial resolution of the scan converter is determind how?
By the number of pixels in the scan converter matrix
What number system is employed by computers to carry out mathmatical operations and represent numbers?
Binary system
In the scan converter, interpolation is performed to do what?
Fill in the empty pixels that occur between scan lines
Without interpolation, which of the following would best describe the resultant B mode image: Very weak echoes in the far field compared to the near field, Poor differentiation between the US signal and the noise floor, Saturation of the white shades on the US monitor, A series of scan lines with blank data between the lines, or A bistable image?
A series of scan lines with blank data between the lines
What three colors are used o a color monitor to produce the range of available colors?
Red, Green, Blue
Which of the following is not an advantage of using SVHS video recorder on your US system: It demonstrates higher resolution in comparison to VHS, It can record in both SVHS and VHS formats, It has a separate color signal resulting in superior color definition, It can play bot VHS and SVHS tapes, or SHVS tapes can be played back on any type of video system?
It demonstrates higher resolution in comparison to VHS
When you freeze an image, where is the echo information stored?
The scan converter
What type of resolution is demonstrated by the number of pixels in the scan converter?
Spatial resolution
Which of the following can be considered an advantage of magneto-optical disk storage?
The data can be erased and rewritten, A large volume of data can be stored on a single disk, Cine loops can be stored on the disk, MO disks are not susceptible to magnetic fields as regular disketts or digital tape
Which of the following adjustments would improve contrast resolution: Increasing # of pixels, Increasing number of scan lines, Increasing number of bits, Increasing number of raster lines, or Decreasing the size of the scan converter matrix?
Increasing the number of bits
Two separate fields are used to produce an image on a video monitor. The purpose of this is to do what?
Reduce flicker in the monitor
Which of the following is associated with improper adjustment of the brightness and contrast on the video monitor: Spatial resolution of the resultant image will be degraded, The operator will likely overgain or undergain the image, The temporal resolution will be reduced, The flicker rate of the video monitor will be increased or The penetration of the transducer will be reduced?
The operator will likely overgain or undergain the image.
Differentation between two very similar reflected signal strengths is most closely associated with which of the following: Number of pixels in the scan converter matrix, Number of raster lines in the scan converter matrix, Dimension of the scan converter matrix, Number of bits per pixel in the scan converter matrix, or Interpolation scheme?
Number of bits per pixel in the scan converter matrix
Analog to digital conversion of the US signal must occur at what part of the imaging process?
Between the transducer and the scan converter
What numbers represent binary numbers?
1's and 0's
Which of the following would improve spatial resolution: Increasing transducer frequency, Increasing focusing, Decreasing PD, Increasing number of pixels on the display page, or all of them?
All of them
What can you improve by changing the portprocessing the gray-scale map?
Contrast resolution
Which of the following describes an analog signal: Discrete values, Fixed steps between values, Continuous variation of signal is possible, Levels are determined by bits, or all of them?
Continuous variation of signal is possible
What is the order in which the signal travels in the US system: Transducer-receiver-display-scan converter, Scan converter-transducer-receiver-display, Scan converter-receiver-transducer-display, Transducer-receiver-scan converter-display, or Receiver-transducer-scan converter-display
Transducer-receiver-scan converter-display
You have expanded the image sector width to improve visualization of a large mass. What can you do to maintain the same temporal resolution you had before your adjustment: Increase digitization bit depth, Increase the number of scan lines, Decrease the number of pixels in the image matrix, Decrease the number of focal zones, or Decrease the PRF
Decrease the number of focal zones
Which of the following improves when frame rate increases: Lateral reso, Longitudinal reso, temporal reso, spatial reso
temporal reso
Which of the following is constant with increased or improved temporal reso: More gray shades, more detal in each image, color Doppler, or Higher frame rate?
Higher frame rate
All of the following decrease temporal resolution except: Lower frame rate, deeper imaging, multi focus imaging, or narrower sector
Narrower sector
A sonographer adjusts an US machine to double the depth of view from 5cm to 10cm. If the frame rate remains the same, which one of the following also changed: Increased line density, wider sector, multi focus imaging turned on, or naarrower sector?
Increased line density
A sonographer adjusts an US machine to change the sector size from 90 to 45 degrees. Nothing else changes. What happens to the frame rate?
It is unchanged
A sonographer adjusts an US machine to change the sector size from 90 to 45 degrees. The frame rate ramained inchanged. What else must have happened?
The imagng depth was halved
A sonographer using phased array US system, turns off the multi focus feature. What is the most likely consequence of this action: Frame rate decreased, temporal reso decreased, imaging quality decreased, or temporal reso increased?
The frame rate decreased
A sonographer increases the line density from 1 line per degree of sector to 3 lines per degree of sector. What is the most likely consequence of this action?
The temporal resolution decreased
Which of the following os the most reasonable initial action to take when the imageon your US system displays only reflectors in a region close to the transducer, but displays nothing in deeper regions: Adjust the systems compensation, Adjust the systems compresion, Use a higher frequency transducer, Increase the output power, or Adjust the reject level.
Adjust the systems compensation
Which of the following is the most reaspnable action to take if the image on the US system displays only echoes arising from bright reflectors at all depths? However no weak reflectors appear anywhere on the image: Adjust the systems compensation, Increase the systems overall gain, Use a higher frequency transducer, Increase the output power, or Adjust the reject level
Adjust the reject level
Which of the following is the most reaspnable action to take when the image on your US system displays only bright reflections at all locations on the image, that arise from both strong and weak reflectors in the body: adjust the systems compensation, Decrease the overall amplification or gain, Use higher Freq transducer, Use lower freq transducer, or Adjsut the reject level?
Decrease the overall amplification or gain
Which of the following is the most reaspnable action to take when the image on your US system displays reflectors only in regions deeper than 5cm, but displays nothing from shallower depths: Adjust the systems compensation, Use higher frequency transducer, Decrease the output power, or adjust the reject level?
Adjust the systems compensation
Which type of pulser generates numerous electrical spikes which ultimately create a single sound pulse?
Phased Array pulsed wave
What determines the acoustic power of a sound beam emitted from a transducer?
The voltage of the pulsers signal
What are the 5 functions of the receiver?
Amplification, Attenuation, Compensation, Compression, Demodulation
True or False: Amplification processes all reflected signals in a similar manner?
True
True or False: Compensation processes all reflected signals in a similar manner?
False
When compensation is properly adjusted what happens to the image?
Identical reflectors appear on the image similarly
All of the following are true of ordinary cathode ray tubes except which statement: They are large vacuum tubes with a phosphor coated screen, Electrons are emitted by a gun ans swept across the front, There are 600 horizontal lines from top to bottom, painted in order from 1-600, There are 60 fields generated each second that combines 30 frames per second?
Ther are 600 horizontal scan line from top to bottom, painted in order is incorrect. Lines are painetd with the Odd numers first then the even numbers and there are only 500 ish horizintal scan lines
Which of the following corectly describes a typical CRT: Interlaced, progressice scan, bistable, or non-interlaced?
Interlaced
Which electronic component is required for gray scale imaging?
The scan converter
All of the following are dis-advantages of analog scan converters Except which: Image fade, Low-resolution image, Image flicker, or deterioration?
Low resolution image
Which of the following statements regarding a bit of computer memory is false: It is the smallest element of an image, Its bistable, 8 bits make one byte, or it is a component of a digital scan converter
It is the smallest element of an image is false
How many gray shades can be represented by a group of 8bits, 4bits, or 2bits
8=256
4=128
2=64
Which of the following statements regarding a pixel is false: It is the smallest element of a digitized image, A collection of bits assigned to each pixel stores the shade of gray, It can display up to 3 shades simultaneously, or Image quality is improved when the number of pixels is high
It can display up to 3 gray shades simultaneously is false
Is the following form of information Digital or Analog: Signal from transducer to the receiver?
Analog
Is the following form of information Digital or Analog: Input signal to the digital to analog converter?
Digital
Is the following form of information Digital or Analog:Output signal from the analog to digital converter?
Digital
Is the following form of information Digital or Analog: Input signal from the analog to digital converter
Analog
Is the following form of information Digital or Analog: Output signal from the digital to analog converter?
Analog
Is the following form of information Digital or Analog: Typical video signal?
Analog
Are the following pre or post-processing procedures: Modifying a frozen image?
Post
Are the following pre or post-processing procedures: Read zoom?
Post
Are the following pre or post-processing procedures: Write Zoom?
Pre
Are the following pre or post-processing procedures: Adjusting the brightness on the CRT?
Post
Are the following pre or post-processing procedures: Increasing the receiver gain
Pre
All of the following are characterisitcs of write zoom magnification except which: Preprocessing function, more pixels in the region of interest, identical regions stored in the scan converter before and after zoom is enabled, or the preferred method of image magnification
Identical regions stored in the scan converter before and after zoom is enabled