What system control converts the numbers stored in memory to proportional voltages that control the brightness on a CRT (cathode ray tube) monitor?
Digital to analog converter
A digital scan converter is another name for what system component?
What control allows the user to freeze and then scroll back through the most recently acquired image frames?
A group of 8 bits is called:
Where are images stored in the ultrasound system?
What is the maximum number of shades of gray in a 8 bit digital scan converter?
The spatial resolution of the scan converter is determined by:
Number of pixels in the scan converter matrix
What system component is most responsible for transmit focusing?
How many levels of information can a single bit represent?
The picture elements in a scan converter matrix are termed:
Digital to analog conversion of the ultrasound signal must occur at what part of the image process?
Between the scan converter and the display
In the scan converter, interpolation is performed to:
Fill in the empty pixels that occur between acoustic scan lines
Without interpolation, which of the following would best describe the resultant B-mode image?
A series of scan lines with blank data between the lines
What three colors are used on a color monitor to produce the range of available colors?
Red, green, blue
When you freeze the ultrasound image, where is the echo information stored?
What type of resolution is determined by the number of pixels in the scan converter?
Which of the following is associated with improper adjustment of the brightness and contrast on the video monitor?
The operator will likely overgain our undergain the image
What can you improve by changing gray-scale map?
Which of the following describes an analog signal?
Continuous variation of the signal is possible
What is the order in which the signal travels in the ultrasound system?
Transducer, receiver, scan converter, display
Of the following, which is the best choice to help you demonstrate tissue boundaries that are not perpendicular to the sound beam?
You want to use 3D imaging to display an anatomic structure because 3D has the following advantage over 2D imaging:
Ability to display orthogonal planes simultaneously and image planes impossible to obtain with 2D imaging
What is meant by the term 4D imaging in nosography?
3D imaging with the addition of time
In this image of an artery there is a calcification with a dark vertical band extending beyond arrow. Which explanation best describes the etiology of the dark band?
Reduction in signal amplitude in tissue distal to a highly attenuating or reflecting object
Which term below most correctly describes Doppler waveform?
What should be done to improve the Doppler waveform?
Change the Doppler angle
What is the source of the echoes depicted by the arrows in this image of the kidney?
What is another name for the hyperechoic artifact distal to the fluid structure?
These B-mode images of the common carotid artery show a graphic overlay indicating the number of lines of sight used to acquire each frame of information. No other system parameter was adjusted. Which statement below is true comparing image A to image B?
Image A has better lateral resolution than image B
In the images what technique is used to fill in the empty data between the scan lines?