worksheet 2
q: Shuttering the digital image will reduce the exposure to the patient.
a: False
q: Window width controls the brightness of the image on the display.
a: False
q: The look-up table that is used to determine the brightness and contrast of an image is unique for each anatomic part.
a: True
q: A graphical representation of a digital image is called a ________.
a: Histogram
q: What does window level control?
a: Brightness
q: In preprocessing, how does the computer adjust for dead pixels?
a: Kernelling
q: Which of the following is not a postprocessing option?
a: Dynamic range compression
q: What causes aliasing?
a: Insufficient sampling frequency
q: What is saturation?
a: When dels have reached their maximum electrical charge and are pure black
q: What type of histogram analysis would be used for a pelvis x-ray?
a: Type 3
q: Which of the following controls the length of the gray scale of a displayed image?
a: Window width
q: Which of the following is an example of postprocessing?
a: windowing and resizing
q: What can throw a histogram analysis off?
a: selecting the wrong part for the exam, in CR, not evenly spacing when multiple imageare imaged, and artifacts
q: What does LUT stand for?
a: Look-up table
q: Put processing steps in order: Values of interest → Histogram → Look up table
a: 2,1,3
q: What would you do to see the edge of the bones during postprocessing?
a: Apply edge enhancement
q: What are the three types of postprocessing domains?
a: Spatial, intensity, frequency
q: Smoothing can increase the visible appearance of noise.
a: False
q: Although Right and Left markers are available electronically, lead markers are strongly recommended for legal reasons.
a: True
q: The speed of any imaging system is always ______ related to exposure required.
a: Inversely
q: Nearly all modern CR and DR systems can be operated without substantial ______ in the image.
a: Noise/mottle
q: No dark digital image should be repeated unless ______ has occurred.
a: Saturation
q: When windowing is applied and saved to PACS, the range available to the radiologist is ______.
a: Reduced/limited/narrowed
q: Smoothing algorithms suppress moderate amounts of ______.
a: Noise/mottle
q: For an image with low contrast, smoothing may lead to loss of ______.
a: Detail
q: For a high-contrast image, edge enhancement may increase ______.
a: Noise
q: For scoliosis series, image ______ software is used to align images.
a: Stitching
q: Point, area, and global processing occur in which domain?
a: Spatial
q: In which domain is the image sorted by pixel values?
a: Intensity
q: Zoom/magnification is what type of processing?
a: Area
q: A look-up table has two columns: ______ and ______.
a: Input, output
q: If dynamic range is limited, data ______ can occur.
a: Clipping
q: Detail processing can be performed in the ______ or ______ domain.
a: Spatial, frequency
q: Kernel operations pass a smaller ______ over each pixel.
a: Sub-matrix
q: ______ is a form of low-pass filtering that softens edges and reduces noise.
a: Smoothing