how scatter affects image contrast.
the general relationship between x-ray beam area
and image contrast.
and illustrate the concept of grid ratio.
What are typical values?
between parallel and focused
the following grid quantities:
improvement factor (K)
explain the following three types of grid cutoff
and describe their effect on images.
distance between grid and tube.
the relationship of contrast improvement to grid
the relationship of patient exposure to grid
the advantages and disadvantages of a low-ratio
the advantages and disadvantages of a high-ratio
the use of grids in mammography.
the differences among the following beam-limiting
devices and the advantages and disadvantages of each.
light localizing collimators
positive beam limitation (automatic collimators)
how grid lines can be eliminated from an image.
an air-gap technique.
What are the advantages and disadvantages? Identify a clinical
procedure where it is routinely used.