Contrast Flashcards
what is contrast?
differences in adjacent densities on a radiographic film
explain short-scale contrast
high contrast increased contrast sharp differences between densities black and white seen in bone work kVp's lower than 70
explain long-scale contrast
low contrast decreased contrast density differences are small shades of gray abdomen/chest exams kVp's higher than 70
major controlling factor of contrast?
kVp
if you increase kVp, what happens to contrast?
why?
decreases
increase scatter
what does kVp control?
quality or penetration of the x-ray beam
what 3 words can describe kVp?
electric potential
strength
quality
if OID increases, what happens to contrast?
contrast increases
used for lateral L-Spines
if body habitus increases, what happens to contrast?
why?
contrast decreases
more interactions; more scatter
if beam restriction increases, what happens to contrast?
why?
contrast increases
reduction of scatter reaching IR
if grid ratio increases, what happens to contrast?
why?
contrast increases
reduction of scatter reaching IR
