radiographic contrast Flashcards
what is contrast
the difference between areas of brightness on an image
contrast & scale have what kind of relationship
inversely proportional
High contrast = short scale
a black and white image will have what contrast? what difference? and what scale?
high contrast
large difference
short scale
a gray image will have what contrast? what difference? and what scale?
low contrast
small difference
long scale
If your entire image is dark, what is wrong?
it has low brightness
If your entire image is gray, what is wrong
low contrast
If your entire image is black and white, whats wrong?
high contrast
If your entire image is white, whats wrong?
it has high brightness
Back in the day, what was the relationship between kVp and contrast?
Higher kVp = low contrast image (gray)
Lower kVp = high contrast image (black & white)
what controls image contrast today
The digital systems & computer algorithms
whats exams need high contrast
extremity exams to see maximum bony detail
& contrast media exams to differentiate soft tissue structures
what exams need moderate contrast
abdomen, pelvis & Lumbar
some gray needed to see soft tissue outline
what exams require low contrast
chest exams to see subtle pulmonary structures and heart outline
