ch. 5 quality Flashcards
how easily details can be seen on a radiograph
radiographic quality
what 3 things affect detail/ quality
radiographic desity, contrast, and geometric factors
what are the 3 geometric factors
magnification, distortion, un-sharpness
what color do x-rays turn film
black
what can cause un-sharpness
patient moving, wrong SID
what does increasing mAs, kVp, developing time, temperature of developer do
create greater density
what can influence density
tissue density and patient thickness
what does decreasing SID do to density
increases it
what is inversely proportional to tissue density
radiographic density
the higher the tissue density, the___ the radiographic density
lower
if thickness of tissue doubles, x-rays reaching film is
halved
what primarily controls radiographic contrast
kVp level
difference in density and mass between 2 adjacent anatomical structures
subject contrast
what causes film fog
light exposure
what does not affect contrast
SID
high contrast=short scale=black to white= low kVp when radiographing what
bone
low contrast=long scale=gray tones=high kVp when radiographing what
soft tissue
what do you do if film background is grey
increase mAs by 30-50%
what does “overexposed” mean
too dark
what do you do if overexposed but bones are white
decrease mAs by 30-50%
what do you do if overexposed and bones are grey
decrease kVp by 10-15%
what does “underexposed” mean
too light
what do you do if underexposed but anatomic silhouetes are not visible
increase kVp by 10-15%
what do you do if underexposed and anatomic silhouetes are visible
increase mAs by 30-50%
