Clinical Imaging Flashcards
which lets more x-rays through, a dense tissue or a less dense tissue?
a less dense tissue
describe how efficiently x-rays pass through air
all x-rays can pass through air
describe how efficiently x-rays pass through soft tissue
some x-rays can pass through
describe how efficiently x-rays pass through bone
no x-rays can pass through
what happens to x-ray film when it is hit by an x-ray?
the area turns black, so black areas are where the x-rays have been able to pass through
what is difficult to see on an x-ray?
tissues beside tissues of similar density
what is a contrast x-ray?
a dense element such as iodine is put in spaces between tissues to allow visible outlines to appear
what is a risk of x-rays?
they use radiation so can cause DNA damage
why is a CT scan a better scan than an x-ray?
it distinguishes between tissues of similar density much better than an x-ray
describe the image produced by a CT
cross-sectional with no superimposition
does a CT scan give a higher or lower dose of radiation than an x-ray?
much higher
name three examples of soft tissues that cannot be distinguished on CT, due to their very similar densities
pelvic organs
muscles
some areas of the brain
does an ultrasound scan involve higher or lower doses of radiation than an x-ray
it involves no radiation
what scan can show soft tissues that would have been missed on CT?
ultrasound
what scan is good to assess for any abnormal fluid collections?
ultrasound
