introduction to diagnostic imaging Flashcards
(56 cards)
when was the X ray invented and by who
1985
Wilhelm Conrad Rontgen
when was the CT (computed tomography) invented and by who
1978
Sir Godfrey Hounsfield
when was the MRI invented and by who
1933
Sir Peter Mansfield
diagnostic imaging
use images to make a diagnosis
interventional radiology
image guided surgery
radiotherapy
high energy radiation - kill cancer
radiologist
dr specialising in interpretation of medical imaging
radiographer
technician
takes images
2 types of diagnostic imaging with ionising radiation
X ray and CT
Nuclear medicine - give radioisotopes and measure the radiation that comes out of them
diagnostic imaging without ionising radiation
ultrasound
MRI
issue with ionising radiation
small dose of cancer causeing substances - cause cancer in subsequent years
effect of ionising radiation with age
when younger, tehre is a higher incidence of developing cancer
but need to look at the risk benefit ratio
describe x-rays
tissue type affect attenuation of the x-rays
pass through low density air and fat - black (fat less black than air)
50% through soft tissue - grey
few through bone - white
metal/contrast agent -really white
why are lungs black on x ray
full of air
what would you see if there was a pneumonia in an x-ray
white because pus
in the thorax what cant an x ray distinguish between
heart muscle,
pericardium,
blood inside the heart
what could a white spot on an abdominal radiograph suggest
l sided kidney stone
what is used to improve radiography quality
contrast:
barium and iodine both very white
barium introduced by swallowing, enema?
iodine into artery or vein
describe CT
use X ray
tube spins
detector spins on opposite side
computer performs calculations to produce cross sectional map of tissue density
what can CT differentiate between that x ray cant
water and soft tissue
what is it called when CTs are expressed in different ways
CT windows
what are CT reconstructions
you can display them in any plane that you want to
allow you to see different things without scanning the patient again
describe the different planes
sagittal - down spine
axial - transverse, cut woman in half
coronal - like surgeons see
describe contrast in CTs
iodine injected into an arm vein
enhances the bv
differentiate pathological from normal tissue
risks:
allergic reaction to iodine
if have kidney damage the iodine will make it worse
