Radiation phlysics/ safety Flashcards
quantity of xrays=
mA
common ma and kvp for pod
50-70kvp and 1-90 mas
Rem
measured exposure
unit of radioactivity used to equate the emissions from different materials
Curie
rule of 15
decrease kvp by 15%=increase MA by 2
place heel closer to
Cathode side (greater intensity)
____kvp favors photoelectric effect
Low,
forms image by photon striking electrons
Pair production
photon with Energy above 1.02 MeV interacts with nucleus
Photonuclear disintegration
ejects one or more nuclear particles at 7MeV
stochastic effect
probability of cancer occurrence increases with dose
breast,bone,leukemia, lung
law of bergonie and tribondeau
most sensitive bone marrow, lymphocytes gi CNS most resistant
linear energy transfer
amount of Energy transferred along path of radiation
high=direct damage to DNA
low= indirect damage of free radicles
spermatozoa delayed, temporary, permanent
delay= 10 RADS, temporary=200 Rads, permanent=500
Fetal dose
10 rads cause 0.1% increase in spontaneous abortion and 1% risk of congenital abnormalities
Entrance dose of foot
1 Rad
Maximum annual dose
1/10th age
annual effective dose
5 rem
skin/hand/feet annual dose
50 rem
osteochondroses of 1st met base
wagner
osteochondroses of medial cuneiform
buchman
osteochondroses of talus
kappis
RA in 5th met
5 mm erosions
h vertebrae
sickle cell
proximal medial tibial metaphysis=
syphilis
