Biological effects of radiation Flashcards
what is the meaning of dosimetry
dosimetry is the measure of radiation dose
what is a reference dose
these are the dose levels set for different types of xray examinations
what is radiation absorbed dose
this is the amount of radiation absorbed from the xray beam
what is the units for radiation absorbed dose
the gray (GY)
1 Gray = 1 J/kg-1
it is common to usee the subunits of the gray as it is a large unit so we would use milligrays and micrograys
what is equivalent dose (Ht)
this is a measure oif the harmful effects of different types of radiation and we are able to measure this by using radiation weighting factors
for example alpha particles cannot penetrate far into tissue and they have a weighting factor of 20
what is the equation to calculate the equivalent dose
equivalent dose (Ht) = radiation absorbed dose x weighting factor of specific type of radiation
measure in sieverts
since the weighting factor for xrays is 1 the equivalent dose would equal the radiation absorbed dose
what is effective dose
this allows the comparison of doses to different body parts
we do this because different tissues have different sensitivities to radiationn so it is important to reflect the risk to different tissues
we do this by using the tissue weighting factors
how do we calculate the effective dose
effective dose = equivalent dose x tissue weighting factor
what is collective effective dose
this is the measure of the total effective dose to a population kmeasured in man-sieverts(man-Sv)
