aecs

Question 1

aec

Answer 1

automated exposure control
found in table and erect buckys
aim to ensure quality and image is persistant and patient dose is ALARP

Question 2

aec control the s in mas

Answer 2

measures legnth of exposure
measures amount of radiation at exit site
when correct amunt is reached the exposure is terminated

Question 3

3 chambers

Answer 3

a capacitor is used to collect and store data
as more charge is stored the capacitor the voltage increases
the voltage sentive swith will flip when enough voltag is reached

Question 4

the decison to use which chamber depends on

Answer 4

density
remeber the pathology,anatomy and artefacts when choosing chamber

Question 5

considerations

Answer 5

accuracy and presicion positioning
tube bucky grid etc allaigned
chambers is on f.o.v
accurate collimation
chamber is in pb
head should be towards lateral chamber end

Question 6

safety

Answer 6

must be quality controlled
safery features that help patients not recieve excessive dose

Question 7

feedback error

Answer 7

use ionasation current from chamber the system checks that
theres a current
the cuurent is large enough that the exposure will not go on too long

Question 8

guard timer

Answer 8

moiters duration of the exposure
will terminate regardless of the aec operation usually after 2 secs
this is very long time for exposre

Question 9

up mAs

Answer 9

decreases time

Question 10

more density

Answer 10

need more photons for aec so we up mas
can lead to longer exposure as aecs aim to get the best image quality

Question 11

up kvp

Answer 11

decreases mas and time