Milliamperes / Time

Question 1

Milliamperes (mA)

Answer 1

controls the current flow to the cathode filament at the time of exposure

Question 1

As mA is __________, filament temperature rises increasing the number of electrons released through ____________.

Answer 1

• increased
• thermionic emission

Question 2

An increase in mA will _______ the number of x-ray photons in the primary beam (quantity)

Answer 2

increase

Question 3

A doubling of mA will _________ radiographic density

Answer 3

double

Question 4

The relationship of mA selected and overall image density is __________

Answer 4

directlyproportional

Ex)
if mA is doubled from 200 to 400, amount of density is also doubled

Question 5

A minimal change in mA of ________ is needed to visually see a change in density

Answer 5

30-35%

Question 6

mA and time does not affect _________

Answer 6

scatter radiation

Question 7

What happens to patient exposure when mA is doubled?

Answer 7

doubling patient exposure

Question 8

Time (s)

Answer 8

Factor that controls length of exposure

Question 9

Milliamperes and time are combined and recognized as a single quantitative factor:

Answer 9

(mAs) milliampere seconds

Question 10

Maintaining the Same Radiographic Density

Answer 10

kV and mAs relationship

Question 11

A _______ in kV by 15% may be compensated for ___________ the mAs

Answer 11

• decrease
• doubling

Question 12

_________ in kV by 15 % may be compensated for by _________ the mAs by half

Answer 12

• increase
• decreasing

Question 13

Maintaining the Same Radiographic Density

Answer 13

mA and time relationship

Question 14

mA and time is ____________

Answer 14

inversely proportional

Question 15

Because mAs is considered as ________, an increase or decrease in one will require a decrease or increase in the other to maintain the same radiographic density.

Answer 15

one value

Question 16

Reciprocity Law

Answer 16

indicates that blackening (density) of the image will remain constant as long as the total energy (total mAs) exposing the image receptor is constant

Question 17

____________ are necessary to prevent patient motion during exposure, which is detrimental to image quality

Answer 17

short exposure times