Producing the image

Question 1

Two areas where contrast may be manipulated

Answer 1

-patient’s thickness
-mechanical variables available to enhance ( radiographic contrast)

Question 2

4 factors that are set on the x-ray unit

Answer 2

-distance
-kV
-mA
-time

Question 3

Normal preset for distance between the x-ray tube and the receptor

Answer 3

40 inches

Question 4

Inverse square law

Answer 4

the intensity of radiation at a location is inversely proportional to the square of the distance

Question 5

kV

Answer 5

increases penetrating power
controls quality of image
-mainly effects contrast. too high = no contrast

Question 6

mA

Answer 6

greater quantity of photons are produced
quantity of radiation
-the higher the number the more interactions which could lead to high-density image (dark)

Question 7

increase penetration

Answer 7

original kV X 1.15(kV+15%)

Question 8

decrease penetration

Answer 8

original kV X 0.85(kV-15%

Question 9

Sante’s rule

Answer 9

(tissue thickness in cm X2) + 40 + grid factor (usually 8 - 10)= initial kVp