Exam 3

Question 1

spatial resolution aka-

Answer 1

digital image display

Question 2

spatial resolution affected by-

Answer 2

-part
-focal spot
-OID
-SID

Question 3

motion of the part-

Answer 3

1/30 of a second max exposure time to limit amount of motion visible on the radiograph

Question 4

false images-

Answer 4

-additional images of the part beam radiograph due to motion
-considered artifacts

Question 5

as motion increases, spatial resolution-

Answer 5

decreases

Question 6

penumbra/blur-

Answer 6

unsharpness caused by motion

Question 7

anode bevel-

Answer 7

angle of anode surface

Question 8

the smaller the focal spot-

Answer 8

the higher the focal spot

Question 9

don’t use small focal spot all the time because-

Answer 9

it would overload/damage x-ray tube

Question 10

use small focal spot for extremities because-

Answer 10

it increases spatial resolution

Question 11

actual focal spot-

Answer 11

specific target area on anode where x-rays are produced

Question 12

projected focal spot-

Answer 12

focal spot size projected from anode toward IR

Question 13

affected focal spot-

Answer 13

area projected onto patient/IR

Question 14

line focus principle-

Answer 14

states beveling anode at steeper angles (more vertical) will cause AFS to be smaller than actual focal spot

Question 15

most target angles of the focal spot vary from-

Answer 15

5-20 (not something you can choose)

Question 16

typical, large focal spots range from-

Answer 16

1mm - 2mm

Question 17

typical small focal spots range from-

Answer 17

.5mm - 1mm

Question 18

focal spot is directly proportional to-

Answer 18

penumbra (focal spot increases, penumbra decreases by 2)

Question 19

spatial resolution can be measured in-

Answer 19

line-pairs per mm test

Question 20

Geometric sharpness & unsharpness-

Answer 20

numeric sharpness that occurs in the image

Question 21

SOD-

Answer 21

distance from the source to the IR to the object being imaged

Question 22

Inverse Square Law-

Answer 22

states intensity of x-ray beam is inversely proportional to square of distance

Question 23

ISL formula-

Answer 23

if reduce SID by ½ intensity will increase by a factor of 4

Question 24

ISL used to determine-

Answer 24

intensity of x-ray beam or receptor exposure

Question 25

square law-

Answer 25

more likely to use because will help determine what technical factors will be

Question 26

square law states-

Answer 26

the change in technical factors (mAs is the only one) should be equal to the square in the change of distance

Question 27

OID inversely proportional to-

Answer 27

image sharpness

Question 28

air-gap technique-

Answer 28

intentionally increase OID to reduce scatter from reaching IR (want to decrease OID as much as possible)

Question 29

magnification-

Answer 29

ratio between size of object in image & actual object