Grids

Question 1

no grid

Answer 1

1

Question 2

5:1

Answer 2

2

Question 3

6:1

Answer 3

3

Question 4

8:1

Answer 4

4

Question 5

8:1

Answer 5

4

Question 6

grades are primarily used to improve image contrast, especially one radio graphing any part that measures…….

Answer 6

10 cm or greater

Question 7

what is the grid composed of

Answer 7

lead strips that absorbs secondary radiation that would otherwise fog the image

Question 8

grid ratio

Answer 8

grid ratio = height of lead strips/ distance between strips
* the higher the grid ratio= cleans up more scatter

Question 9

10:1

Answer 9

5

Question 10

12:1

Answer 10

5

Question 11

16:1

Answer 11

6

Question 12

if the height of the led strips is 1.6 mm in the distance between the led strips is 0.1 mm the ratio of the grid is?

Answer 12

1.6/0.1 = 16
grid ratio 16:1
* DONT FORGET :1

Question 13

A grid has led strips of 5 mm high, 0.5 mm apart and 1.6 mm wide. What is the current ratio?

Answer 13

5/0.5 = 5
5:1 grid
* distract is the 1.6 mm wide!!!
if your answer doesn’t come out to a normal grid ratio, you used the wrong factor!!!

Question 14

what is the grid conversion formula

Answer 14

mAs1/ mAs2= GCF1/GCF2

Question 15

Off level grid errors

Answer 15

occurs when the tube is angled across the long axis of the grid strips.
-can be a result of improper tube or grid positioning

Question 16

Off center grid error

Answer 16

central ray of the beam is off center from the center of a focused grid
- overall loss of RE across the entire image

Question 17

Off focus grid error

Answer 17

happens when a grid is used at a distance other than that specified focal range

Question 18

Upside down grid error

Answer 18

if the grid is used upside down it will result in serve grid cut off

Question 19

The morie effect

Answer 19

happens more in mobile x ray or cross table hips
- happens to CR cassettes
- a wavy artifact caused by grid lines running parallel to the laser scanning motion

Question 20

a grid should be employed when

Answer 20

1. a body part is over 10 cm
2. Kvp is above 60

Question 21

Grids improve

Answer 21

contrast

Question 22

Higher grid ratio allows ______ scatter radiation to pass through

Answer 22

less

Question 23

interspace material options for grids

Answer 23

• carbon fiber
• aluminum
• plastic
  NEVER LEAD

Question 24

what is a stationary grid

Answer 24

used for table top x rays or mobile radiography
- doesn’t move during exposure

Question 25

moving grid

Answer 25

table or wall bucky
the grid moves during exposure

Question 26

focused grid

Answer 26

the SID has to be correct
only used at a certain SID

Question 27

grid cut off

Answer 27

an unwanted absorption of primary x-rays we want the primary beam to pass through the grid to the IR. Ideally, only the scatter radiation is absorbed
- most often seen the parallel grids

Question 28

air gap technique is an alternative method to using _____

Answer 28

grids
image receptor is placed 10-15 cm from the patient.
a large portion of scattered x rays will not interact with the IR

Question 29

fluoro uses

Answer 29

lower grids