RDGR Mobile

Question 1

What is the typical kVP ranges for mobile device?

Answer 1

40-130 kVp

Question 2

What is the typical mAs ranges for mobile device?

Answer 2

0.04-320 mAs

Question 3

is the generator output at a high frequency or low frequency?

Answer 3

High frequency

Question 4

is AEC available on some mobile untis?

Answer 4

Yes

Question 5

What are 3 things to consider for the beam on mobile?

Answer 5

• Anode heel effect
• Grids
• Source-to-image receptor distance (SID)

Question 6

which side of the tube has a decrease of image density?

Answer 6

anode side

Question 7

What is Anode Heel effect more pronounced with?

Answer 7

• Short SID
• Larger field sizes
• Small anode angles

Question 8

Optimal imaging requires that a grid be…

Answer 8

• Level
• Centered to the central ray
• Used at recommended focal distance/range

Question 9

What is grid-cut off?

Answer 9

an unwanted absorption of x-rays via an x-ray grid

Question 10

How should you angle grids for the direction of the rid lines?

Answer 10

angle in the direction of the grid lines (long axis), not against

Question 11

What are three ways to prevent grid cut off?

Answer 11

• Identify the direction of the grid lines if angling CR
• Direct CR to center of the grid
• Use recommended focal range

Question 12

How much off centered do you have to be mispositioned for transverse grid cut off?

Answer 12

1-1.5 inches

Question 13

How to fix grid cut off from focal range?

Answer 13

images taken at distances greater or less than produce cutoff

Question 14

What is off-level grid cutoff?

Answer 14

grid placed on a unstable surface such as the mattress of a bed and/or the grid to tilt “off level, causing grid cutoff

Question 15

What is off-centered grid cutoff?

Answer 15

1-1.5” transverse off centering results in cutoff

Question 16

What is off-focus grid cutoff?

Answer 16

images taken at distances greater or less than can produce cutoff

Question 17

what is the upside-down grid cutoff?

Answer 17

inverting a focused grid causes pronounced grid cutoff

Question 18

What grid cut offs cause overall loss of denstiy?

Answer 18

• off level grid

- Off center grid

Question 19

What grid cut off causes reduced density on the lateral margins?

Answer 19

• off focus grid

- Upside-down grid (most severe when grid is used upside-down)

Question 20

how much kVp should be increased for every how many cm of body tissue?

Answer 20

Increase 2 kVp for every 1 cm of a body part

Question 21

source to skin distance must not be less than what?

Answer 21

12”

Question 22

When bringing mobile into a room wtih a patient supine, where is the base of the mobile?

Answer 22

postioned toward middle of bed

Question 23

When bringing mobile into a room, with a patient seated, where should the base of mobile be?

Answer 23

parallel or 45 degrees toward the foot end of the bed

Question 24

What are additional markers on mobile images?

Answer 24

• Time of examination
• patient position (supine/upright)
• Exposure factors
• RIS systems (accesion numbers)

Question 25

What is the SID for common practice of chest x-ray for mobile?

Answer 25

60” for upright

48” for supine

Question 26

Where is the CR for chest?

Answer 26

T7, perpendicular to long axis of sternum

about 3” below jug notch

Question 27

When do you use a grid for chest x-rays?

Answer 27

when Kvp is higher than 90

Question 28

For chest radiography, which side is facing down for fluid levels? Air levels?

Answer 28

Fluid levels= affected side down

Air levels=affected side up

Question 29

What structures are seen on an abdomnal x-ray?

Answer 29

• Abdominal organs
• Calcifications
• Tumor masses

Question 30

What structures should be seen on a pelvis x-ray?

Answer 30

• Pelvis, including both hips
• Sacrum and coccyx
• Head, neck, trochanters, proximal portions of the femora

Question 31

Where is the CR directed for a neonate for chest, abdomen?

Answer 31

Chest=nipple line

Abdomen=iliac crest

Question 32

Should you ask the patients nurse if it is ok to sit the patient up with a tube in?

Answer 32

Yes

Question 33

for pleural drainage tubes where should the tube be placed for a Pneumothorax? Pleural effusion?

Answer 33

Pneumothorax= anterior and superior

Pleural effusion=posterior and inferior