RDGR Mobile Flashcards
What is the typical kVP ranges for mobile device?
40-130 kVp
What is the typical mAs ranges for mobile device?
0.04-320 mAs
is the generator output at a high frequency or low frequency?
High frequency
is AEC available on some mobile untis?
Yes
What are 3 things to consider for the beam on mobile?
- Anode heel effect
- Grids
- Source-to-image receptor distance (SID)
which side of the tube has a decrease of image density?
anode side
What is Anode Heel effect more pronounced with?
- Short SID
- Larger field sizes
- Small anode angles
Optimal imaging requires that a grid be…
- Level
- Centered to the central ray
- Used at recommended focal distance/range
What is grid-cut off?
an unwanted absorption of x-rays via an x-ray grid
How should you angle grids for the direction of the rid lines?
angle in the direction of the grid lines (long axis), not against
What are three ways to prevent grid cut off?
- Identify the direction of the grid lines if angling CR
- Direct CR to center of the grid
- Use recommended focal range
How much off centered do you have to be mispositioned for transverse grid cut off?
1-1.5 inches
How to fix grid cut off from focal range?
images taken at distances greater or less than produce cutoff
What is off-level grid cutoff?
grid placed on a unstable surface such as the mattress of a bed and/or the grid to tilt “off level, causing grid cutoff
What is off-centered grid cutoff?
1-1.5” transverse off centering results in cutoff
What is off-focus grid cutoff?
images taken at distances greater or less than can produce cutoff
what is the upside-down grid cutoff?
inverting a focused grid causes pronounced grid cutoff
What grid cut offs cause overall loss of denstiy?
- off level grid
- Off center grid
What grid cut off causes reduced density on the lateral margins?
- off focus grid
- Upside-down grid (most severe when grid is used upside-down)
how much kVp should be increased for every how many cm of body tissue?
Increase 2 kVp for every 1 cm of a body part
source to skin distance must not be less than what?
12”
When bringing mobile into a room wtih a patient supine, where is the base of the mobile?
postioned toward middle of bed
When bringing mobile into a room, with a patient seated, where should the base of mobile be?
parallel or 45 degrees toward the foot end of the bed
What are additional markers on mobile images?
- Time of examination
- patient position (supine/upright)
- Exposure factors
- RIS systems (accesion numbers)
What is the SID for common practice of chest x-ray for mobile?
60” for upright
48” for supine
Where is the CR for chest?
T7, perpendicular to long axis of sternum
about 3” below jug notch
When do you use a grid for chest x-rays?
when Kvp is higher than 90
For chest radiography, which side is facing down for fluid levels? Air levels?
Fluid levels= affected side down
Air levels=affected side up
What structures are seen on an abdomnal x-ray?
- Abdominal organs
- Calcifications
- Tumor masses
What structures should be seen on a pelvis x-ray?
- Pelvis, including both hips
- Sacrum and coccyx
- Head, neck, trochanters, proximal portions of the femora
Where is the CR directed for a neonate for chest, abdomen?
Chest=nipple line
Abdomen=iliac crest
Should you ask the patients nurse if it is ok to sit the patient up with a tube in?
Yes
for pleural drainage tubes where should the tube be placed for a Pneumothorax? Pleural effusion?
Pneumothorax= anterior and superior
Pleural effusion=posterior and inferior
