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where are the portable xray units commonly used?
- pt room
- er
- icu
- surgery and recovery rooms
- nursery and neonatal units
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when was mobile xray equiment first used?
- battlefield during WW1
- units were carried to field sites
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are portable units as sophisticated as stationary units?
false
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what are the usual 2 controls on a portable?
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what is the mas range?
0.4- 320
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what is the kvp range?
40- 130
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what are the two types of mobile x-ray machines/
- battery powered
- capacitor discharge
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describe the battery powered portable unit
- uses two different sets of batteries (lead-acid, or nickel- cadmium)
- one powers driving of machine
- one set provides power to x-ray tube
- fully charged batteries can:
- make 10-15 exposures
- be driven reasonable distances
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describe the capacitor discharge portable unit
- no batteries
- carries two metal plates that hold electrical charge
- capacitor units must be charged prior to each use
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what are the advantages and disadvantages of a battery-operated unit
- Adv:
- cordless
- provide constant kvp and mas
- Disadv:
- heavy
- hard to control
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what is "deadman" type of break?
stops machine instantly when push-handle released
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what are the advantages and disadvantages of capacitor discharge units?
- adv:
- lightweight, smaller and easier to maneuver
- require much less time to charge than battery units
- disadv:
- cant handle thick body parts due to voltage drop during exposure
- must be charged prior to each use
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what is the Nomad?
- for places with no electricity or chemical processors
- mainly for dental x-rays
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what are the 3 important technical factors that must be clearly understood to perform optimum mobile examinations?
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what must you consider when using a grid?
- must be level
- x-ray beam must be properly centered to grid
- correct focal distance must be used
- best grids for mobile rad have ratios of 6:1 or 8:1 and a focal range of 36-44 inches
- make sure grid is fastened to cassette properly if tape-on grid is used
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what must you consider when using anode heel effect?
- correct placement of anode-cathode (usually marked on tube housing) with respect to anatomy
- anode should be on thinner part (t-spine)
- heel effect increases with short SID, large field sizes (more common in mobile radiography
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what are the things you should remember when positioning the portable machine?
- if exam in supine postion, move base of machine to middle of bed
- if seated upright, base at end of bed
- lateral and decub positions, place base parallel or perpendicular to bed
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what is the single most effective radiation protection measure?
distance
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what is the minimal safe distance from beam?
6 feet
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where is the safest place to stand during a portable exam?
right angle to pt and primary beam
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when should you shield pt's gonads?
- x-raying children
- person is of reproductive age
- pt requests
- gonads lie in or near useful beam
- when shield will not interfere with anatomy of interest
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what is the minimum source to skin distance?
12 inches
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what should you consider when moving a patient?
- never move pt or part without:
- assessing ability to move or ability to tolerate movement
- should also check with staff to obtain assistance and permission to move a part that has had surgery or fractured
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