Transcript THE X-RAY UNIT - Montgomery College

THE X-RAY UNIT
THE BASICS
WHAT FOUR COMPONENTS ARE IN
TYPICAL RADIOGRAPHIC ROOM?
1. X-RAY TUBE
2. OPERATING CONSOLE
3. HIGH VOLTAGE GENERATOR
4. X-RAY TABLE
THE X-RAY TUBE
Chapter 6 in Bushong
• OVERHEAD
Ceiling suspension
Sets of rails-controls
longitudinal/transverse
positioning
Telescoping column
for controlling vertical
distance.
• FLOOR
Tube-support column
mounted on floor
Same positioning
options as overhead
Counter weight on
back of telescoping
column. Why?
OTHER COMPONENTS ON XRAY TUBE
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Collimator light
Collimator controls
Transverse lock
Horizontal lock
Longitudinal lock
Vertical lock
Tube head lock
Tape Measure
• C-arm
• Protective housing
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Isotrophically
Window
Useful beam
Leakage
• Acceptable level of leakage is….?
CHAPTER 5
What is the typical voltage range?
What is the typical current range?
X-RAY TABLE
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Must be radiolucent
Can be tilted
Float
Holds bucky
Has weight limit of 300lbs(Carbon-fiber)
Easily cleaned, hard to scratch and without
crevices
X-RAY CONSOLE
• Allows the radiographer to control the x-ray
tube current (mA) and the voltage (kVp) so
that a useful image is produced.
• ? Controls the quantity
• ? Controls the quality
• What does a line voltage compensator do?
AN R/F ROOM
• Contains a radiographic unit
• Contains a fluoroscopic unit
– located under radiographic table
– used in studies where it is necessary to watch a
procedure on a monitor using x-rays.
HIGH VOLTAGE
GENERATOR
Housed within the x-ray room
Mobile radiography
mAs AND THE IMAGE ON
THE FILM Fauber pgs 51-53
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What is mAs?
mAs = the mA X exposure time
mAs is the quantity of x-rays
mAs produces the overall
blackening(DENSITY) on the film or
brightness on filmless image receptors
• Pg 53-note the relationship between density
and brightness
kVp and the image produced on
the film (pgs 53-57)
• What is kVp?
• Controls the quality or penetrating quality
of the x-ray beam
• Produces the varying shades of gray on the
film. (variations of brightness and density)
• Gray scale
• Long or low and short or high contrast
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Anatomic part and contrast
• Range of densities
• Tissue composition
• Pgs 57-58
Intro to Digital Imaging
Fauber and Carter
• Carter pgs 80-82
• Does KVP matter anymore?
• Does mAs matter anymore?
Four radiographic qualities
• Density
• Contrast
-----------------------• Spatial resolution
• Recorded detail
• Size/Shape distortion
• Overall blackness
• Difference between
adjacent densities
----------------------• Smallest object detected
(DR)
• Sharpness of the lines of
an image
• Misrepresentation of the
true size or shape of image
Controlling and influencing factors
• What might control or influence the four
radiographic qualities?
• Density
• Contrast
• Recorded detail
• Distortion
• Images 4-28,4-29, 4-30, 4,31 pg 104 Fauber
• Images 5-11, 5-15, Figure 5-16, all images on pg
130-131 Fauber
Sharpness vs. Visibility
• Driving on a foggy night (visibility)
• Driving after having drops in your eyes
(Sharpness)
Good images vs Bad images
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Over exposed
Over penetrated
Poor detail
distortion