exposures 9 and 10 Flashcards
Amount of scattered radiation that hits the film can be controlled by either p101
Preventing the production of scatter in patients_____
Preventing scatter from reaching the ____ after it is produced in patients body
Preventing the production of scatter in patients body
Preventing scatter from reaching the film after it is produced in patients body
Scattered radiation reduces radiographic _____ by placing layer of ____ or grey ness over the image p 101
.Scattered radiation reduces radiographic contrast by placing layer of fog or grey ness over the image p 101
Collimator p 101
Device that prevents production of _____ in the patients body
Device that prevents production of scatter in the patients body
Grid p 101
Device that prevents ____ from reaching the film
Device that prevents scatter from reaching the film
Bucky p 101
Used to ____ the grid during the exposure
Used to move the grid during the exposure
Primary radiation p102
Produced in ____ and is aimed toward the patients ____
Produced in X-ray tube and is aimed toward the patients body
Photons in beam enter the body and interact with ____ in patients body. Sometimes photons ____, ____through, and put ___ on film. Photons can be sometimes ____
P 101
.
Photons in beam enter the body and interact with atoms in patients body. Sometimes photons absorbed, pass through, and put density on film. Photons can be sometimes scattered.
P 101
Scattered radiation p 102
When primary ____ hits an atomic ____ usually in patients body the. Photon is ____off atomic particle and primary photon is ___
scatter can :3
When primary photon hits an atomic particle usually in patients body the. Photon is deflected off atomic particle and primary photon is scattered
Can scatter back toward X-ray tube, shoot out the patient, or hit xray film
Scattered radiation travels in a different direction from _____ radiation and ___energy p 102
.
Scattered radiation travels in a different direction from primary radiation and loses energy p 102
Scattered radiation that hits film affects the film by putting ____on it. Puts a layer of ____ equally overall whole image making to appear ____ contrast . Density distinctions between adjacent structures ____ and some structures are ____. Scatter produces an image with very ____ scale contrast and reduces ____ of whole image
P 102
.
Scattered radiation that hits film affects the film by putting density on it. Puts a layer of grey equally overall whole image making to appear low contrast . Density distinctions between adjacent structures muted and some structures are hidden. Scatter produces an image with very long scale contrast and reduces quality of whole image
Scattered radiation produces _____contrast p 102
.low
Grid p 102
Creator?
Placed between — and —
____scattered radiations and prevents scatter from reaching and affecting film
____ contrast
Gustavave Bucky
Placed between patient and film
Absorbs scattered radiations and prevents scatter from reaching and affecting film
Increases contrast
Grid increases _____ p 102
.contrast
Grids are made to match _____ of cassette and xray film . Constructed of ____ strips aka ____ foil strips p 103
Grids are made to match size of cassette and xray film . Constructed of lead strips aka lead foil strips p 103
Interspace p 103
Each ____ strip separated from spaces
Each grid strip separated from spaces
Interspaces can be type of 3
with _____ material p 103
.Interspaces can be type of cardboard fiber, plastic or aluminum with radiolucent material p 103
Face of grid
_____of grid
Surface of grid
Line of grid p 103
____ lines on face of grid
let’s radiographer know direction of ____ line
Center lines on face of grid let’s radiographer know direction of grid line
Most common grid p 104
Focused grid
Focused grid p 104
Grid strips placed at ____ during construction they are not all placed parallel. Strips at center are ____ and strips at sides are ____where strips are more angled as closer to end. This matches how photons emerge from X-ray tube due to its ____shape
Grid strips placed at edge during construction they are not all placed parallel. Strips at center are parallel and strips at sides are angled where strips are more angled as closer to end. This matches how photons emerge from X-ray tube due to its cone shape
Focused grid lets ____ beam in and absorbs ____ photons
.Focused grid lets primary beam in and absorbs scatterd photons
____ radiation passes through grid whereas ____ radiation is absorbed by grid
.
Primary radiation passes through grid whereas scattered radiation is absorbed by grid
Parallel grid p 104
Same as focused grid but grid strips are not at ____ . Strips are ___ to each other
Same as focused grid but grid strips are not at angle . Strips are parallel to each other
Crossed grid p 105
Aka (2)
Combo of —- grids. One parallel grid is placed on top each other but one is turned —-degrees so that lines of two grids cross each other .
Patterns —- most radiation but doesn’t work with —- X-ray tube
Aka criss- cross grid and cross hatch grid
Combo of parallel grids. One parallel grid is placed on top each other but one is turned 90 degrees so that lines of two grids cross each other .
Patterns absorbs most radiation but doesn’t work with angled X-ray tube
Grid ratio p 105
Relationship between (2)
Most common(5)
Relationship between height if lead strips and distance between lead strips
Most common
5: 1
6: 1
8: 1
12: 1
16: 1
Grid ratio is the way the radiographer determines how much scatter radiation the grid will ____or clean up.
.
Grid ratio is the way the radiographer determines how much scatter radiation the grid will absorb or clean up.
High grid ratio ____will absorb more scattered radiation than lower ratio grid ___.Grid absorbs scattered X-rays that hit grid ___
.
High ratio grid absorbs ____ scattered radiation than low ratio grid p 106
.High ratio grid absorbs more scattered radiation than low ratio grid p 106
Grid frequency p 107
Number of ____line per ____
Usual range ___-___ lines per inch
Grid with ____ grid lines per inch is more efficient at absorbing scattered radiation because it has more____in it
Number of grid line per inch
Usual range 60-110 lines per inch
Grid with more grid lines per inch is more efficient at absorbing scattered radiation because it has more lead in it
Grid cut off p 107
Unwanted absorption of ____ radiation by the grid
Aka grid ___
Areas that appear ____ color or less ___
Unwanted absorption of primary radiation by the grid
Aka grid stripping
Areas that appear lighter or less dense
Grid cut off with focused grid six general ways p 107
Wrong source image distance is used- lateral edges light
X-ray tube is angled against the grid lines- light across xray
Grid is angled in relation to the xray beam- light across xray
X-ray tube is not centered so that the central ray is over the center of the grid- light across xray
Grid is used upside down- light edges and center xray good
Bucky catapulting grid lines- lighter and darker across image
Grid focusing distance p 107
Acceptable range where ____is used with focused grid
Imaginary point in space ___ the face of focused grid
Extend the height of focused grid strips, they would converge or meet at a point somewhere ___the face of grid
Acceptable range where Sid is used with focused grid
Imaginary point in space above the face of focused grid
Extend the height of focused grid strips, they would converge or meet at a point somewhere above the face of grid
Grid strips of a focused grid are ____ so that they are aligned with pattern of xray beam
Focal range- tolerance range that extends a little above and below the ___ ____ distance.
Acceptable range of _____ that can be used with focused group
X-ray tube is placed either above or below the focal range, ___ ____ ___can occur
.Grid strips of a focused grid are angled so that they are aligned with pattern of xray beam
Focal range- tolerance range that extends a little above and below the grid focusing distance. Acceptable range of source image distances that can be used with focused group
X-ray tube is placed either above or below the focal range, grid cut off can occur
Use the ___within the grids focal range to avoid grid cut off
.sid
Angling the X-ray tube ____ the grid lines will produce noticeable grid cut off p 108
Angling the tube across the grid lines, ____ to center line of the grid will produce grid cut off
.Angling the X-ray tube against the grid lines will produce noticeable grid cut off
Angling the tube across the grid lines, perpendicular to center line of the grid will produce grid cut off
To avoid grid cut off do not angle the xray beam ____ the grid lines
.against
Grid cut off also occurs if the X-ray tube is ____ but the grid is an angle. Causes the xray beam to be directed ____the grid lines
Grid cut off also occurs if the X-ray tube is straight but the grid is an angle. Causes the xray beam to be directed against the grid lines
Avid grid cut off the beam and grid must be _____ to each other p 109
.Avid grid cut off the beam and grid must be Perpendicular to each other p 109
Central ray must be positioned at the ______ line of the grid to avoid grid cut off. P 109
Grid cut off is produced when the X-ray tube is moved ____ the grid lines, or _____to the way the grid lines run in the grid
Grid cut off is produced when the X-ray tube is moved across the grid lines, or perpendicular to the way the grid lines run in the grid
Top side of grid should placed ____ the xray beam with film ____the grid p 110
A less ____ image will be displayed in very center of radiograph and the sides will appear almost ___
.Top side of grid should placed toward the xray beam with film underneath the grid p 110
A less dense image will be displayed in very center of radiograph and the sides will appear almost dark
The _____ of the grid must face the X-ray tube to avoid grid cut off p 110
.The center of the grid must face the X-ray tube to avoid grid cut off p 110
Bucky p 11
Moves the ____ during xray exposure. This movement ____the grid lines so they will not be imaged on the radiograph
Moves the grid during xray exposure. This movement blurs the grid lines so they will not be imaged on the radiograph
Bucky movement ___ the grid lines p 11
.blurs
Most common type of Bucky p 111
_____ Bucky
Moves _____side to side during exposure
If moves to slow or too fast called ____grid
Reciprocating Bucky
Moves grid side to side during exposure
If moves to slow or too fast called capturing grid
Bucky device is _____ xray table p 111
Can be installed in ____ radiograph
Grid is positioned ____ the tray and cassette
Can be installed in upright radiograph
Grid is positioned above the tray and cassette
Grid selection factors p 112
_____of the body part being examined
The _____ used
Amount of ____ used
Possibility of producing _____
Grid ____
Size of the body part being examined
The KVp used
Amount of contrast used
Possibility of producing grid cut off
Grid pattern
A grid should be used when patients body part measures more than ____cm
____ scatter is produced when patients body part is large because more atoms for the xray photons collide
.10 cm
More
Grid should be used when the KVp has to be set above _____
Scattered radiation is produced at ____ KVp
.70 KVp
High
At techniques above 90 KVp a grid ratio of at least ____
High grid ratio is used , grid will be able to absorb____ scattered radiation
High contrast- ____grid ratio should be used- more chance for ______
P 112
.At techniques above 90 KVp a grid ratio of at least 8:1
High grid ratio is used , grid will be able to absorb more scattered radiation
High contrast- high grid ratio should be used- more chance for grid cut off
Crossed grid p 112
Absorb ____scattered radiation . Grid lines will absorb ____ radiation no matter which way the tube is angled
Absorb most scattered radiation . Grid lines will absorb primary radiation no matter which way the tube is angled
Radiographer needs ____ the exposure factor whenever a grid is being used
Two reasons
Radiograph taken without a grid has ____ scattered radiation than one with a grid. Scattered radiation puts _____ even though it’s unwanted.
Grid- makes ____ dense film, lead in grid absorbs primary radiation which takes away ___
Amount of technique compensates or the amount of exposure increase or decrease necessary depends on what grid ____was used for original exposure compared to second exposure
.Radiographer needs increase the exposure factor whenever a grid is being used
Two reasons
Radiograph taken without a grid has more scattered radiation than one with a grid. Scattered radiation puts density even though it’s unwanted.
Grid- makes less dense film, lead in grid absorbs primary radiation which takes away density
Amount of technique compensates or the amount of exposure increase or decrease necessary depends on what grid ratio was used for original exposure compared to second exposure
____ should be the factor used to compensate for grid use because ____does not change the amount of scattered radiation produced p 113
.
Mas should be the factor used to compensate for grid use because mas does not change the amount of scattered radiation produced p 113
Grid ratio and multipliers
No grid-1 5:1-2 6:1-3 8:1-4 10/12:1-5 16:1-6
____prevent production of too much scattered radiation in the patients body
P 115
Collimating
