Chapter 12: Scatter Control
Help!
|
|
||||
|---|---|---|---|---|---|
| air gap technique | Method for limiting the scatter reaching the IR. Scatter will miss the IR if there is increased distance between the patient and IR
🗑
|
||||
| aperture diaphragm | Simplest type of beam-restricting device, constructed of a flat piece of lead that has a hole in it
🗑
|
||||
| automatic collimator | Automatically limits the size and shape of a primary beam to the size and shape of the IR. Also called a positive beam-limiting device
🗑
|
||||
| beam-restricting device | Changes the shape and size of the primary beam; located just below the x-ray tube housing
🗑
|
||||
| beam restriction | Refers to a decrease in the size of the projected radiation field, also known as collimation
🗑
|
||||
| Bucky | The Potter-Bucky diaphragm located directly below the radiographic tabletop, which contains the grid and holds the IR
🗑
|
||||
| Bucky factor | Can be used to determine the adjustment in milliampere/second needed when changing from using a grid to non-grid (or vice versa) or for changing to grids with different grid ratios; also called the grid-conversion factor (GCF)
🗑
|
||||
| collimation | Refers to a decrease in the size of the projected radiation field, also known as beam restriction
🗑
|
||||
| collimator | Located immediately below the tube window where the entrance shutters limit the x-ray beam field size
🗑
|
||||
| cone | Essentially an aperture diaphragm that has an extended flange attached
🗑
|
||||
| convergent line | An imaginary line if points were connected along the length of a linear focused grid
🗑
|
||||
| convergent point | An imaginary point, if imaginary lines were drawn from each of the lead lines in a linear focused grid
🗑
|
||||
| cross-hatched grid | Has lead lines that run at a right angle to one another
🗑
|
||||
| crossed grid | Has lead lines that run at a right angle to one another
🗑
|
||||
| cylinder | Essentially an aperture diaphragm that has an extended flange attached to it
🗑
|
||||
| focal distance | The distance between the grid and the convergent line or point. Also known as the grid radius
🗑
|
||||
| focal range | The recommended range of SID measurements that can be used with a focused grid
🗑
|
||||
| focused grid | Has lead lines that are angled, or canted, to approximately match the angle of divergence of the primary beam
🗑
|
||||
| grid | A device that has very thin lead strips with radiolucent interspaces; intended to absorb scatter radiation emitted from the patient before it strikes the IR
🗑
|
||||
| grid cap | Contains a permanently mounted grid and allows the IR to slide in behind it
🗑
|
||||
| grid cassette | An IR that has a grid permanently mounted to its front surface
🗑
|
||||
| grid conversion factor (GCF) | Can be used to determine the adjustment in milliampere/second needed when changing from using a grid to a non-grid (or vice versa) or for changing to grids with different grid ratios; also called the Bucky factor
🗑
|
||||
| grid cutoff | A decrease in the number of transmitted photons that reach the IR because of some misalignment of the grid
🗑
|
||||
| grid focus | The orientation of a grid's lead lines to one another
🗑
|
||||
| grid frequency | Expresses the number of lead lines per unit length in inches, centimeters, or both
🗑
|
||||
| grid pattern | Refers to the linear pattern of the lead lines of a grid
🗑
|
||||
| grid ratio | The ratio of the height of the lead strips to the distance between them
🗑
|
||||
| interspace material | Radiolucent strips between the lead lines of a grid, generally made of aluminum
🗑
|
||||
| lead mask | Changes the shape and size of the projected x-ray field; similar to an aperture diaphragm
🗑
|
||||
| linear grid | Has lead lines that run in one direction only
🗑
|
||||
| Moiré effect | A zebra pattern artifact that can occur during CR imaging if the grid frequency is similar to the laser scanning frequency or if a grid cassette is placed in a Bucky
🗑
|
||||
| nonfocused grid | Has lead lines that run parallel to one another; also called a parallel grid
🗑
|
||||
| parallel grid | Has lead lines that run parallel to one another; also called a nonfocused grid
🗑
|
||||
| positive beam-limiting device (PBL) | Automatically limits the size and shape of the primary beam to the size and shape of the IR; also called an automatic collimator
🗑
|
||||
| wafer grid | A stationary grid placed on top of the IR
🗑
|
Review the information in the table. When you are ready to quiz yourself you can hide individual columns or the entire table. Then you can click on the empty cells to reveal the answer. Try to recall what will be displayed before clicking the empty cell.
To hide a column, click on the column name.
To hide the entire table, click on the "Hide All" button.
You may also shuffle the rows of the table by clicking on the "Shuffle" button.
Or sort by any of the columns using the down arrow next to any column heading.
If you know all the data on any row, you can temporarily remove it by tapping the trash can to the right of the row.
To hide a column, click on the column name.
To hide the entire table, click on the "Hide All" button.
You may also shuffle the rows of the table by clicking on the "Shuffle" button.
Or sort by any of the columns using the down arrow next to any column heading.
If you know all the data on any row, you can temporarily remove it by tapping the trash can to the right of the row.
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Created by:
setelinea
Popular Radiology sets