Chapter 18 - The Grid
Quiz yourself by thinking what should be in
each of the black spaces below before clicking
on it to display the answer.
Help!
|
|
||||
|---|---|---|---|---|---|
| Why does a grid improve contrast? | show 🗑
|
||||
| show | when body part thickness exceeds 10 cm and when kVp is above 60
🗑
|
||||
| A thin, flat, rectangular device made by placing a series of radiopaque lead strips side by side separated by a radiolucent interspace material, the interspace material is thicker and usually made of aluminum. | show 🗑
|
||||
| show | linear grids
🗑
|
||||
| show | focused grids
🗑
|
||||
| show | The more effective the grid is at absorbing scatter, the greater the patient dose to receive adequate exposure and the less exposure will be received by the image receptor
🗑
|
||||
| show | selectivity and contrast improvement ability
🗑
|
||||
| show | The contrast improvement factor (K):
K=Radiographic contrast with the grid/Radiographic contrast without the grid
🗑
|
||||
| When the tube is angled across the long axis of the grid strips, what error can occur? | show 🗑
|
||||
| placing the patient at a greater object-to-image distance, creating an air gap between the patient and the image receptor, reducing the amount of scatter reaching the image receptor, improving contrast without the use of a grid. | show 🗑
|
||||
| show | grid replacement software
🗑
|
||||
| show | c. decrease in kVp
🗑
|
||||
| What would the grid ratio be if the lead strips are 4 mm high and are separated by an interspace of 0.50 mm? | show 🗑
|
||||
| show | it increases
🗑
|
||||
| show | grid frequency
🗑
|
||||
| What happens to the selectivity when a grid has a higher lead content? | show 🗑
|
||||
| show | it increases
🗑
|
||||
| What type of error occurs when the tube is angled across the long axis of the grid strips? | show 🗑
|
||||
| show | the Moire effect
🗑
|
||||
| When the lead content of the grid increases, what happens to the ability of the grid to remove scatter and improve contrast? | show 🗑
|
||||
| Two linear grids placed on top of one another so that the lead strips form a criss-cross pattern | show 🗑
|
||||
| A grid created with the central grid strips parallel with the strips and becoming more inclined as they move away from the central axis; the lines would intersect along a point in space called the line of convergence | show 🗑
|
||||
| A device used to improve contrast of the radiographic image | show 🗑
|
||||
| The result of the primary beam being angled into the lead strips | show 🗑
|
||||
| The number of grid lines per inch or centimeter | show 🗑
|
||||
| show | grid ratio
🗑
|
||||
| A grid with lead strips running in only one direction | show 🗑
|
||||
| show | parallel grid
🗑
|
||||
| show |
🗑
|
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:
teresachristensen
Popular Radiology sets