|
| |
|
X-ray grids are commercially
available with either focused or parallel lead strips, and
these two types are produced in either linear or crossed grid configuration.
The focused grid has its leads angled progressively in such a way that lines
drawn through each lead and continued out of the grid will intersect at a
point known as the grid focus. When strips are not progressively angulated
but are perpendicular to the surface of the grid, the grid is termed
"parallel" (See Figure-1). |
 |
|
Both the focused or parallel grids may be made in
either the linear or crossed grid type. The linear grid is made with the
lengths of all its leads in the same direction. The crossed grid is usually
two linear grids, one on top of the other, with the leads of the top grid
crossing those of the lower grid (See Figure 2).
In general, the crossed grid will remove more scattered radiation than a
linear grid of ratio equal to the combined ratios of its two parts, e.g., a
crossed grid, each of whose parts has 5:1 ratio, will remove more scattered
radiation than a linear grid of 10:1 ratio. This advantage is more striking
at voltages under 100 KVP. |
The advantage of the linear grid over the crossed grid
is that it may be used in tilted-tube techniques without undue "cut-off" in
the radiograph. This is true with grid ratios 8:1 and lower and only if the
angle of tilt of the tube is in a direction parallel to the length of the
leads.
Tilting the tube at an angle across the leads will result in serious density
reduction (cut off) on the film. With higher ratio grids, tube angling must
be slight or focal distance long to avoid marked density variation.
|
|
 |
Simply call 888-459-9729 to request your pricing.
E-Mail your request to:
[email protected].
Fax your request to: Your purchase order or
Download our Quote Request form
(type right in the PDF
file or write in it), print it and then fax it to 440-942-1388
|
