The filter grid used by DR is the same as that used by ordinary X-ray machines.
They are made of parallel strips of high attenuation material (such as lead) filled with low attenuation material (such as carbon fiber or organic spacers). The strips may be oriented along their longitudinal axis or crosswise. Since scattered radiation increases in “thicker” patients and larger fields of view, a wire grid can be used in this case to improve image contrast.
The working ability of the wire grid is described by the grid ratio, which is the ratio of the height (h) of the lead bars and the distance between the two lead bars, that is, the spacing (D). 70-90 kVp technologies typically use an 8:1 grid ratio, >90 kVp technologies use 12:1. Strip linear density (number of strips per cm) is 1/(D+d), where d is the thickness of the strip. This is usually 20-60 bars per cm.
The grid is mainly divided into the following four types
Virtual Grid: No actual grid used; latest innovation in reducing scatter by digitally reconstructing radiographs
Focus grid (most grids): The strips are slightly inclined so that they are focused in space, so must be used at the specified focal length
Parallel grids: for short fields or long distances
Moving Grids (also known as Potter-Bucky or Reciprocating Grids): Eliminates thin grid lines that may appear on images when using focus or parallel grids; cannot be used for portable movies
Rasters are typically used in radiography, with even raster ratios, such as 4:1, 6:1, 8:1, 10:1, or 12:1.
We Huading Electronics provide filter grids of various sizes and grid ratios, welcome to inquire, hotline +8617616362243!
Author：X Ray Grids Maker
Tel: +86 536-8882360
Company: Weifang Newheek Electronic Tech Co., Ltd.
Address: E Building of Future Star Scientific Innovation Industrial Zone of No.957 Wolong East Street, Yulong Community, Xincheng Sub-District Office, Weifang Hi-tech Zone, Shandong Province, China