Which grid type provides the most effective scatter cleanup?

Which grid type provides the most effective scatter cleanup?

• A. Air Gap Technique
• B. Focused Grids
• C. Crosshatch Grids
• D. Parallel Grids

Answer: (C)

Scatter cleanup relies on how well the grid can absorb photons that are not traveling in the primary beam. Crosshatched grids use two linear grid grids placed at right angles, so lead strips block scatter coming from multiple directions as it exits the patient. That two-directional absorption means a much larger portion of scattered photons are removed before reaching the image receptor, which preserves image contrast more effectively than grids with a single orientation. Air-gap technique reduces scatter by increasing the distance between patient and detector, but it’s not a grid and doesn’t provide the same robust, directional suppression of scatter as a high‑ratio, two‑direction grid. Parallel grids offer good alignment simplicity but only block scatter well in one direction, and focused grids are designed to conform to beam divergence at a specific distance, improving primary transmission but still not matching the two‑direction scatter rejection of crosshatched grids.

Scatter cleanup relies on how well the grid can absorb photons that are not traveling in the primary beam. Crosshatched grids use two linear grid grids placed at right angles, so lead strips block scatter coming from multiple directions as it exits the patient. That two-directional absorption means a much larger portion of scattered photons are removed before reaching the image receptor, which preserves image contrast more effectively than grids with a single orientation.

Air-gap technique reduces scatter by increasing the distance between patient and detector, but it’s not a grid and doesn’t provide the same robust, directional suppression of scatter as a high‑ratio, two‑direction grid. Parallel grids offer good alignment simplicity but only block scatter well in one direction, and focused grids are designed to conform to beam divergence at a specific distance, improving primary transmission but still not matching the two‑direction scatter rejection of crosshatched grids.