What is the advantage of a focused grid compared to a parallel grid?

A focused grid is better aligned with the x-ray beam than a parallel grid, which helps to minimize grid cut-off. Grid cut-off occurs when the x-ray beam is not adequately aligned with the grid's strips, resulting in reduced exposure and image quality. Focused grids are designed such that their lead strips are angled to match the divergence of the x-ray beam as it moves away from the focal spot, meaning that they effectively capture more of the useful radiation while filtering out scattered radiation.

This alignment significantly enhances the efficiency of the grid, leading to a more uniform exposure across the image receptor. With less grid cut-off, radiologists can expect improved image quality and greater diagnostic accuracy, which is crucial in medical imaging. Therefore, the decreased grid cut-off is the primary advantage of a focused grid compared to a parallel grid, making it a better choice for many imaging scenarios.