In annual QC, which parameter is used to verify proper grid alignment?

• A. Grid alignment
• B. Screen/film contact
• C. Cassette matching
• D. Image centering

Answer: (A)

Grid alignment testing checks that the grid is properly aligned with the X-ray beam and the image receptor so the primary beam passes through the grid evenly. When the grid isn’t perpendicular or centered with the beam, grid cutoff occurs, especially at the edges, causing uneven exposure and density across the image. This is different from screen/film contact, which looks at how well the screen and film sit together; cassette matching, which checks that the cassette and grids fit properly; and image centering, which focuses on placing the anatomy in the center of the image rather than verifying grid performance. So, verifying grid alignment directly ensures the beam passes cleanly through the grid and maintains uniform exposure.