Which area of an image should be shuttered due to shadows from the collimator?

Which area of an image should be shuttered due to shadows from the collimator?

• A. Collimator shadows
• B. Image edges
• C. Cardiac silhouette
• D. Lung fields

Answer: (A)

Shuttering focuses on removing non-diagnostic data at the edges where the x-ray beam is trimmed by the collimator. The collimator’s edges cast shadows along the image margins, and those border areas don’t contain useful anatomy. Masking those shadowed borders keeps only the true patient structures in view and prevents edge artifacts from affecting interpretation or image processing. The other options refer to actual anatomy or generic image edges, not to the specific artifact caused by the collimator shadows.

Shuttering focuses on removing non-diagnostic data at the edges where the x-ray beam is trimmed by the collimator. The collimator’s edges cast shadows along the image margins, and those border areas don’t contain useful anatomy. Masking those shadowed borders keeps only the true patient structures in view and prevents edge artifacts from affecting interpretation or image processing. The other options refer to actual anatomy or generic image edges, not to the specific artifact caused by the collimator shadows.