What effect does overbeaming help to minimize at the outer edges of the CT image?

Overbeaming refers to the practice of expanding the X-ray beam size beyond the area of interest during a CT scan. This technique is primarily employed to reduce penumbral effects, which are areas of partial shadowing or blurring at the periphery of the image caused by the shape of the X-ray beam and the geometry of the detection system.

The penumbral effect occurs because the edges of the CT slice may not receive full exposure, leading to a less defined image border and potentially impacting diagnostic accuracy. By using overbeaming, the width of the beam ensures that even the outer edges are adequately covered, effectively minimizing these blurred regions and providing a sharper, more accurate image without the soft edges that would be visible if only the central portion of the beam were used.

The other options, while relevant to image quality, do not directly correlate with the specific improvement that overbeaming targets. For instance, while noise artifacts and image blurring can impact the overall quality of CT images, they are affected by different factors such as the reconstruction algorithms, patient motion, or inadequate exposure rather than just the beam geometry at the edges of the image. Scatter radiation is managed with other techniques like using collimators or specific reconstruction algorithms that can adjust for scattered