What does overbeaming refer to in computed tomography?

Overbeaming in computed tomography refers to the practice of adjusting the collimator settings in such a way that the beam width is increased. This allows the prenumbra, which is the area just outside the sharp edge of the main radiation beam, to extend beyond the active detectors. When this occurs, a larger portion of the beam is being used than what the detectors can effectively capture, which may lead to areas of under-utilization of the detected image data and cause potential artifacts or unnecessary exposure.

This adjustment is significant because it can affect the radiation dose received by the patient; although the primary intention may not be to enhance image quality per se, the resultant increase in the radiation field can lead to a situation where the patient dose is not optimized versus the resultant image quality. Thus, understanding the balance between overbeaming practices and their implications is essential for ensuring optimal imaging while minimizing unnecessary patient exposure.