As the angle of the face of the anode increases from 5 degrees to 15 degrees, what is the effect on spatial resolution?

As the angle of the face of the anode increases, specifically from 5 degrees to 15 degrees, spatial resolution tends to decrease. This phenomenon stems from the anode's angle impacting the effective focal spot size.

When the anode angle is steeper (in this case, moving from 5 degrees to 15 degrees), the effective focal spot size increases. A larger effective focal spot leads to a reduction in spatial resolution because it results in more penumbra at the edges of the radiation field. Penumbra is the blurred area that may occur at the edges of the image due to the diffusion of radiation. Consequently, with an increase in the anode angle, the details in the image may not be as sharp or well-defined, deteriorating spatial resolution.

Thus, an increase in the angle of the anode face decreases spatial resolution, which is critical in radiographic imaging to ensure that fine details are captured clearly, leading to accurate diagnoses.