Using a short SID with a large IR is likely to increase which phenomenon?

Using a short Source-to-Image Distance (SID) combined with a large Image Receptor (IR) can indeed increase the anode heel effect. The anode heel effect refers to the variation in x-ray intensity across the field of view, where the intensity is greater on the cathode side of the tube and decreases towards the anode side. This effect is more pronounced with shorter SIDs because the x-rays emitted from the anode have to travel a shorter distance to reach the IR, which amplifies the non-uniform distribution of the beam intensity.

In configurations with a larger IR, the chances of experiencing this effect increase, as the incoming x-rays can exhibit significant discrepancies across the imaging area. The positioning of the anode and cathode directly influences how much of this gradient will affect the final image—acidic vs. cathodic uptake—resulting in a more noticeable belt around the edges where the anode heel effect is at play. Thus, understanding SID and the associated geometrical factors is essential for radiographic imaging, especially when aiming for uniform exposure across a large field.