Which side of the x-ray beam is more intense due to the heel effect?

The heel effect is an important phenomenon in radiology that describes the variation in x-ray intensity across the beam. In an x-ray tube, the cathode side is where the x-ray tube filament is located, and it emits electrons that produce x-rays when they strike the target. The anode side, opposite the cathode, is where the x-rays are emitted.

When x-rays are generated, they have their highest intensity on the cathode side. This is primarily due to the geometric positioning of the beams as they pass through the anode. The heel of the anode absorbs some of the x-rays, leading to a decrease in intensity on that side. Consequently, there is a greater intensity of x-rays on the cathode side compared to the anode side.

This uneven distribution of x-ray intensity means that the side closest to the cathode will produce images with denser or more penetrating x-rays, while the area near the anode may show less intensity and detail due to its slightly lower energy output and absorption effects. Understanding the heel effect is crucial for practitioners, as it influences how radiographs are taken and can determine the placement of the x-ray beam relative to the anatomy being imaged for optimal results.