What accurately describes the "heel effect" in diagnostic radiology?

The "heel effect" in diagnostic radiology refers specifically to the phenomenon where the intensity of the x-ray beam is higher at the cathode side and decreases toward the anode side of the x-ray machine. This effect is due to the geometry of the x-ray tube and the angle of the anode, which causes some of the x-rays produced to be absorbed or scattered before they reach the imaging target. As a result, images captured on the anode side may exhibit lower exposure levels compared to those captured on the cathode side, affecting the overall quality and interpretability of radiographic images.

In practice, technologists often need to position the denser parts of a patient's body (like the heart or spine) towards the cathode side to take advantage of the increased beam intensity. This understanding is crucial for optimizing image quality and minimizing radiation dose to the patient.