the prominent heel effect in mammography is due to a
Heel effect In X-ray tubes, the heel effect or more accurately, the anode heel effect is a variation of the intensity of X-rays emitted by the anode depending on the direction of emission. Due to the geometry of the anode, X-rays emitted towards the cathode are in general more intense than those emitted perpendicular to the cathodeâ€“anode axis. The effect stems from the absorption of X-ray photons before they leave the anode in which they are produced. The probability of absorption depends on the distance the photons travel within the anode material, which in turn depends on the direction of emission.[1][2]
Single transverse palmar crease In humans, a single transverse palmar crease is a single crease that extends across the palm of the hand, formed by the fusion of the two palmar creases (known in palmistry as the "heart line" and the "head line") and is found in people with Down syndrome.[1][2][3] However, it is not an indication that a person with single transverse palmar crease has to have Down syndrome. It is also found in 1.5% of the general population in at least one hand.[4]