What should the CR orientation be for the dorsal plantar axial projection of the calcaneus?

What should the CR orientation be for the dorsal plantar axial projection of the calcaneus?

• A. Inferior
• B. Superior
• C. 45° caudal
• D. 20° cephalad

Answer: (C)

In the dorsal plantar axial projection of the calcaneus, the central ray (CR) orientation is directed at an angle to properly visualize the anatomy of the heel bone and provide an optimal image. For this specific projection, the CR is angled at 20 degrees cephalad. This upward angling helps to project the calcaneus into the center of the radiographic film or detector, allowing for improved visualization of the bone's shape and any potential pathologies.

Using a 20-degree cephalad angle is crucial because it correctly aligns the beam with the natural curvature of the foot and the position of the calcaneus, facilitating an accurate representation of the subtalar joint and preventing superimposition of other structures. This angling enhances the diagnostic quality of the image, making it easier for radiologists to interpret the findings related to the calcaneus.