Where should the central ray be directed for a lateral ankle X-ray?

For a lateral ankle X-ray, the central ray should be directed through the medial malleolus. This is because the medial malleolus serves as a crucial anatomical landmark for positioning the X-ray beam accurately. When the central ray is positioned at the medial malleolus, it ensures that the entire ankle joint, including the talus, tibia, and fibula, is properly visualized in profile. Accurate alignment is essential for diagnostic clarity, allowing for a comprehensive view of potential fractures or other pathologies in the area.

Other anatomical landmarks, such as the lateral malleolus, calcaneus, or base of the 5th metatarsal, do not provide the necessary view of the ankle joint structure in a lateral projection. They may misalign the central ray and result in inadequate imaging, which is why they are not suitable choices for this particular positioning.