CT‑scan Bone Density as Brain Marker

AI can derive vertebral bone mineral density from routine chest CTs and those derived values associate with later cognitive decline and progression of white‑matter damage on MRI. The observation is longitudinal but not causal; it likely reflects shared age‑related metabolic processes that affect bone and brain health. — If validated, opportunistic BMD measurements from existing imaging could become an inexpensive early‑warning signal for cognitive risk, raising questions about screening, consent, follow‑up care, and health‑equity.