A Head-Within-A-Head

摘要

A patient with elevated alkaline phosphatase underwent whole body bone imaging with Tc-99m methylenediphosphonate. Pelvic and lower extremity images showed typical widening and increased density along trabecular and cortical lines typical for Paget's disease. The lateral skull view is remarkable for its "head-within-a-head" appearance. The posterior view, showing greater involvement of the base of the skull, extending posteriorly and laterally, while decreasing toward the parietal area, explains the double contour seen from the lateral perspective.