Picture Frame Vertebral Body | Radiology Signs

Picture Frame Vertebra is a classic finding of the mixed/sclerotic phase of Paget’s disease of bone. It results from thickening of all four cortical margins of the vertebral body (the superior and inferior endplates as well as the anterior and posterior cortices) with relative preservation of central vertebral body trabecular architecture, creating a characteristic “framed” appearance. It should not be confused with the rugger jersey spine of renal osteodystrophy/hyperparathyroidism, which involves only the superior and inferior endplates rather than all four margins.

Why is it called so?

The term “Picture Frame Vertebra” describes the distinctive radiographic appearance: dense sclerotic bone forms along all four cortical margins of the vertebral body, creating a bright rectangular rim that visually “frames” the relatively lucent central vertebral body on radiographs or CT, resembling a picture surrounded by a dense border or frame.

Pathophysiology

In Paget’s disease, the disorganized coupling of excessive osteoclastic bone resorption and compensatory osteoblastic bone formation preferentially thickens the cortical margins of the vertebral body (endplates as well as anterior and posterior cortex) while central cancellous bone develops a coarsened trabecular pattern of relatively lower density. This differential remodeling produces the characteristic framed vertebral body appearance on cross-sectional and projectional imaging. Other Paget-related musculoskeletal findings include cortical thickening, bone enlargement, and increased risk of pathologic fracture.

Alternative names: None

Other associated named signs: Cotton-wool appearance (skull), ivory vertebra, rugger jersey spine (a related but distinct sign of renal osteodystrophy affecting only the endplates)

References

1. Theodorou DJ, Theodorou SJ, Kakitsubata Y. Imaging of Paget disease of bone and its musculoskeletal complications: review. AJR Am J Roentgenol. 2011.