Question

Paget’s disease.

Hint:

In Paget’s disease, look for characteristic X-ray findings such as cortical thickening, coarsened trabecular patterns, and bowing deformities, particularly in the pelvis and long bones.

Answer 1

Step 1: Overview of Paget’s Disease.
Paget’s disease of bone is a chronic disorder characterized by abnormal bone remodeling, leading to enlarged and deformed bones. It is most commonly seen in the pelvis, spine, and long bones. The disease can cause pain, fractures, and deformities due to the abnormal bone formation and resorption.
Step 2: Imaging Features of Paget’s Disease.
1. X-ray Findings:
- Thickened cortical bone: The most characteristic feature is cortical thickening, especially in long bones. The cortex may appear enlarged or expanded, giving the bones a “candle wax” appearance.
- Coarsened trabecular pattern: The trabeculae of the bones appear enlarged and thickened, producing a more prominent pattern in the affected area.
- Bowing deformities: In long bones, bowing may be observed, especially in the femur and tibia.
- Fractures: Pathologic fractures due to weakened bone structure are common.
- Osteolytic lesions: In the early stages of Paget’s disease, there may be areas of bone resorption with lytic lesions that appear as radiolucent areas on X-ray.
2. Bone Scintigraphy:
- Paget’s disease shows increased uptake of the radiopharmaceutical in the affected bones due to the high metabolic activity of the involved bone areas.
3. CT Scan:
- Cortical thickening and trabecular changes are clearly visible, especially in the pelvis and spine. - CT is useful in assessing complications like fractures or deformities.
4. MRI:
- Bone marrow changes: MRI can show abnormal bone marrow signal changes, often associated with Paget’s disease.
- MRI is helpful for evaluating complications like osteomyelitis or nerve impingement due to vertebral involvement.
Step 3: Complications in Paget’s Disease.
- Osteoarthritis: Degenerative changes may occur in joints adjacent to Paget-affected bones, particularly in the hips and knees.
- Fractures: Weakened bones are prone to fractures, particularly in the weight-bearing areas like the pelvis and femur.