Discriminating between acute osteoporotic and pathological vertebral fractures is sometimes challenging. This may be especially true in the elderly population, in which both osteoporosis and malignant disease often co-occur, and vertebral fractures of both kinds are common and indeed may coexist. MRI is the superior imaging modality to make this determination 1,2.
Benign compression fractures
The following features favor the diagnosis of a benign fracture:
- no bony destruction
- preserved normal fatty bone marrow T1WI signal
- low signal intensity band on T1WI and T2WI indicating a fracture line
- fluid sign
- retropulsion (not posterior bulging) of the posterosuperior cortex of the vertebral body
- no epidural mass
- multiple compression fractures
Pathological compression fractures
The following features favor the diagnosis of a pathological fracture:
- fracture with bony destruction (on CT)
- replaced signal of the vertebral body, especially extending into the pedicles or posterior elements (on MR) 2
- convex bulging (not retropulsion) of the posterior vertebral cortex into the spinal canal 2
- epidural or paraspinal mass
- other vertebral metastases
Contrast enhancement of the fractured vertebral body was in some studies 1 not helpful in differentiating between osteoporotic and metastatic vertebral fractures, as they both usually present with heterogeneous, intense enhancement.