Focal fatty deposits in spinal bone marrow
Focal fatty deposits/replacement in spinal bone marrow are well-defined focal fat islands within the bone marrow of the spine or other parts of the axial skeleton.
Common in older individuals, related to age but not to sex.
This process is a normal variant. Histologically, it is typical focal fatty replacement of hematopoietic bone marrow +/- the presence of associated pathologic changes such as spondylitis, kyphoscoliosis, and spondylosis.
It is clearly demonstrated on MRI as small focal areas of high signals on T1WI and T2WI with suppressed signals on fat saturation sequences.
- vertebral hemangiomas: most common differential diagnosis, they usually have coarsened trabeculae, high signal on T1WI and mostly high on T2WI +/-hyperintense on STIR depending on the degree of fat and vascular components
- melanoma metastasis
- post-radiation therapy
- bone marrow hemorrhage
- Modic type 2 endplate degenerative changes
- lipoma: very rare
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