49 year-old male with history of MRSA bacteremia, severe back pain, and known T10 metastasis.
Other pertinent findings:
1. Marked discitis/osteomyelitis of T12-L1 vertebral bodies. Epidural disease causes minimal central canal stenosis at this level.
2. Focal enhanced of T8 spinous process and of right T8-T9 facet and neuroforamen is primarily concerning for infection.
3. Suspicion for left anterolateral paraspinal abscess at the level of L1-L2.
4. Known T10 metastasis.
Osteomyelitis involves inflammation of the bone almost exclusively secondary to bacterial infection. Most commonly involved locations (in descending order) are the lower limbs, vertebrae (lumbar > thoracic > cervical), radial styloid, and SI joint.
Osteomyelitis in children is more often related to hematogenous spread, favoring the metaphyseal regions. In adult, direct invasion is more common, typically involving the epiphysis or subchondral regions.
Vertebral osteomyelitis and discitis are favored to be secondary to hematogenous seeding. Common complications are sepsis and epidural abscess, however can spontaneously resolve in children especially before 8 years of age.
MRI is the most sensitive and specific modality and is able to detect soft tissue and joint complications. The earliest feature is bone marrow edema.
Differential Diagnosis:
A pictorial review of osteomyelitis.
https://www.jbsr.be/articles/10.5334/jbr-btr.1300/