A 55-year-old woman with diabetes and a foot ulcer presents with chills and back pain; which imaging study best confirms suspected vertebral osteomyelitis?

• A. Foot X-ray
• B. MRI of the thoracic spine
• C. CT chest
• D. Ultrasound abdomen

Answer: (B)

When vertebral osteomyelitis is suspected, MRI of the spine is the imaging study of choice because it uniquely detects early bone marrow edema, disc space involvement, and soft-tissue changes, including any epidural abscess. This makes it the most sensitive and specific test for confirming spinal infection and its complications, guiding urgency and type of treatment. In this clinical scenario, diabetes and a foot infection raise the risk of hematogenous spread to the spine, so prompt MRI can reveal the extent of infection and any associated abscess that might require intervention. A foot X-ray looks at the wrong area and misses spinal pathology; CT of the chest isn’t ideal for early marrow changes in the spine; ultrasound of the abdomen wouldn’t evaluate the spine at all. Therefore, MRI of the thoracic spine best confirms vertebral osteomyelitis.