In suspected osteomyelitis, which statement is true?

• A. X-ray is a definitive rule-out test
• B. X-ray may be normal early; MRI is more sensitive for early disease
• C. Ultrasound is best for bone marrow edema
• D. CT cannot detect bone changes

Answer: (B)

In the early stage of suspected osteomyelitis, plain X-rays often appear normal because bone changes take time to develop and show up on radiographs. MRI, however, detects bone marrow edema and inflammatory changes much earlier, making it the most sensitive test for early osteomyelitis. CT can reveal cortical destruction and sequestra but is less sensitive than MRI for early marrow involvement, and ultrasound is mainly useful for soft-tissue issues rather than detecting early bone marrow changes. So the statement that X-ray may be normal early and MRI is more sensitive for early disease reflects how imaging responds to early infection.