In evaluation of occult fractures, which imaging modality is most sensitive for early detection?

• A. MRI of the affected region
• B. CT scan
• C. Bone scan
• D. Ultrasound

Answer: (A)

When a fracture isn’t visible on initial X-rays, the imaging test that best detects it early is an MRI of the affected region. MRI observes bone marrow edema, which is a hallmark of an acute fracture even when the cortex looks intact on X-ray. This makes MRI highly sensitive for occult fractures, allowing diagnosis and appropriate immobilization sooner to prevent displacement or complications.

Bone scans can show injury earlier than X-rays, but they’re less specific and slower to obtain. CT scans reveal fracture lines and cortical disruption well, but they may miss early intraosseous or subtle fractures that haven’t produced cortical changes yet. Ultrasound isn’t reliable for deep, occult fractures in many sites.