In a suspected occult hip fracture with negative initial radiographs, which imaging modality is most sensitive for detecting the fracture?

• A. CT
• B. MRI
• C. Ultrasound
• D. Plain X-ray

Answer: (B)

When a hip fracture is suspected but the initial X-rays are negative, you need imaging that can pick up subtle bone and bone-marrow changes rather than just cortical disruption. Magnetic resonance imaging excels here because it can visualize bone marrow edema and other signal changes that occur with acute fracture, even when the fracture line isn’t visible on X-ray or CT. This makes MRI the most sensitive test for identifying occult femoral neck fractures early.

CT can show fractures that X-rays miss, but it is less reliable for nondisplaced or occult fractures in the acute phase because it emphasizes cortical bone and may miss marrow edema or very subtle fracture lines. Ultrasound isn’t effective for detecting deep hip fractures, and plain X-rays will remain negative in these occult cases. Therefore MRI is the best choice to confirm or exclude an occult hip fracture promptly.