Which imaging feature helps confirm contusions on MRI?

• A. Susceptibility-weighted imaging highlights microhemorrhages.
• B. Diffusion-weighted imaging shows only diffusion restriction in edema.
• C. CT is superior for detecting microhemorrhages in contusions.
• D. T1-weighted MRI shows no useful information.

Answer: (A)

Contusions from traumatic brain injury often involve tiny hemorrhages at the cortical–subcortical junctions. The imaging feature that best confirms these hemorrhagic contusions is susceptibility-weighted imaging, because SWI is highly sensitive to magnetic susceptibility differences caused by blood products like deoxyhemoglobin and hemosiderin. This makes even small microhemorrhages appear clearly as dark foci, providing strong evidence of contusion where other sequences may miss them. Diffusion-weighted imaging can show edema-related changes but isn’t specific for hemorrhagic contusions; T1 offers limited acute information, and CT is less sensitive to small microhemorrhages than MRI. So SWI is the most reliable way to confirm contusions on MRI.