Which MRI finding best identifies tissue that is already damaged and is part of the standard imaging protocol?

Which MRI finding best identifies tissue that is already damaged and is part of the standard imaging protocol?

• A. DWI shows acute infarct
• B. FLAIR shows edema
• C. MRA reveals vessel occlusion
• D. T2-weighted imaging shows chronic changes

Answer: (A)

Diffusion-weighted imaging detects restricted diffusion from cytotoxic edema that occurs early in acute ischemia, so it highlights tissue that has already sustained injury. This makes it the best marker for damaged tissue and it is a standard part of acute stroke MRI protocols. FLAIR can show edema, but it often lags behind in the early hours and doesn’t pinpoint acutely damaged tissue as precisely. Vessel occlusion seen on MRA shows the flow problem rather than the current tissue status. T2-weighted imaging tends to reflect longer-standing changes rather than acute injury.

Diffusion-weighted imaging detects restricted diffusion from cytotoxic edema that occurs early in acute ischemia, so it highlights tissue that has already sustained injury. This makes it the best marker for damaged tissue and it is a standard part of acute stroke MRI protocols. FLAIR can show edema, but it often lags behind in the early hours and doesn’t pinpoint acutely damaged tissue as precisely. Vessel occlusion seen on MRA shows the flow problem rather than the current tissue status. T2-weighted imaging tends to reflect longer-standing changes rather than acute injury.