Diffusion restriction on MRI indicates what in brain imaging?

Diffusion restriction on MRI indicates what in brain imaging?

• A. Vasogenic edema
• B. Cytotoxic edema due to acute ischemia
• C. Demyelination
• D. Chronic scar

Answer: (B)

Diffusion restriction on MRI points to cytotoxic edema from acute ischemia. When energy failure occurs, ions pump failures cause water to flood into cells, making them swell and shrinking the extracellular space. Water diffusion becomes highly restricted, so diffusion-weighted imaging shows bright signal with a corresponding low signal on the ADC map. That pattern is classic for acute ischemic injury. Vasogenic edema, by contrast, increases extracellular water and tends to show higher diffusion (not restricted). Demyelination and chronic scar don’t produce the same restricted diffusion pattern.

Diffusion restriction on MRI points to cytotoxic edema from acute ischemia. When energy failure occurs, ions pump failures cause water to flood into cells, making them swell and shrinking the extracellular space. Water diffusion becomes highly restricted, so diffusion-weighted imaging shows bright signal with a corresponding low signal on the ADC map. That pattern is classic for acute ischemic injury. Vasogenic edema, by contrast, increases extracellular water and tends to show higher diffusion (not restricted). Demyelination and chronic scar don’t produce the same restricted diffusion pattern.