Which MRI sequence readily allows visualization of edema and pathology due to water sensitivity?

Which MRI sequence readily allows visualization of edema and pathology due to water sensitivity?

• A. T1-weighted
• B. T2-weighted
• C. FLAIR
• D. STIR

Answer: (D)

Edema signals reflect increased water content in tissues, so sequences that emphasize water content show edema as bright signals. A fat-suppressed T2-weighted sequence does this even more clearly: it keeps the water-related brightness but removes the surrounding fat signal. Short Tau Inversion Recovery (STIR) does exactly that—nulls fat and highlights water-rich abnormalities—so edema and related pathology stand out prominently. While standard T2-weighted imaging already highlights edema, STIR provides better contrast in areas with a lot fat, making edema more conspicuous. T1 is not optimal for water content, and FLAIR, though useful for certain CNS lesions by suppressing CSF, does not emphasize edema as distinctly as STIR in this context.

Edema signals reflect increased water content in tissues, so sequences that emphasize water content show edema as bright signals. A fat-suppressed T2-weighted sequence does this even more clearly: it keeps the water-related brightness but removes the surrounding fat signal. Short Tau Inversion Recovery (STIR) does exactly that—nulls fat and highlights water-rich abnormalities—so edema and related pathology stand out prominently. While standard T2-weighted imaging already highlights edema, STIR provides better contrast in areas with a lot fat, making edema more conspicuous. T1 is not optimal for water content, and FLAIR, though useful for certain CNS lesions by suppressing CSF, does not emphasize edema as distinctly as STIR in this context.