Gas on T2 is which signal intensity?

Gas on T2 is which signal intensity?

• A. Bright
• B. Dark
• C. Isointense
• D. Very dark

Answer: (B)

Gas has essentially no hydrogen protons to produce an MR signal, so it creates a signal void. On T2-weighted images, fluids with high water content appear bright due to longer T2 relaxation, while substances with negligible signal appear dark. Since gas provides no signal, it shows up as dark (hypointense) on T2. It wouldn’t be bright or iso­intense relative to surrounding tissues, so dark is the correct description.

Gas has essentially no hydrogen protons to produce an MR signal, so it creates a signal void. On T2-weighted images, fluids with high water content appear bright due to longer T2 relaxation, while substances with negligible signal appear dark. Since gas provides no signal, it shows up as dark (hypointense) on T2. It wouldn’t be bright or iso­intense relative to surrounding tissues, so dark is the correct description.