What it means
T1 and T2 are two measures of how quickly tissues settle back after each radio pulse from the scanner. Each image type is set up to highlight one of them, so the same body part looks different on each. On T1 images, fat is bright and fluid is dark. On T2 images, fluid and swelling are bright, and fat usually stays fairly bright. T2 hyperintense simply means bright on T2 images.
When it matters
T1 and T2 are image types, not findings, so they need no action on their own. Comparing a spot on both helps the radiologist work out what it is. Dark on T1 and very bright on T2 often means fluid, as in a simple cyst. Bright on T1 can point to fat or blood. Other sequences, such as FLAIR, diffusion and images after contrast, add more clues.
Questions to ask your doctor
- Is my finding bright or dark on the T1 and T2 images?
- Does that pattern suggest fluid, fat or solid tissue?
- Were images taken after contrast, and what did they add?
