Share your insights

Help us by sharing what content you've recieved in your exams


MRI sequences [advanced]

T1 and T2 weighted

  • T1 vs T2 difference:

On T2, H2O (including CSF) = bright
Includes oedema which signifies disease

  • Bright on both = fat
  • Grey on both = soft tissues
  • Black on both = bone, air, flowing blood

Gadolinium-enhanced

Same as T1 but…

  • Gadolinium, a contrast agent, is given
  • Enhances areas of leaky blood vessels (pathological tissues e.g. tumours, areas of inflammation/infection)

Fluid-attenuated (FLAIR)

Same as T2 but…

  • Flowing water (like CSF) is supressed, so appears black
  • Only non-flowing water appears bright
  • Helps differentiate pathologic oedematous lesions from normal flowing water (like CSF)

Fat-supressed

  • Fat supressed T1 or T2
  • Used to make fat appear dark
  • Often used when giving gadolinium contrast on T1, or on T2 to allow fluid to stand out

Diffusion-weighted image (DWI)

  • Shows passive diffusion of water
  • Consists of two main images:
    • DWI – combination of actual diffusion and T2 (restricted diffusion = bright)
    • ADC – represents actual diffusion without T2 effects (restricted diffusion = dark)
  • Cytotoxic oedema = bright on DWI and dark on ADC
  • Most useful when looking for ischaemic brain tissue in stroke
  • Note, DWI is derived from T2; therefore, some tissues that are bright on T2 also appear bright on DWI (T2 shine through effect)

No comments yet πŸ˜‰

Leave a Reply

OSCEstop T&Cs

We appreciate your trust and want to keep you informed about how we use your data and the terms of service. By agreeing to our terms and conditions, you'll help us provide you with the best possible experience.

Cookies πŸͺ

Key terms and conditions 🎩

Do you agree to our Terms and Conditions & Cookie Policy?