MRI Week 4 - Brain/Orbits/Base of Skull w/ Pulse Sequences

Different Sequences

• T1 + T2 + PD + FATSAT + INVERSION RECOVERY (IR) + STIR (Short Tau Inversion Recovery)

• Spin Echo + Fast Spin Echo + Gradient Echo

T1

• White matter = White

• Grey Matter = Grey

• CSF = DARK (Not the best to Differentiate)

Additional:

• Use Gadolinium (contrast)

• We can see another part of the tumour demonstrates contrast enhancement

T1

T1 Post Gad

T2

• White Matter = Darker

• Grey Matter = Brighter

• CSF = Bright (Not the best to Differentiate)

Additional:

• FLAIR (Fluid Attenuated Inversion Recovery) --> Dark CSF

• Most common modifier for T2

• Same Tumour stands out more against white matter

• White matter = STILL Darker

• Grey Matter = STILL Brighter

• Even though CSF is Hypointense

T2

T2 FLAIR

Proton Density

• Intermediate Sequence

• Used to be used for White matter lesions

• Taken over by Flair imaging for brains

• Mainly used for MSK

Proton Density

SWI

Susceptibility Weighted Imaging

• Good for stagnant Blood

• More sensitive

Gradient Echo

• White Matter = Darker

• Grey Matter = Brighter

• CSF = Bright (Not the best to differentiate)

used for:

• bleeds

SWI

Gradient Echo