7/17/2019 Mri Stroke Iskemik

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STROKE ISKEMIK 

MRI is more time consuming and less available than CT, but has significantly higher sensitivity andspecificity in the diagnosis of acute ischaemic infarction in the first few hours after onset.

• diffusion weighted imaging (DI! " #DC$

o diffusion restriction may be seen within minutes following the onset of ischaemia % 

o correlates well with infarct core

o for detailed discussion of DI and #DC in stro&e see diffusion weighted MRI in

acute stro&e

• T'weighted imaging and )*#IR$

o less sensitive than DI in the first few hours to parenchymal change

o loss of normal signal void in large arteries may be visible immediately

o after +' hours infarcted tissue becomes high signal -

o sulcal effacement and mass effect develop and become maimal in the first few days

o fogging$ between % wee&s (pea& '/ wee&s! infiltration of inflammatory cells may

reduce T' signal such that it becomes relatively isointense to normal parenchyma.

• T

o low intensity roughly mirrors high T' " )*#IR signal

o cortical laminar necrosis or pseudolaminar necrosis may be seen as a ribbon of

intrinsic high T signal, usually after ' wee&s (although it can be seen earlier! -

• T C0$

o arterial enhancement (a&a intravascular enhancement!$

can be seen very early (-' hours! although it is more common at about

day /

lasts approimately wee& -

seen in 12-3 of cases

o parenchymal enhancement$

usually begins towards the end of the first wee& - 

usually lasts less than ' wee&s4 if longer than this the presence of an

underlying lesion should be considered -

o meningeal enhancement -$

uncommon

seen in the first wee&, typically / days

usually fades by the start of the second wee&

• 5R6"7I$

o highly sensitive in the detection of haemorrhage