When we compare the findings on T2WI and DWI in time we will notice the following:
- In the acute phase T2WI will be normal, but in time the infarcted area will become hyperintense.
- The hyperintensity on T2WI reaches its maximum between 7 and 30 days. After this it starts to fade.
- DWI is already positive in the acute phase and then becomes more bright with a maximum at 7 days.
- DWI in brain infarction will be positive for approximately for 3 weeks after onset (in spinal cord infarction DWI is only positive for one week!).
- ADC will be of low signal intensity with a maximum at 24 hours and then will increase in signal intensity and finally becomes bright in the chronic stage.
Perfusion MR Imaging
Perfusion with MR is comparable to perfusion CT.
A compact bolus of Gd-DTPA is delivered through a power injector.
Multiple echo-planar images are made with a high temporal resolution.
T2* gradient sequences are used to maximize the susceptibility signal changes.
A compact bolus of Gd-DTPA is delivered through a power injector.
Multiple echo-planar images are made with a high temporal resolution.
T2* gradient sequences are used to maximize the susceptibility signal changes.
Now we can see that there is a severe mismatch.
Almost the whole left cerebral hemisphere is at risk due to hypoperfusion.
This patient is an ideal candidate for therapy.
Almost the whole left cerebral hemisphere is at risk due to hypoperfusion.
This patient is an ideal candidate for therapy.
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