Signal intensities on T2WI and DWI in time (courtesy Dr M. Law)

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.

Reference