PLAT and ischemia: Our results are consistent with clinical study using serial MRI on patients after stroke, which revealed an increase in stroke volume from several hours to 3–5 days after stroke onset [35] Interestingly, both T2WIs and DWIs can detect ischemic lesion as early as 5 h after PT when demarcation is not clear and penumbral ischemic tissue is salvageable using tPA in clinic, suggesting that MRI is a useful tool for the detection of very acute ischemia.