Thrombolysis is an effective but potential deleterious therapy and should t
herefore be limited to patients with acute intracerebral vessel occlusion a
nd salvageable tissue. MRI currently develops towards the new diagnostic st
andard for the selection of stroke patients eligible for acute thrombolytic
treatment and acute stroke studies. Diffusion- and perfusion-weighted MRI
provides diagnostic information not available from neurological assessments
or from CCT and conventional spin-echo MRI. As high-speed DWI and PWI prot
ocols become standardized, a 15-min integrated stroke protocol of employing
echo-planar imaging (EPI) can be routinely performed in the setting of acu
te clinical stroke. The combination of these MR techniques is suitable to d
efine tissue at risk of infarction that is potentially salvageable brain ti
ssue (an estimate of the ischemic penumbra) and may respond to early recana
lization even beyond 3 h after stroke onset. The extension of the therapeut
ic window for thrombolytic therapy towards 6 h in a subpopulation of acute
stroke patients might open the way for the successful reperfusion therapy i
n more stroke patients. (C) 2001 Elsevier Science Ltd. All rights reserved.