CT and MRI in the diagnosis of acute stroke and their role in thrombolysis

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.