Modern imaging modalities in the assessment of acute stroke

The aim of this review was to present the modern concepts of diagnostic imaging in acute stroke. Neuroimaging in acute stroke aims at diagnosing the condition as early as possible and assessing the extent of parenchymal perfusion and the intracranial vessels patency. A modern approach would involve a combination of various imaging modalities as multidetector computed tomography and high field magnetic resonance imaging. A non-enhanced computed tomography (CT) is used to detect hemorrhage or to identify early signs of ischemic stroke. CT angiography finds evidence of intravascular thrombi or significant stenoses, and CT perfusion displays brain tissue at risk of irreversible alterations that can be salvaged therapeutically. Magnetic resonance imaging (MRI) is a more sensitive modality than CT in diagnosing acute brain ischemia. MR diffusion-weighted imaging is more sensitive than conventional MR sequences in hyperacute stage. MR angiography as a non-invasive and non-ionizing imaging method is used as an alternative modality to CT angiography. To find brain tissue at risk diffusion- and perfusion-weighted magnetic resonance imaging modalities are used. The authors present briefly the modern neuroimaging modalities used in patients with transient ischemic attack, minor stroke and venous infarction. By combining different imaging techniques in a multimodal approach we can acquire the information necessary for therapeutic planning and differentiate patients who need thrombolysis.