Imaging of Cerebral Stroke with Different MRI Techniques

*Diagnosis of ischemic stroke has been improved by the use of magnetic resonance(MR) imaging.*Diffusion Weighted Images (DWI) is superior to CT and conventional MRI sequences in early detection of hyperacute and acute ischemic stroke.*The combination DWI with Perfusion Weighted Images (PWI) enables identification of tissue at risk of infarction which is characterized by the mismatch between an area of restricted diffusion and a larger area with ischemic but still viable tissue on perfusion-weighted images.* MRA can pinpoint the cause of infarction mainly in large proximal vessels than distal smaller ones more in hyperacute and acute ischemic stages.*Contrast-enhanced T1-weighted images can show arterial enhancement in hyperacute and strokes due to slow or collateral flow.*The most striking changes in patients with cerebral infarction on MRS is the appearance of lactate with reduction in NAA and total Cr/PCr with variations in the concentrations of Cho.*Initial CT is important in early cases of stroke to diagnose Intracranial hemorrhage.*Based on the most mature form of the hemoglobin present in the clot, five stages of evolving ICH have been described. Each has specific appearance on conventional MRI and DW images.*MR angiography is a sensitive tool to demonstrate pathologic findings in extra- and intracranial arteries in hemorrhagic stroke as occlusion, spasm or intracranial aneurysms.