MR imaging of evolving ischaemic stroke

Abstract

These MR images are from days 1 (12.5 h after symptom onset), 5 and 30 following presentation of a 79-year-old man with recurrent episodes of left hemiplegia, and who on examination had the findings of a right total anterior circulation infarct. Each column consists of images obtained using different MR techniques. From left to right: standard T2-weighted images (T2WI); three columns of images from diffusion imaging – the diffusion weighted images (DWI) themselves, the apparent diffusion coefficient (ADC) maps, and the calculated fractional anisotropy (FA); two columns of images related to perfusion – the relative regional cerebral blood flow (rCBF) and the relative mean transit time (rMTT). On T2WI (column 1), fluid is high (bright) signal. While T2WI can be sensitive to early ischaemic stroke, as long as early injury results in increased fluid (oedema) the injury is better appreciated on T2 later (day 5). By day 30, however