Plain scan shows subtle hypodensity in the left occipital lobe; this was only seen retrospectively after reviewing the CTA and perfusion images. The CTA shows tapering and occlusion of the left occipital artery (arrows). MTT is raised consistent with ischaemia. The areas of MTT elevation also have corresponding low CBV, corresponding to mainly core infarct rather than penumbra. This is supported by the established parenchymal changes.