Insular Ribbon - Imaging Sign
Loss of the grey-white diffrentiation in the external capsule/insula is called the insular ribbon sign that can be lost in acute stroke.
Gaze deviation is ipsilateral (ie. same side) as the ischemic brain hemisphere. Eyes point towards the affected side.
The Hyperdense MCA Sign - Essential Finding
The increased density of the MCA or any other intracranial vessel should be treated with suspicion for presence of thrombus. Comparison with other vessels, dural venous sinuses, history of previous contrast from another radiologic study, or delayed contrast excretion post previous administration could be consideration. Unilateral and asymmetric hyperdensity in any vessel of any size can be suggestive of presence of acute cloth and should be further investigated with a CT Angiogram CTA.
ICA Occlusion - Look at the skull base for
Hyperdense M2 - Imaging Sign
The course of the MCA through the Sylvian Fissue, so-called M2 Branches after the triforcation of the M1 segment, can appear hyperdense indicative of cloth within the vessel.
The Insular Ribbon Sign
PCA Territory loss of Grey White - Look out For
PCA territory infarct can be subtle on non-contrast CT of the head. Make sure you look in this vascular territory and strutinize the grey white differentiation in all vascular territories, including the PCA and the ACA.
Calcified Emboli - Imaging Sign
Look for small calcific emboli with the vessels. These could be acute or chronic but are suggestive of proximal embolic source, such as a ruptured calcified plaque.
Tmax (red) and CBV (blue) demonstrate very increased time of transit of blood, and very low blood volume in the exact same areas. This is no perfusion mismatch here and all the brain tissue has been infarcted with no pneumbra present to save.
Hemorrhagic Transformation in an Infarcted Region
Susceptibility sequences SWI demonstrate diffuse hemorrhagic change within an area of previous Infarct. With corresponding diffusion DWI restriction in the right panel.