Importance of Windowing and Levelling

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The often quoted ideal stroke windows are 35 35 , or 40 40. But it is suggested to always window and level yourself based on your visual preferences. Many factors such as monitor grey scale values can affect the final output, so better to rely on a window and level that is comfortable for you in detecting the subtle grey-white differentiation. 

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. 

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

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. 

Diffuse Hypoxic Ischemic Injury

Diffuse loss of grey/white differentiation with presence of pseudo-subarachnoid sign, diffuse edema and loss of sulci, and tonsillar herniation through foramen magnum in keeping with diffuse hypoxic ischemic injury.

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