Time is brain!
So you don’t have time to struggle w/that stroke alert head CT.
Here’s are the FIVE main the CT findings in acute stroke.
--Hyperdense artery sign
Occurs when you see the thrombus in the artery.
Thrombus appears hyperdense bc clot is denser than normal flowing blood—& CT is just a measure of density.
--Blurred basal ganglia/lentiform nucleus.
Usually this region is a triangle of low density white matter surrounding the high density lentiform nucleus
In an acute infarct, this triangle becomes blurred, bc the lentiform nucleus becomes edematous & similar in density to white matter.
--Hypodense regions of brain
When O2 & ATP run out, Na/K pump stops working
Osmotic gradient causes Na & H20 rush into the cell.
More water in the cell = lower density. For every 1% increase in H20 there is a 2.5 HU decrease in density
Means damage is irreversible
--Insular ribbon
Insula is an internal MCA watershed between the lenticulostriates & M2 sylvian branches
Infarcts relatively early with low blood supply & becomes a low density ribbon
--Sulcal effacement
Normally, brain has sulci that look like ice cracks/crevasses along its surface.
As water accumulates in dead cells, swelling occurs, & the crevasses are effaced by the swollen brain
So now you know the 5 main signs of acute infarct on CT—remember, if you see these five, soon that brain won’t be alive!