Hyperdence Middle Cerebral Artery :Quantification of CT Density in Strocke and Non-Strocke Patients

AbstracBackgrounThe hyperdense middle cerebral artery sign refers to an appearance of increase attenuation of the proximal (MCA) that is often associated with thrombosis of the M1 MCA segment and may be the only diagnostic feature on computed tomography early after ischemic stroke.To evaluate the CT density number of hyperdense MCA presented with hyperacute and acute stroke and comparing the measurements with those of non-stroke patients with hyperdense MCA on the baseline non-enhanced brain CT. MethodsThis study is comparison cross sectional study included two groups; group A: patients aged ≥35 years with clinical diagnosis of hyperacute (first 6 hours) or acute (6 hours-4 days) stroke who were referred to the CT unit and group (B) patients aged ≥35 years referred to the CT unit for various indication with no clinical evidence of stroke who were labeled by two radiologists as normal brain CT. ResultsThis study showed there is a statistically significant difference between the mean density of the dense MCA at the site of stroke (48 HU) when compared tothecontralateral MCA (39.7 HU) with average difference in density value of 8.3 HU (p<0.001), the same applies when tested against the dense MCAS in the non-stroke group (42.2 HU) with average difference of 5.8 HU (p<0.002). However, no significant difference was found when testing the density in the non-stroke group against that of the contralateral MCAS in stroke group (p=0.2). Moreover, significant variation was observed between the density ratio of stroke and non-stroke patients (1.29 vs 1.02, p=0.009). A cutoff MCA density of 41.7 HU was proposed to the predict pathological state.ConclusionHyperdense MCA is associated with acute ischemic stroke exhibit higher CT attenuation value that of contralateral normal vessel or dense MCAS in healthy individuals. A CT density value of >41.7 HU is suggested as the best limit to mark the distinction.