Yi, Zhang

Background and Objective Hyperdense middle cerebral artery (HDMCA) sign is an early sign seen on CT head after acute ischemic stroke indicating acute arterial thrombosis. We aimed to measure HDMCA sign objectively. Methods We conducted a retrospective analysis of prospectively collected data from 151 cases of acute ischemic stroke eligible for IV rt-PA by time criteria, admitted to Mayo Clinic from March, 2002 through June, 2011. Admission CT Head was studied to identify HDMCA sign. All patients had either 24 hour CT head or MRI head to confirm the stroke in the same vessel territory. MCA was measured in Hounsfield units and was compared to the contralateral MCA. Receiver Operating Characteristic (ROC) curve analysis was performed to calculate sensitivity and specificity. Results Mean admission NIHSS score was 11±7. HDMCA sign was seen in 93 (62%) patients. ROC curve analysis for ipsilateral MCA Hounsfield units had an area under the curve 0.88 (p<0.001, CI 0.83-0.94) which showed 50 HU or more had 48% sensitivity and 98% specificity. Ratio of ipsilateral to contralateral MCA HU had an area under the curve 0.94 (p<0.001, CI 0.90-0.98) which showed ratio of 1.23 had 67% sensitivity and 98% specificity. A combination of either ipsilateral HU more than equal to 50 or a ratio of ipsilateral to contralateral MCA HU more than equal to 1.23 had 77% sensitivity, 95% specificity, 96% positive predictive value and 72% negative predictive value. Conclusion A combination of ipsilateral HU more than equal to 50 or a ratio of ipsilateral to contralateral MCA HU more than equal to 1.23 can objectively identify HDMCA sign with good sensitivity and high specificity.