Abstract WP365: Utility of Hyperdense Middle Cerebral Artery Sign for Earlier Activation of Endovascular Team

Abstract

Introduction: The hyperdense MCA sign has been used as a marker of an underlying large vessel occlusion (LVO)/thrombus in the non-contrast head CT of acute stroke patients. However, due its low sensitivity, it has not been used routinely for definitive diagnosis of LVO. Furthermore, clinicians also have the ability to obtain further imaging with CT angiography to better visualize the vessels in most patients. However, this further imaging can take on average up to an additional 30 minutes due to delays in acquisition, patient cooperation, processing and image transmission time. We wanted to look for a simple sign on the early imaging (non-contrast HCT) to determine if we could activate the neuro interventional suite faster. Hypothesis: When present, the hyperdense MCA sign can accurately predict presence of a LVO and identify patients eligible for endovascular therapy sooner than vessel imaging. Methods: We retrospectively looked at all initial non-contrast head CTs for all consecutive stroke patients presenting to our facility in 2017 (n=86), with a last known well time (LKW) < 6 hours and NIHSS > 4, for the presence of a hyperdense MCA sign. We then reviewed subsequent imaging (CTA) to determine if LVO was actually present. Results: The hyperdense MCA sign was present in 17 (out of 86) cases, all of which had an LVO on CTA. The positive predictive value (PPV) was 100% indicating that there was a high probability that subjects with a positive hyperdense MCA sign will have a LVO. There were 12 cases with an LVO on CTA did not have a hyperdense MCA sign showing a sensitivity of 58.6%, thus the absence of a hyperdense MCA sign does not exclude LVO. Conclusion: Quick delivery of appropriate treatments for acute stroke patients have been linked to better outcomes. Given our analysis of cases with NIHSS > 4 and LKW < 6 hours, it seems that presence of a hyperdense MCA sign on the initial non-contrast HCT leads to a high level of certainty that an LVO is present. Perhaps this sign, in combination of LKW and NIHSS, can be used to activate the neuro interventional team while additional imaging is being obtained.