Automated Assessment of Leptomeningeal Collaterals on CT Angiograms

AbstractThe primary goal of this study is to develop an automated scoring system of leptomeningeal collaterals based on CT angiographyCTAas a quantitative assessment of acute ischemic strokeLeptomeningeal collaterals provide an alternate path of blood flow in the setting of a proximal vessel occlusionThe presence and effectiveness of leptomeningeal collateralsi ecollateral statusvaries significantly from patient to patientCollateral status has been shown to be correlated with both patient outcome and risk of hemorrhagic transformationsuggesting that rapid and accurate assessment of the collaterals would provide a powerful tool for treatment evaluationThe current gold standard for collateral scoring is performed by subjective analysis of retrograde filling in invasive digital subtraction angiogramsDSAThough CTA is more limited than DSA in the direct evaluation of collateralsthe presence of collaterals may also be evaluated in CTA by the tree pattern of vessel filling around the site of occlusionSeveral manual assessment techniques based on CTA have been proposed in the literaturebut all are subjective and require significant human interventionDuring Phase Iwe deployed a web based system for automated assessment of stroke collaterals based on CTAand we used it in a preliminary study of collateral status for stroke assessmentIn this Phase II STTR proposalthe specific aims areto improve the integration of our system with clinical workflowsexpand the system to also compute CT perfusion stroke measuresso as to provide a unified platform for comparing and combining CTA collateral and CT perfusion assessment metricsandtest the hypotheses that the combined use of CTA collateral and CT perfusion measures outperforms either method independently for treatment efficacy prediction in stroke patients NarrativeLeptomeningeal collateral vessels provide connections between vascular territories in the brain when occlusions occure gwhen a person suffers a strokeThe number and connectivity of collateral vessels varies significantly from patient to patientand they have been shown to play an important role in stroke outcomesproviding blood flow to tissue at riskRapid and effective patient specific determination of the presence and connectivity of collaterals is needed in acute stroke situations to determine which treatments will be effectiveWe propose to develop an automated system to evaluate collateral vessel trees from computed tomography angiographyCTAimages and to offer that system as an algorithms as a serviceAaaSproduct