Abstract 3842: Angiographic Assessment Of Leptomeningeal Collateral Perfusion Parameters Following Experimental Transient Middle Cerebral Artery Occlusion

Abstract

Objectives: This work aims to develop and validate an angiographically based quantitative assessment of leptomeningeal collateral perfusion (QLCP) in experimental reversible middle cerebral artery occlusion (MCAO). Methods: Pial collaterals were assessed during MCAO using an angiographically based transient MCAO model in eight mongrel dogs (20-30 kg). Angiographic images were analyzed using a custom-made MATLAB program which measured contrast density over time. Using bivariate linear fit analysis relative cerebral blood volume (rCBV), relative transit time (rTT) and relative cerebral blood flow (rCBF) derived from regions of interest (ROI) from the normal and abnormal hemispheres were extracted and compared to one hour post reperfusion MRI based infarct volume calculations and leptomeningeal collateral scoring using previously published methods. Results: QLCP was reproducibly assessed but variably predictive of infarct volume on one hour post reperfusion mean diffusivity maps using rCBV (p<0.0001; r2=0.937), rTT (p = 0.05, r2 = 0.494), and rCBF (p=0.0024, r2=0.807). Leptomeningeal collateral scoring variably correlated with rCBV (p<0.0001, r2 = 0.948), rTT (p=0.0285, r2= 0.578) and rCBF (p0.0021, r2= 0.817). Conclusion: QLCP was validated in an experimental MCAO model based on correlation with a leptomeningeal collateral scoring system. QLCP assessment of rCBV is a better predictor for infarct volume than rTT or rCBF in a transient MCAO model. It is noteworthy that an angiographically based assessment of rCBV, rTT and rCBF differs from CT and MRI based assessments. In particular , the time frame used and the relative density of the vasculature on the derived color maps differ ( figure 1). figure 1: QLCP derived cerebral blood volume map. The boxes indicate regions of interest for analysis.