AUTHOR=Knauss Samuel , Albrecht Carolin , Dirnagl Ulrich , Mueller Susanne , Harms Christoph , Hoffmann Christian Johannes , Koch Stefan Paul , Endres Matthias , Boehm-Sturm Philipp 

TITLE=A Semiquantitative Non-invasive Measurement of PcomA Patency in C57BL/6 Mice Explains Variance in Ischemic Brain Damage in Filament MCAo

JOURNAL=Frontiers in Neuroscience

VOLUME=14

YEAR=2020

URL=https://www.frontiersin.org/journals/neuroscience/articles/10.3389/fnins.2020.576741

DOI=10.3389/fnins.2020.576741

ISSN=1662-453X

ABSTRACT=<p>Numerous studies on experimental ischemic stroke use the filament middle cerebral artery occlusion (fMCAo) model in C57BL/6 mice, but lesion sizes in this strain are highly variable. A known contributor is variation in the posterior communicating artery (PcomA) patency. We therefore aimed to provide a semiquantitative non-invasive <italic>in vivo</italic> method to routinely assess PcomA patency. We included 43 male C57BL/6 mice from four independent studies using a transient 45 min fMCAo model. Edema-corrected lesion sizes were measured by magnetic resonance (MR) imaging 24 h after reperfusion. Time-of-flight MR angiography was performed 7 days before and 24 h after fMCAo. Scores of PcomA size measured 24 h after, but not scores measured 7 days before fMCAo were negatively correlated with lesion size. Variability in PcomA patency explained 30% of the variance in our cohort (<italic>p</italic> &lt; 0.0001, coefficient of determination <italic>r</italic><sup>2</sup> = 0.3). In a simulation using parameters typical for experimental stroke research, the power to detect a true effect of <italic>d</italic> = 1 between two groups increased by 15% when an according covariate was included in the statistical model. We have demonstrated that <italic>in vivo</italic> measurement of PcomA size is feasible and can lead to increased accuracy in assessing the effect of treatments.</p>