苹果淫院

厂辫别补办别谤:听Josefina Maranzano, MD. PhD.

Assistant Professor, Department of Anatomy, Universit茅 du Qu茅bec 脿 Trois-Rivi猫res

Adjunct Professor, Neurology and Neurosurgery, 苹果淫院

Talk Abstract:听MRI-histology correlation studies of the听ex vivo听brain mostly employ fresh, extracted (ex situ) specimens, aldehyde fixed by immersion. This method entails manipulation of the fresh brain during extraction, introducing several disadvantages: deformation of the specimen prior to MRI acquisition; introduction of air bubbles in the sulci, creating artifacts; and uneven or poor fixation of the deeper regions of the brain.

We propose a new paradigm to scan the听ex vivo听brain, exploiting a technique used by anatomists: fixation by whole body perfusion, which implies fixation of the brain听颈苍听蝉颈迟耻. This allows scanning the brain surrounded by fluids, meninges, and skull, thus preserving the structural relationships of the brain in vivo and avoiding the disadvantages of听ex situ听scanning. Hence, our study aimed to assess: 1) whether months of听in situ听fixation results in a loss of fluid around the brain, 2) whether听in situ听fixation modifies antigenicity for myelin and neuron specific markers, and 3) whether听in situ听fixation improves the registration of听ex vivo听brain images to standard neuroanatomical templates in pseudo-Talairach space.

Our initial results show that most specimens retain fluids in the subarachnoid and ventricular spaces; that all T1-weighted images were successfully processed through a validated pipeline used with听in vivo听MRIs without any modification to run on the听ex vivo-in situ听scans, successfully registering to a standard brain template, more accurately than an听ex vivo-ex situ听scan. Further, all specimens exhibited positive antigenicity for myelin and neuron specific antigens.

We conclude that MRI and histology study of the听ex vivo-in situ听brain fixed by perfusion is feasible and allows for听in situ听MRI imaging for at least 10 months post-mortem prior to histology analyses.