Non-invasive monitoring of cortical volume alterations in rat brains using a clinical 3T whole body MRI scanner

Research on neurodegenerative disorders is increasingly important in an aging population. Therefore, noninvasive detection of local changes in cerebral volume which can be accomplished by MRI, is in focus of clinical investigations. Animal models are playing a pivotal role in geriatric research, but many labs do not have access to dedicated animal MRI scanners. In this study we show that deformation based morphometry of the rat brain can be achieved with data acquired on a human 3T whole body system using a multi purpose 8-channel coil with overlapping coil elements of 5 cm diameter for optimized SNR. For the morphometric evaluation a T2-weighted hyperecho based TSE sequence (SPACE) was employed with an isotropic resolution of 0.33 mm. Deformation based morphometry, a fully automatic intensity based method, was used to detect the cerebral volume changes on 3 and 26 months old rats. On animals, a cortical dysplasia was induced on the day of birth by freeze lesions in the right-hemispheric motor cortex. We found a volume decrease in the lesion surrounding the primary somatosensory cortex with progression in aging animals. The volume changes are in accordance with age-dependent reduced performance in a dexterity test. Keywords— MRI, rats, whole body scanner,DBM, morphometry