Magnetic resonance imaging of the neonatal piglet brain

INTRODUCTION: Appeal for the domestic pig as a preclinical model for neurodevelopmental research is increasing. One limitation, however, is lack of magnetic resonance imaging (MRI) methods for brain volume quantification in the neonatal piglet. The purpose of this study was to develop and validate MRI methods for estimating brain volume in piglets. RESULTS: The results showed that MRI and manual segmentation reliably estimated the changes in volume of different brain regions in 2- and 5-wk-old piglets. Substantial increases in the volumes of all brain regions examined were evident during the 3-wk period. DISCUSSION: MRI can provide accurate estimates of brain region volume during the neonatal period in piglets. A piglet model that can be used in longitudinal studies may be useful for investigating how experimental (e. g., nutrition, infection) factors affect brain growth and development. METHODS: Anatomic MRI data (non-longitudinal) were acquired from 2-and 5-wk-old piglets using a three-dimensional T1-weighted magnetization-prepared gradient echo (MPRAGE) sequence on a MAGNETOM Trio 3T imager. Manual segmentation was performed for volume estimates of total brain, cortical, diencephalon, brainstem, cerebellar, and hippocampal regions. The MRI-based hippocampal volume estimates in 2-wk and 5-wk old piglets were validated using histological techniques and the Cavalieri method.