Magnetic resonance imaging of the neonatal piglet brain

Abstract

ArticlesTranslational Investigation nature publishing group 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.

Early Life Iron Deficiency Impairs Spatial Cognition in Neonatal Piglets ,2

“…Despite the prevalence of this problem, the mechanisms for the effects of iron deficiency on cognition are poorly understood. The pig may be an excellent preclinical model in which to study the mechanisms underlying iron deficiency-induced cognitive impairment in human neonates due to similar brain growth and structure (27,28,30), limited iron stores at birth (33), and the ease of early life cognitive testing due to pigsÕ precocial nature (34,35). In addition, previous work has shown that at birth, the percentage of adult brain weight is more similar in piglets (25%) and humans (26%) than in other common animal models used to study brain development [i.e., monkey (76%) and rat (12%) (29)].…”

“…Piglets were scanned using a Siemens MAGNETOM Trio 3T Imager using a Siemens 32-channel head coil (Siemens). Brain images were acquired using a 3D T1-weighted, magnetization-prepared, rapid gradient-echo sequence, as previously described (30,39), with a final voxel size of 0.35 mm 3 0.35 mm 3 1.0 mm. Volumes were determined using a protocol previously described (30), which included 3D visualization software (AMIRA, Visage Imaging) and a Wacom Cintiq 21UX graphic input screen with a stylus pen (Wacom).…”

“…The neonatal piglet is an emerging animal model for studying neurodevelopment due to parallels with human brain structure (26), including gyral pattern and distribution of gray and white matter (27,28) and perinatal growth patterns (29,30). These similarities make the piglet an excellent model for assessing the neurological effects of nutritional deficiencies or interventions during the neonatal period (31,32).…”

Development of new population-averaged standard templates for spatial normalization and segmentation of MR images for postnatal piglet brains

“…In recent years, MRI has been used to assess structural brain development in piglets and human infants [11,12]. For example, Fang et al used T1-weighted images and histological analyses to evaluate myelination in the fiber tracts of the central nervous system (CNS) during development for fifteen female Bamamini piglets aged 2-6 months [13].…”

Early postnatal respiratory viral infection induces structural and neurochemical changes in the neonatal piglet brain

“…Moreover, their physical size allows neuroimaging instruments designed for humans to be used with piglets. Indeed, structural MRI, functional MRI, and positron emission tomography have all been conducted in pigs (Conrad et al, 2012b; Fang et al, 2005; Jakobsen et al, 2006). Additionally, piglets can undergo cognitive testing at a young age and show greater overlap with humans in genes involved in immunity compared to rodents (Dawson, 2011; Dilger and Johnson, 2010; Meurens et al, 2012).…”