MR technology for biological studies in mice

Abstract

Mouse models are crucial for the study of genetic factors and processes that influence human disease. In addition to tools for measuring genetic expression and establishing genotype, tools to accurately and comparatively assess mouse phenotype are essential in order to characterize pathology and make comparisons with human disease. MRI provides a powerful means of evaluating various anatomical and functional changes and hence is growing in popularity as a phenotypic readout for biomedical research studies. To accommodate the large numbers of mice needed in most biological studies, mouse MRI must offer high-throughput image acquisition and efficient image analysis. This article reviews the technology of multiple-mouse MRI, a method that images multiple mice or specimens simultaneously as a means of enabling high-throughput studies. Aspects of image acquisition and computational analysis in multiple-mouse studies are also described.

Maze training in mice induces MRI-detectable brain shape changes specific to the type of learning

“…Its small size, however, presents a challenge for MRI, which can be partially compensated for by increasing the scan time or using fixed specimens along with MR contrast agents to obtain exquisite resolution. We used the latter approach to scan fixed brains at 32-μm isotropic resolution for this study, with three specimens scanned simultaneously with independent transmit/receive coils to allow for adequate throughput Nieman et al, 2005Nieman et al, , 2007. Anatomical measures obtained from these fixed specimens have been used in multiple phenotyping studies Clapcote et al, 2007;Spring et al, 2007;Lerch et al, 2008a,b;Mercer et al, 2009;Ellegood et al, 2010;Yu et al, 2010), and validated against stereology (Lerch et al, 2008b;Spring et al, 2010), where the MR measures were found to have greater sensitivity at discriminating between groups compared to classic tissue slice-based techniques (Lerch et al, 2008b).…”

Enhanced delineation of white matter structures of the fixed mouse brain using Gd‐DTPA in microscopic MRI

“…In addition, this multiple-mouse imaging method requires a magnet with a large bore to accommodate as many radiofrequency coils as possible. As the maximum gradient strength generally decreases with the bore size, it may be a limiting factor in achieving high spatial resolution (17).…”

Divalent metal transporter, DMT1: A novel MRI reporter protein

“…Compared to other live animal imaging methods, MRI does not suffer the limitations in tissue penetration of optical microscopy or ultrasound, and has much better spatial resolution than bioluminescence or micro-PET (1). Despite these advantages, moving MRI into the realm of "molecular imaging" by developing effective MRI reporter genes continues to be a major challenge (2).…”