Possibilities and limitations for high resolution small animal MRI on a clinical whole-body 3T scanner
To investigate the potential of a clinical 3 T scanner to perform MRI of small rodents.
Materials and methods
Different dedicated small animal coils and several imaging sequences were evaluated to optimize image quality with respect to SNR, contrast and spatial resolution. As an application, optimal grey-white-matter contrast and resolution were investigated for rats. Furthermore, manganese-enhanced MRI was applied in mice with unilateral crush injury of the optic nerve to investigate coil performance on topographic mapping of the visual projection.
Differences in SNR and CNR up to factor 3 and more were observed between the investigated coils. The best grey-white matter contrast was achieved with a high resolution 3D T2-weighted TSE (SPACE) sequence. Delineation of the retino-tectal projection and detection of defined visual pathway damage on the level of the optic nerve could be achieved by using a T1-weighted, 3D gradient echo sequence with isotropic resolution of (0.2 mm)3.
Experimental studies in small rodents requiring high spatial resolution can be performed by using a clinical 3 T scanner with appropriate dedicated coils.
KeywordsMRI Rodents Clinical scanner High spatial resolution 3 T Morphometry MEMRI
We thank Noras MRI products GmbH and Siemens Medical for their support and the mechanical workshop of the Friedrich-Schiller University Jena for their help in creating the various head holders.
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