Recall that DTI uses diffusions gradients on top of positioning gradients,Ĭardiac pulsations also contribute to image degradation. Vibrations contribute with displacements of up to 1mm per axis every time a gradient is launched. The quality of the images is also affected by unavoidable vibrations produced in the acquisition system. Surface coils make the setup easier, but at the expense of an exponential degradation of image quality with increased distance from the coil. Maintaining the animal’s head in a fixed position between acquisitions. Use of human scanning units or human fitted acquisition devices to scan small animals ĭifferences in the positioning of the animals’ heads in volumetric coils Some of the main reasons for this apparent scarcity include setup difficulties such as: However, most DTI work in the field, including the references cited above, describes histological and biological studies with imaging support only in post-mortem stages.ĭespite the apparent benefits of using animals in research, few references focus on in-vivo imaging analyses. These facts open new possibilities to study the evolution of illnesses or degeneration processes associated with human motor-capabilities impairment and behavioral disorders, including, for example: Parkinson –, Wallerian degeneration, , epilepsy, , schizophrenia – and multiple sclerosis, , among others. The rat’s motor circuits are homologous to many motor patterns in human primates, demonstrated by direct functional comparison. Rats are among the most commonly used species for motor neurological modeling –. The use of animal models allows monitoring of functional and fundamental cognitive aspects over time. Keywords: Neurodegenerative Diseases, Small Animal MRI, Animal Models, Diffusion Tensor Imaging, Image Enhancementĭiffusion tensor imaging (DTI) in small animals is a framework that provides critical insights into brain anatomy in health and disease. The strategy is the foundation to study human neurodegenerative diseases and neurodevelopment as well. This manuscript presents a strategy to display neuronal trending representations that follow the corticospinal tract’s pathway and neuronal integrity in small rodents. Although these water diffusion methods have proven to be successful in detecting neuronal structure at the submillimeter scale, they yield noisy results when applied to the resolutions required by small animals or when facing low myeline contents as in neonates and young children. Neurons’ integrity is now indirectly visible under specialized mechanisms that use water displacement to track static boundaries. Magnetic resonance, in particular, favors long-term analysis and monitoring since its methods do not perturb the organ functions nor compromise the metabolism of the animals. Thanks to recent technological advances in imaging, animals do not need to be sacrificed. More avidly than other human organs, we study the brain through animal models due to the complexity of experimenting directly on human subjects, even at a cellular level where the skull makes tissue sampling harder than in any other organ. Testing on small animal models is roughly the only path to transfer science-based knowledge to human use.
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