Rodent models are being used with greater frequency in studies of spinal cord injury and disease . MRI has great potential for noninvasive time course measurements of spinal cord pathology. The increase in the signal to noise ratio (SNR) with high field imaging permits the acquisition of submillimeter resolution in an in vivo system. We define microimaging as imaging with an inplane resolution of under 200 microns. This figure demonstrates the feasibility of using gradient echo imaging in combination with the half birdcage RF coil to achieve an in vivo inplane resolution less than 200 microns and optimal contrast between gray and white matter in the rat spinal cord. Image acquisition parameters: TR/TE/flip angle=500/12ms/40-60o, matrix=256x245, FOV=30mm, resolution=117x117x700mm.

MRI has become a non-invasive microscope. It already has far better resolution than the first microscopes but it doesn't harm the living tissue in the process.

In collaboration with Dr. Trevor Owens [Montreal Neurological Institute] and Dr. Jack Hoopes [Department of Neurosurgery, Dartmouth Medical School], we are using MR microscopy to study spine structure in models of multiple sclerosis and after radiation damage. The figure shows a high resolution image of a rat spine.The butterfly shape shows grey matter inside the round spine. The top of the image corresponds to the top of the rat.

This is a three-dimensional image looking down on the back of a rat. The image has been cut away near the bottom to show two planes of view. A single vertebrae shows up dark and in cross-section near the bottom of the image.