Magnetic resonance microscopy in neurologic models.

Magnetic resonance imaging techniques have been developed to permit imaging with slice thickness less than 1 mm and pixels of 50 x 50 microns. Special purpose gradient and radiofrequency coils and three-dimensional imaging techniques enable acquisition of images with sufficient signal to noise to utilize these microscopic picture elements. Live 200 g rats were imaged enabling clear definition of gray and white matter structures. Examples include the Sylvian aqueduct and the substantia nigra. Three-dimensional microscopic images of live chick embryos enabled definition of ventricles and brain parenchyma as well as measurement of T1 over the set of 16 contiguous 1.2 mm slices.