MICROANATOMY OF THE EXCISED HUMAN SPINAL-CORD AND THE CERVICOMEDULLARY JUNCTION EXAMINED WITH HIGH-RESOLUTION MR-IMAGING AT 9.4 TESLA

PURPOSE: To study in detail the MR anatomy of the spinal cord and the cervicomedullary junction that could serve as a reference for clinical MR studies. METHODS: Specimens of fresh human spinal cord and formali n-fixed cervicomedullary transition zones were imaged with a 9.4-T ver tical bore magnet. Using a multisection spin-warp pulse sequence the p arameters were selected to produce essentially proton density images. RESULTS: The images obtained depict the microanatomical organization o f the spinal cord and cervicomedullary junction. In the spinal cord, t he central gray has the expected higher signal intensity compared with the white matter, which is, apart from its darker general appearance, characterized by the presence of a dense radially structured neurogli al framework of high signal intensity. Anatomically more complex regio ns such as the dorsal root entry zone, the adjacent posterior horn com plex, and the crossing fibers of the cervicomedullary junction are see n as well as parts of the microvascular system. CONCLUSION: Although c ellular details are still beyond the limits of this investigation, the images at 9.4 T show the spinal cord and cervicomedullary junction wi th detail comparable to low-power microscopic images of fixed sections , especially with respect to distinguishing gray and white matter, nuc lei, tracts, and angioarchitecture.