RT Journal Article SR Electronic T1 MR detection of secondary changes remote from ischemia: preliminary observations after occlusion of the middle cerebral artery in rats. JF American Journal of Neuroradiology JO Am. J. Neuroradiol. FD American Society of Neuroradiology SP 945 OP 950 VO 18 IS 5 A1 Nakane, M A1 Tamura, A A1 Nagaoka, T A1 Hirakawa, K YR 1997 UL http://www.ajnr.org/content/18/5/945.abstract AB PURPOSE To determine whether secondary MR changes occur in the thalamus or the substantia nigra after middle cerebral artery (MCA) occlusion in rats.METHODS Sprague-Dawley rats were subjected to MCA occlusion. At varying intervals, proton density-, T1-, and T2-weighted images were obtained with a 4.7-T superconductive MR unit.RESULTS T2-weighted images revealed an area of high signal intensity in the ipsilateral substantia nigra 4 days after occlusion. A lesion of low signal intensity appeared in the ipsilateral thalamus 7 days after surgery on proton density- and/or T2-weighted images.CONCLUSION MR showed secondary changes in the thalamus and the substantia nigra after MCA occlusion in rats. MR imaging should provide more information on the neuropathology of the delayed neuronal degeneration after cerebral ischemia.