MRI of the Posttraumatic Cerebral Parenchymatous Injuries

ABSTRACT

The authors retrospecitviely analyzed the MRI findings of the 8 head-injured patiens who had showed persistent unconsciousness and severe neurologic deficite after trauma. T2-weighted MR images disclosed high signal intensity lesions of various size and shape at lobar white matter and corpus callosum, subcortical gray matter, brain stem, and cerebral cortex, and assisted greatly in understanding the neurologic deficits of the corresponding patients. The lesions were mostly multiple and involved multiple structures. CT's revealed in those patients only small hemorrhages, suspicious low densities, such nonspecific findings as slit ventricles and diffuse brain atrophy, or no abnormality at all. Post-traumatic parenchymatous lesions detected by MR images were either missed or quite underestimated on CT's. MRI was very supeior to CT in the detection and anatomic localization of nonhemorrhagic intraaxial cerebral injuries. especially in the cases of small corical contusions, brainstem and white matter injuries. For the evaluation of the acute posttraumatic patients, CT ios indicated in order to fastly detect intracranial hemagomas which may need emergent surgical evacuation. If CT findings does not explain the neurologic degicits of the patients, especially in the late stage. MRI is indicated. MRI is expected to play a major role in the diagnosis of shear injuries involoving white matter and brainstem where CT has been of little contribution or misleading.