Detection of acute thalamo-mesencephalic infarction: diffusion abnormality precedes T2 hyperintensity

Abstract

Objective - To examine the time course of signal changes in diffusion-weighted magnetic resonance imaging (DW-MRI) and T2-weighted MRI in a case of cerebral infarction in the posterior circulation territory. Materials and methods - Diffusion- and T2-weighted MRI and comparison of signal changes in these sequences at 4 h, 1 day and 4 days after the onset of clinical symptoms caused by acute thalamomesencephalic infarction. Results - Four hours after the onset of symptoms, signal changes in DW-MRI revealed an infarction in the territory of the posterior perforating thalamic artery, whereas no signal changes were detected in T2-weighted MRI. In follow-up MRI 1 an 4 days after infarction, however, a marked hyperintensity matching the location of the diffusion deficit could be identified in T2 images. Conclusion - Signal changes in DW-MRI precede T2 hyperintensity after infarction in the posterior circulation territory after hemispheric infarction.