Magnetic Resonance Imaging: Significance of Early Ischemic Changes on Computed Tomography

The significance of early ischemic changes (EICs) on CT remains controversial. MRI may provide relevant information in patients with EICs. Methods: EICs were assessed in patients with acute ischemic stroke. MRI was promptly performed at presentation after CT and repeated on day 1. The relationship between EICs and MRI parameters was assessed with one-way ANOVA for analysis of continuous variables and by the χ 2 test for the analysis of variables with a binary outcome. Results: Fourty-eight patients underwent CT and MR imaging before treatment with recombinant tissue plasminogen activator (age: 63 ± 14 years). EICs were graded as absent in 28 patients, 33% of the middle cerebral artery (MCA) territory in 5 patients. NIHSS score was higher in patients with EICs that covered more than one third of the MCA territory (19 ± 3) compared to those without EICs (12 ± 5; p = 0.04). Patients who had major EICs had a larger acute lesion volume in diffusion-weighted imaging (DWI; 140 ± 78 cm 3 ) compared to those without EICs (33 ± 51 cm 3 , p < 0.0001). Regional cerebral blood flow, regional cerebral blood volume, time to peak and mean transit time values were not significantly different in the study groups. Conclusion: EICs reflect mainly a larger DWI lesion.