[The clinical efficacy of magnetic resonance with diffusion-weighted sequences in the assessment of acute cerebral ischemia].

Purpose: To evaluate the efficacy of diffusion weighted Magnetic Resonance Imaging in the diagnosis of acute ischemic infarction and correlate the signal changes observed in the acute phase with final brain damage.

Material And Methods: Fifteen patients (six women and nine men: mean age 68 years) with acute ischemic stroke (within 12 hours) underwent diffusion MRI. All the patients were selected on the basis of sudden focal neurologic symptoms and CT findings excluding other conditions than ischemia. MRI was performed with a 1.5 T magnet with echo-planar gradients. All the patients underwent follow-up CT and/or MRI.

Results: Diffusion MRI, performed in the acute phase, showed signal changes in all the patients whose infarction was later confirmed by CT or MRI. In 10 of 12 patients with positive diffusion imaging, CT was normal. FLAIR sequences showed the lesions in 4 of 12 cases. In the 2 patients with transient ischemic attack diffusion MRI was normal as well as follow-up examinations. Apparent Diffusion Coefficients values in the infarcted area were almost half those of the contralateral normal brain. Final damage (as assessed by CT or MRI) was larger than observed in acute diffusion images in all cases but one.

Conclusion: Because of its high sensitivity and specificity, diffusion MRI is going to play a more important role in the management of acute ischemic stroke patients.