PT - JOURNAL ARTICLE AU - Wang, Paul Y-K. AU - Barker, Peter B. AU - Wityk, Robert J. AU - Uluğ, Aziz M. AU - van Zijl, Peter C. M. AU - Beauchamp, Norman J. TI - Diffusion-Negative Stroke: A Report of Two Cases DP - 1999 Nov 01 TA - American Journal of Neuroradiology PG - 1876--1880 VI - 20 IP - 10 4099 - http://www.ajnr.org/content/20/10/1876.short 4100 - http://www.ajnr.org/content/20/10/1876.full SO - Am. J. Neuroradiol.1999 Nov 01; 20 AB - Summary: Diffusion-weighted MR imaging is generally thought to be highly sensitive for the diagnosis of acute stroke. We report two cases of hyperacute stroke with absence of changes on diffusion-weighted images within 4 hours of symptom onset. Follow-up studies, performed 4 days later, showed infarction in regions compatible with the clinical presentation and (in one case) with the initial perfusion deficit. These cases indicate that normal findings on diffusion-weighted images in patients with suspected cerebral ischemia do not rule out impending infarction.