Thrombolytic reversal of acute human cerebral ischemic injury shown by diffusion/perfusion magnetic resonance imaging

Diffusion magnetic resonance imaging provides an early marker of acute cere bral ischemic injury. Thrombolytic reversal of diffusion abnormalities has not previously been demonstrated in humans. Serial diffusion and perfusion imaging studies were acquired in patients experiencing acute hemispheric ce rebral ischemia treated with intra-arterial thrombolytic therapy within 6 h ours of symptom onset. Seven patients met inclusion criteria of prethrombol ysis and postthrombolysis magnetic resonance studies, presence of large art ery anterior circulation occlusion at angiography, and achievement of vesse l recanalization. Mean diffusion-weighted imaging lesion volume at baseline was 23 cm(3) (95% confidence interval [95% CI], 8-38 cm(3)) and decreased to 10 cm(3) (95% CI, 3-17 cm(3)) 2.5 to 9.5 hours after thrombolysis. Mean apparent diffusion coefficient lesion volume decreased from 9 cm(3) (95% CI , 2-16 cm(3)) at baseline to 1 cm(3) (95% CI, 0.4-2 cm(3)) early after thro mbolysis. A secondary increase in diffusion volumes was seen in 3 of 6 pati ents at day 7. In all 4 patients in whom perfusion imaging was obtained bef ore and after treatment, complete resolution of the perfusion deficit was s hown. Diffusion magnetic resonance signatures of early tissue ischemic inju ry can be reversed in humans by prompt thrombolytic vessel recanalization. The ischemic penumbra includes not only the region of diffusion/perfusion m ismatch, but also portions of the region of initial diffusion abnormality.