Final infarct size after acute stroke: prediction with flow heterogeneity.

PURPOSE

To compare acute measurements of flow heterogeneity (FH) and mean transit time (MTT) with follow-up data to determine which method yields better predictive measures of final infarct volumes.

MATERIALS AND METHODS

Twenty-three patients with symptoms of stroke underwent magnetic resonance (MR) imaging during the acute stage, and the tissue at risk was estimated from MTT maps and maps generated by means of detecting abnormal FH. Final infarct volumes were calculated from T2-weighted follow-up MR image measurement. The Wilcoxon signed rank test was performed to compare the two predictive maps (MTT and FH) with T2-weighted follow-up maps.

RESULTS

Eleven (48%) patients experienced infarct growth. Both the MTT and the FH maps enabled prediction of 10 of these cases. There were five false-positive cases with MTT measurement but three with FH measurement. In terms of predicting final infarct volumes, the final infarct size on the MTT maps was overestimated by 75%. The final infarct size on the FH maps also was overestimated, but by only 15%. MTT map measurements were significantly different from follow-up MR image measurements (P =.005), but FH map measurements were not (P =.059).

CONCLUSION

FH maps may enable more precise prediction of final infarct volume in stroke patients.