Objectives: Diffusion weighted MRI image (DWI) improves the prediction of the early risk of stroke after transient ischemic attack (TIA). Hyperintense acute reperfusion marker (HARM) is occasionally observed in patients with TIA. The predictive value of HARM in TIA is not well known.
Methods: This is a retrospective study of patients who were diagnosed as TIA. From June 2008 to June 2014, 759 consecutive patients with TIA underwent DWI and axial postcontrast fluid attenuated inversion recovery images (FLAIR) within 24 hours after onset of symptoms. Presence of positive DWI findings, HARM on postcontrast FLAIR image, atrial fibrillation (AF), other risk factor of cardioembolic stroke, and recurrence of stroke were assessed.
Results: DWI and HARM was positive in 276 (36.4%) and 28 (3.7%) patients. 45 (5.9%) patients had AF and 123 (16.2%) patients were diagnosed cardioembolic TIA. Recurrence of stroke was higher in patients with HARM (25.0%) than patients with DWI (6.5%) and lesion negative TIA (5.1%). Cardioembolic TIA (26.1% vs 10.3%) and AF (11.6% vs 2.6%) were common in patients with DWI than lesion negative TIA significantly. There were no statistically significant difference of cardioembolic TIA (14.3% vs 26.1%) and AF (3.6% vs 11.6%) between HARM and DWI group.
Conclusion: TIA with HARM is associated with the high risk of stroke recurrence. Taking postcontrast FLAIR image improves the prediction of the risk of stroke after TIA.