Brain imaging in transient ischemic attack – redefining TIA

Transient ischemic attack (TIA) has recently been redefined to incorporate the latest clinical and neuroimaging information that has shed new light on TIA pathophysiology. Patients suffering from TIA are at a substantial risk of subsequent stroke, but quantifying this risk is difficult as TIA patients are a heterogeneous population and there are multiple TIA mimics. Clinical scores for prediction of stroke risk are principally based on patient history and potentially understate actual risk. Magnetic resonance imaging (MRI), in particular diffusion-weighted imaging (DWI) performed in the first days following TIA, reveals relevant focal ischemic abnormalities in 21–68% of patients. These lesions predict stroke recurrence, functional dependence and subsequent vascular events. Adding imaging information to clinical scores improves prediction of stroke risk following TIA. Alongside clinical judgement, use of MRI has the potential to change the management of TIA patients and is the imaging modality of choice for this condition.