文摘
Diffusion-weighted magnetic resonance imaging (DWI MRI)-negative transient ischaemic attack (TIA) in hyperacute stroke is a well-known clinical entity. However, no precise analysis of this phenomenon has been reported. We identified 10 patients with TIA or reversible ischaemic neurological deficits (RIND) with no focal hyperintensity on DWI MRI among 108 consecutive acute stroke patients who underwent DWI MRI. In these patients, we analysed the apparent diffusion coefficient (ADC) and determined the ipsilateral/contralateral ratio (IC ratio) to elucidate factors that may contribute to this phenomenon. Each patient also underwent simultaneous magnetic resonance angiography (MRA). The mean IC ratio in our study population was 0.976. Of the 10 patients, 7 had a proximal vascular stenosis on MRA. We discuss the pathophysiology underlying negative DWI MRI results in patients with TIA or RIND.