Discrepancy between perfusion- and diffusion-weighted images in ischemic stroke: A case report

With the development of multi-slice computed tomography (CT) technology, perfusion CT angiography (p-CTA) is now widely used for the diagnosis of acute cerebral infarction. Although p-CTA has the advantage of distinguishing between an ischemic penumbra and an infarct core, more research is needed with respect to its clinical use.

A healthy 36-year-old man experienced sudden dizziness while swimming. His dizziness persisted irrespective of the change in position, and then improved during transport. He had no neurological abnormality when he arrived at the emergency room.

CT perfusion findings suggested left cerebellar infarction. P-CTA revealed a markedly delayed mean transit time, delayed time to peak, and increased cerebral blood volume in the left posterior inferior cerebellar artery territory at admission. However, the diffusion-weighted image (DWI) taken a few hours later revealed a large right cerebellar infarction.

Because of the time window, thrombolysis could not be performed and anti-platelet therapy was started.

Dysarthria and right-sided limb ataxia were newly developed before DWI (after p-CTA). Persistent foramen ovale was detected through transesophageal echography and identified as the cause of the stroke.

This case report suggests that dynamic image changes can occur within a short period of time depending on the vascular status and hemodynamic changes of the patients.