Cerebellar Infarction Diagnosed by the 'Hyperdense Sign' on Plain CT.

We hereby present a case of thrombus or possible vertebral artery dissection (VAD), but no confirmatory evidence in a young adult male, diagnosed using an unusual but pivotal imaging clue, the "dense vertebral artery sign" observed on non-contrast computed tomography (CT). This finding led to the initial suspicion and subsequent confirmation of VAD. This report underscores the diagnostic value of subtle vascular signs on plain CT imaging that are frequently overlooked but can result in prompt and life-saving intervention. This report is of particular significance in emergency settings, where advanced imaging modalities such as MRI and CT angiography may not be readily available.