A 68-year-old male presents to the emergency department with sudden onset right-sided weakness and aphasia. An urgent MRI brain is performed. Which MRI sequence is most crucial for the early detection of acute ischemic stroke within minutes to hours of symptom onset?

Explanation

Diffusion-Weighted Imaging (DWI) is highly sensitive for detecting acute ischemic stroke within minutes to hours of symptom onset. In acute ischemia, cytotoxic edema leads to restricted diffusion of water molecules, which manifests as high signal intensity on DWI and low signal intensity on the Apparent Diffusion Coefficient (ADC) map. This allows for very early detection, crucial for guiding thrombolytic therapy.