What imaging technique is most commonly used to diagnose a possible stroke?

A CT (Computed Tomography) scan is the most commonly used imaging technique to diagnose a stroke because it is readily available, quick to perform, and highly effective in detecting both ischemic strokes (caused by a blockage) and hemorrhagic strokes (caused by bleeding in the brain).

CT scans can quickly identify the presence of bleeding, which is critical in immediate stroke management. Time is essential in treating strokes, and the speed of a CT scan allows for prompt diagnosis, enabling appropriate interventions to begin rapidly.

In contrast, while MRI (Magnetic Resonance Imaging) is also a useful tool, it typically takes longer to perform and may not be available in all emergency departments. X-rays are not effective for diagnosing strokes, as they do not provide sufficient detail of the brain's soft tissue. Ultrasound is primarily used for assessing blood flow in vessels and is not a standard diagnostic tool for stroke assessment in the brain itself. Thus, the CT scan remains the preferred imaging technique for stroke diagnosis in emergency medical settings.