Final answer:
The gold standard diagnostic test for ischemic stroke is Magnetic resonance imaging (MRI).
Step-by-step explanation:
The gold standard diagnostic test for ischemic stroke is Magnetic resonance imaging (MRI). MRI uses strong magnetic fields and radio waves to create detailed images of the brain, allowing healthcare professionals to visualize any abnormalities or blockages in the blood vessels and identify areas of ischemic damage. Other imaging techniques, such as computed tomography (CT) scan, positron emission tomography (PET) scan, and cerebral angiography, may also be used to diagnose and evaluate stroke but are not considered the gold standard.