Answer:
The neurologist most likely used the functional magnetic resonance imaging
Explanation:
Functional magnetic resonance imaging, abbreviated as fMRI, is used for monitoring and measuring the brain activity by detecting the changes in the blood flow. This imaging technique is based on the principle that when a particular area or region of the brain is being used, the blood flow to that area or region increases.
Therefore, the neurologist most likely used the functional magnetic resonance imaging.