Someone who wanted to examine changes in the levels of various brain metabolites following a concussion could use:

A) diffusion tensor imaging (DTI) .
B) electrocardiogram (ECG) .
C) positron emission tomography (PET) .
D) magnetic resonance spectroscopy (MRS) .

Brain Metabolites

Substances produced during metabolism, which occur and can be measured in the brain, providing insights into brain function and health.

Concussion

Damage to the brain caused by a blow to the head.

Magnetic Resonance Spectroscopy

Magnetic Resonance Spectroscopy is a non-invasive diagnostic technique that uses magnetic fields and radio waves to analyze the chemical composition of tissues, often used in conjunction with MRI for brain imaging.