Which technique compares successive MRI scans to reveal blood flow and brain activity?

Functional MRI (fMRI) is the technique that specifically compares successive MRI scans to observe changes in blood flow and consequently assess brain activity. Unlike standard MRI, which primarily provides structural imaging of the brain, fMRI measures the hemodynamic response associated with neural activity. When a specific brain region is activated, it requires more oxygen, leading to increased blood flow to that area. By taking multiple scans over time, fMRI can create a dynamic representation of brain function, allowing researchers and clinicians to see which parts of the brain are active during various tasks or in response to different stimuli.

In contrast, Diffusion Tensor Imaging (DTI) focuses on the movement of water molecules in brain tissue and is primarily used to assess white matter integrity, rather than blood flow or brain activity. Standard MRI provides detailed images of brain structure but does not track changes in blood flow or neuronal activity. Multimodal MRI encompasses techniques that can combine structural, functional, and diffusion imaging, but fMRI is specifically tailored for tracking blood flow in relation to brain activity, making it the most suitable choice for this question.