Functional MRI (fMRI)

What it is

Functional MRI (fMRI) is an MRI technique that maps which brain areas are active during specific functions — such as moving, speaking, or sensing. By identifying these critical "eloquent" areas near a glioma, fMRI helps surgeons plan an operation that protects important functions.

Understanding Functional MRI (fMRI)

Different brain regions perform different functions, and these can vary somewhat between individuals — and a tumor can sometimes shift them. fMRI works by detecting the small increases in blood flow that occur in active brain areas: while the person performs tasks during the scan (such as moving a hand, or doing language tasks), fMRI shows which areas "light up," mapping functions like movement, language, and sensation. Knowing where these critical areas sit relative to the tumor helps the surgical team plan the safest approach to remove as much tumor as possible while preserving function. fMRI is often combined with diffusion tensor imaging (mapping pathways) and, during surgery, with direct brain mapping. Together these tools make function-preserving glioma surgery possible, especially near eloquent areas. Understanding functional MRI in gliomas clarifies how mapping brain functions aids surgical planning.

Why it matters

Understanding functional MRI helps patients and families see how mapping critical brain functions before surgery helps protect abilities like movement and language — guiding a safer approach to removing a glioma near important areas.