The Role of fMRI and Tractography in Neurosurgical Planning

‍

When planning brain surgery, neurosurgeons walk a fine line: removing as much pathological tissue as possible while preserving the patient’s critical cognitive and motor functions, as well as the important communications pathways. That’s where brain mapping using functional MRI (fMRI) and tractography playssplays an important role.
‍

By mapping areas responsible for language, motor function, and memory, fMRI provides detailed, patient-specific data that can be integrated into neuronavigational systems, enhancing surgical precision and improving outcomes. Tractography on the other hand helps show the paths between these critical areas.
‍

In this post, we’ll explore how fMRI and tractography support neurosurgical decision-making and why they are becoming must-have tools in pre-surgical planning.
‍

Want a full breakdown of hardware, paradigm setup, and workflow for clinical fMRI?
Download the free guide: Clinical fMRI: Where Do I Start?

Why Use fMRI and tractography for Neurosurgery?

Conventional MR imaging can provide information about the structure of the brain with unprecedented detail. This is not the full picture, however.

Functional MRI detects changes in blood oxygenation level (the BOLD signal) whilst the subject performs specific tasks, revealing which areas are being engaged to process and produce language, to generate movement, or to perform other functions.

Diffusion tractography provides an indicator of white matter pathways within the brain, thus showing the channels of communication between eloquent areas.

This is especially critical when:

• A tumor is located near or within eloquent cortex

• The benefits of preserving certain functions within the brain such as motor, language and memory, outweigh the risks of a sub-optimal resection

• The surgical approach can be tailored to avoid key fiber pathways  

“These measurements make it possible to both lateralise and localise the part of the brain controlling that process on an individual basis,”
Taken from Clinical fMRI: Where Do I Start?

fMRI for Language and Motor Mapping

Two of the most common clinical uses of fMRI in neurosurgery are:
‍

Language Mapping

• Tasks such as word generation, verb generation, and sentence completion are used to activate language networks

• This helps to identify important areas responsible for the production and comprehension of language (Broca’s area, Wernicke’s area), among others

• One key endpoint is to determine language dominance, thus informing the risk of operating on one or other side of the brain

For best results, we recommend using at least three language paradigms to ensure strong confidence in the activation maps.
‍

Motor Mapping

• Tasks can include finger tapping, foot movement, or tongue movement

• This helps identify areas of the primary motor cortex - particularly important when mass effect causes shift in normal brain tissue
  ‍

Integrating Diffusion Tractography

Surgical teams want to understand the underlying white matter pathways within the brain. Diffusion Tractography allows for visualization of critical tracts such as:

• The arcuate fasciculus (language)

• The corticospinal tract (motor)

• The uncinate fasciculus (memory/emotion)
  ‍

These integrated data sets, when exported to neuronavigation platforms such as those from BrainLab, Stryker, or Medtronic, provide powerful tools as a surgical guide.

“It is essential to choose a software....that allows for the export of BOLD overlays and diffusion fibre groups to presurgical planning stations,”
– Clinical fMRI: Where Do I Start?

How NordicNeuroLab Supports Surgical Planning

NordicNeuroLab provides an end-to-end solution that enables precise, reproducible pre-surgical mapping:
‍

nordicAktiva – For standardized stimulus delivery in multiple languages
Visual and audio systems – For clear task presentation. Made for the MR environment.
nordicMEDiVA – A semi-automated approach to provide export-ready BOLD and tractography data

Together, these tools help radiographers and radiologists deliver reliable functional maps that surgeons can trust.

Why This Matters for Patients

Using fMRI and tractography for neurosurgical planning:
‍

• Reduces the risk of postoperative deficits

• Enables more conservative or aggressive resections where appropriate

• Improves patient outcomes

It turns imaging into a decision-making tool, giving surgeons a blueprint to operate with precision and safety.

Get the Full Guide

Curious how to get started? Need help building a system and workflow your surgical team can rely on?

Download: Clinical fMRI: Where Do I Start?

‍

‍