Clinical fMRI
Functional MRI (fMRI) is an advanced MRI technique that can show which areas of the brain are involved in particular functions, such as language and movement.
At CISC, clinical fMRI is currently used to support pre-operative planning for patients with brain tumours, particularly those being considered for awake craniotomy. Patients perform simple tasks during the scan while we measure changes in brain activity. The resulting maps can help the neurosurgical team understand the relationship between the tumour and important areas of brain function, supporting decisions about the safest and most appropriate surgical approach.
The maps help the neurosurgical team identify areas of important brain function in relation to the tumour. This information can be used alongside other clinical and imaging information to plan surgery, with the aim of maximising tumour resection while minimising the risk of permanent neurological deficits.
The location of a tumour can provide an indication of which functions may be at risk, but there is considerable variation between individuals. Brain tumours can also cause functional reorganisation, meaning that important functions may not be located in exactly the same place in every person. fMRI can therefore help identify the areas involved in language and movement for each individual patient.
A language assessment helps establish a baseline of your language abilities before surgery. This provides a point of comparison for the Speech and Language Therapist (SALT) and helps them select appropriate language tasks for use during surgery.
What to expect at your appointment
fMRI appointments are very similar to MRI but there are some additional elements.
The MRI scan itself usually last approximately 45-60min. Your entire appointment will be longer, as it includes time for language assessment and/or task training as well as the scan.
Most appointments are finished within 3 hours.
Please note, you will NOT require an injection of contrast for this scan.
Language assessment
The location of your tumour determines which tasks you will be asked to complete. These may include only language or motor or, a combination of the two.
If language tasks are included, you will first meet with the Speech and Language Therapist. They will explain what to expect on the day of surgery and answer any queries you may have. They will also guide you through some basic tasks, such as picture naming, to make a baseline assessment that can be used during surgery.
If language is not required, you will go directly to task training.
Task Training
You will meet with Robyn, Clinical fMRI Lead, who will explain each task you will be asked to perform during your scan. You will have a chance to practice each one and see what it looks like on the computer before you go in for the scan. Do not worry if you make mistakes -- the odd error will not change the resulting maps. You will not be judged on how well you perform these tasks.
Staff are happy to answer any questions you may have along the way.
Scan
In addition to the typical setup for MRI, for fMRI, there is a mirror attached to the top part of the equipment that allows you to see a computer screen behind the scanner. The tasks will appear on this screen. If you wear glasses, it would be useful if you bring your prescription along with you as we have MRI safe lenses that we can prepare. If you have contact lenses, this would be more comfortable for you.
It is very important to remain as still as possible during the scan, as movement can affect the accuracy of the functional maps.
Tasks
During the scan, you will be asked to perform the tasks you practiced. The Clinical fMRI Lead will check in with you between each task and remind you of the instructions for the next task.
Each task will take approximately 5 minutes.
Language tasks include completing sentences, naming pictures, and generating verbs or antonyms in response to a word prompt.
Motor tasks include tapping each finger to your thumb, tapping your feet, smiling / pouting, or moving your tongue back and forth.
Additional images
In addition to the tasks, you will have 2 scans lasting approximately 5min each; one is a routine structural scan used to overlay the functional maps and one is a diffusion scan called DTI which can be used to map the white matter connections between the areas of your brain. You don’t need to do anything but relax for these 2 scans.
After the scan
You are free to leave.
Functional activity will be analysed in specialist software, coloured, and overlaid onto your brain images to create a functional map. These maps are integrated into your clinical records at the hospital and will be reviewed by the clinical team alongside your other scans and assessments as they plan your treatment pathway.