Functional magnetic resonance imaging (fMRI) is a type of neuroimaging modality that allows researchers and clinicians to visualize which parts of the brain are active when completing tasks or being exposed to stimuli. It operates on the principle that active areas of the brain require a greater supply of oxygenated blood than inactive areas. fMRI scans measure these differences in blood flow to create images of brain activity that allow for inferences into cognitive, sensory, and motor function.
Examining the brain in function
Richard is examining the activities of different parts of the brain. Functional MRI can show which parts of the brain are activated when people are performing different activities. Our studies include using functional MRI which involves having subjects in an MRI machine, and alternating between doing tasks, and resting.
One example of a task that is used in this research is called the n-back test. In the n-back test subjects are shown sequences of letters, and asked to indicate if the letter currently on the screen matches the letter that was displayed ‘n’ letters ago
Functional MRI
Functional MRI is used to assess blood flow and just where there is activity in your brain. The clinician can see which part of your brain performs what task. The information from an fMRI is important when considering a procedure, like brain surgery, where a brain area is going to be impacted after contemplating and deciding to conduct a surgery on a specific brain area, fMRI will help the neurosurgeon strategize their surgery by highlighting areas to avoid because they perform an important function. Functional MRI does not have an age restriction; thus, both adults and children can have an fMRI.
Circumstances or processes that may require such planning include:
- Epilepsy. If epilepsy does not respond to medications or any other treatment options, there may be an opportunity for epilepsy surgery.
- Brain tumors. If there is any growth, including cancerous and benign tumors, it is possible the necessary option would be to surgically remove the mass.
- Radiation therapy to the brain. Radiation therapies that use precision can treat cancerous masses, problems with circulation, and a variety of brain injuries.
- Post treatment scans. Post-treatment or post-intervention scans help determine differences in brain function in the event of a medical intervention.
- Investigations are also being conducted for fMRI to reach other conclusions. There is support for it being potentially helpful in biobehavioral feedback therapy.
How does an fMRI scan work?
An fMRI scan works quite similarly to an MRI. You will lie on a table that can move you through the machine. An fMRI usually employs a conventional ring-shaped MRI scanner, because most open MRIs do not have a sufficient, strong enough magnet.
During an fMRI, your head will be inside a specially-designed head coil, which fits like a helmet. The head coil helps to improve clarity of images. You will wear special headphones that cancel out sound from the MRI machine, while still allowing for healthcare providers including MRI technologists and radiologists, to communicate with you for instructions..
The two systems of performing tasks are the event system and the block system.
Block system: this system will have you perform a task for a short time, and then you will rest for a short time. The time periods are called blocks.
Event system: this system will have you perform a series of tasks, and there will not be a rest period between tasks.
Your provider may also want part of your fMRI to be a “resting state” scan. You will basically lie in the scanner (your provider may ask you to either keep your eyes open or closed) while they view and measure the difference between doing an activity versus a resting state in your brain.
How should I prepare
Eating and drinking before an MRI varies based on your exams, and the facilities. The best approach is to eat food and take medication as you typically do unless the doctor or MRI facility explicitly states otherwise.
Patients are required to disclose any pregnancy to their doctor and technologist. MRI has been performed without negative consequences to the patient; the fetus resides in a strong magnetic field. Therefore, pregnant patients should only be scanned with MRI during the first
Conclusion
Functional MRI (fMRI) has changed the ways in which we are able to observe the human brain in task-based engagement. This machine is a non-invasive means to dynamically view how different areas of the brain respond based on experience and based on changes in contextual engagement by assessing blood flow and oxygenation. It supports our new technologies, clinical diagnostics, and improvements in neuroscience research to start to understand how the brain works. Although we do not measure neuronal activity directly and the temporal resolution is quite limited, fMRI gives us high spatial resolution and great safety, in many cases.
Frequently Asked Questions
Q. How does fMRI detect brain activity?
fMRI detects changes in blood flow to indicate brain activity. When brain cells are active, they burn more oxygen and as a result, before the brain is even aware of it
Q. How does a functional MRI measure neural activity via?
Functional MRI scanners can detect the changes in the magnetic properties of blood, allowing researchers to discover through a specified task the brain regions that are being used.
Q. What is the mechanism of functional MRI?
Functional MRI, or fMRI, is a measure of brain activity as it indirectly measures neural activity through blood flow to the brain. More specifically, fMRI determines neural activity using the blood oxygen level dependent signal (BOLD).
Q. How does a functional MRI work?
Functional magnetic resonance imaging (fMRI) is a newer imaging modality that, due to increased blood flow to the brain,
Q. What is the mechanism of fMRI?
Functional magnetic resonance imaging (fMRI) is a measure of blood flow to the brain and is referred to as a measure of activity in brain cells.
