What is Functional Magnetic Resonance Imaging?
Functional magnetic resonance imaging (fMRI) is based on the same technology that Magnetic Resonance Imaging (MRI) uses with one key difference. While MRI’s use a strong magnetic field and radio waves to create detailed images of the body and structures like tissue and organs fMRI’s provide detailed images of blood flow and activity. With the ability to view blood flow patterns physicians can see how and when the brain is functioning and not just the structure itself.
The primary forms performed use Blood-Oxygen-Level Dependent (BOLD) contrast imaging to evaluate brain and spinal cord functioning. In the BOLD technique haemodynamic changes in the amount of blood that tissue is receiving, blood-volume changes, or changes in oxygen levels in response to neuronal activity are measured when tasks are performed. More recently a newer technique called the Resting-State fMRI (rsfMRI or R-fMRI) has gained attention. In this technique, the fMRI is used to measure the interactions or functional connectivity that occurs in the brain while no tasks are preferred.
What are fMRIs used for?
FMRIs allow physicians to visualize the brain and understand how the brain is functioning at rest and during cognitive or behavioral activity, and to determine if there is a decrease or increase in blood flow in one or more regions of the brain. This allows them to determine which part of the brain is handling critical functions such as thought, speech, vision, movement and sensation.
FMRs can easily collect whole brain data in minutes and be used to:
- Detect Alzheimer’s, Dementia and patients at risk who are in a preclinical state of forgetfulness
- Analyze white matter in the brain to predict the increased risk of stroke, dementia, and death
- Assess the effects of a stroke, traumatic brain injury, concussions, Alzheimer’s or Dementia on brain function
In addition, fMRIs are used preoperatively to map the brain near critical speech or motor brain regions and to monitor brain tumors. Using an fMRI to evaluate brain function in these cases allows physicians to monitor patients and plan surgeries by localizing critical brain areas to determine surgical procedures and if any risks are associated with surgery.
Today research is being conducted around the world to determine the effectiveness of fMRIs as a diagnostic tool to evaluate a variety of conditions that affect cognitive function. This research includes:
- Attention deficit disorder (ADD)
- Bipolar Disorder
- Developing drugs for the central nervous system