Magnetic resonance imaging (MRI) of the brain uses a magnetic field, radio waves, and a computer to create a detailed image of the complex structure of brain tissues. For a brain MRI, the head is scanned with the help of an MRI machine. An MRI of the brain provides a clear and detailed cross-sectional image of the area of the brain that provides a three-dimensional representation of the brain. These cross-sectional images can be projected and stored on a computer or printed on film. Since brain MRIs produce better soft tissue images than X-ray reports and can distinguish between the gray and white matter of the brain, they help locate defects in brain tissues such as tumors, pituitary masses, radiation damage to the brain, brain swelling, blood flow abnormalities, optic glioma and brain aneurysm with greater accuracy and precision. MRI has been able to identify lesions in the brain in approximately 95% of patients compared to CT which identified lesions in approximately 25% of patients. An MRI technique called diffusion/perfusion is used to scan the brain and helps detect a stroke within minutes of its onset, allowing for earlier treatment.
Unlike X-rays, which are harmful to the brain, MRIs are a safer option for brain scanning because they don’t have significant side effects. Gradient magnets are used to alter the magnetic field in the area to be scanned while magnetic force is applied. Brain MRI helps the technician to focus on the exact area of the patient’s brain that they want to scan.
A new study has evolved in which brain MRIs are now widely used for polygraph tests, as well as to identify if a person is lying. It does this by tracking blood flow in certain areas of the brain, indicating increased lying activity.