Brain Scans
Progress in medical science and imaging has revealed not only brain structures, but functions as well.
Today, we can even watch the brain in action. The first device that was used to measure the brain was an electroencephalograph. It took readings of the brain's electrical activity. It is referred to as an EEG.
Visit Secret Life of the Brain: Scanning the Brain to learn more about the different types of brain scans.
Electroencephalograph - EEG
An EEG is a recording of electrical signals from the brain made by hooking up electrodes to the subject's scalp
Computerized Tomography – CAT Scan
Doing a CAT scan involves putting the subject in a special, donut-shaped x-ray machine that moves around the person and takes many x-rays.
Then, a computer combines the 2-dimensional x-ray images to make the cross-sections or 3-dimensional images.
Positron Emission Tomography – PET Scan
In a PET scan, the subject is injected with a very small quantity of radioactive glucose.
The PET then scans the absorption of the radioactivity from outside the scalp.
Magnetic Resonance Imaging – MRI/fMRI
In an MRI/fMRI, the subject is placed on a moveable bed that is inserted into a giant circular magnet.
A detailed picture of the brain’s soft tissue is taken by aligning spinning atoms in a strong magnetic field.
Magnetoencephalography - MEG
In MEG, magnetic detection coils bathed in liquid helium are poised over the subject's head.
The brain's magnetic field induces a current in the coils, which in turn induces a magnetic field in a special, incredibly sensitive instrument called a superconducting quantum interference device, or SQUID.
Visit Brain Imaging to learn the advantages and disadvantages of many of these types of scans.
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