Tools We Use to Study the Brain

CAT scan (computer axial tomography) is an X-ray procedure that combines many X-ray images with the aid of a computer to generate cross-sectional views and, if needed, three-dimensional images of the internal organs and structures of the body. CAT scans are performed to analyze the internal structures of various parts of the body. 
Source: 
http://www.becomehealthynow.com/article/diagradiology/639/
http://www.medicinenet.com/cat_scan/article.htm


Structural Magnetic Resonance Image is a radiology technique that uses magnetism, radio waves, and a computer to produce images of body structures. An MRI scan can be used as an extremely accurate method of disease detection throughout the body and is most often used after the other testing fails to provide sufficient information to confirm a patient's diagnosis.
Source:
http://www.medicinenet.com/mri_scan/article.htm

Diffusion-Tensor MRI (DTI) is a method that provides a description of the diffusion of water through tissue, and can be used to highlight structural changes in tissue tracts. This form of MRI measures how water molecules diffuse through body tissues and it is used to diagnose conditions like stroke or disorders like multiple sclerosis. 
Source:
http://www.hopkinsmedicine.org/psychiatry/research/neuroimaging/research_methods/diffusion_tensor.html
http://www.livescience.com/39074-what-is-an-mri.html

EEG (electroencephalograph) is a test that measures and records the electrical activity of your brain. An EEG is one of the main diagnostic tests for epilepsy and may also play a role in diagnosing other brain disorders.

Source:
http://www.webmd.com/epilepsy/electroencephalogram-eeg-21508
http://www.mayoclinic.org/tests-procedures/eeg/basics/definition/prc-20014093













PET Scan (Positron emission tomography)  is an imaging test that can help reveal how your tissues and organs are functioning. PET works by using a scanning device (a machine with a large hole at its center) to detect positrons (subatomic particles) emitted by a radionuclide in the organ or tissue being examined.
Source:
http://www.mayoclinic.org/tests-procedures/pet-scan/basics/definition/prc-20014301
http://www.hopkinsmedicine.org/healthlibrary/test_procedures/neurological/positron_emission_tomography_pet_scan_92,P07654/


fMRI (functional MRI) is a technique for measuring brain activity. It works by detecting the changes in blood oxygenation and flow that occur in response to neural activity – when a brain area is more active it consumes more oxygen and to meet this increased demand blood flow increases to the active area and it can also be used to produce activation maps showing which parts of the brain are involved in a particular mental process.

Source:

http://psychcentral.com/lib/what-is-functional-magnetic-resonance-imaging-fmri/0001056

TMS (transcranial magnetic stimulation)  is a procedure that uses magnetic fields to stimulate nerve cells in the brain to improve symptoms of depression. TMS is a non-invasive method of brain stimulation that relies on electromagnetic induction using an insulated coil placed over the scalp, focused on an area of the brain thought to play a role in mood regulation; the coil generates brief magnetic pulses, which pass easily and painlessly through the skull and into the brain. 
Source:
http://www.mayoclinic.org/tests-procedures/transcranial-magnetic-stimulation/basics/definition/prc-20020555
http://www.hopkinsmedicine.org/psychiatry/specialty_areas/brain_stimulation/tms/