Brain Imaging Techniques

• CT Scan: Computerized Topograph Scan

• MRI: Magnetic Resonance Imaging

• fMRI: Functional Magnetic Resonance Imaging

• PET Scan: Positron Emission Tomograph Scan

• EEG: Electroencephalogram

CT Scans: An x-ray of the brain.

A CT scan is essentially a computerized assembly of several x-ray images taken from a series of different angles. With a CT, the resolution is much better than conventional x-rays, and the detail that can be seen is much greater. 

        MRI is a noninvasive imaging technique that does not use x-rays.   The process involves passing a strong magnetic field through the head.  The magnetic field used is 30,000 + times that of the earth's magnetic field.  It's effect on the body, however, is harmless and temporary.  The MRI scanner can detect radiation from certain molecules, which are present in different concentrations in different tissues. 

Tumor in Wernicke’s Area

PET measures the emission of positrons from the brain after a small amount of radioactive isotopes, or tracers,  have been injected into the blood stream.  A common example is a glucose-relative with embedded fluor-18.   With this molecule, the activity of different regions of the brain can be measured.  The result is a three-dimentional map with the brain activity represented by colors. 

PET

SCANS

P

E

T

S

C

A

N

S

Dopamine

After Implant of Dopamine-secreting Tissue

Brain Development in First Year of Life

Normal Brain ADHD Brain

EEG Cap

EEG of Mouse with Epileptic Seizure

Deep Sleep Alert

The Evolution of the Brain

The Brain

The Brain

Brainstem the oldest part and central core of the brain,

beginning where the spinal cord swells as it enters the skull

responsible for automatic survival functions

Medulla [muh-DUL-uh] base of the brainstem controls heartbeat and breathing

THALAMUS

•It relays to the cerebral cortex information received from diverse brain regions. Sort of a requisite 'last pit stop' for information going to cortex. •Axons from every sensory system (except olfaction) synapse here as the last relay site before the information reaches the cerebral cortex

CEREBELLUM

Alcoholims causes brain shrinkage to the cerebellum

The Limbic System

Hippocampus Is particularly involved with memory phenomena, specially with the formation of long-term memory (the one that, sometimes, lasts forever).

Amygdala A little almond shaped structure, connects with the hippocampus.

Emotion and Memory are closely connected.

The pituitary gland may be king, but the power behind the throne is clearly the hypothalamus.

Lobes of the Cerebral Cortex

MotorArea

Sensory Area

LANGUAGE CENTERS

Speaking the Written Word Speaking the Heard Word

Angular Gyrus

Speak & Understand, Unable to Read

Disrupts UnderstandingDisrupts Speaking