BRAIN IMAGING

1
BRAIN IMAGING
2
NEUROIMAGING

• Various techniques to either directly or
  indirectly image the structure,
  function/pharmacology of the brain
• Neuroimaging falls into two broad categories
• Structural imaging deals with the structure of
  the brain and the diagnosis of gross (large
  scale) intracranial disease (such as tumor), and
  injury
• Functional imaging used to diagnose metabolic
  diseases and lesions on a finer scale (such as
  Alzheimer's disease) and also for neurological
  and cognitive psychology research and building
  brain-computer interfaces

3
Brain Imaging Techniques

• Computed axial tomography (CT scan)
• Magnetic resonance imaging (MRI)
• Functional magnetic resonance imaging
• Electroencephalography (EEG)
• Positron emission tomography (PET)

4
CT Scan

• CT scans use a series of X-ray beams passed
  through the head. The images are then developed
  on sensitive film. This method creates
  cross-sectional images of the brain and
• shows the structure of the
• brain, but not its function.

5
MRI

• MRI uses the detection of radio frequency signals
  produced by displaced radio waves in a magnetic
  field. It provides an anatomical view of the
  brain.
• Advantages
• No X-rays or radioactive material is used.
• Provides detailed view of the brain in different
  dimensions.
• Safe, painless, non-invasive.
• No special preparation (except the removal of all
  metal objects) is required from the patient.
  Patients can eat or drink anything before the
  procedure.
• Disadvantages
• Expensive to use.
• Cannot be used in patients with metallic devices,
  like pacemakers.
• Cannot be used with uncooperative patients
  because the patient must lie still.
• Cannot be used with patients who are
  claustrophobic (afraid of small places). However,
  new MRI systems with a more open design are now
  available

6
PET Scan

• A scanner detects radioactive material that is
  injected or inhaled to produce an image of the
  brain. Commonly used radioactively-labeled
  material includes oxygen, fluorine, carbon and
  nitrogen. When this material gets into the
  bloodstream, it goes to areas of the brain that
  use it. This method provides a functional view of
  the brain.
• Advantages Provides an image of brain activity.
• Disadvantages Expensive to use Radioactive
  material used.

7
PET SCANS IN ADULTS

• In men who had ADHD, PET scans showed that they
  processed a memory task in visual areas in the
  occipital lobe of the brain, as
• indicated by the yellow
• spots in the left image.
• Non-ADHD men used
• the temporal and frontal
• lobes, shown at right.

8
MRI OF ADHD BRAIN
9
PET SCAN
10
Bipolar

• From left view of a normal brain patient with
  bipolar disorder has enlarged ventricles bright
  white spots of hyperintensity associated with
  bipolar illness.

11
Bipolar

• The left amygdala and related structures (yellow
  area where lines intersect) are part of an
  emotion-regulating brain circuit where children
  with bipolar disorder showed greater activation
  than controls
• when rating their fear of
• neutral faces.

12
Healthy vs. Disorders