Scanning techniques

• There is a 5-second time lag between the brain activity and the image shown on the screen.
• CT Scan is a method that examines the brain by taking a large number of X-rays of it.
• The person lies inside the donut-shaped scanner during a CT Scan.
• Stillness is required during a CT Scan as the scanner slowly rotates around the person's head.
• CT Scans produce images that are cross-sections of the brain.
• Once all the images from a CT Scan are put together, a detailed picture of the brain is created.
• CT Scans are useful for revealing abnormalities in the brain.
• The quality of the images from a CT Scan is much higher than traditional X-rays.
• There are ethical issues surrounding injecting radioactive substances into people.
• fMRI measures changes in blood oxygen levels in the brain.
• PET scans are expensive and the results are not easy to understand and interpret.
• PET scans show changes in blood flow in the brain.
• fMRI results are produced on a computer screen as a 3D image.
• The images produced by fMRI are extremely clear and show activity to the millimetre.
• When a brain area is active it uses more oxygen so therefore more blood is directed to this area, this is known as the haemodynamic response.
• fMRI is expensive and only effective if the person stays completely still.
• fMRI shows important information about which areas of the brain are being used at any one time.
• fMRI does not use radiation.
• CT Scans require more traditions than traditional X-rays, more detail and complexity the more radiation used.
• CT Scans only provide structural information and do not give information about brain activity.
• PET Scan measures metabolic activity in the brain.
• During a PET Scan, a person is injected with a small amount of radioactive substance which is then taken up by the brain and the areas that are most active will absorb the most.