Scanning Techniques

• What shape does a CT scan have?

  Large doughnut-shaped scanner.
• What does a CT scanner do?

  Takes lots of X-rays of brain which are combined to make a detailed picture.
• What is a positive evaluation of CT scans?

  Quality is higher than traditional X-ray.
• What is a negative evaluation of CT scans?

  High levels of radiation and only produces still images.
• What is a person who is about to undergo a PET scan injected with?

  Radioactive glucose.
• What happens in a PET scan?

  Once the radioactive glucose has made its way to the brain, brain activity is shown on a computer screen.
• What is a positive evaluation of PET scans?

  Shows brain in action and localisation of function.
• What is a negative evaluation of PET scans?

  Expensive and may be unethical because of radiation.
• How does an fMRI scan work?

  Measures change in blood oxygen levels.

  Displayed as a 3D computer image.
• What does a fMRI scan measure?

  Changes in blood oxygen levels.
• What is a positive evaluation of fMRI scans? 


  Superior as produces clear images without use of radiation.
• What is a negative evaluation of fMRI scans? 


  Expensive and have to stay very still.