studying the brain

• computerised tomography/CT scans

  • uses x-ray radiation
  • digital X-ray detectors used to pick up X rays exiting patients body
  • dense tissue absorbs more x-rays so show up lighter
  • shows physical structures but not direct functions
  • not recommended for pregnant patients or children
• magnetic resonance imaging(MRI scans)

  • uses magnetic field and radio waves
  • soft tissue clearly seen and at a higher resolution than CT scans
  • identifies areas of damaged tissue not brain function
  • useful for tumour diagnosis
  • more expensive than CT however doesnt carry risks of x-rays
  • MRIs can interfere with medical devices eg pace makers
• functional MRI/FMRI scans

  • allows brain function to be studied in real time
  • shows location of oxygenated blood in the brain thus showing the active regions
  • measure ratio of oxygenated and deoxygenated haemoglobin
  • change in blood flow measured
• PET scans

  • uses radioactive tracers which collect in areas where there is increased blood flow, metabolism or neurotransmitter activity
  • amount of radioactive tracer present in a brain region can indicate if region is active or inactive
  • studies structure and function of brain in real time