methods used in neuroscience: computer imaging

methods used in neuroscience: computer imaging

1. These methods are used widely in a clinical setting but are also providing new and important information about the structure and function of the brain.

2. computerized tomography CT

   • X-rays are beamed at many angles through the head and the amount of radiation absorbed is measured by a detector. A computer determines the density of tissue and a CT scan is produced.

3. magnetic resonance imaging MRI

   • Magnetic fields are used to generate signals from protons in tissue. This method provides good spatial resolution of the brain (i.e. ‘anatomical’ images). It is also non- invasive (i.e. drugs, X-rays etc. are not used) and is considered to be very safe for human subjects. 3-D images of the brain can be generated with modern computer technology.

4. positon emission tomography PET

   • Tracers or drugs containing positron-emitting radio nucleotides are injected into the blood supply or are inhaled as a gas (e.g. radioactive oxygen). These substances are taken up by active regions of the brain. Positrons are converted into photons which are detected by the PET scanner and active regions of brain can be visualises e.g. language areas during reading or spoken tasks.