Hack3.Positron Emission Tomography: Measuring Activity Indirectly with PET


Hack 3. Positron Emission Tomography: Measuring Activity Indirectly with PET

PET is a radioactivity-based technique to build a detailed 3D model of the brain and its activity.

Positron emission tomography (PET) is more invasive than any of the other imaging techniques. It requires getting a radioactive chemical into the bloodstream (by injection) and watching for where in the brain the radioactivity ends upthe "positron emission" of the name. The level of radioactivity is not dangerous, but this technique should not be used on the same person on a regular basis.

When neurons fire to send a signal to other neurons, they metabolize more energy. A few seconds later, fresh blood carrying more oxygen and glucose is carried to the region. Using a radioactive isotope of water, the amount of blood flow to each brain location can be monitored, and the active areas of the brain that require a lot of energy and therefore blood flow can be deduced.

1.4.1. Pros

  • A PET scan will produce a 3D model of brain activity.

1.4.2. Cons

  • Scans have to take place in bulky, expensive machinery, which contain the entire body.

  • PET requires injecting the subject with a radioactive chemical.

  • Although the resolution of images has improved over the last 30 years, PET still doesn't produce as fine detail as other techniques (it can see activity about 1 cm across).

  • PET isn't good for looking at how brain activity changes over time. A snapshot can take minutes to be assembled.

Myles Jones & Matt Webb



    Mind Hacks. Tips and Tools for Using Your Brain
    Mind Hacks. Tips and Tools for Using Your Brain
    ISBN: 596007795
    EAN: N/A
    Year: 2004
    Pages: 159

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