Meaning of Cylus: Cylus is a modern English respelling of the name Silas, which is a short form of the Greek name Silouanos, which is a variant of the Latin name Silvanus, which is derived from the Latin word silva, meaning wood, forest.
Overview. A positron emission tomography (PET) scan is a type of nuclear imaging test that shows the metabolic activities (energy usage) of your brain. While X-ray, CT, and MRI scans look at the anatomy of your brain, a PET scan can give your doctor information about how your brain is working.
Shades of blue and black indicate decreased or no activity within a brain region. In essence, a PET scan produces a âmapâ of the active brain. Scientists can use PET scans to see what happens in the brain when a person is engaged in a physical or mental activity, at rest, or even while sleeping or dreaming. Certain tracers can track the activity of brain chemicals, for example neurotransmitters such as dopamine and serotonin.