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.
Also, the stroke region may be too small to be seen on CT scan, or it may be in a part of the brain (brain stem or cerebellum) which the CT scan does not image well. Depending on the results of the CT scan, your doctor may wish to obtain additional testing, including an MRI scan. CT scan uses X-rays to take pictures of your skull and brain. The patient lies in a tunnel-like machine while the inside of the machine rotates and takes X-rays of the head from different angles.