Xenon-enhanced CT scanning is a method of computed tomography (CT scanning) used for neuroimaging in which the subject inhales xenon gas while CT images are made. The method can be used to assess changes in cerebral blood flow in the period shortly after a traumatic brain injury, or to detect or indicate the location of a stroke. The diffusion of the gas into the tissues shows how much blood flow each area is getting.
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Xenon-enhanced CT scanning Wikipedia(Text) CC BY-SA