133Xe and stable Xe inhalation measurements of cerebral blood flow in health and disease.

Advantages and disadvantages of 133Xe inhalation method for measuring regional cerebral blood flow by external sodium iodide detectors are compared to those of the 35% stable xenon (Xe) inhalation method for measuring local cerebral blood flow using the CT scanner. Clinical applications are reviewed. At present, 133 Xe is the most widely available method. Advantages are established safely, availability of normal values, reasonable cost effectiveness, and wide applicability. Disadvantages are poor resolutions and errors due to lack of knowledge of solubility of xenon in abnormal tissues. Advantages of the Xes CT method are excellent resolution and measurement of tissue solubility of abnormal tissues. Disadvantages are subjective subanesthetic affects in some subjects (including numbness, light headedness, restlessness) and expense of Xes gas).