Organ Characterization with nuclear-medicine tomography

摘要

A method is described for performing in vivo analyses of the time-varying absolute radioactivity of selected human organs, following intravenous injection or oral administration of a radiopharmaceutical. It may be employed to quantitate the absolute activities of a physiologically important radioactive isotope within an organ over a predetermined test period. The time-activity relationship can in turn be used to analyze physiological factors—that is, the functions and activity of an organ, including the physical and chemical processes involved—so as to give the regional blood flow to the organ, and the metabolic function of the organ as represented by its organification of the radioactively labeled drug. The method can also be used to determine the morphological factors—that is, the form and structure—of an organ, such as its depth within the patient. It is directly applicable, for example to the diagnosis of diseases of the thyroid, the liver, and the kidneys, and to the localization of tumors using labeled antibodies. The method is based on the recording, analysis and interpretation of photon emissions (γ-, x-, and coincidence photons) observed during specific tomographic scans of the organ interest. Its practical implementation is disclosed in U.S. Patent 4,682,604 dated 28 July 1987, granted to the authors.