period of SEMI-ABSORPTION of radioactive materials

From Big Medical Encyclopedia

PERIOD of SEMI-ABSORPTION of radioactive materials — a time term during which of digestive tract a half of the radioactive materials which came to it is soaked up. The pct serves as an indirect quantitative index of digestion of feedstuffs in intestines.

Determination of Pct is carried out by method of external radiometry (see. Absorption ) and profile scannings (see). In a nerve a case after summing of results of measurements build schedules of dependence of speed of absorption of the radioactive material accepted inside from time which passed from this point. Items determine directly by the schedule or by a special formula. At almost healthy people of Pct of marked neutral fat, measured in the specified way, from 2,5 to 6 hours 6 min. hesitate, averaging 4 hours 8 min. +-30 min. The method of profile scanning allows to receive curve distributions of radioactive material in went. - kish. a path through certain time terms and on them by mathematical processing to calculate Pct of radioactive material.

Bibliography: Ishmukhametov A. I. Radio isotope diagnosis of diseases of the digestive system, M., 1979, bibliogr.; Distribution and biological effect of radioisotopes, under the editorship of Yu. I. Moskalyov, page 112, M., 1966.

A. I. Ishmukhametov.