A fundamental study of sup(99m)Tc-DTPA renoscintiphoto

The present study consists of a series of sequential whole-body macroautoradiography of rats to investigate the mode of transference of this material in the body. Besides, optimum technical conditions for the autoradiography with sup(99m)Tc were investigated. The analysis of autoradiograms was done referring the following three items; qualitative analysis, measurement of radioactivity, and computer analysis. Among them, the computer analysis was considered to be one of the objective and reliable methods. The specific distribution of this tracer to the urinary system was investigated with passage of time and phase, by means of whole-body autoradiography in the rat. In the early phase, comparatively high accumulation of this tracer in the blood, lung, and liver was observed, and their disappearance patterns were also similar. In the kidney, rapid distribution of this tracer to the cortex and also to the pelvis was observed from its early phase. Reaccumulation of this tracer to the cortex was also observed on re-circulation of the blood into the kidney, but its intrarenal transference was observed in a short time. The pattern of sequential intrarenal distribution of this tracer was similar to that of the other GFR substances. However, clear discrimination between so-called vascular, functional, and excretory phases was hardly made by sup(99m)Tc-DTPA renoscintiphoto. (J.P.N.)