Radioisotope renogramに関する臨床的研究 第1編: 131I-sodium iothalamate renogramについての研究

Abstract

In this paper, studies on 131I-sodium iothalamate renogram and its quantitative analysis are reported. [I] 131I-sodium iothalamate and its excretion from kidney. 1) Sodium iothalamate is the newest addition to a group of contrast media that are utilized in excretory urography. Radioactive sodium iothalamate has been successfully used to measure glomerular filtration rate CGFR). Sigman et al have determined that the renal clearance of 131I-sodium iothalamate in man closely approximates that of inulin. 2) The urinary excretion rate of 131I-sodium iothalamate in normal subject was 33.46±1.78%. 3) The correlation between sodium thiosulfate clearance by single injection method and urinary excretion rate of 131I-sodium iothalamate was excellent. 4) The renal extraction ratio of 131I-sodium iothalamate gave a nearly time-independent value. [II] 131I-sodium iothalamate renogram and its quantitative analysis. 1) Although many reports are available concerning the measurement of GFR using radioactive sodium iothalamate by the renal clearance technique, very few renographic studies with 131I-sodium iothalamate have been presented. 2) 131I-sodium iothalamate renogram in a normal subject has three phases like 131I-Hippuran renogram, but its peak is low and the slope is less steep. This makes a qualitative analysis rather difficult. On the other hand, the quantitative analysis of 131I-sodium iothalamate renogram using analog simulation technique made it possible to calculate GFR. 3) Filtration fraction (FF) is the ratio of filtration rate to renal plasma flow. Analyzing 131I-sodium iothalamate renogram and 131I-Hippuran renogram by analog simulation method, FF is easily calculated. Some interesting informations were available from thus calculated FF. In conclusion, 131I-sodium iothalamate is usefully used as a tracer in renography and its quantitative analysis by simulation technique affords clinically valuable informations about glomerular function.