A STUDY OF RENOSCINTIGRAM

Abstract

I. Basic Study.
Experiments were performed for the following purposes: (1) to determine the distribution of RI-Neohydrin (²⁰³Hg and ¹⁹⁷Hg-Neohydrin) in the body, (2) to investigate the radiation effects of RI-Neohydrin on the kidneys and (3) to evaluate the tracing ability of the Renoscintigram by means of phantom experiment.
(1) The rabbits were divided into 10 groups and 30μCi of ²⁰³Hg-Neohydrin were administered intravenously to each of the rabbits. Then the rabbits were sacrificed in 5 minutes, 30 minutes, 1 hour, 2 hours, 3 hours, 12 hours, 1 day, 7 days, 21 days and 30 days. The animals were autopsied immediately after sacrifice. The various organs were counted for radiation (count/min./mg).
Autoradiography was done to illustrate the distribution of Neohydrin in the kidney.
(2) The rabbits were divided into six groups by the doses administered (²⁰³Hg-Neohydrin 1, 3 and 10μCi/kg, ¹⁹⁷Hg-Neohydrin 3, 10 and 50μCi/kg) and the results were compared with that of the control group with 1.95mg of plain Neohydrin. The animals were sacrificed in 2nd, 5th, 1 week, 3 weeks, 7 weeks and 21 weeks following the administration and the kidneys were removed immediately for the studies.
(3) The scintiscanning procedures were performed using kidney phantoms containing 50μCi of ²⁰³Hg-Neohydrin each and with the cavities of 1cm, 2cm, 3cm and 4cm in diameter. The scintiscanner (Aloka JSS-103 B) was equiped with a cut off system as a background eraser. The scanning was performed with cut off level at 40-80%.
The results were as follows;
(1) RI-Neohydrin was most heavily concentrated in the cortex of the kidney, and especially in the primary tubular cells. The highest count rate was obtained about 30-60 minutes after injection. The count was still present in the cortex even in 30 days after injection.
(2) Temporary tissue reaction due to the radiation by ²⁰³Hg or ¹⁹⁷Hg-Neohydrin was noticed in the five groups. Their characteristic histological findings consisted of swelling of the primary tubular cells, hyaline droplets degeneration and swelling of the glomeruli and its adhesion to the Bowman's capsules. These changes were most remarkable in 1 week after administration. Recovery was noted in 3 weeks in ²⁰³Hg-Neohydrin groups. The changes in the ¹⁹⁷Hg-Neohydrin groups were less and recovery was quicker.
(3) The cavities less than 2cm in diameter were not demonstrated in the scintigram as a filling defect. The scintigram was well controled by the cut off level.
II. Clinical Study
Two hundred clinical materials in the Department of Urology, Jikei University School of Medicine, from July 1965 to September 1967 were reviewed. Of these cases the excretory urographies and renal scannings were performed simultaneously. In addition retrograde pyelography, renal angiography and renography etc. were done as needed. For the scintiscanning of the kidneys 100-150μCi of ²⁰³Hg-Neohydrin was injected intravenously for adults except for 7 cases which received ¹⁹⁷Hg-Neohydrin. The patients were kept in prone position for an hour after the administration and were scanned with cut off level at 30-50%.
The observation was made on every case and 14 cases were reported in details comparing Renoscintigram with excretory urography and other examinations. The relation between uptake of RI-Neohydrin by renal tissue (renal tubular cells) and renal function was studied histologically.
The results were as follows;
(1) ²⁰³Hg-Neohydrin and ¹⁹⁷Hg-Neohydrin were employed with good scanning results. ¹⁹⁷Hg-Neohydrin was shown to cause less radiation effect, than ²⁰³Hg-Neohydrin, but clinically ²⁰³Hg-Neohydrin was easier to use in Japan currently.
(2) Uptake of RI-Neohydrin by renal tissue (renal tubular cells) was known to be parallel to r