203Hg-Neohydrinによる,腎scintigram及び腎摂取率の研究 第I篇: 腎scintigramの基礎的検討

Abstract

The fundermental problems in the renal scintigram by m eans of 20Hg-Neohydrin were investigated. Conclusions were drawn as follows. 1) Concerning the factors of definition of th e apparatus, noteworthy remarks, proper conditions and their effects for the renal scintigram were briefly described. a) A sufficient elimination of the back scatters was able to be accom plished by using more than 200 Key of the detection energy. b) The proper scan speed and line space were 40-60cm/min. and 2-3mm respectively. c) Determination of the rate down ratio is profitable to be achieved on t he basis of the uptake rate. d) T he effects of back ground erase of the limitor were experimentally demonstrated under inferiorer condition than the actual isotope distribution of the body on renal scintigram. e) By a collimator with 7cm of the focal distance, scanning must be mad e at the closest distance from the skin surface of the back. f) The proper direction of scan mus t be towarded to the right angle to the long axis of the body in the respect for comparison of the both kidneys. g) For scanning of wide areas as kidney, an app aratus having a recording system, with a dot of wide vertical range is suitable, even though various apparatuses have more or less advantages. 2) The results of studies on renal uptake rate of 2, 3Hg and the course of body back-ground suggested that the most proper conditions for renal scintigram in normal kidney is obtained between 2 and a half hours and 3 hours following the intravenous administration of 203HgNeohydrin. 3) An estimation of the internal radiation dose to the whole body and the kidney was made in cases of 100pc intravenons administration of zolig-Neohydrin. The radiation dose to the kidney was calculated on the basis of 203Hg-renal uptake-rate curve, which is supposed to be more accurlate method than calculations so far used. It was found that the doses on the central axis of the body and on the central axis of the kidncy were 55.8 mRad and 21.7 Rad respectively. It is noted that the administration of 203Hg should be minified as little as possible since the radiation dose to the kidney is considered to be rather massive. 4) For the renal scintigram, a use of highly sensitive collimalor is pref e rable because of its specificity of internal radiation. A comparative study was performed on the adaptability of several different collimators for the renal scintigram. It was found that the 7.hole honey cone type is qualified for our purpose, so that the standards and iso-responce curve of the type were illustrated. 5) Using a body phantom, the size of detectable intrarenal focus was estimated. A glass bead of 2.0 cm diameter was the smallest one detected in the kidney phantom. Scinti-scanning was performed on experimental ischemic kidney. A sufficient diagnostic value was recognized not only in stenosis of main renal artery but also in stenosis of branch artery. 7) On experimental stenosis of branch renal artery, the scintigram was made according to the section method which was found to be advantageous than ordinal methods.