RADIOISOTOPES
Online ISSN : 1884-4111
Print ISSN : 0033-8303
ISSN-L : 0033-8303
Labelling of Colloid with 99mTc by Electrolytic Method and Application to Liver Scanning
Hisashi BUNKOIkuro TATSUNOSotoe KATO
Author information
JOURNAL FREE ACCESS

1974 Volume 23 Issue 12 Pages 706-711

Details
Abstract

Recently there appeared several99mTc labelled liver scanning agents. They were99mTc2S7colloid, 99mTc-Sn-colloid, 99mTc-microaggregated albumin and more recently 99mTc-phytate, and could be used with simple labelling procedure. These were relatively small particles, and uniformity of these liver scanning agents was difficult to assess, and it was somewhat difficult to use these agents as quantitative liver scanning agents. In this regard, colloid seemed to be useful because of its uniformity of the particle size (about 4μ in diameter) .
The authors intended to label colloid with99mTc by electrolytic method of Ikeda, et al., and performed basic and animal experiments and clinical evaluation of99mTc-colloid as liver scanning agent
99mTc-colloid labelled by Ikeda's original method showed marked macroaggregation within one hour after labelling. So the authors modified the original method in the point of pH adjustment usingNaHCO3immediately after labelling (pH=1.2→pH=6-7) . The labelling efficiency of the99mTc-colloid was over 94-99%. Particle size of the colloid observed with microscope was about 4μ and fairly uniform. The half time of blood disappearance and peak accumulation time in the liver of99mTc-colloid in man were 1.1 min and 10 min respectively. The linear scans showed clear single peak at the level of the liver, and body background of the chest was slightly higher than that of abdomen. Animal experiments showed about 20% of the total dose remained in the lungs, and it seemed difficult to use99mTc-colloid clinically. However, none of the liver scans of the clinical cases showed such marked lung uptake. The effective half life in the liver in experimental animal and in man were 6 hr and 5.5 hr, and in the spleen, 4.8 hr and 3.2 hr, respectively. Splenic visualization was more marked in99mTc-colloid than in99mT c-Sn-colloid.
From these results, 99mTc-colloid prepared by electrolytic method seemed to be useful in clinical application.

Content from these authors
© Japan Radioisotope Association
Previous article Next article
feedback
Top