Rodney D. Ice

Preparation, quality control and clinical acceptance of labeled Macrotec.

Thirty minutes after reconstitution, radiochemical purity determinations of the lung-scanning agent Macrotec (99m-Tc-MAA) indicated 95-100% technetium labeling: 76% of the particles had a mean diameter of 10-50 mu. Rat tissue distribution studies indicated lung uptake of 98% at 15 minutes. The biological half-life in the lung was 8.3 hours. In 12 patients requiring emergency lung scans, 9 scans were rated excellent. No liver, spleen or thyroid uptake or adverse reactions were noted.

BETA EMITTOR IDENTIFICATION BY QUENCH ANALYSIS

Abstract A technique has been developed for the identification of beta emittors utilizing the quantity of associated quench produced in a liquid scintillation detection system. By comparing ratios of associated quench of a standard beta emittor with the quench produced by an unknown, relative absorption curves were produced. A standard curve was generated using the calculated slopes of several beta absorption curves. Utilization of the standard curve permits identification of unknown beta emittors. The presence of outside contaminants such as urine, salts, and dust do not significantly alter the response. The techniques may be incorporated into routine biological monitoring of radiation workers or in analyzing environmental samples.