The influence of experimental conditions on the preparation of 99mTc-pyrrolidino-methyl tetracycline [99mTc-PMT] in the form of an instant kit.

The effects of varying the experimental conditions of the preparation of the renal scanning agent 99mTc-PMT on its organ distribution have been investigated. The stability of 99mTc-PMT was determined in vitro. A procedure for the preparation of this agent is recommended.

Investigation of the parameters related to the formation of 99mTc-pyrophosphate complexes using gel chromatography column scanning.

Using gel chromatography two different 99mTc-PPi complexes (complex I and II) were observed under various pH-values. In neutral medium complex II was the main product while in acidic or alkaline media complexes I and II were formed. Our results related to the organ distribution in mice revealed that complex II is a bone-seeking agent whereas complex I concentrates in the kidneys.

Scintiphotographic patterns of liver and spleen in a case of situs inversus evaluated by 99mTc-tin colloid.

Whereas normal liver and spleen scintiphotos with 99mTc- tin colloid are characterized by homogenous distribution of radiocolloid in the liver and slight uptake of radiotracer over the spleen in the anterior view, this report demonstrates that there is high radiotracer uptake in the spleen and slight uptake in the posterior view in a case of situs inversus.

Instant 99mTc-labelled glucoheptonate kit for kidney imaging.

Gelchromatography column scanning has been used to study the fractions of reduced hydrolyzed 99mTc, 99mTc-pertechnetate and 99mTc-chelate in a 99mTc-glucoheptonate (GH) preparation. A stable high labelling yield of 99mTc-GH complex in the radiopharmaceutical has been obtained with a concentration of 40-50 mg of glucoheptonic acid-calcium salt and not less than 0.45 mg of SnCl2.2 H2O at an optimal pH between 6.5 and 7.0. The stability of the complex has been found significantly affected when sodium hydroxide solution was used for the pH adjustment. However, an alternative procedure for final pH adjustment of the preparation has been investigated providing a stable complex for the usual period of time prior to the injection. The organ distribution and the blood clearance data of 99mTc-GH in rabbits were relatively similar to those reported earlier. The mean concentration of the radiopharmaceutical in both kidneys has been studied in normal subjects for one hour with a scintillation camera and the results were satisfactory.

Ytterbium-169-phytate: a potential new radiopharmaceutical for functional scintigraphy of the liver.

A new radiopharmaceutical for liver scintigraphy has been prepared by reacting 169YbOCl with Na phytate under conditions which yield a labelling efficiency of more than 99% over a wide pH range. In rabbits the resultant colloidal preparation shows a rapid elimination from the blood and high initial uptake in liver. Subsequently about 90% of the liver activity is lost within 3 days, the remainder being eliminated more slowly. The radiopharmaceutical is non-toxic and has a shelf-life of about 3 months. Scintigrams obtained in patients with hepatomegaly suggest that this new agent gives better visualization of space occupying lesions of the liver than 99mTc-Sn colloid. The radiation dose to the patient from this agent is low and comparable with that from other radiopharmaceuticals used for liver scintigraphy.