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- Author or Editor: A. Al-Hilli x
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Abstract
A method for preparing99mTc-citrate complex, using instantly formed cuprous ions for the reduction of pertechnetate is described. The labelling kinetics, formation rate and stability of99mTc-Cu-citrate complex were studied. Gel filtration using column scanning technique has been found to be a reliable and unique tool for determining the amount of99mTc-fractions as a function of time in the preparation. The kidney uptake and excretion characteristics suggest a potential usefulness of99mTc-Cu-citrate complex for renal function studies. The safety measures for the amount of the complex to be injected in man have been estimated.
Abstract
A new formulation of stannous-dextran (Sn-Dx) freeze dried kit, containing 60 mg dextran (Dx-70) and 0.08 mg SnCl2·2H2O, to be labelled with99mTc, has been developed. At pH 6.5–7.0. the labelling efficiency was greater than 95%. Gel chromatography column scanning technique was applied for radiochemical purity determination of99mTc-Dx preparation and the degree of in vivo plasma protein binding. Not less than 70% of the administered activity was bound to plasma and remained constant over a 1h period. The biological behaviour after intravenous injection of99mTc-Dx kit was characterized by high and efficient yield of the radiopharmaceutical. The preliminarly clinical results on normal subjects showed that the radiopharmaceutical could be a useful agent for scintigraphy of leg lymph vesel, pelvic and inguinal lymph nodes. The activity uptake in liver and kidney (60 min) was relatively very low, whereas the urinal bladder activity (30 min) represents the drainage of the activity entering the blood stream after interdigital injection of99mTc-Dx.
Abstract
The formulation of a freeze-dried sulphide colloid kit, to be directly labelled with technetium is based on the preparation of tin/II/ sulphide precolloid, stabilized with carboxy methyl cellulose. The formation kinetics of the labelled colloid assessed by GCS-method showing a fast reduction of99mTc-pertechnetate, forming reduced99mTc-colloid with subsequent build-up of the labelled sulphur colloid. This is assumed to be due to the formation of99mTc/V/ to be bound to sulphide precolloid of the kit. The blood clearance data of the labelled colloid in rabbits showed two exponential disappearance phases of radioactivity from blood with biological half times of 3 and 67 min. The results of organ distribution in mice show that more than 85% of the administered activity is accumulated in the liver indicating a high colloidal yield of optimal particle size. The dynamic studies of the labelled colloid achieved in normal subjects using gamma camera indicate a rapid blood clearance and high liver uptake with low surrounding tissue background.
Abstract
The distribution of four different commercially available A, B, C, D kits (99mTc-sulfur colloid) for hepatoimaging was compared in mice by organ radioassay and in rabbits for blood clearance. The distribution of kits A and C (single step kits) was assessed in the human by blood clearance, external liver, spleen measurement, and scintillation camera imaging. Kit A reaches a high concentration in liver within 15–20 minutes with relatively high surrounding tissue background, and superior spleen scintiphotos. However, when kit C was used, a high activity concentration in the liver was reached within 10–15 minutes with low tissue background and faint visualization of the radiotracer in the spleen. Blood clearance of the four99mTc-sulfur colloids was determined in rabbits. The data obtained indicated that the four hepatoagents exhibit rapid blood clearance but the initial decrease of blood activity curve of kit D was relatively faster than the other three hepatic agents. The biodistribution is similar for the four99mTc-S-colloids but the blood retained higher activity residue using kit A compared with others. The formation of99mTc-sulfur colloid using kits B, D (multistep kits) involves many steps after the addition of99mTcO 4 – to the reagent. These procedures are time consuming, required facilities at the medical institutions and give rise to the radiation exposure. While single step kits A and C have the same diagnostic value, the use of kit C allows a reduction of absorbed radiation, which may be useful in the liver exploration in children.
