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Biomedical subjects

W E Barnes

Publications and source records attributed to W E Barnes.

29 records · Page 2Linked to original sources

Absorbed radiation dose from radionuclidic impurities in several 123I-labeled radiopharmaceuticals.

The radiation dose to patients from RISA, sodium iodohippurate, and rose bengal labeled with commercially available 123I and its accompanying radioimpurities has been studied. The extra radiation dose to target organs was found to range from 29% to 97% that due to 123I alone when the radiopharmaceutical is administered at calibration time. Additional delay in the time of administration increases the relative impurity dose.

Drug Contamination↗

Tc-99m labeled complexes of aldehydes and glutamate as cholescintigraphic agents.

Tc-99m pyridoxylidene glutamate has proven to be an excellent biliary scanning agent, far superior in many respect to the commonly used I-131 rose bengal. The preparation of the compound as previously reported by Baker et al is too time consuming and requires the use of an autoclave which is not available in most nuclear medicine departments. In our facility, we have been preparing similar compounds using several aldehydes and monosodium glutamate to make labeled complexes having the same pharmacological characteristics. The mixture of monosodium glutamate, aldehyde, and Tc-99m pertechnetate is made slightly alkaline, purged with helium, and placed in a sealed vial. The vial, which is protected by a wire basket, is then heated in a laboratory oven at 130 degrees C for a period of 15 to 20 minutes. During this time, the technetium is reduced to a lower valence state and bound to the complex formed. Chromatographic data show that these compounds are chemically similar to that previously reported. The compounds prepared concentrate in the gall bladder of the rabbit in less than 10 minutes. Kinetic studies have been performed on dogs with a scintillation camera and small digital computer to measure rates of blood clearance, liver and gall bladder uptake, and excretion into the intestine. The aldehyde -- glutamate complex promises to be a useful scanning agent for the diagnosis of biliary and hepatocellular diseases.

Aldehydes↗

Dual-channel facilitation of the 99mTc radiocardiogram.

A refinement of the radionuclide-angiocardiogram is described using a low deadtime scintillation camera and hardwire data storage, processing, and display system for the purpose of anatomic definition of the passage of a radioactive bolus through the carciopulmonary circulation by dual-channel, dual-color, subtraction methodology. The summation of the bolus pathway is displayed as a static frame of reference for the sequential kinetic image. The technique is noninvasive and employs 15 mCi of 99mTc pertechnetate. This procedure may be employed as the conventional bolus study for determining the cardiac kinetics ordinarily obtained by the method. The opportunity of viewing the bolus position in relation to its entire pathway significantly facilitates defining the multiple areas of interest the observer may wish to study.

Coronary Circulation↗