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Biomedical subjects

C S Marcus

Publications and source records attributed to C S Marcus.

At least 55 records · Page 3Linked to original sources
PubMed1985

Pulmonary imaging in pregnancy. Maternal risk and fetal dosimetry.

A Tc-99m macroaggregated albumin (MAA) perfusion lung scan and a Tc-99m DTPA aerosol ventilation scan were performed for suspicion of pulmonary embolism (PE) in a patient who was ten weeks pregnant. There was considerable reluctance on the part of the obstetricians to permit this study. Standard MIRD dose estimates to the fetus were performed, which showed a maximum fetal exposure of about 50 mrem. It was concluded that the risk to mother and fetus from undiagnosed and untreated PE is much greater than the negligible risk to the fetus from the radiation exposure; fear of fetal radiation damage should not be a deterrent to performing these scans.

Adult↗
PubMed1985

Pediatric renal iodine-123 orthoiodohippurate dosimetry.

Radiation exposure to the kidney from iodine-123 orthoiodohippurate ([123I]OIH) and any associated [124I]OIH contamination may vary by a factor of several hundred depending upon the health of the kidney. Calculations of kidney dose were made for patients with the following renal states: normal, acute tubular necrosis (ATN), obstruction, and renal transplant. The dosimetry was based on a minimum practical administered activity (MPAA) of 200 microCi for pediatric patients and 500 microCi for adults. High-grade obstruction of recent onset and severe ATN are the only disease processes which could result in high exposures, and this is due primarily to the contribution of 124I. For selected cases, OIH labeled with pure 123I should be very seriously considered.

Adult↗
PubMed1985

Contribution of contaminant indium-114m/indium-114 to indium-111 oxine blood dosimetry.

Indium-114m and 114In appear as contaminants in commercial preparations of [111In]oxine at a level of about 0.05% at time of calibration (TOC). The contribution of these contaminants to the radiation absorbed dose from [111In]oxine leukocyte, platelet, and erythrocyte imaging procedures has been evaluated. When the absorbed dose from these contaminants is expressed as a percent of the 111In dose to the same organ from a given procedure, the contaminants contribute an additional 0.16 to 12% of the 111In dose, and in one case, that of the spleen from [111In]oxine labeled erythrocytes, they contribute an additional 33%. Commercial samples of aqueous-based [111In]oxine contain levels of 114mIn/114In sufficient to result in a mild to moderate increase in the absorbed radiation dose to the patient. Strict quality control procedures must be maintained by suppliers to prevent higher contamination levels. It is advisable to avoid using 111In products of this nature later than about 3 days after the time of calibration.

Blood Platelets↗
PubMed1983

Determination of organ area. Application to thyroid.

A method has been developed for the quantification of a projected organ area using a standard gamma camera with pinhole collimation and computer processing of two vertically displaced images. Formulae have been derived expressing the uniquely determined quadratic relationship between object area and aperture distance with respect to projective image areas. This technique is extremely simple and its successful application to thyroid imaging is described.

Humans↗
PubMed1983

Uptake of Tc-99m MAA by the liver during a thromboscintigram/lung scan.

A young man with a swollen left leg was referred to us for a thromboscintigram/lung scan. The unexpected visualization of the liver during the flow study after intravenous injection of Tc-99m MAA into the dorsal veins of both feet provided the clue to his underlying problem. He was shown to have extensive venous collateralization in the left pelvis, and to a lesser degree on the right, due to a large pelvic mass. This was shown to consist of metastases from a previously treated testicular carcinoma. Venous drainage from the legs was shunted into the mesenteric circulation, which them emptied into the portal vein, thereby carrying the radiopharmaceutical to the liver. No uptake was seen in the spleen.

Adult↗
PubMed1977

Preparation and high-performance liquid chromatography of iodinated diethylstilbestrols and some related steroids.

Diethylstilbestrol and estradiol have been converted to their mono- and poly-iodinated derivatives by electrophilic substitution of positive iodine into the activated aromatic rings. Both chemical and electrochemical procedures have been employed for the iodination, and the latter procedure proved to be superior. These iodinated derivatives have been purified by preparative high-performance liquid chromatography, and characterized by ultraviolet and mass spectroscopy.

Chemical Phenomena↗