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Biomedical subjects

H J Dworkin

Publications and source records attributed to H J Dworkin.

11 recordsLinked to original sources
PubMed1992

Radiation safety considerations for post-iodine-131 thyroid cancer therapy.

The purpose of this study was to develop guidelines based on direct patient measurements as to when 131I-treated thyroid cancer patients may resume close personal contact after release from the hospital. External exposure rates were measured on 27 patients using a calibrated ionization survey meter. The patients' exposure rates were measured at the time of release from the hospital and 2-7 days post-hospital discharge. Measurements were taken at 1, 0.6 and 0.3 meters from the patient's upright body axis (stomach to thyroid). Vertical movement of the survey instrument was utilized to obtain the maximum reading each time. All patients had exposure rates less than 2 mR/hr at 1 meter at 2-4 days post-hospital discharge. Eight-eight percent (21/24) had exposure rates less than 2 mR/hr at 0.6 meter at 2-4 days post-hospital discharge. Guidelines can be prepared specifically for thyroid cancer therapy patients that are rational and consistent with existing radiologic health standards.

Adult↗
PubMed1991

Radiation safety considerations for post-iodine-131 hyperthyroid therapy.

The purpose of this study was to develop guidelines based on patient measurements as to when iodine-131- (131I) treated hyperthyroid patients may resume close personal contact. External exposure rates were measured on 59 patients using an ionization survey meter in the upright position. The initial measurement was recorded within 20 min post-dose administration at one meter. Exposure rates were measured 2-11 days post-dose administration at 1, 0.6, and 0.3 meters from the patient's thyroid. In the administered dose range of 3 to less than 12 mCi of 131I, all 40 patients measured less than or equal to 2.0 mR/hr at one meter on Day 0, and 25 patients (25/29) were less than or equal to 2.0 mR/hr at 0.6 meter on Days 2-4. Guidelines can be prepared based on the administered dose that are rational and in conformity with existing radiologic health standards.

Breast Feeding↗
PubMed1989

Splenic imaging in a patient with functional asplenia.

A 65-year-old woman presented with right upper extremity paralysis and left cerebrovascular accident. A routine complete blood count (CBC) demonstrated Howell-Jolly bodies on peripheral smear, and a liver-spleen scan showed absent splenic sulfur colloid uptake suggesting functional asplenia. A subsequent heat damaged red blood cell study demonstrated a normal sized spleen with preserved sequestering function, thereby excluding anatomic asplenia, vascular alterations, or congenital anomalies in the differential diagnosis of functional asplenia. This case illustrates the use of Tc-99m heat damaged red blood cells as a unique and useful diagnostic aid in identifying the presence and size of a spleen in patients with functional asplenia. It also demonstrates an apparent qualitative separation of splenic functions in processing sulfur colloid and heat damaged red blood cells.

Aged↗
PubMed1989

Phantom feet on digital radionuclide images and other scary computer tales.

Malfunction of a computer-assisted digital gamma camera is reported. Despite what appeared to be adequate acceptance testing, an error in the system gave rise to switching of images and identification text. A suggestion is made for using a hot marker, which would avoid the potential error of misinterpretation of patient images.

Aged↗
PubMed1977

The incidental detection of gallium-67 citrate in a urinoma following a right pyeloplasty: a case report.

An abnormal accumulation of radionuclide was identified within the right juxtadiaphragmatic and juxtahepatic spaces during gallium-67 citrate scintigraphy in a post-pyeloplasty patient. Its mode of presentation, the recent pyeloplasty and the known biologic distribution of gallium suggested that it represented gallium-67 concentration within a postoperatively created urinoma. Diagnosis was confirmed by excretory urography and laparotomy.

Adolescent↗
PubMed1977

Effect of particle number on lung perfusion images: concise communication.

Twelve normal mongrel dogs were injected with decreasing numbers of 99mTc-labeled macroaggreagated albumin particles (99mTc-MAA), and lung images were recorded using both parallel-hole and pinhole collimators. The quality of normal lung images was found to decrease with decreasing numbers of injected radiolabeled particles (from 10,000 to 250 particles per injection). The quality was unaffected by adding carrier MAA. The minimum number of particles compatible with a good-quality image of the normal human lung is approximately 60 radiolabeled particles per gram of lung.

Animals↗
PubMed1976

The effect of carrier technetium in the preparation of 99mTc-human serum albumin.

Accumulation of daughter 99Tc in 99Mo-99mTc generator systems may adversely affect the preparation of certain 99mTc radiopharmaceuticals. In a study of the effect of "carrier" technetium on the radiochemical purity of 99mTc-human serum albumin, varying amounts of 99Tc were added to a commercially available electrolytic kit. The maximum amount of 99Tc that could be added to such a kit and still maintain radiochemical purity above 90% was about 3 X 10(15) atoms. When kits containing 10(16) 99Tc atoms were electrolyzed for the conventional 42 sec, the radiochemical purity was only 50.8%. However, when the electrolysis time was varied, it was found that electrolysis for 80 sec yielded a product with greater than 90% radiochemical purity. Four solutions to the problem created by the 99Tc carrier effect are described.

Isotope Labeling↗
PubMed1975

Vial retention of technetium-99m sulfur colloid in commercial kits.

Vial retention of technetium-99m sulfur colloid in five commercial kits used for the preparation of this radiopharmaceutical was studied. Radiochromatography and microscopic particle sizing were performed on all products; the biologic distribution in rats of two products was tested. Loss of activity attributable to vial retention was evident with only two products. The resulting loss of specific concentration did not affect biologic distribution. The cause of the "plating-out" of the radiopharmaceutical on the interior reaction vial surface was not determined, although the gelatin component of the product was suspected to be a factor.

Colloids↗
PubMed1975

A calibrated dose dispenser for gaseous 133Xe.

A device that permits accurate dispensing of individual doses of 133Xe from multicurie ampuls is described. The advantages include economy, flexibility in dose selection, and radiologic safety.

Respiratory Function Tests↗