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Biomedical subjects

S M Pinsky

Publications and source records attributed to S M Pinsky.

36 records · Page 2Linked to original sources
PubMed1976

Thyroid cancer occurring as a late consequence of head-and-neck irradiation. Evaluation of 1056 patients.

From January 1 to September 30, 1974, we examined 1056 of 5266 subjects (20.1%) who had received therapeutic irradiation primarily for infections and inflammatory disease of the upper respiratory tract at our institution during the 1940's and 1950's. The tonsillar and nasopharyngeal region was the treatment site in 85% of those examined. Palpable nodular thyroid disease was found in 16.5%, and nonpalpable lesions were detected by 99m Tc pertechnetate thyroid imaging in an additional 10.7%, for a prevalence of nodular disease of 27.2%. Operation on 71% with nodular disease revealed thyroid cancer in 33% (60 of 182). Preliminary analysis for potential risk factors suggests a correlation between radiation exposure and the presence of thyroid nodules (P less than 0.001). These findings indicate that nodular thyroid disease, both benign and malignant, continues as a major health problem for at least 35 years in exposed subjects.

Adolescent↗
PubMed1976

Gallium-67 tumor scanning.

Since its introduction in 1969, 67Ga has become the most widely employed tumor-scanning agent in nuclear medicine. While 67Ga is far from being the ideal tumor-scanning agent, it remains the best available isotope for this purpose. Gallium-67-citrate has been found to be of value in the staging and reevaluation of lymphomas as well as in detecting the extent and recurrence of lung tumors, breast tumors, malignant melanomas, testicular tumors, brain tumors, and malignant lesions involving the liver. In order to obtain maximum diagnostic value from gallium scanning, several technical factors have to be taken into consideration as well as an understanding of the nature of "false-positive" scans.

Acute Disease↗
PubMed1976

The sensitivity and specificity of 99mTc-sulfur colloid liver imaging in diffuse hepatocellular disease.

The sensitivity and specificity of 99mTc-sulfur colloid liver-spleen imaging in diffuse hepatocellular disease and the significance of image patterns found in these diseases are presented. By visually quantifying the image alterations found in biopsy-proven cases of diffuse hepatocellular disease and analyzing the correlation between the histological diagnosis and the quantified image alteration (individually and by groups), the 99mTc-sulfur colloid liver-spleen image was found to be highly sensitive (83%). Relative discriminatory values were derived for each image finding and a specific image pattern was found in cirrhosis.

Colloids↗
PubMed1976

Evaluation of labeling procedures and in vivo stability of 99mTc-red blood cells.

Stable labeling of red blood cells (RBCs) with 99mTc, in yields of about 66%, was achieved by using stannous chloride as a reducing agent. In a study of 12 patients, the stability of technetium-labeled RBCs in the circulation varied significantly among individuals, but the average biologic half-life of the labeled cells was 16.8 hr. Although the labeling yield was lower when the labeling was carried out without EDTA with the addition of stannous chloride after the pertechnetate, this sequence appears to be the best for labeling RBCs for use in obtaining images of the blood pool or the cardiovascular system because of the increased viability of the RBCs.

Erythrocytes↗
PubMed1976

Radionuclide venography: significance of delayed washout; visualization of the saphenous system.

Venograms were obtained on dogs in which venous thrombosis had been surgically induced. Radionuclide venograms, obtained after injection of 99mTc-labeled microspheres or macroaggregated albumin, showed decreased radioactivity over the areas of venous thrombosis and increased radioactivity over areas of venous stasis. Scintigrams of veins excised after an injection of labeled particles did not delineate thrombi, areas of crush-injured vein, or the venous valves. Delay in the washout of radioactivity on a venogram indicates stasis due to impeded venous flow in the area of thrombosis. A modified technique was developed to obtain simultaneous images of the superficial and deep veins of the leg. Visualization of the superficial veins not only permits detection of superficial abnormalities, but also assists interpretation of the venographic observations of the deep veins.

Animals↗
PubMed1976

Rapid determination of oxidation state of unbound 99mTc and labeling yield in 99mTc-labeled radiopharmaceuticals.

Current techniques for determining the radiochemical purity of 99mTc-labeled radiopharmaceuticals are limited by the variety of compounds that can be tested or the length of time required to complete the test. A chromatographic method, based on the use of two solvents (0.9% saline and acetone) and a stationary phase made of silica-coated cellulose strips, solves these problems for water-soluble 99mTc-labeled radiopharmaceuticals. With this method, the oxidation state of unbound 99mTc and the labeling yield of 99mTc-labeled radiopharmaceuticals can be quickly determined: the whole procedure takes only a few minutes to run. This system compares favorably with lengthier procedures and with a commercially available kit.

Chromatography↗
PubMed1976

Radionuclide angiography with 99m technetium-RBCs.

When properly labeled 99mTc-RBCs are injected into a patient, these labeled cells are fairly stable in the circulation thus allowing scintigraphic studies on cardiovascular system. Among various modified techniques published for 99mTc-RBCs labeling, incubation of RBCs with 99mTc pertechnetate then with tin yielded 99mTc-RBCs most stable in the circulation. Average labeling efficiency of 99mTc-RBCs was 66%. After an injection of about 10 mCi 99mTc-RBCs, clear images of the heart chambers and major vessels could be obtained using a gamma camera. Resolution of vascular structures improved significantly when images were taken using gamma camera equipped with pinhole collimator. Radionuclide angiography with 99mTc-RBCs was very useful in detection of abdominal aortic aneurysm, evaluation of mediastinal mass--thoracic aortic aneurysm, and detection of abnormality in a smaller vessel such as carotid artery. Advantages of this procedure are (1) the technique is simple and noninvasive; (2) it has capability of functional evaluation by obtaining flow study; and (3) multiple and repetitive static views can be obtained even several hours after an injection.

Aged↗
PubMed1974

Pitfalls in Tc99m polyphosphate skeletal imaging.

The quality of Tc-PP scans is best in younger patients. In all age groups quality is adversely affected by free TcO4-. This should be suspected if excessive background is present or marked accumulation is noted in the thyroid gland. Direct physician supervision of all studies is recommended. Symptomatic and roentgenographically positive areas may then be determined for special interpretative attention. Objects which attenuate activity should be removed or noted. Potential sources of superficial contamination (product spill, urine, saliva) must be known and considered when extraneous activity does not correlate with skeletal structures or clinical findings. Normal variations in skeletal uptake of Tc-PP include asymmetries between periarticular areas on the right and left, local increases due to physiologic calvarial thickening and uptake in persistently visualized sternal ossification centers. Apparent variations in the vertebral activity may be due to focal plane effects of rectilinear scanners. Hyperemia can cause diffusely increased Tc-PP localization in an entire extremity. This effect may completely obscure a lesion or obscure the extent of a lesion. Tc-PP excretion through the kidneys occasionally provides useful morphologic or functional information concerning the urinary tract which should be inspected on all scans. Abnormal soft tissue uptake occurs in a variety of conditions including healing wounds and some malignant tumors. A large percentage of patients over 40 years of age demonstrate localization of Tc-PP in the walls of the femoral vessels.

Adolescent↗