Search PubMed⌕ Search

Biomedical subjects

V J Sodd

Publications and source records attributed to V J Sodd.

At least 37 records · Page 2Linked to original sources
PubMed1976

Cesium-129 myocardial scintigraphy to quantify myocardial infarction in dogs.

The sizes of surgically induced acute myocardial infarctions were quantified in a study of 28 dogs. Four projections (right and left anterior oblique, anterior, and left lateral) were obtained with 129Cs myocardial scintigraphy. Control images, taken before surgery, were compared with images taken 24-72 hr after coronary artery ligation. From postmortem examination the size of the infarct was determined and expressed as a percentage of the total left ventricle. On a standard diagram four independent observers marked the infarcted areas in each projection, expressed the severity of involvement in each area, and determined overall infarction size as a percentage of the total left ventricle. A nonlinear least-squares method was also employed to derive the size of the infarct, using the results from each observer's diagram. There were positive correlations between each observer's percentage estimate and the autopsy results. The overall accuracy of the least-squares method was similar to that of the individual observers. In this study, Observer 3 proved that acute myocardial infarcts can be quantified accurately from multiple scintigraphic projections of the myocardium, but the other three observers had difficulty in estimating infarct size. This difficulty probably resulted from the lack of well-validated criteria to aid the observer in determining the area of infarction, the severity of involvement within that area, or the total size of a myocardial infarct. Improvement in these estimates will require the development of definitive criteria, the use of optical scanners or computer processing, and combinations of radionuclides.

Animals↗
PubMed1976

The use of radioactive cesium chloride for imaging of malignant and benign pulmonary lesions.

129CsCl was investigated as an agent for imaging tumors of the lung, and based on the results of 56 patients studied, it has proved to be highly sensitive in detecting primary malignant tumors of the lung. The differentiation between pulmonary malignant lesions and tuberculosis appears to be feasible. However, false-positive images in patients with benign conditions are inevitable.

Adenocarcinoma↗
PubMed1976

Intercomparison of myocardial imaging agents: 201Ti, 129Cs, 43K, and 81Rb.

Thallium-201, 129Cs, 43K, and 81Rb were evaluated as "static" myocardial-imaging agents. Optimal settings of the scintillation camera were determined for each agent. Accumulation for good-quality images can be started as early as 5 min after the dose with 43K, 10 min with 201T1, and 30 min with 129Cs. Imaging times were comparable for 43K, 129Cs, and 201T1 (using the 80-keV x-rays). High-energy photons from the 81Rb preparation, largely from 82mRb contaminant, made it impossible to obtain an interpretable image without the addition of more shielding. Absorbed radiation dose from 81Rb is lower than that from 43K, 129Cs, and 201T1. The highest background activity was observed with 81Rb, followed by 43K, 129Cs, and 201T1 in that order. Overall, 201T1 was best suited for imaging acute myocardial infarction with currently available equipment, and 129Cs was next best. However, because of instrument setting and commercially obtained preparations, 81Rb could not be properly compared with the other radionuclides in our study.

Animals↗
PubMed1975

Effects of myocardial hypoxia and ischemia on myocardial scintigraphy.

The effect of regional myocardial ischemia and hypoxia on myocardial scintigraphy was studied in patients and dogs after intravenous administration of cesium-129. Seven men with angiographically proved ischemic heart disease underwent exercise testing and 129Cs was given immediately when ischemia was manifested in the electrocardiogram. Defects were not evident in the scintigrams of any patient. Failure to visualize a defect might be related to delayed uptake of 129Cs by the myocardium (maximal uptake in 45 minutes). The ischemic state was dissipated before the disparity in uptake between normal and ischemic myocardium could be visualized. Cesium-129 is useful for identifying acute myocardial infarcts but should not be used to visualize transient exercise-induced regional ischemia. Six dogs were given 129Cs after induction of regional myocardial hypoxia by perfusion of the anterior descending coronary artery with venous blood. In each, scintigraphy revealed a defect that resolved after reperfusion with arterial blood. Two other dogs were given 129Cs before perfusion with hypoxemic blood; neither dog manifested a defect. Since perfusion was maintained by a pump these results suggest that the major cause of the scintigraphically observed defect was inadequate cellular uptake of 129Cs rather than excessive cellular loss. Since regional myocardial hypoxia produced a reversible defect, scintigraphic studies might overestimate the size of an acute myocardial infarct in man by including the ischemic zone surrounding the infarct.

Adult↗
PubMed1975

Dosimetry of four heart-imaging radionuclides: 43K, 81Rb, 129Cs, and 201Ti.

In conjunction with research into the relative clinical suitability of radionuclides for heart imaging, estimates of the radiation dosimetry for 43K, 81Rb, 129Cs, and 201Tl were calculated. Estimates of absorbed radiation dose for the heart, kidneys, liver, lungs, testes, and whole body of the standard man were computed from published distribution data in rats via the MIRD method by assuming that the concentration in each organ per initial mean whole-body concentration is the same in rats and humans. The whole-body absorbed radiation doses from 81Rb, 129Cs, 201Tl, and 43K are 0.08, 0.17, 0.24, and 0.60 rads/mCi administered intravenously. In general, the organ doses from the four radionuclides follow the same order.

Animals↗