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Biomedical subjects

E C Glass

Publications and source records attributed to E C Glass.

28 records · Page 2Linked to original sources
PubMed1986

Effect of region of interest selection on first-pass radionuclide cardiac output determination.

In principle, region of interest (ROI) selection should not affect the measurement of cardiac output by the first-pass technique with a radioactive intravascular indicator. Clinical application of the method requires that this theoretical hypothesis be tested. Sixty-eight left anterior oblique first-pass studies were acquired with a scintillation camera and computer using red blood cells labeled in vitro with 99mTc. Calculated mean cardiac output varied in the following order with respect to ROI: lung greater than right heart greater than left ventricle greater than whole heart (both ventricles) greater than aorta. Similar variations were observed in patients both with and without valvular regurgitation. Regions of interest over left ventricle or whole heart yielded the best correlations with cardiac output by thermodilution (r = 0.96, 0.95, respectively, n = 28) as well as the smallest interobserver variations (r = 0.994, 0.995, respectively, n = 33). First-pass studies with [99mTc]red blood cells labeled in vitro can yield accurate, reproducible determinations of cardiac output provided that the effect of ROI selection is recognized and that regions are properly selected.

Adolescent↗
PubMed1984

Measurement of metabolic extraction of tracers in the lung using a multiple indicator dilution technique.

Selective pulmonary uptake of many natural and synthetic substances has been demonstrated by physiologists and pharmacologists using isolated perfused lung preparations or invasive techniques. It is difficult, however, to relate these laboratory studies to disease processes and to the study of problems encountered in a clinical environment. Our goal was to develop a noninvasive method for studying the pulmonary uptake of tracer substances using available radiotracers, gamma cameras, and computers that would give information similar, if not identical, to that from the invasive laboratory methods, and that could be applied in a clinical setting. The multiple-indicator dilution technique, modified for external counting, is well suited for such studies of pulmonary uptake of tracer substances. In this study, Tc-99m micro sulfur colloid (Tc-99m micro SC) was used as an intravascular reference tracer, N-isopropyl-p-[123I]iodoamphetamine (I-123 IMP) as a cellular test tracer amine, and In-111 DTPA as an extracellular tracer. Calculated first-pass lung uptakes of I-123 IMP and In-111 DTPA were 0.92 +/- 0.04 and 0.17 +/- 0.04, respectively, relative to the reference tracer. Using this approach, the first-pass pulmonary extraction of a variety of radiolabeled test tracers can be measured in a clinical environment in a variety of physiologic settings.

Amphetamines↗
PubMed1980

Immediate renal imaging and renography with 99mTc methylene diphosphonate to assess renal blood flow, excretory function, and anatomy.

99mTc methylene diphosphonate (99mTc MDP) was evaluated as a clinical renal imaging agent in 20 patients referred for bone scintigraphy. Sequential scintigraphy, which was started immediately after injection, yielded blood flow studies of high quality, and subsequent images accurately delineated renal anatomy and excretion in nonazotemic patients. In comparison with delayed images, early images were vastly superior in quality and demonstrated improved target-to-nontarget activity ratios(p less than 0.001) and improved lesion detectability (p less than 0.01). Renal imaging performed incidental to bone scintigraphy with MDP can be greatly enhanced by initiating sequential scintigraphy immediately after injection.

Adolescent↗
PubMed1978

Ventricular visualization on brain scan with intracranial hemorrhage in disseminated phycomycosis.

Infections with fungi of the class Phycomycetes result in distinctive tissue changes characterized by growth of hyphae in and around blood vessels, causing necrosis and hemorrhagic infarction of tissue. A brain scan on a patient with a phycomycotic intracranial aneurysm demonstrated ventricular visualization at a time when there was clinical and autopsy evidence of rupture of the aneurysm.

Brain↗