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Biomedical subjects

G C Hart

Publications and source records attributed to G C Hart.

22 records · Page 2Linked to original sources

The random walk function in the analysis of time-activity curves from dynamic radionuclide studies.

The random walk function is a mathematical function derived from studies of the mass transport and flow of diffusible materials through tubes. Approximations to the function were first used some time ago in the field of cardiac tracer dilution curves, but in the absence of rapid and reproducible curve fitting the method never became commonplace. The current study uses the latest curve-fitting techniques and shows how the method may be used with precision in the analysis of time-activity curves from dynamic oesophageal and blood flow studies. The physiological basis of the method is given and parameters obtained which relate to both the rate of flow and the local dispersion of the bolus.

Esophagus↗

Moiré interference in gamma camera quality assurance images.

Moiré interference effects have been noted in gamma camera images for some time. Recent work has shown that the effects are still prevalent with the current generation of cameras, though apparently dependent upon collimator design. All previous work has been related to bar phantom images only. This paper also demonstrates a variety of moiré effects using the Anger "pie" phantom. Some of the principles underlying moiré interference as they apply to gamma cameras are given and possible uses of the effects are discussed, as well as the limitations they impose upon the use of certain test objects in routine quality assurance testing.

Interferometry↗