title: Reproducibility of gamma camera data.
abstract: The increasing use of quantification in the interpretation of nuclear medicine images requires a knowledge of the errors associated with the estimation of the activity in a volume of interest from the recorded count rate data. Using sources of known cross-sectional area from 1 to 25 cm2, errors caused by variations in the count rate, day of measurement, source position in the camera field of view, and source size are evaluated. The effect of source depth in tissue-equivalent (TE) medium on the reproducibility of the data is also investigated. For a given source size at a known depth, variations in camera response lead to an error (SD) of a least 6% that increases as either the source size or the depth of the source in TE medium is increased. Failure to estimate accurately the true depth of the organ can also be a major source of error. The use of two conventional types of flood correction technique ('count-skipping' and matrix division) is found to increase the error only in the case of the smallest source.
mesh_terms: D008961:Models, Structural; D011877:Radionuclide Imaging / Q000295:instrumentation / Q000592:standards*; D013667:Technetium
chemical_list: D013667:Technetium