STANDARDIZATION OF PHOTORECORDING AND DISPLAY FOR SCINTIGRAPHY

Abstract

In order to obtain standardized scintigraphy in all radioisotope laboratories, photorecording conditions for radioisotope imaging were evaluated technically by Radioisotope Committee of Japanese Society of Radiological Technology. First of all the imaging technique each radioisotope laboratory was surveyed by imaging with the standard phantom, next it was undertaken to determine the best condition of film density, information density, cut off level, rate down and line spacing for photoscintigraphy using X-ray film. The optimum film density of volume source in liver, lung and kidney scintigraphy was 1.5-1.7 at maximum value. However for positive imaging such as bone, brain and tumor scanning the optimum film density was 0.5 at surrounding tissue area. It is desired that the scintigraphy with short life nuclide such as ^<99m>Tc information density over 1,000 counts/cm^2 on the maximum point and if possible, over 2,000 counts/cm^2 with scanner and over 5,000 counts/cm^2 with scinticamera. It is a general rule to set non-contrast enhancement and non-cut off for photoscintigraphy. The optimum line spacing of scanning is 2-3 min.