Technetium-99m Cysteine—An Agent for Renal Scintigraphy

The preparation of technetium-99m cysteine and its evaluation as an agent for renal scintigraphy are discussed. The techniques of preparation and chromatographic separation of the product are described. Organ distribution studies in 10 rats showed rapid uptake of activity in the liver over the first half hour, and after six hours, high activity in the kidney with little activity in the liver. Single posterior views were obtained on 85 patients and normal volunteers by rectilinear scanning after an intravenous dose of 0.5 to 3.0 mc of technetium-99m cysteine. In most cases, the scintigrams were performed for renal localization prior to an iodohippurate renogram. Of the 26 cases where abnormal scintigrams were expected, the report was accurate in 22 cases. Three of the four remaining reports described pathology where it existed but were not accurate in localization; the fourth instance was a false negative report. The advantages of technetium-99m cysteine for renal scintigraphy are its easy preparation and its moderately high renal activity for a period exceeding one hour.