Computerized helical scanning to determine the location of specific nuclides in the human body

The purpose of this investigation was to develop a method to locate and to trace the movement of gamma-emitting nuclides in human subjects by scanning the body helically with a collimated scintillation detector. The counting system was a helical scanner and a 4K analyzer. An IBM 360 computer was used to reduce the counting data. For each scan of the body, as many as 4096 separate measurements were made of the level of activity at positions along the helical path of the detector as it moved around and along the body. The results were in the form of computer-produced isometric and/or isocount contour plots showing the location and relative quantities of the specific nuclides in the different sections of the body. Positions on the surface of the body were plotted as a function of gamma activity and gamma energy. Results are given for 12 scans that were obtained from three different persons. Changes in the distribution of the activity in the body were determined as a function of time by repeated scans of the same individual. The results of this study show that helical scanning can be used to determine the total body distribution of gamma-emitting nuclides in humans. If the helical configuration is used, repeated scans are not necessary in order to cover the surface of the body between the selected limits of the scan. Large quantities of data are rapidly reduced to the final results by a high-speed computer.