Measurement of temporal changes in whole-body radionuclide distribution with a profile scanner

Our linear scanner has been instrumented to acquire data in digital form that are entered easily into a computer for quantitative analysis of linear distribution of activity and whole-body retention. The instrumentation consists of an external amplifier, a single-channel analyser, a multichannel analyser operated in multi-scale mode, and paper tape punch. When a scan table speed of 8 in/min (other speeds are available) and analyser timing of 3 s/channel (also variable) are used, a total-body linear scan requires 10 min and 200 channels of analyser memory. Each channel thus represents about 1 cm of body length. A camera attached to the multichannel analyser oscilloscope provides a record of the linear scan. The linear scan data stored in the multichannel analyser are transferred to paper tape. With information on patient identification, anatomical landmarks, etc., the scan data are entered into the computer and stored on magnetic tape. Our computer analysis program calculates the amount of activity in the whole-body and the fraction of activity in each of eight sections of the body defined by the landmarks. The program also can be used to compare the results with earlier scans and calculate changes of distribution with time. (author)