SPECT in the Year 2000: Basic Principles

Schematic diagram of SPECT data acquisition. For each projection view, the computer sends a message to the gamma camera to step to the next viewing angle and, after the camera sends a message back to the computer that it is ready to acquire, the computer acquires the projection image at that angle for a specified time. The actual time t required for each view is the sum of the camera step time plus the projection image acquisition time. The total SPECT study acquisition time is T = mt, where m is the number of views acquired (in this case, 60 views over 360°, at 6° intervals).