Calibration of detector sensitivity in positron cameras

An improved method for calibrating detector sensitivities in a positron camera has been developed. The calibration phantom is a cylinder of activity placed near the center of the camera and fully within the field of view. The calibration data are processed in such a manner that the following two important properties are achieved: (1) the estimate of detector sensitivity is unaffected by the sensitivities of the other detectors; and (2) the estimates are insensitive to displacements of the calibrating phantom from the camera center. Both of these properties produce a more accurate detector calibration