An adjustable zoom-made gain control for computerized gamma-camera systems.

Many nuclear medicine departments use a digital computer to process scintillation-camera images. For optimal use of the computer, there should be a means to amplify the position signals of each scintillation event by an appropriate amount before their conversion to digital form. What is needed is a series of calibrated gains from which the best value may be chosen. Many systems now in use do not provide such a selection. The circuitry described here provides an inexpensive solution to this problem. It may be inserted between the camera and the computer's analog-to-digital converters to provide the desired amplification. No internal modification of the computer or the camera is required.