An electronic "diaphragm" for the gamma camera, with adjustable zooming and offset.

We describe a new device for data acquisition from a gamma camera using an electronic spatial "diaphragm," with variable offset and zooming. The device, mainly applied to cardiac studies, permits selection of the desired part of the field of vision to be digitized and to zoom, before the computer acquisition. The spatial diaphragm spans 0.4-0.9 of the diameter of the FOV, and the amplification factor from 1.1 to 2.5.