Abstract: A gamma camera of the invention fitted with a pin-hole cone for acquiring photographic type images, i.e. having a tungsten end fitting disposed at the small end of a truncated cone and provided with a pin-hole therethrough, is suitable for forming a point image of an object to be observed on the basis of gamma radiation emitted therefrom, transmitted through the pin-hole and magnified on reaching the inlet to the scintillator. The truncated cone is modular in structure: the pin-hole cone is mainly constituted by a base, a first truncated cone of suitable thickness for stopping low energy gamma radiation, and a second truncated cone superposable at will on the first so that the assembled cones are of sufficient thickness to stop high energy gamma radiation.

Abstract: The invention relates to a method for processing locating pulses supplied by a gamma camera and to a gamma camera utilizing this method. In accordance with the invention, locating pulses (X.sup.+,X.sup.-,Y.sup.+,Y.sup.-) are taken into account by a calculator circuit (12) which performs the standardization of an (X,Y) coordinate signal proportional to the difference of two locating pulses (X.sup.+ -X.sup.-) along an axis by the sum of these same two locating pulses (X.sup.+ +X.sup.-) along this axis.

Abstract: In a gamma camera utilizing a collimator, a scintillator, a network of photomultiplier tubes and an array of matrices of resistors, the balanced pulses supplied by this array are measured by integration in an integrator stage which supplies locating pulses. These locating pulses serve the purpose of generating coordinate signals applied to a visual display device. Prior to integration, the direct interference components affecting the balanced pulses are eliminated by capacitive coupling of the array of matrices to the integrator stage. In order to prevent this coupling introducing means direct components at high counting rates, the output of this coupling means is periodically forced to assume the value of a base potential.