Abstract: The investigated object containing a source of positrons is placed into a system of n position and energy-sensitive gamma radiation detectors (Di), each having detection elements (Dijk), where one of a pair of annihilation photons interacts in the detection element (D1jk) and the other interacts in another detection element (D2jk). The detectors store the coordinates of simultaneously affected detector elements, the time of interactions and the energies E1 and E2 of the annihilation photons. The recorded events in the detection elements (D1jk) and (D2jk) leads to recognition of individual pairs of annihilation photons. An analysis is performed of the registration of the photons by the detection elements (D1jk) and (D2jk) with energies in the interval from 507 keV to 513 keV to obtain an approximate spatial depiction of positions of positron annihilation and, registration of the photons from the positron annihilation with significantly Doppler shifted energies outside of that interval.

Abstract: The investigated object containing a source of positrons is placed into a system of n position and energy-sensitive gamma radiation detectors (Di), each having detection elements (Dijk), where one of a pair of annihilation photons interacts in the detection element (D1jk) and the other interacts in another detection element (D2jk). The detectors store the coordinates of simultaneously affected detector elements, the time of interactions and the energies E1 and E2 of the annihilation photons. The recorded events in the detection elements (D1jk) and (D2jk) leads to recognition of individual pairs of annihilation photons. An analysis is performed of the registration of the photons by the detection elements (D1jk) and (D2jk) with energies in the interval from 507 keV to 513 keV to obtain an approximate spatial depiction of positions of positron annihilation and, registration of the photons from the positron annihilation with significantly Doppler shifted energies outside of that interval.

Abstract: The present invention relates to a pixel detector (10), comprising a semiconductor sensor layer (12), in which charges can be generated upon interaction with particles to be detected. The semiconductor layer defines an X-Y-plane and has a thickness extending in Z-direction. The detector further comprises a read-out electronics layer (14) connected to said semiconductor layer (12), said read-out electronics layer (14) comprising an array of read-out circuits (20) for detecting signals indicative of charges generated in a corresponding volume of said semiconductor sensor layer (12). The neighbouring read-out circuits (20) are connected by a relative timing circuit configured to determine time difference information between signals detected at said neighbouring read-out circuits (20).