Apparatus of the location of a region in the human body, in particular of a thrombus venous by the absorption of a radio - active substance, in particular the i 125

摘要

A device for determining the depth of venous thrombosis in the legs made of a property of 1 ′ 1 125. This property lies in the fact that in about half of all the disintegrations, two photons are emitted simultaneously. These two photons coinciding, as the photons transmitted separately, have an energy of approximately 28 kev. A detector of the scintillations coinciding 1 receives the photons emitted as a photon of energy of 56 kev. The ratio between the number of photons emitted individually and the number of photons coinciding can thus be determined this quotient is a parameter which depends strongly on the distance between the detector and the source of radiation and which makes it possible to determine the depth of the thrombus.