The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 16, 1992
Filed:
Dec. 08, 1989
Christopher J Thompson, Montreal, CA;
The Royal Institute For The Advancement of Learning, Montreal, CA;
Abstract
Arrays of scintillation crystals disposed on the circumference of a cylinder are used to detect the annihilation photons emitted after positron decay of isotopes within a body section. At the point of equi-probable depth of gamma ray interaction the surface treatment of each crystal is modified to absorb the light which otherwise would have been reflected by a small length of that surface. While light emitted from the rear of the crystal is nearly constant with depth, light emitted from the top front of the crystal is much reduced if the gamma ray interacts behind the absorbing band. When readout devices measure the light emitted from the top-front and rear face simultaneously it is possible to detect the region of interaction. This can be used to improve the spatial resolution of a positron imaging system.