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:
Sep. 11, 2001
Filed:
Nov. 12, 1998
Mark S. Andreaco, Knoxville, TN (US);
Charles W. Williams, Powell, TN (US);
Michael E. Casey, Knoxville, TN (US);
Ronald Nutt, Knoxville, TN (US);
CTI Pet Systems, Inc., Knoxville, TN (US);
Abstract
A depth of interaction detector block for improving the spatial resolution and uniformity in modern high resolution PET systems over an entire FOV. An LSO crystal layer, a GSO crystal layer, and a light guide are stacked on each other and mounted on a 2×2 PMT set, so that the corners of the phoswich are positioned over the PMT centers. The crystal phoswich is cut into a matrix of discrete crystals. The separation of the LSO and the GSO layers by pulse shape discrimination allows discrete DOI information to be obtained. The block design provides an external light guide used to share the scintillation light in four PMTs. The 4 PMT signals S,are connected to an amplifier box which offers a 4 pole semi-Gaussian shaping for each of the four PMT signals, a sample clock for triggering the ADC cards and a fast sum signal &Sgr;,S,of the four PMT signals S,for pulse shape discrimination. A CFD provides a START signal for the time to pulse height converter. The fast sum signal is in addition differentiated and integrated with a fast filter amplifier and connected to a CFD, which provides a STOP signal for the TAC. The outputs of the shaped PMT signals and the TAC are connected to two ADC cards running under computer control.