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:
Dec. 26, 1995
Filed:
Nov. 19, 1993
Hugh T Morgan, Highland Heights, OH (US);
Bryce G Thornton, Concord, OH (US);
Picker International, Inc., Highland Hts., OH (US);
Abstract
A rotatable gantry portion (16) is rotatably mounted on the stationary gantry portion (18) of a SPECT camera. A plurality of radiation detector heads (10a, 10b, 10c) are mounted to the rotating gantry. A transmission radiation source holder and collimator assembly (40, 42) is mounted to the rotatable gantry portion opposite one of the detector heads. A transmission radiation source (60) is mounted in a lead shield (62) with an opening (64) pointing toward an examination region (12). A shutter (66) is rotatable between a closed position in which a lead arc segment (70) blocks the opening (64), a calibration orientation in which tin (72) covers opening (64), and an open position in which an opening (74) is aligned with the opening (64). A safety interlock means (80) locks the shutter in the closed position and against rotation when the radiation source holder is removed from the rotatable gantry portion. A collimator (42) has lead side walls (200) and tin or tin alloy septa (202). When radiation from the radiation source strikes the lead side walls, they emit characteristic lead x-rays of about 88 keV whereas the tin radiates x-rays of only about 30 keV. A filter (210) includes an inner layer (212) of tin for attenuating any remaining 88 keV lead x-rays coming from the transmission line source assembly and converting them to about 30 keV radiation. The filter has an outer layer (214) for attenuating the radiation around 30 keV.