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:
Oct. 28, 1997
Filed:
Dec. 29, 1995
Horace H Hines, San Jose, CA (US);
William K Braymer, Pleasanton, CA (US);
John R Liebig, San Jose, CA (US);
ADAC Laboratories, Milpitas, CA (US);
Abstract
A method of calibrating an attenuation map for use in emission imaging in a gamma camera system. The attenuation map is generated using a transmission scan of the object of interest. The map includes a number of attenuation coefficients for the object. A computer program for generating the attenuation map includes an instruction for scaling the attenuation coefficients in the map from the transmission energy level to the emission energy level using a scaling factor. The scaling factor includes an effective attenuation coefficient for water, which is determined empirically. To determine the effective attenuation coefficient, the number of photons which pass from a transmission source through known depths of water using the emission energy level is counted. The effective attenuation coefficient is computed based on a standard equation describing the attenuation of photons by an absorber. The scaling factor used by the computer program is then set based on the effective attenuation coefficient.