George L Roberson

US Patent:

6624425, Sep 23, 2003

Filed:

May 3, 2001

Appl. No.:

09/847929

Inventors:

David T. Nisius - Des Plaines IL
George P. Roberson - Tracy CA
David C. Camp - Danville CA
David Entwistle - Buffalo Grove IL

Assignee:

Bio-Imaging Research, Inc. - Lincolnshire IL

International Classification:

G01T 100

US Classification:

250393, 25036301

Abstract:

A method and apparatus are provided for assaying a waste container. The method includes the steps of forming a plurality of slices through a volume of the waste container, performing a relatively fast passive prescan to measure a level of radioactivity of each of the plurality of slices and identifying at least some slices of the plurality of slices having a relatively high level of radioactivity. In addition, the method includes the steps for performing a relatively fast active prescan of the drum to determine the average attenuation of the plurality of slices. The method further includes the steps of determining an passive assay time for the identified slices based upon the measured radioactivity and average attenuation and performing relatively slow passive and active CT scans of the identified slices based upon the determined passive and active CT assay time to quantify a source of the measured radioactivity by weight.