Gregory Cooley

US Patent:

58347801, Nov 10, 1998

Filed:

May 29, 1996

Appl. No.:

8/654542

Inventors:

Hugh T. Morgan - Highland Heights OH
Gregory G. Cooley - Chardon OH
Bryce G. Thornton - Concord OH
Steven G. Plummer - Hudson OH

Assignee:

Picker International, Inc. - Highland Heights OH

International Classification:

G01T 1166
G01T 1161

US Classification:

25036304

Abstract:

A gamma camera system includes two or more radiation detector heads and which are mounted opposite each other to a gantry for rotation about a subject. A transmission radiation source assembly is mounted to the front face of at least one of the detectors and can be moved across the face of the detector. The source assembly includes a radiation attenuating housing, a leaded bronze source holder, and a radionuclide source. The radionuclide source is retained in a longitudinal groove disposed in the source holder. The source holder may be rotated into open, closed, and access positions. The transmission radiation emitted by the source assembly is directed across the examination region, attenuated by the subject, and detected by the opposed detector. The gamma camera system also includes a filter which selectively attenuates the transmission radiation based on the attenuation profile of the object so as to prevent saturation of the opposed detector. An image representation is reconstructed using the radiation emitted by the subject and corrected in accordance with the transmitted radiation data.

US Patent:

60607122, May 9, 2000

Filed:

Feb 4, 1998

Appl. No.:

9/018609

Inventors:

Hugh T. Morgan - Highland Heights OH
Gregory G. Cooley - Chardon OH
Bryce G. Thornton - Concord OH
Steven J. Plummer - Hudson OH

Assignee:

Picker International, Inc. - Cleveland OH

International Classification:

G01T 1166

US Classification:

25036304

Abstract:

A gamma camera system includes two or more radiation detector heads and which are mounted opposite each other to a gantry for rotation about a subject. A transmission radiation source assembly is mounted to the front face of at least one of the detectors and can be moved across the face of the detector. The source assembly includes a radiation attenuating housing, a leaded bronze source holder, and a radionuclide source. The radionuclide source is retained in a longitudinal groove disposed in the source holder. The source holder may be rotated into open, closed, and access positions. The transmission radiation emitted by the source assembly is directed across the examination region, attenuated by the subject, and detected by the opposed detector. The gamma camera system also includes a filter which selectively attenuates the transmission radiation to obtain a desired attenuation profile which prevents saturation of the opposed detector. The filter includes at least one layer of radiation attenuating material of uniform thickness but varying in width in a direction substantially parallel to a direction of motion of the source assembly.