Benjamin C Welch

US Patent:

6429432, Aug 6, 2002

Filed:

Nov 26, 1999

Appl. No.:

09/449787

Inventors:

Colin J. McNaught - Annapolis MD
Douglas Arthur Kieper - Norfolk VA
Benjamin Lawrence Welch - Hampton VA
Lee Holland Fairchild - Poquoson VA

Assignee:

Dilon Technologies, Inc. - Newport News VA

International Classification:

G01T 1161

US Classification:

25036302, 25037009

Abstract:

An adjustable gamma radiation isolation shield that effectively shields the gamma camera from potentially interfering radiation emitted from sources other than the particular anatomical portion under examination. The shield is placed adjacent to the breast or other body portion under examination on the side thereof opposite that addressed by the gamma camera i. e. , at about 90Â to the viewing angle of the camera. The shield includes a first gamma ray permeable layer capable of absorbing fluorescent low energy radiation produced by a second adjacent gamma radiation absorbing layer or any other source. In operation, the breast is located between the gamma camera/detector and shield. Gamma radiation emitted by the radiopharmaceutical-containing breast impinges the gamma camera for measurement and simultaneously penetrates the gamma permeable layer and is absorbed by the gamma radiation absorbing layer. Fluorescence produced upon absorption of the gamma radiation is inhibited from reintroduction into the gamma camera by absorption in the first gamma permeable layer that absorbs this secondary radiation. Gamma or other potentially interfering radiation entering the system from beyond the gamma radiation absorbing layer is similarly absorbed and any secondary fluorescent radiation produced therein absorbed by the first gamma permeable layer.