Radiation imager collimator

• US 6,175,615 B1
• Filed: 04/12/1999
• Issued: 01/16/2001
• Est. Priority Date: 04/12/1999
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Edic, Peter Michael, Wirth, Reinhold Franz, Guru, Shankar Visvanathan
• Primary Examiner(s): Bruce, David V.
• Assistant Examiner(s): Hobden, Pamela R.
• Application Number:
  US09/289,819
• Time in Patent Office: 645 Days
• Field of Search: 378/145, 378/147, 378/149, 250/515.1
• US Class Current: 378/149
• CPC Class Codes: G21K 1/02 using diaphragms, collimators
• CPC Class Codes: G21K 1/025 using multiple collimators, e.g. Bucky screens; other devices for eliminating undesired or dispersed radiation

Abstract

A collimator 100 for use in a radiation imaging system 10, and a method for making such collimators, are provided, wherein the collimator 100 is capable of collimating radiation in two orthogonal planes. The collimator in one embodiment includes a block 101 of radiation absorbing material having a plurality of focally aligned channels 102 extending therethrough; in a second embodiment, the collimator includes first and second collimation204, 212 sections having a respective first plurality of focally aligned plate sets 201 and a respective second plurality of focally aligned plate sets 203 disposed orthogonally to the first plurality of plate sets. The method for making the collimator includes generating a CAD drawing, generating from the CAD drawing one or more stereo-lithographic files, and using the stereo-lithographic files to control an electro-deposition machining machine which creates the channels in the block.

Claims

1. A collimation apparatus comprising:

a block of radiation-absorbing material having a front face and a rear face, a thickness of a said slab being defined as a distance between said front face and said rear face; and

a plurality of channels formed within and extending through said slab, each of said plurality of channels having an entrance opening and an exit opening, said plurality of channels being separated by and defined by a plurality of channel walls collectively comprising a web of said radiation absorbing material, said web comprising the portion of said slab material remaining after said plurality of channels are formed in said slab;

wherein each of said plurality of channels has a central longitudinal axis, and wherein said longitudinal axes of said plurality of channels intersect at a point located at a predetermined distance from said front face of said slab.

2. A collimation apparatus as recited in claim 1 wherein said slab of radiation absorbing material comprises material selected from the group consisting of tungsten, lead, and natural uranium.

3. A collimation apparatus as recited in claim 1 wherein each of said plurality of channels comprises a plurality of walls, and wherein each of said walls is tapered such that said walls converge to said point where said longitudinal axes of said channels intersect.