CT imaging system with multiple peak x-ray source

• US 7,120,222 B2
• Filed: 06/05/2003
• Issued: 10/10/2006
• Est. Priority Date: 06/05/2003
• Status: Active Grant

• Current Assignee: GE Medical Systems Global Technology Company LLC (GE Healthcare Technologies, Inc.)
• Original Assignee: General Electric Company
• Inventors: Hoffman, David M.
• Primary Examiner(s): Ho, Allen C.
• Application Number:
  US10/250,132
• Publication Number:
  US 20040247082A1
• Time in Patent Office: 1,223 Days
• Field of Search: 378/5, 378/16, 378/19, 378/92, 378/98.9, 378/98.11, 378/124, 378/134, 378/137, 378/138, 378/144, 378156-159, 378/115, 378/116, 378/143, 378/57
• US Class Current: 378/5
• CPC Class Codes: A61B 6/027 characterised by the use of a particular data acquisition trajectory, e.g. helical or spiral
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: A61B 6/4007 characterised by using a plurality of source units
• CPC Class Codes: A61B 6/4021 involving movement of the focal spot
• CPC Class Codes: A61B 6/4035 the source being combined with a filter or grating
• CPC Class Codes: A61B 6/4241 using energy resolving detectors, e.g. photon counting
• CPC Class Codes: A61B 6/482 involving multiple energy imaging
• CPC Class Codes: H01J 2235/068 Multi-cathode assembly
• CPC Class Codes: H01J 35/064 Details of the emitter, e.g. material or structure H01J35/065 takes precedence

Abstract

An x-ray source (32) for performing energy discrimination within an imaging system (10) includes a cathode-emitting device (82) emitting electrons and an anode (81) that has a target (80) whereupon the electrons impinge to generate an x-ray beam (93) with multiple x-ray quantity energy peaks (116 and 120). A method of performing energy discrimination in the imaging system (10) includes emitting the electrons. The x-ray beam (93) with the x-ray quantity energy peaks (116 and 120) is generated. The x-ray beam (93) is directed through an object (44) and is received. An x-ray image having multiple energy differentiable characteristics is generated in response to the x-ray beam (93).

Claims

1. An x-ray source for performing energy discrimination within an imaging system comprising:

a plurality of cathode-emitting devices emitting a plurality of electrons; and

a single rotating anode having a plurality of targets oriented whereupon said plurality of electrons impinge to generate a plurality of x-ray beams; and

a plurality of filters simultaneously filtering said plurality of x-ray beams to generate a post-filter x-ray beam having an x-ray distribution with simultaneously a plurality of x-ray quantity versus energy peaks defined as a plurality of peaks in the number of x-rays at multiple energy levels.

2. An x-ray source as in claim 1 wherein said a plurality of cathode-emitting device comprises:

a first cathode-emitting device emitting a first plurality of electrons; and

a second cathode-emitting device emitting a second plurality of electrons.

3. An x-ray source as in claim 2 wherein said first cathode-emitting device emits said first plurality of electrons at a first kVp and said second cathode-emitting device emits said second plurality of electrons at a second kVp.

4. An x-ray source as in claim 1 wherein said plurality of filters comprises a stationary filter.

5. An x-ray source as in claim 1 wherein said plurality of filters comprises a rotating filter.

6. An x-ray source as in claim 1 wherein said plurality of filters comprises:

a first filter filtering a first x-ray beam; and

a second filter filtering a second x-ray bear.

7. An x-ray source as in claim 1 comprising:

a first filter having a first energy pass range; and

a second filter having a second energy pass range.

8. An x-ray source as in claim 1 wherein said plurality of targets are on different sides of said single rotating anode.

9. An x-ray source as in claim 1 wherein said plurality of targets are on different surfaces of said single rotating anode.

10. An imaging system comprising:

an x-ray source comprising;

a plurality of cathode-emitting devices emitting a plurality of electrons; and

at least one anode having at least one target oriented relative to said plurality of cathode-emitting devices whereupon said plurality of electrons impinge to generate a plurality of x-ray beams; and

a plurality of filters simultaneously filtering said plurality of x-ray beams to generate a post-filter x-ray beam having simultaneously a plurality of x-ray quantity versus energy peaks defined as a plurality of peaks in the quantity of x-rays at a plurality energy levels; and

an energy differentiating detector receiving said post-filter x-ray beam and generating an x-ray signal having material energy density differentiating information.

11. An imaging system as in claim 10 comprising:

a filter rotating device coupled to said plurality of filters; and

a controller electrically coupled to said filter rotating device and rotating said plurality of filters.

12. An imaging system as in claim 11 wherein said controller transitions between each filter in said plurality of filters for each view within a plurality of views.

13. An imaging system as in claim 10 further comprising an x-ray detector measuring a plurality of x-ray quantity energy levels of said x-ray beam.

14. An imaging system as in claim 13 wherein said x-ray detector measures said plurality of x-ray quantity energy levels corresponding to each of said plurality of x-ray quantity peaks.

15. An imaging system as in claim 13 wherein said x-ray detector measures said plurality of x-ray quantity energy levels in at least one energy bin.