Computed tomography apparatus also employable for X-ray diagnostic examinations

• US 20030002626A1
• Filed: 06/20/2002
• Published: 01/02/2003
• Est. Priority Date: 06/20/2001
• Status: Active Grant

• Current Assignee: Siemens Healthcare GMBH (Siemens AG)
• Original Assignee: Siemens AG
• Inventors: Hoheisel, Martin, Sklebitz, Hartmut
• Granted Patent: US 6,823,039 B2
• Time in Patent Office: Days
• US Class Current: 378/98.8
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: A61B 6/4266 characterised by using a plurality of detector units A61B6/4014 takes precedence
• CPC Class Codes: A61B 6/4417 related to combined acquisition of different diagnostic modalities
• CPC Class Codes: A61B 6/4452 the source unit and the detector unit being able to move relative to each other
• CPC Class Codes: A61B 6/5235 combining images from the same or different ionising radiation imaging techniques, e.g. PET and CT
• CPC Class Codes: G01N 2223/419 computed tomograph
• CPC Class Codes: G01N 2223/612 biological material
• CPC Class Codes: G01N 23/046 using tomography, e.g. computed tomography [CT]

Abstract

A computed tomography apparatus has a gantry with an X-ray source and an x-ray detector, and at least one further, curved solid-state radiation detector that is movable into and out of the beam path of the x-ray source is provided in the gantry.

Claims

1. A computed tomography apparatus comprising:

a rotatable gantry;

an x-ray source mounted on said gantry which emits an x-ray beam proceeding along a beam path;

an x-ray detector mounted on said gantry in said beam path, said x-ray source and said x-ray detector being rotatable by said gantry around an examination volume for obtaining signals from said x-ray detector for generating a tomogram; and

a curved, solid-state radiation detector mounted on said gantry in addition to said x-ray detector, said curved, solid-state radiation detector being movable into and out of said beam path.

2. A computed tomography apparatus as claimed in claim 1 wherein said curved, solid-state radiation detector is mounted on said gantry so as to be movable in front of said x-ray detector.

3. A computed tomography apparatus as claimed in claim 1 wherein said curved, solid-state detector has a bending radius r, with r≧

a and r≧

b/2, wherein a is a spacing between said x-ray detector and said x-ray source, and wherein b is an inside diameter of said gantry.

4. A computed tomography apparatus as claimed in claim 1 wherein said solid-state radiation detector is mounted on said gantry to be movable into said beam path by displacement along a circular path proceeding around a rotational axis of said gantry.

5. A computed tomography apparatus as claimed in claim 4 wherein said circular path has a rotational axis coinciding with said rotational axis of said gantry.

6. A computed tomography apparatus as claimed in claim 1 wherein said curved solid-state radiation detector is mountable on said gantry to be movable into said beam path by displacement parallel to a rotational axis of said gantry.

7. A computed tomography apparatus as claimed in claim 1 wherein said curved solid-state radiation detector is movable along a motion direction into said beam path and has a front edge which enters first into said beam path, and wherein said computed tomography apparatus further comprises electronic components for driving and readout of pixels of said curved solid-state radiation detector, said electronic components being mounted at edges of said curved solid-state radiation detector other than said front edge.

8. A computer tomography apparatus as claimed in claim 1 wherein said curved solid-state radiation detector has a plurality of pixels each having a size, with the respective sizes of said pixels decreasing toward straight edges of said curved solid-state radiation detector.

9. A computer tomography apparatus as claimed in claim 1 wherein said curved solid-state radiation detector has a plurality of pixels at respective positions, with the respective positions of the pixels being located in a tangential direction and in an axial direction to minimize distortion in an image produced by signals from said curved, solid-state radiation detector compared to a flat panel radiation detector.

10. A computed tomography apparatus as claimed in claim 1 further comprising a control device disposed remote from said curved solid-state radiation detector, and further comprising a wireless signal transmission system for transmitting signals picked up by said solid-state radiation detector to said control device and for transmitting control signals from said control device to said curved solid-state radiation detector.

11. A computed tomography apparatus as claimed in claim 10 wherein said wireless transmission system is selected from the group consisting of optical transmission systems and electromagnetic transmission systems.

12. A computed tomography apparatus as claimed in claim 10 wherein said wireless transmission system is an infrared transmission system.

13. A computed tomography apparatus as claimed in claim 10 wherein said wireless transmission system is an antenna system.

14. A computed tomography apparatus as claimed in claim 1 further comprising a control device disposed remote from said curved solid-state radiation detector, and a stationary wiper ring and a plurality of wiper contacts interacting with said stationary wiper ring for transmitting signals picked up by said curved solid-state radiation detector to said control device and for transmitting control signals from said control device to said curved solid-state radiation detector.

15. A computed tomography apparatus as claimed in claim 1 further comprising a radiation diaphragm allocated to said x-ray source in said beam path for varying a size of a radiation field of said x-ray beam.

16. A computed tomography apparatus as claimed in claim 1 further comprising a control device for operating said diaphragm to vary said size of said ray field.

17. A computer tomography apparatus as claimed in claim 1 further comprising a control device connected to said x-ray source for controlling said x-ray source independently of whether said x-ray beam is incident on said x-ray detector or said curved solid-state radiation detector.