CONE BEAM COMPUTED TOMOGRAPHY VOLUMETRIC IMAGING SYSTEM

• US 20150150524A1
• Filed: 05/17/2013
• Published: 06/04/2015
• Est. Priority Date: 05/18/2012
• Status: Active Grant

• Current Assignee: CareStream Health Incorporated
• Original Assignee: CareStream Health Incorporated
• Inventors: Yorkston, John, Foos, David H.
• Granted Patent: US 10,092,256 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: A61B 6/06 Diaphragms
• CPC Class Codes: A61B 6/4007 characterised by using a plurality of source units
• CPC Class Codes: A61B 6/4085 Cone-beams
• CPC Class Codes: A61B 6/42 Arrangements for detecting radiation specially adapted for radiation diagnosis
• CPC Class Codes: A61B 6/4405 the apparatus being movable or portable, e.g. handheld or mounted on a trolley
• CPC Class Codes: A61B 6/488 involving pre-scan acquisition
• CPC Class Codes: A61B 6/501 for diagnosis of the head, e.g. neuroimaging or craniography
• CPC Class Codes: A61B 6/54 Control of apparatus or devices for radiation diagnosis
• CPC Class Codes: G06T 2207/10141 Special mode during image acquisition
• CPC Class Codes: G06T 2207/10144 Varying exposure
• CPC Class Codes: G06T 2207/10148 Varying focus
• CPC Class Codes: G06T 2207/10152 Varying illumination
• CPC Class Codes: G06T 2211/412 Dynamic
• CPC Class Codes: H01J 2235/162 Rotation
• CPC Class Codes: H01J 2237/045 Diaphragms
• CPC Class Codes: H01J 35/24 Tubes wherein the point of impact of the cathode ray on the anode or anticathode is movable relative to the surface thereof
• CPC Class Codes: H01J 37/09 Diaphragms; Shields associated with electron or ion-optical arrangements; Compensation of disturbing fields

Abstract

Embodiments of methods and/or apparatus for a radiographic imaging can include a plurality of x-ray sources disposed in a curve and a detector configured to revolve relative thereto. In one embodiment, a CBCT imaging method and/or apparatus can include performing a first scan at a first speed using stationary angularly distributed x-ray sources to acquire first CBCT projection data that impinge a detector of a first field of view (FOV), identifying an area of interest within the first FOV, and performing a second scan at a second speed using the x-ray sources acquire second CBCT projection data that impinge a portion of the detector of a second smaller FOV including the area of interest within the first FOV using second emissions by the x-ray sources, where the second speed is greater than the first speed.

Claims

1. A method of performing radiographic examination by a radiographic CT imaging system, the radiographic CT imaging system to include a plurality of stationary x-ray sources disposed in a curve and a detector configured to revolve relative to the plurality of x-ray sources, the radiographic examination method comprising

performing a first scan at a first rotation speed using the plurality of x-ray sources and the detector to acquire first CT projection data of a first field of view (FOV) of an object using first emissions by the plurality of x-ray sources that impinge the detector;

identifying a plane of interest within the first FOV;

performing a second scan at a second rotation speed using the plurality of stationary x-ray sources and the detector to acquire second CT projection data of a second smaller FOV including the plane of interest within the first FOV using second emissions by the plurality of x-ray sources that impinge a portion of the detector,

where the second rotation speed is greater than the first rotation speed; and

outputting the data of the first CT projection data and the second CT projection data from the detector.

2. The method of claim 1, further comprising:

rotating the detector independently of the stationary plurality of x-ray sources during the first scan and the second scan.

3. The method of claim 1, where first irradiation angles are maintained for the duration of the first scan by at least one spatial restriction device to limit a cross-section of the first emissions from the plurality of x-ray sources, and

where second irradiation angles are maintained for the duration of the second scan by the at least one spatial restriction device to limit a cross-section of the second emissions from the plurality of x-ray sources.

4. The method of claim 1, where the first emissions and the second emissions determine volumetric images of an overlapping FOV.

5. The method of claim 1, further comprising moving the plurality of x-ray sources and the detector relative to the first FOV before obtaining the second FOV in the second scan, where the plurality of x-ray sources are aligned to the plane of interest in the second scan.

6. The method of claim 1, further comprising moving an object relative to the plurality of x-ray sources and the detector before obtaining the second FOV in the second scan.

7. The method of claim 1, where the detector is configured to output first CT projection data and second CT projection data (i) wirelessly during each of the first scan and the second scan, (ii) wirelessly after each of the first scan and the second scan, or (iii) from a docked, tethered position after each of the first scan and the second scan.

8. The method of claim 1, where the plurality of x-ray sources are sequentially fired during both the first scan and the second scan, and where the detector is battery powered and outputs the data of the first CT projection data and the second CT projection data wirelessly.

9. The method of claim 1, further comprising injecting a contrast agent to quantitatively measure contrast uptake and contrast outflow during the second CT scan, where the second CT scan comprises repeatedly performing the second scan a plurality of times at a prescribed time interval.

10. The method of claim 9, where subsets of the plurality of x-ray sources each emit at a different energies during the second scan, where each circuit of the detector passing the of the plurality of x-ray sources in each of the second scans comprises less than 3 seconds.

11. A radiographic CT imaging system, comprising:

a plurality of x-ray source emissions disposed in a curve;

a battery powered detector configured to revolve relative to the plurality of x-ray source emissions; and

at least one spatial restriction device to limit a cross-section of the plurality of x-ray source emissions;

where the plurality of x-ray source emissions, the detector and the at least one spatial restriction device are configured in both of (i) a first configuration to obtain a first field of view (FOV) of first emissions of the curved x-ray source emissions that impinge the detector and (ii) a second configuration to obtain a second smaller FOV of second emissions of the curved x-ray source emissions that impinge the detector, and

where the first emissions and the second emissions determine a volumetric image of an overlapping FOV.

12. The radiographic CT imaging system of claim 11, where a first scan is performed at a first rotation speed using a plurality of x-ray sources in a first curved spatial arrangement in the first configuration and a second scan faster scan is performed at a second rotation speed using the plurality of x-ray sources in the first curved spatial arrangement in the second configuration.

13. The radiographic CT imaging system of claim 12, where the plurality of x-ray sources and the detector are moved relative to the first FOV before obtaining the second FOV in the second scan.

14. The radiographic CT imaging system of claim 12, where the plurality of x-ray sources are fixed in a continuous closed curve, where the detector is configured to mechanically independently rotate relative to the stationary plurality of x-ray sources, where the radiographic CT imaging system is a CBCT system, where the CBCT system is configured to operate in each of a first volumetric radiographic imaging mode, a second general radiographic imaging mode, or a third fluoroscopic radiographic imaging mode.

15. The radiographic CT imaging system of claim 11, where the detector is configured to output first CT projection data in the first configuration and second CT projection data in the second configuration (i) wirelessly during each of a first scan and a second scan, (ii) wirelessly after each of the first scan and the second scan, or (iii) from a docked, tethered position after each of the first scan and the second scan.

16. The radiographic CT imaging system of claim 11, where the at least one spatial restriction device comprises a plurality of collimators,

where each collimator is configured to operate in coordination with at least one associated x-ray source to collimate a beam of x-rays toward the detector for each of the first configuration for the first FOV and in the second configuration for the second FOV.

17. The radiographic CT imaging system of claim 11, where the plurality of curved x-ray source emissions are provided by a single battery operated x-ray source.

18. The radiographic CT imaging system of claim 11, where the at least one spatial restriction device comprises a plurality of collimators,

where each collimator is configured to operate in coordination with two or more associated x-ray sources to collimate a beam of x-rays toward the (patient) detector for each of the first configuration for the first FOV and in the second configuration for the second FOV.

19. The radiographic CT imaging system of claim 11, where the at least one spatial restriction device comprises at least one collimator that moves angularly between at least a first position in the first configuration and a second position in the second configuration, where the second position is based on an area of interest within the first FOV.