Imaging system and method overcoming obstructions using independently controllable detectors

• US 9,297,913 B2
• Filed: 05/26/2015
• Issued: 03/29/2016
• Est. Priority Date: 12/20/2013
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Grobshtein, Yariv, Bouhnik, Jean-Paul
• Primary Examiner(s): Kim, Kiho
• Application Number:
  US14/721,407
• Publication Number:
  US 20150276949A1
• Time in Patent Office: 308 Days
• US Class Current: 1/1
• CPC Class Codes: A61B 6/037 Emission tomography
• CPC Class Codes: A61B 6/4258 for detecting non x-ray radiation, e.g. gamma radiation A61B6/037 takes precedence
• CPC Class Codes: A61B 6/4266 characterised by using a plurality of detector units A61B6/4014 takes precedence
• CPC Class Codes: A61B 6/503 for diagnosis of the heart
• CPC Class Codes: A61B 6/545 involving automatic set-up of acquisition parameters
• CPC Class Codes: A61B 6/547 involving tracking of position of the device or parts of the device
• CPC Class Codes: G01T 1/161 Applications in the field of nuclear medicine, e.g. in vivo counting apparatus for radiation diagnosis A61B6/00
• CPC Class Codes: G01T 1/1642 using a scintillation crystal and position sensing photodetector arrays, e.g. ANGER cameras
• CPC Class Codes: G01T 1/1647 Processing of scintigraphic data not related to a particular imaging system G01T1/2992
• CPC Class Codes: G01T 1/2985 In depth localisation, e.g. using positron emitters; Tomographic imaging (longitudinal and transverse section imaging; apparatus for radiation diagnosis sequentially in different planes, steroscopic radiation diagnosis); using external radiation sources A61B6/02
• CPC Class Codes: G06T 11/005 Specific pre-processing for tomographic reconstruction, e.g. calibration, source positioning, rebinning, scatter correction, retrospective gating

Abstract

Imaging systems, methods, and computer readable mediums are provided. Image detectors are installed in a gantry to detect image information related to a subject. If obstructions are detected related to the field of view of an image detector, a system matrix can be updated accordingly. Thus, upon image reconstruction, artifacts related to obstructions can be minimized or altogether eliminated. This system can be a Nuclear Medicine (NM) imaging system to acquire Single Photon Emission Computed Tomography (SPECT) image information.

Claims

1. An imaging system comprising:

a gantry;

a plurality of imaging detector units, each detector unit comprising a detector arm installed in the gantry and a detector head;

wherein at least one of the detector heads is movable such that its angle can be altered with respect to its detector arm;

a controller in communication with the plurality of detector units, configured to control the angle of the at least one detector head; and

wherein if the controller detects an obstruction in a field of view of a detector head, the controller updates a system matrix to include obstruction information related to the obstruction.

2. The imaging system of claim 1, wherein the controller:

receives image information detected by the detector units;

reconstructs the image information into images using the updated system matrix; and

outputs the images to a display, printer, memory, or computer network.

3. The imaging system of claim 1, wherein the controller performs the steps of:

adjusting the angle of a detector head;

acquiring location and orientation information for the detector head at its new angle;

generating a field of view determination for the detector head based on said location and orientation information;

determining whether a region-of-interest (ROI) of an imaging subject is within the detector field of view;

if the ROI is within the field of view, the controller acquires image information detected by the detector head even if an obstruction is within the field of view; and

if the ROI is outside the field of view, the controller does not acquire image information detected by the detector head.

4. The imaging system of claim 3, wherein:

the controller acquires the location and orientation information from a position sensor installed in the detector unit.

5. The imaging system of claim 1, wherein:

the updating of the system matrix to include obstruction information includes inputting zeros into the matrix elements related to the pixels that are obstructed.

6. The imaging system of claim 1, wherein:

the detector head movement is a pivot movement with respect to its respective detector arm.

7. The imaging system of claim 1, wherein:

each detector head is extendable and retractable with respect to the gantry along its respective detector arm.

8. The imaging system of claim 1, wherein:

each detector head includes a plurality of detector elements that detect SPECT emissions.

9. The imaging system of claim 1, wherein:

the system matrix is a data structure in memory that describes the physics of the imaging system.

10. An imaging method, comprising:

pivoting a detector head of an image detector unit, the image detector unit attached to a gantry;

determining whether an obstruction is in the field of view of the detector head; and

updating a system matrix to include information related to the obstruction.

11. The imaging method of claim 10, further comprising:

acquiring location and orientation information for the detector head at its current angle;

generating a current field of view determination for the detector head based on said location and orientation information;

determining whether a region-of-interest (ROI) of an imaging subject is within the detector current field of view;

if the ROI is within the current field of view, a controller acquires image information detected by the detector head even if an obstruction is within the field of view; and

if the ROI is outside the current field of view, the controller does not acquire image information detected by the detector head.

12. The imaging method of claim 10, further comprising:

receiving image information detected by the detector unit;

reconstructing the image information into images using the updated system matrix; and

outputting the images to a display, printer, memory, or computer network.

13. The imaging method of claim 12, wherein:

the image information includes SPECT information.

14. The imaging method of claim 10, wherein:

the updating of the system matrix to include information related to the obstruction includes inputting zeros into the matrix elements related to the pixels that are obstructed.

15. The imaging method of claim 10, further comprising:

updating the system matrix based on installation information and subject scan information.

16. The imaging method of claim 10, wherein:

the detector head comprises a plurality of detector elements and a collimator;

the field of view is determined by the coverage of said detector elements and a collimator configuration.

17. The imaging method of claim 10, further comprising:

determining whether a ROI is within a field of view of the detector head;

second pivoting of the detector head in the same direction as the first pivoting if the ROI is within the field of view; and

stopping the pivoting of the detector head if a detector pixel in the field of view reaches an end of the ROI before reaching an obstruction.

18. A non-transitory computer readable storage medium having stored thereon a computer program comprising instructions, which, when executed by a computer, cause the computer to:

issue an instruction to pivot a detector head of an image detector unit, the image detector unit attached to a gantry;

determine whether an obstruction is in the field of view of the detector head; and

update a system matrix to include information related to the obstruction.

19. The computer readable storage medium of claim 18, further causing the computer to:

acquire location and orientation information for the detector head at its current angle;

generate a field of view determination for the detector head based on said location and orientation information;

determine whether a region-of-interest (ROI) of an imaging subject is within the detector field of view;

if the ROI is within the field of view, acquire image information detected by the detector head even if an obstruction is within the field of view; and

if the ROI is outside the field of view, not acquire image information detected by the detector head for the current position of the detector head.

20. The computer readable storage medium of claim 18, further causing the computer to:

receive image information detected by the detector units;

reconstruct the image information into images using the updated system matrix; and

output the images to a display, printer, memory, or computer network.