Nuclear medicine imaging systems and methods having multiple detector assemblies

• US 10,213,174 B1
• Filed: 01/05/2018
• Issued: 02/26/2019
• Est. Priority Date: 01/05/2018
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Grobshtein, Yariv, Wald, Shai, Grimberg, Gillan Michael, Efrati, Ken, Bouhnik, Jean-Paul
• Primary Examiner(s): Kim, Kiho
• Application Number:
  US15/862,839
• Time in Patent Office: 417 Days
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: A61B 6/037 Emission tomography
• CPC Class Codes: A61B 6/04 Positioning of patients; Tiltable beds or the like operating tables A61G13/00; operating chairs A61G15/00
• CPC Class Codes: A61B 6/4241 using energy resolving detectors, e.g. photon counting
• CPC Class Codes: A61B 6/4266 characterised by using a plurality of detector units A61B6/4014 takes precedence
• CPC Class Codes: A61B 6/4275 using a detector unit almost surrounding the patient, e.g. more than 180°
• CPC Class Codes: A61B 6/5205 involving processing of raw data to produce diagnostic data
• CPC Class Codes: G01B 11/2433 for measuring outlines by shadow casting
• CPC Class Codes: G01T 1/1603 with a combination of at least two different types of detector see provisionally also G01T1/16
• CPC Class Codes: G01T 1/1614 with semiconductor detectors G01T1/24 takes precedence
• CPC Class Codes: G01T 1/1635 involving relative movement between detector and subject; scanning beds profile scanning G01T1/166; positioning patients, tiltable tables for radiation diagnosis A61B6/04
• CPC Class Codes: G01T 1/1642 using a scintillation crystal and position sensing photodetector arrays, e.g. ANGER cameras
• 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

Abstract

Nuclear medicine (NM) imaging system includes a plurality of detector assemblies that each have a movable arm and a detector head that is coupled to the movable arm. The movable arm is configured to move the detector head toward and away from an object. The NM imaging system also includes at least one processor configured to determine a body contour of the object and determine an acquisition configuration using the body contour. The acquisition configuration includes at least three of the detector heads positioned in a dense group that borders the body contour. The detector heads in the dense group are primary detector heads. The at least one processor is also configured to move at least one of the object or one or more of the primary detector heads so that the primary detector heads are in the dense group near the object.

Claims

1. A nuclear medicine (NM) imaging system comprising:

a gantry including a cavity that is sized and shaped to receive an object therein, the cavity being oriented relative to mutually perpendicular longitudinal, vertical, and horizontal axes, the cavity extending lengthwise along the longitudinal axis;

a plurality of detector assemblies distributed at least partially around the cavity, each of the detector assemblies in the plurality including a movable arm and a detector head that is coupled to the movable arm, the movable arm configured to move the detector head toward and away from the object within the cavity; and

at least one processor configured to execute programmed instructions stored in memory, wherein the at least one processor, when executing the programmed instructions, is configured to;

determine a body contour of the object within the cavity, the body contour representing an exterior surface of the object positioned within the cavity;

determine an acquisition configuration based on the body contour, the acquisition configuration including at least three of the detector heads positioned in a dense group that borders the body contour, the detector heads in the dense group being primary detector heads;

move at least one of the object or one or more of the primary detector heads so that the primary detector heads are in the dense group near the object.

2. The NM imaging system of claim 1, wherein the dense group of the primary detector heads includes at least one of:

(a) two or more of the primary detector heads being immediately adjacent to one another such that the primary detector heads abut each other or have a tolerance gap therebetween;

or

(b) two or more of the primary detector heads being incapable of moving closer to the object because the primary detector heads are extended to a maximum length or blocked by another primary detector head.

3. The NM imaging system of claim 1, wherein the detector heads are spaced apart from adjacent detector heads by respective separation distances, the primary detector heads of the dense group having an average separation distance between one another, the average separation distance between the primary detector heads being less than an average separation distance between the other detector heads.

4. The NM imaging system of claim 1, wherein the longitudinal axis is a central longitudinal axis of the cavity and wherein each of the primary detector heads is positioned a working distance away from the longitudinal axis, the at least one processor configured to determine imaging positions of the primary detector heads by calculating a minimum of an average of the working distances of the primary detector heads, the imaging positions being at least partially based on positions of the primary detector heads where the minimum occurs.

5. The NM imaging system of claim 1, wherein the detector heads are configured to move within a radial range defined between a minimum radial distance and a maximum radial distance, the maximum radial distance being a point at which the primary detector head cannot move closer to the object, the at least one processor configured to determine imaging positions of the primary detector heads by calculating a maximum of an average of the radial distances of the primary detector heads, the imaging positions being at least partially based on positions of the primary detector heads where the maximum occurs.

6. The NM imaging system of claim 1, wherein the primary detector heads are separated from adjacent primary detector heads by separation distances, the at least one processor configured to determine imaging positions of the primary detector heads by calculating a minimum of an average of the separation distances, the imaging positions being at least partially based on positions of the primary detector heads where the minimum occurs.

7. The NM imaging system of claim 1, wherein the detector heads include photon detectors that are rotatable about a sweep axis, the at least one processor configured to acquire persistence images by detecting photons at different rotational positions of the photon detectors, the at least one processor also configured to determine imaging positions of the primary detector heads at which a maximum photon-detection rate is expected based on the persistence images.

8. The NM imaging system of claim 1, further comprising a table positioned within the cavity and extending lengthwise along the longitudinal axis, the table being movable in a direction along the horizontal axis and movable in a direction along the vertical axis, wherein the at least one processor is configured to request a local support for changing an orientation of the body contour with respect to the table, wherein the at least one processor moves the table and the at least one detector head based on the body contour supported by the local patient support.

9. The NM imaging system of claim 1, further comprising a table positioned within the cavity and extending lengthwise along the longitudinal axis, the table being movable in a direction along the horizontal axis and movable in a direction along the vertical axis, wherein the table is configured to position the patient for imaging a torso of the patient while at least one of the arms of the patient is supported along a local support that is outside the cavity.

10. The NM imaging system of claim 1, further comprising an array of light emitters and an array of light detectors, each of the light emitters configured to direct light signals toward at least one of the light detectors, wherein the at least one processor is configured to determine the body contour based on the light detectors that do not detect the light signals from the light emitters when the object is positioned within the cavity.

11. The NM imaging system of claim 1, wherein the at least one processor is configured to determine the body contour using proximity sensor devices (PSDs) coupled to respective detector heads of the group of detector assemblies, the PSDs being activated when the PSDs engage the object or when the PSDs are within a predetermined distance from the object, wherein the detector assemblies communicate signals to the at least one processor, the signals being indicative of a position of the PSD.

12. A method comprising:

positioning an object within a cavity of a nuclear medicine (NM) imaging system, the NM imaging system including;

a cavity that is sized and shaped to receive the object therein, the cavity being oriented relative to mutually perpendicular longitudinal, vertical, and horizontal axes, the cavity extending lengthwise along the longitudinal axis;

a plurality of detector assemblies distributed at least partially around the cavity, each of the detector assemblies in the plurality including a movable arm and a detector head that is coupled to the movable arm;

determining a body contour of the object within the cavity, the body contour representing an exterior surface of the object positioned within the cavity;

determining an acquisition configuration based on the body contour, the acquisition configuration including at least three of the detector heads positioned in a dense group that borders the body contour, the detector heads in the dense group being primary detector heads;

moving at least one of the object or one or more of the primary detector heads so that the primary detector heads are in the dense group along the object.

13. The method of claim 12, wherein the dense group of the primary detector heads includes at least one of:

(a) two or more of the primary detector heads being immediately adjacent to one another such that the primary detector heads abut each other or have a tolerance gap therebetween;

or

(b) two or more of the primary detector heads being incapable of moving closer to the object because the primary detector heads are extended to a maximum length or blocked by another primary detector head.

14. The method of claim 12, wherein the detector heads are spaced apart from adjacent detector heads by respective separation distances, the primary detector heads of the dense group having an average separation distance between one another, the average separation distance between the primary detector heads being less than an average separation distance between the other detector heads.

15. The method of claim 12, wherein the object is positioned on a table within the cavity, the method further comprising positioning a local support between the table and the object, thereby changing an orientation of the body contour with respect to the table, wherein moving the body contour includes the body contour having the orientation changed by the local support.

16. The method of claim 12, further comprising determining imaging positions of the primary detector heads, wherein the imaging positions of the primary detector heads are a function of at least one of:

(i) a maximum of an average working distance of the primary detector heads from the longitudinal axis, the longitudinal axis being a central longitudinal axis of the cavity;

(ii) a maximum of an average radial distance of the primary detector heads from respective starting positions;

or

(iii) a minimum of an average separation distance between the primary detector heads.

17. The method of claim 12, wherein the detector heads include photon detectors that are rotatable about a sweep axis, the method further comprising acquiring data for persistence images by detecting photons at different rotational positions of the photon detectors and determining the imaging positions of the primary detector heads at which a maximum photon-detection rate is expected.

18. A method comprising:

positioning a patient within a cavity of a nuclear medicine (NM) imaging system, the NM imaging system including;

a cavity that is sized and shaped to receive the patient therein, the cavity being oriented relative to mutually perpendicular longitudinal, vertical, and horizontal axes, the cavity extending lengthwise along the longitudinal axis;

a plurality of detector assemblies distributed at least partially around the cavity, each of the detector assemblies in the plurality including a movable arm and a detector head that is coupled to the movable arm;

determining a body contour of the patient within the cavity without an arm of the patient positioned alongside a torso of the patient, the body contour representing an exterior surface of the patient positioned within the cavity;

determining an acquisition configuration based on the body contour, the acquisition configuration including at least three of the detector heads positioned in a dense group that borders the body contour, the detector heads in the dense group being primary detector heads;

moving at least one of the patient or one or more of the primary detector heads so that the primary detector heads are in the dense group along the patient.

19. The method of claim 18, further comprising providing a local support that is positioned proximate to the patient such that the arm of the patient may rest upon the local support during imaging.

20. The method of claim 18, further comprising positioning a local support between the table and the patient, thereby changing an orientation of the body contour with respect to the table, wherein moving the table includes the body contour having the orientation changed by the local support.