Gating With Anatomically Varying Durations

• US 20090201291A1
• Filed: 12/28/2006
• Published: 08/13/2009
• Est. Priority Date: 01/13/2004
• Status: Active Grant

• Current Assignee: Spectrum Dynamics LLC
• Original Assignee: Spectrum Dynamics LLC
• Inventors: Gluhovsky, Leonid, Rousso, Benny, Ravhon, Ran, Ziv, Omer, Dichterman, Eli, Ben-Haim, Shiomo
• Granted Patent: US 9,470,801 B2
• Time in Patent Office: Days
• US Class Current: 345/424
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: A61B 5/415 the glands, e.g. tonsils, adenoids or thymus
• CPC Class Codes: A61B 5/416 the spleen
• CPC Class Codes: A61B 5/418 lymph vessels, ducts or nodes
• CPC Class Codes: A61B 5/7285 for synchronising or triggering a physiological measurement or image acquisition with a physiological event or waveform, e.g. an ECG signal A61B6/5205, A61B6/541, A61B8/5207, A61B8/543 take precedence
• CPC Class Codes: A61B 6/037 Emission tomography
• CPC Class Codes: A61B 6/503 for diagnosis of the heart
• CPC Class Codes: A61B 6/541 involving acquisition triggered by a physiological signal
• CPC Class Codes: A61B 8/0883 for diagnosis of the heart
• CPC Class Codes: A61B 8/543 involving acquisition triggered by a physiological signal
• CPC Class Codes: G01T 1/1644 using an array of optically separate scintillation elements permitting direct location of scintillations G01T1/1645 takes precedence
• CPC Class Codes: G01T 1/1663 Processing methods of scan data, e.g. involving contrast enhancement, background reduction, smoothing, motion correction, dual radio-isotope scanning, computer processing for measuring spatial distribution of radiation G01T1/2992; general purpose image data processing G06T1/00; computerized tomography G06T11/003; Ancillary equipment colour printers G01T1/1666
• CPC Class Codes: G06T 11/005 Specific pre-processing for tomographic reconstruction, e.g. calibration, source positioning, rebinning, scatter correction, retrospective gating
• CPC Class Codes: G06T 11/006 Inverse problem, transformation from projection-space into object-space, e.g. transform methods, back-projection, algebraic methods
• CPC Class Codes: G06T 11/008 Specific post-processing after tomographic reconstruction, e.g. voxelisation, metal artifact correction
• CPC Class Codes: G06T 2207/10104 Positron emission tomography [PET]
• CPC Class Codes: G06T 2207/30048 Heart; Cardiac
• CPC Class Codes: G06T 2211/436 Limited angle

Abstract

A method for reconstructing a radioactive emission image of an overall volume having first and second volumetric regions, each volumetric region having respectively independent dynamic characteristics. The method comprises the following steps: a) obtaining radioactive emissions from the overall volume, including the volumetric regions, b) reconstructing an initial radioactive emission image of the volumetric region according to the radioactive emissions, c) segmenting the initial radioactive emission image to delineate the first and second volumetric regions, and d) separately reconstructing the first and the second volumetric regions according to the respectively independent dynamic characteristics.

Claims

1. A method for reconstructing a radioactive emission image of an overall volume having first and second volumetric regions, each volumetric region having respectively independent dynamic characteristics, the method comprising:

a) obtaining radioactive emissions from the overall volume, including said volumetric regions;

b) reconstructing an initial radioactive emission image of said volumetric region according to said radioactive emissions;

c) segmenting said initial radioactive emission image to delineate said first and second volumetric regions; and

d) reconstructing said first and second volumetric regions according to said respectively independent dynamic characteristics.

2. The method of claim 1, wherein said obtaining radioactive emissions further includes obtaining timing data by a method selected from the group consisting of time stamping, time binning, and a combination thereof.

3. The method of claim 2, wherein the timing data are employed in gating, and further wherein different gating is employed for said first and second volumetric regions, based on their respectively independent dynamic characteristics.

4. The method of claim 3, wherein each of said gating may be of a dynamically varying duration.

5. The method of claim 2, and further including a third volumetric region, of third independent dynamic characteristics, and further wherein a still different gating is employed for said third volumetric regions, based on its third independent dynamic characteristics.

6. The method of claim 1, wherein said obtaining radioactive emissions includes obtaining without timing data, by prescanning, for defining said first and second volumetric regions, and further including:

obtaining a second set of radioactive emissions from the overall volume, including said volumetric regions, after the reconstructing the initial radioactive emission image, the second set including timing data,

wherein said separately reconstructing includes separately reconstructing said first and second volumetric regions according to said respectively independent dynamic characteristics, from said second set.

10. The method of claim 6, wherein obtaining a second set of radioactive emissions, further includes independently directing detecting resources to said first and second volumetric regions, so as to concentrate detecting resources on the volumetric region of greater dynamic activity.

11. The method of claim 1, wherein separately reconstructing further includes independently carrying reconstruction of said first and second volumetric regions, to different levels of accuracy, so as to concentrate reconstruction resources on the volumetric region of greater dynamic activity.

12. The method of claim 1, wherein said separately reconstructing comprises using object implantation for refining the reconstruction of said first and second volumetric regions.

13. The method of claim 1, further comprising displaying said radioactive emission image and allowing a system user to mark at least one of said first and second volumetric regions, said segmenting being performed according to said mark.

14. The method of claim 1, wherein said first volumetric region confine a heart.

16. The method of claim 1, wherein said radioactive emission image comprises a plurality of voxels, and further wherein said segmenting is performed according to a voxel value threshold.

20. The method of claim 1, wherein segmenting said initial radioactive emission image to delineate said first and second volumetric regions, is based on their respectively independent dynamic characteristics.

21. The method of claim 1, further comprising estimating the radiation intensity of the visceral background of said radioactive emission image, wherein said segmenting is performed according to said estimation.

25. The method of claim 1, wherein said radioactive emissions are obtained using a single photon emission computed tomography (SPECT) camera.

26. The method of claim 25, wherein said SPECT camera comprises a plurality of detecting units, further comprising dynamically determining a spectral energy bin for each detecting unit, thereby enabling at least a first time binning according to said spectral energy bin.

31. The method of claim 1, further comprising expending the segmentation of said first volumetric region.

34. The method of claim 1, wherein said initial radioactive emission image is represented by a system of voxels, further comprising:

providing a structural image of a region of interest in said system of voxels; and

constructing an anatomical construction of voxels, for said system of voxels, in which voxel boundaries are aligned with boundaries of structural objects of said first volumetric region, based on said structural image,

said separately reconstructing being based on said anatomical construction of voxels.

7-9. -9. (canceled)

15. (canceled)

17-19. -19. (canceled)

22-24. -24. (canceled)

27-30. -30. (canceled)

32-33. -33. (canceled)

35-37. -37. (canceled)

38. A method for reconstructing a radioactive emission image of an overall volume having first and second volumetric regions, each volumetric region having respectively independent dynamic characteristics, the method comprising:

(a) obtaining a structural image of the overall volume, including said volumetric regions, by a structural imager, selected from the group consisting of a CT, an MRI, and an ultrasound, to delineate said first and second volumetric regions;

b) delineating said first and second volumetric regions;

c) obtaining radioactive emissions from the overall volume, including said volumetric regions;

d) reconstructing said first and second volumetric regions according to said respectively independent dynamic characteristics.

39. An apparatus for reconstructing a radioactive emission image of an overall volume having first and second volumetric regions, of respectively independent dynamic characteristics, comprising:

at least one detecting unit configured for obtaining radioactive emissions from the overall volume;

an image reconstruction module, operatively connected to said at least one detecting unit, configured for generating a radioactive emission image of said overall volume according to said radioactive emissions; and

a segmentation module configured for segmenting said radioactive emission image to delineate said first and second volumetric regions;

wherein said image reconstruction module separately reconstructs said first and second volumetric regions according to said respectively independent dynamic characteristics.

40-75. -75. (canceled)

76. A method for reconstructing a volumetric image of an overall volume from radioactive emissions, the method comprising:

a) obtaining radioactive emissions from the overall volume to reconstruct an initial volumetric image;

b) providing at least one relation between said initial volumetric image and at least one biological property of a predefined organic structure in at least one region of the overall volume; and

c) reconstructing the volumetric image using said at least one relation.

77. The method of claim 76, wherein said reconstructing comprises at least one iteration of a group consisting of:

filtered back-projection (FBP), ordered subset expectation maximization (OSEM), and expectation-maximization (EM).

78. The method of claim 76, wherein said at least one biological property are anatomic properties.

79. The method of claim 76, wherein said at least one biological properties are obtained by fitting said initial volumetric image to an volumetric model.

80. The method of claim 79, wherein said volumetric model comprises at least one member of a group consisting of a physical model, a geometrical model, a parametric model, a statistical model, a kinetic model, and an anatomic model.

81. The method of claim 80, wherein said volumetric model is time dependent.

82. The method of claim 76, wherein said at least one biological property are obtained by fitting said initial volumetric image to a structural image of at least one region of the overall volume obtained by a structural imager selected from a group consisting of:

a computerized tomography (CT), a magnetic resonance imager (MRI), a single photon emission computed tomography (SPECT) camera, Positron emission tomography (PET), and an ultrasound.

83. The method of claim 76, wherein said reconstructing comprises using said at least one relation for estimating a kinetic process.

84. The method of claim 76, wherein said reconstructing comprises using said at least one relation for further scanning at least one region of said overall volume, thereby creating the volumetric image.

85. The method of claim 84, wherein said using comprises defining parameters of said scanning from at least one of a group consisting of:

a sensitivity value, an integration time, a rotation translational detector, and motional detector.

86. The method of claim 76, wherein said reconstructing comprises directing detecting resources to at least one region of said overall volume according to said at least one relation.

87. The method of claim 76, wherein said reconstructing is performed according to a dynamic scanning pattern, further comprising changing said dynamic scanning pattern according to said at least one relation.

88. The method of claim 76, wherein said obtaining further comprises obtaining timing data on at least one independent dynamic characteristic of at least one region of said overall volume and using said at least one independent dynamic characteristic for said providing.

89. The method of claim 88, wherein said at least one independent dynamic characteristic comprises a member of a group consisting of:

a motion pattern of said at least one region, a kinetic of a radiopharmaceutical of said at least one region.

90. The method of claim 88, wherein said providing comprises using said timing data for a member of a group consisting of:

gating and binning.

91. The method of claim 76, wherein said radioactive emissions are obtained using for a member of a group consisting of:

a single photon emission computed tomography (SPECT) camera and a photon emission computed tomography (PECT) camera.

92. The method of claim 76, wherein said reconstructing comprises using said at least one relation for modifying a resolution of the volumetric image.

93. The method of claim 76, wherein said predefined organic structure defines a set of boundaries of at least a portion of a tissue, said reconstructing comprises aligning at least one region of said volumetric image according to said at least one relation.

94. The method of claim 76, wherein said providing comprises allowing a user to mark at least one volumetric region, said at least one relation being defined according to said mark.

95. The method of claim 76, wherein said reconstructing comprises defining at least one region of interest (ROI) according to said at least one relation and instructing at least one detecting unit according to said ROI.

96. The method of claim 76, wherein said reconstructing comprises weighting at least one voxel intensity value of said initial volumetric image according to said at least one relation.

97. The method of claim 76, wherein said reconstructing comprises adjusting at least one voxel intensity value of said initial volumetric image according to said at least one relation.

98. The method of claim 76, wherein said radioactive emissions is emitted from a plurality of radiopharmaceuticals each having a spectral emission profile, said providing comprises identifying a pattern combining each said spectral emission profile in said in at least one region and determining said at least one relation according to said identification.

99. The method of claim 76, wherein said obtaining comprises obtaining first radioactive emissions emitted from a first group of radiopharmaceuticals, said reconstructing comprises using said first radioactive emissions and second radioactive emissions emitted from a second group of radiopharmaceuticals.

100. An apparatus for reconstructing a volumetric image of an overall volume from radioactive emissions, the method apparatus:

at least one detecting unit configured for obtaining radioactive emissions from the overall volume to reconstruct an initial volumetric image;

an image reconstruction module configured for defining at least one relation between said initial volumetric image and at least one biological property of a predefined organic structure in at least one region of the overall volume and reconstructing the volumetric image using said at least one relation.

101. The apparatus of claim 100, wherein said image reconstruction module is configured for defining at least one region of interest (ROI) according to said at least one relation, at least one of said at least one detecting unit being configured for instructing detecting resources to concentrate on said ROI.

102. The apparatus of claim 100, wherein said at least one of said at least one detecting unit is configured for instructing said detecting resources to adjust a member of a group consisting of detecting resolution, detecting sensitivity, and detecting scanning pattern.

103. The apparatus of claim 100, further comprising a segmentation module configured for segmenting said initial volumetric image to delineate first and second volumetric regions, said image reconstruction module being configured for separately defining independent said at least one relation for each said first and second volumetric regions and reconstructing said first and second volumetric regions according to respectively said independent at least one relation.