Method and apparatus for cone beam CT dynamic imaging
First Claim
Patent Images
1. A method for forming an image of an object, the method comprising:
- (a) performing a cone-beam scan of the object in a scanning plane by using a cone-beam emitter and a detector to perform a half-circle scanning geometry so as to obtain projection data for a plurality of rows;
(b) weighting the projection data with a weighting factor to produce weighted projection data, wherein the weighting factor decreases as the rows become farther from the scanning plane; and
(c) forming the image from the weighted projection data.
2 Assignments
0 Petitions
Accused Products
Abstract
A cone-beam scanning system scans along a half circle. The reconstruction uses a weighting function which decreases for rows farther from the scan plane to take the redundancy of the projection data into account. Another embodiment uses a circle plus sparse helical scan geometry. Image data can be taken in real time.
-
Citations
33 Claims
-
1. A method for forming an image of an object, the method comprising:
-
(a) performing a cone-beam scan of the object in a scanning plane by using a cone-beam emitter and a detector to perform a half-circle scanning geometry so as to obtain projection data for a plurality of rows;
(b) weighting the projection data with a weighting factor to produce weighted projection data, wherein the weighting factor decreases as the rows become farther from the scanning plane; and
(c) forming the image from the weighted projection data. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. A method for forming an image of an object, the method comprising:
-
(a) performing a cone-beam scan of the object in a scanning plane by using a cone-beam emitter and a detector to perform a circle or partial circle plus spiral scanning geometry so as to obtain projection data, wherein the scanning geometry comprises a circle or partial circle scanning geometry and a spiral scanning geometry, and wherein the projection data comprise projection data taken only at discrete points along the spiral scanning geometry; and
(b) forming the image from the projection data. - View Dependent Claims (9, 10, 11, 12)
-
-
13. A system for forming an image of an object, the system comprising:
-
a cone-beam emitter;
a detector;
a gantry for causing relative movement of the emitter and the detector for performing a cone-beam scan of the object in a scanning plane by using a cone-beam emitter and a detector to perform a half-circle scanning geometry so as to obtain projection data for a plurality of rows; and
a processor, receiving the projection data, for weighting the projection data with a weighting factor to produce weighted projection data, wherein the weighting factor decreases as the rows become farther from the scanning plane and forming the image from the weighted projection data. - View Dependent Claims (14, 15, 16, 17, 18, 19)
-
-
20. A system for forming an image of an object, the system comprising:
-
a cone-beam emitter;
a detector;
a gantry for causing relative movement of the emitter and the detector for performing a cone-beam scan of the object in a scanning plane by using a cone-beam emitter and a detector to perform a circle or partial circle plus spiral scanning geometry so as to obtain projection data, wherein the scanning geometry comprises a circle or partial circle scanning geometry and a spiral scanning geometry, and wherein the projection data comprise projection data taken only at discrete points along the spiral scanning geometry; and
a processor, receiving the projection data, for forming the image from the projection data. - View Dependent Claims (21, 22, 23)
-
-
24. A device for producing a cone beam CT image of an object, the device comprising:
-
a gantry frame;
at least one motor for moving the gantry frame to form a data acquisition geometry;
a source of cone-beam radiation attached to the gantry frame to move with the gantry frame;
a two-dimensional detector attached to the gantry frame to move with the gantry frame, the two-dimensional detector being disposed in a path of the radiation;
a support on which the object rests while the projection images of the object are taken, the support supporting the object such that the object is disposed between the source of cone-beam radiation and the two-dimensional detector; and
at least one computer system to control scan of an object, perform reconstruction of the object and image analysis of images. characterized in that;
the source of radiation is a cone beam source of radiation;
the images taken are cone beam CT projection images of the object;
the at least one motor moves the gantry frame so that a volume scan of the object can be taken by synchronously rotating the source and the detector around an axis passing through the object to form a data acquisition geometry for cone beam volume computed tomography, the volume scan resulting in image signals;
the at least one motor moves the gantry frame or the support up or down while the source and the detector synchronously are moved around an axis passing through the object to form a data acquisition geometry for cone beam volume computed tomography, the volume scan resulting in image signals;
the three-dimensional cone beam CT image is formed from the image signals by performing a cone beam computed tomography reconstruction on the image signals to produce a three-dimensional attenuation coefficient distribution of the object and, the at least one motor comprises a motor for moving the source and the two-dimensional detector to define a data acquisition geometry. - View Dependent Claims (25, 26, 27, 28, 29, 30, 31, 32)
-
-
33. A device for producing a cone beam CT image of an object, the device comprising:
-
a gantry frame;
at least one motor for moving the gantry frame to form a data acquisition geometry;
a source of radiation attached to the gantry frame to move with the gantry frame;
a two-dimensional detector attached to the gantry frame to move with the gantry frame, the two-dimensional detector being disposed in a path of the radiation;
a support on which the object rests while the projection images of the object are taken, the support supporting the object such that the object is disposed between the source of radiation and the two-dimensional detector; and
at least one computer system to control scan of a breast, perform reconstruction of the breast and image analysis of images;
characterized in that;
the source of radiation is a cone beam source of radiation;
the images taken are cone beam CT projection images;
the at least one motor moves the gantry frame so that a volume scan of the object can be taken by synchronously rotating the source and the detector around an axis passing through the object to form a data acquisition geometry for cone beam volume computed tomography, the volume scan resulting in image signals;
the at least one motor moves the gantry frame or the support up or down while the source and the detector synchronously are moved around an axis passing through the object to form a data acquisition geometry for cone beam volume computed tomography, the volume scan resulting in image signals;
the three-dimensional cone beam volume CT image is formed from the image signals by performing a cone beam volume computed tomography reconstruction on the image signals to produce a three-dimensional attenuation coefficient distribution of the breast;
the at least one motor moves the gantry frame so that the two-dimensional detector takes a volume scan of the object;
the device further comprises a slip ring on the gantry frame for providing the connection to the electrical power to the on-gantry components and the communication between the two-dimensional detector and the computer system; and
the at least one motor moves the gantry frame so that the two-dimensional detector takes a volume scan of the object.
-
Specification