INTENSITY-MODULATED, CONE-BEAM COMPUTED TOMOGRAPHIC IMAGING SYSTEM, METHODS, AND APPARATUS
First Claim
1. A method for operating computed tomographic imaging using a radiation source and a plurality of detectors to generate an image of an object, the method comprising the steps of:
- a) defining desired image characteristics;
b) performing calculations to determine the modulation intensity to be applied to the radiation source by at least a first aperture modulator or collimator to generate the desired image characteristics; and
c) modulating the radiation source using the at least a first collimator to generate a desired pattern of fluence between the beam source and the object to be imaged.
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Abstract
Disclosed are methods for reconstructing a three-dimensional image of an object'"'"'s volume of interest using computed tomography that employs conical-beam, intensity-modulated projections of this object. In one embodiment, a plurality of collimating devices serves to modulate the aperture of the radiation source thereby acting to modulate the intensity of the source upon the object. Also provided are image processing devices, examination apparatus, as well as a computer-readable medium and a program element adapted and configured to perform aspects of the methods disclosed herein.
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Citations
24 Claims
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1. A method for operating computed tomographic imaging using a radiation source and a plurality of detectors to generate an image of an object, the method comprising the steps of:
- a) defining desired image characteristics;
b) performing calculations to determine the modulation intensity to be applied to the radiation source by at least a first aperture modulator or collimator to generate the desired image characteristics; and
c) modulating the radiation source using the at least a first collimator to generate a desired pattern of fluence between the beam source and the object to be imaged. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
- a) defining desired image characteristics;
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20. A method for generating a three-dimensional image of a scanned object from a plurality of cone-beam projections passed through the object and attenuated thereby, the method comprising:
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(a) positioning a source at a position on a predetermined scan path; (b) passing a projection of cone-beam X-ray radiation comprising a plurality of projection rays from the source through an object, the cone-beam projection being attenuated by at least a first collimator, and by partial absorption in the object; (c) detecting radiation intensity of the attenuated cone-beam projection on an area detector; (d) obtaining a two-dimensional attenuation image of the cone-beam projection from the detected radiation intensity; (e) generating an intermediate, locally reconstructed, three-dimensional image with constant values assigned along each projection ray; (f) at least once repeating steps (d)-(e); and (g) summing the plurality of intermediate, locally reconstructed, three-dimensional images obtained for the plurality of cone-beam projections to obtain an ultimate, reconstructed, three-dimensional image of the object.
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21. A cone-beam tomography apparatus comprising a radiation source, a radiation detector, a support for an object to be scanned by radiation from the radiation source, a computer-readable storage medium storing computer-executable software for generating a reconstruction of cone-beam radiation attenuation in an object, the software comprising:
- code for obtaining and generating an intermediate, locally reconstructed, three-dimensional image with constant values assigned along each projection ray;
code for summing the plurality of intermediate, locally reconstructed, three-dimensional images obtained for the cone-beam projections to obtain an ultimate, reconstructed, three-dimensional image of the object; and
code for displacing the source and detector relative to the support in a predetermined scan path for radiation transmitted from the source, through an object positioned by the support, and to the detector.
- code for obtaining and generating an intermediate, locally reconstructed, three-dimensional image with constant values assigned along each projection ray;
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22. A method for forming an image of an object, the method comprising:
- (a) exposing the object to a cone beam of radiation rendered spatially coherent by its passage through at least a first collimator;
(b) projecting the spatially coherent collimated conical beam of radiation onto the object and collecting the radiation which has passed through the object in at least a first detector to produce detected data;
(c) deriving, from the detected data, at least a first image; and
(d) repeating step (c) at least once to form a plurality of images of at least a first region of interest within the object.
- (a) exposing the object to a cone beam of radiation rendered spatially coherent by its passage through at least a first collimator;
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23. A system for forming an image of an object, the system comprising:
- (a) a source of a cone beam of radiation rendered spatially-coherent by at least a first collimator;
(b) a detector for receiving the spatially-coherent radiation which has passed through the object to produce detected data; and
(c) a computer, receiving the detected data, for deriving from the detected data at least a first three-dimensional image of at least a first region of interest within the object. - View Dependent Claims (24)
- (a) a source of a cone beam of radiation rendered spatially-coherent by at least a first collimator;
Specification