Radiographic apparatus
First Claim
1. A radiographic apparatus for obtaining images of sectional planes in a region of interest of an object under examination by an image reconstruction using projection data acquired by radiographing the object from varied scan positions, said apparatus comprising:
- a radiation source for irradiating said object with penetrating electromagnetic waves;
an area detector opposed to said radiation source across said object for detecting electromagnetic waves transmitted through said object;
scanning means for synchronously moving said radiation source and said area detector for scanning action; and
a back projection unit for performing an image reconstruction to generate three-dimensional volume data of the region of interest by projecting projection data detected in the varied scan positions back to predetermined lattice points of a three-dimensional lattice virtually set to the region of interest of the object radiographed.
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Accused Products
Abstract
A driver drives an X-ray tube and a flat panel X-ray detector synchronously to scan sectional planes to be imaged of an object under examination. A back projection unit projects projection data detected in varied scan positions to predetermined lattice points of a three-dimensional lattice virtually set to the region of interest of the object radiographed. An image reconstruction is carried out to generate three-dimensional volume data of the region of interest. The three-dimensional volume data of the region of interest is generated quickly without repeating a radiographic operation.
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Citations
20 Claims
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1. A radiographic apparatus for obtaining images of sectional planes in a region of interest of an object under examination by an image reconstruction using projection data acquired by radiographing the object from varied scan positions, said apparatus comprising:
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a radiation source for irradiating said object with penetrating electromagnetic waves;
an area detector opposed to said radiation source across said object for detecting electromagnetic waves transmitted through said object;
scanning means for synchronously moving said radiation source and said area detector for scanning action; and
a back projection unit for performing an image reconstruction to generate three-dimensional volume data of the region of interest by projecting projection data detected in the varied scan positions back to predetermined lattice points of a three-dimensional lattice virtually set to the region of interest of the object radiographed. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A radiographic apparatus for obtaining images of sectional planes in a region of interest of an object under examination by an image reconstruction using projection data acquired by radiographing the object from varied scan positions, said apparatus comprising:
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a radiation source for irradiating said object with penetrating electromagnetic waves in form of a divergent beam;
an area detector opposed to said radiation source across said object for detecting electromagnetic waves transmitted through said object;
scanning means for setting two non-orbital tracks opposed to each other across the object, moving said radiation source along one of said non-orbital tracks, and moving said area detector in synchronism therewith along the other non-orbital track;
a convolution unit for performing a convolution process on the projection data detected in the varied scan positions; and
a back projection unit for performing the image reconstruction to generate three-dimensional volume data of the region of interest by projecting the projection data convoluted by said convolution unit back to predetermined lattice points of a three-dimensional lattice virtually set to the region of interest of the object radiographed. - View Dependent Claims (18, 19, 20)
said scanning means is arranged to move one of said radiation source and said area detector linearly in a first direction, and to move the other linearly in synchronism therewith in a second direction parallel and counter to said first direction, with the sectional planes to be imaged of the object placed in between; and
said back projection unit is arranged to project the projection data for the varied scan positions back to the predetermined lattice points of the three-dimensional lattice, coordinates of said projection data being corrected according to an angle formed between a virtual center axis of revolution extending substantially through the center of the region of interest of the object and perpendicular to the sectional planes to be imaged, and a straight line extending from said radiation source in each of said varied scan positions to the center of said area detector.
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19. A radiographic apparatus as defined in claim 17, wherein said area detector is a flat panel detector or an image intensifier.
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20. A radiographic apparatus as defined in claim 18, wherein said area detector is a flat panel detector or an image intensifier.
Specification