摘要:
A method includes reconstructing measured projection data using an iterative statistical reconstruction algorithm that reduces image artifact caused by differences in variances in projections of the measured projection data used to update a voxel of the image for one or more voxels of the image. A reconstructor includes a processor that reconstructs measured projection data using an iterative statistical reconstruction algorithm that reduces or mitigates image artifact caused by differences in variances in projections used to update a voxel of the image for one or more voxels of the image. A computer readable storage medium encoded with computer executable instructions, which, when executed by a processor of a computer, cause the processor to: reduce image artifact caused by differences in variances in projections used to update a voxel of an image for one or more voxels of the image using an iterative statistical reconstruction algorithm.
摘要:
An imaging system includes a radiation source (110) that emits radiation that traverses an examination region. A controller (116) activates the radiation source (110) to emit radiation and deactivates the radiation source (110) to stop radiation emission. The controller (116) selectively activates the radiation source (110) to emit radiation at one or more pre-determined angles. In another embodiment, the imaging system includes a data processing component (124) that generates a virtual three dimensional image of an object of interest of the scanned subject based on the image data. In another embodiment, the imaging system is in a communication with a data manipulation and packaging component (128) that generates at least a two dimensional or a three dimensional data set based on the volumetric image data and packages the data set in an object provided to a remote system (132) that manipulates and navigates through the data set.
摘要:
The present invention relates to image processing device (5) for generating a time series of 3D volume images showing the blood flow in a vascular tree of an object (40), based on a first series of X-ray projection images (D) of the object acquired from different projection directions and a second and a third series of X-ray projections images (E, F) of the object acquired alternately at a first or second fixed projection plane, respectively, during inflow of contrast agent into the vascular tree of the object. In order to allow image reconstruction of unambiguous structures in the object of interest, and, in particular, the generation of 3D volume images showing the blood flow in a vascular tree of an object even if that vascular tree comprises non-tubular structures, such as aneurysms, an image processing device is proposed comprising: a reconstruction unit (51) for reconstruction of a 3D volume image of said object from said first series of X-ray projection images (D), a segmentation unit (52) for segmentation of the vessel tree from said 3D volume image, —a forward projection unit (54) for forward projection of the segmented vessel tree onto said first and projection plane (R1, R2), respectively, and a mapping unit (55) for mapping of the image values of pixels of the vessel tree in said second and third, respectively, series of X-ray projection images onto corresponding voxels of said 3D volume image to obtain said time series of 3D volume images showing the blood flow in the vascular tree of the object.
摘要:
The invention relates to an X-ray imaging device for visualizing the blood flow in a coronary vascular tree of a patient. According to the invention a first set (1) of X-ray projection images of the vascular tree is recorded during various phases of the heart cycle with simultaneous recording of the ECG (2) of the patient. By means of a suitable program control, computer means (17) of the device according to the invention a reconstruction then follows of the three-dimensional structure of the vascular tree during the various phases of the heart cycle. The invention proposes, to determine the time-dependent concentration of contrast agent within the reconstructed three-dimensional structure of the vascular tree, that local image areas within the X-ray projection images of the second set (6) assigned to individual vascular segments (5, 8) are located in accordance with the spatial positions of the vascular segments (5, 8) in the relevant phase of the heart cycle. The concentration of contrast agent in the area of the vascular segments (5, 8) is then determined by evaluation of the X-ray absorption within the local image areas found.
摘要:
CuFe2P is used in a plain bearing or as a plain bearing material. A plain bearing composite material which comprises a supporting layer is provided with a bearing metal layer based on CuFe2P.
摘要:
A system (100) includes an interventional apparatus (102) and an imaging scanner (101). The interventional apparatus includes a interventional instrument (204) configured to perform an image-guided interventional procedure for a patient. The interventional apparatus includes a position detector (122) that detects a position of the interventional instrument within a region of the patient at which the image-guided interventional procedure is performed from outside of the region of interest and generates a signal indicative of the detected position. The imaging scanner includes a controller (114) that activates the imaging scanner to scan the region of interest and the interventional instrument therein for one or more data acquisition cycles based on the movement signal.
摘要:
A method includes reconstructing measured projection data using an iterative statistical reconstruction algorithm that reduces image artifact caused by differences in variances in projections of the measured projection data used to update a voxel of the image for one or more voxels of the image. A reconstructor includes a processor that reconstructs measured projection data using an iterative statistical reconstruction algorithm that reduces or mitigates image artifact caused by differences in variances in projections used to update a voxel of the image for one or more voxels of the image. A computer readable storage medium encoded with computer executable instructions, which, when executed by a processor of a computer, cause the processor to: reduce image artifact caused by differences in variances in projections used to update a voxel of an image for one or more voxels of the image using an iterative statistical reconstruction algorithm.
摘要:
The present invention relates to a computed tomography system (10) and a corresponding method which enable tracking of a contrast material bolus and which involve a reduced radiation dose. The proposed computed tomography system (10) comprises an acquisition unit including an X-ray source (18) and an X-ray detector (30) for acquiring projection data sets (42, 44, 46), a reconstruction unit (41) for reconstructing a planning image (48) from a first projection data set (42), an identification unit (52) for identifying a region of interest (40) in the planning image (48), a selection unit (54) for selecting a projection angle (60) through the region of interest (40), a calculator (62) for calculating a target projection value (64) for a projection of said region of interest (40) with the selected projection angle (60), a control unit (32) for controlling said acquisition unit to acquire a second, reduced projection data set (44) including projection data from projections of said region of interest (40) with the selected projection angle (60), and a comparator (68) for comparing projection values of the second projection data set (44) with the target projection value (64), wherein the control unit (32) is adapted to control the acquisition unit to initiate the acquisition of a third projection data set (46) based on the comparison result (70) and to reconstruct a diagnostic image (50) from the third projection data set (46).
摘要:
An imaging system includes a radiation source (310) configured to rotate around an examination region about a z-axis and having a focal spot that emits a radiation beam that traverses the examination region. The system further includes a radiation sensitive detector array (314) with a plurality of detector pixels that detects radiation traversing the examination region and generates projection data indicative of the detected radiation. The system further includes a dynamic post-patient filter (316) including one or more filter segments (402, 802, 902, 1004, 1102). The filter is configured to selectively and dynamically move in front of the detector array between the detector array and the examination region and into and out of a path of the radiation beam illuminating the detector pixels during scanning an object or subject based on a shape of the object or subject, thereby filtering unattenuated radiation and radiation traversing a periphery of the object or subject.
摘要:
The invention relates to a forward projection apparatus for performing a forward projection through an image (22), wherein at least one of a number of rays (20, 21) for performing the forward projection, a ray spacing between the rays and a kernel width of an interpolation kernel for calculating interpolated values located on the rays is varied depending on the ray width relative to an effective image element spacing between image elements (24) of the image. This allows reducing artifacts in simulated projection data and, thus, in an image, which is iteratively reconstructed by using the simulated projection data. For example, if the number of provided rays and/or the ray spacing between the provided rays is varied, aliasing artifacts can be reduced. Moreover, if the ray spacing between the provided rays and/or the kernel width of the interpolation kernel is varied, artifacts caused by varying effective kernel widths may be reduced.