摘要:
One embodiment of the present invention is a method for imaging an object with a computed tomographic (CT) imaging system that includes steps of helically scanning the object with a multi-slice CT imaging system to acquire attenuation measurements of the object, the measurements including more than two conjugate samples for estimation of a projection at a plane of reconstruction of the object; and filtering and backprojecting the attenuation measurements of the object, including the more than two conjugate samples, to reconstruct at least one image slice of the object. An improved sampling pattern and better use of the attenuation samples obtained during a scan is thus provided.
摘要:
A method for reconstructing an image of an object includes scanning an object using a computed tomographic (CT) imaging apparatus to acquire projections of the object. A set of thresholds are determined utilizing the projections, and selected smoothing kernels are associated with the thresholds. The method further includes utilizing the smoothing kernels and the projections to produce smoothed projections in accordance with the thresholds and filtering and backprojecting the smoothed projections to generate an image of the object.
摘要:
A CT Fluoro system which, in one embodiment, includes an integrated controller, image reconstruction algorithms for increasing the speed of image display, and an enhanced image display, is described. The integrated controller enables the radiologist to maintain control of the system throughout the fluoro scan. The image reconstruction algorithms are generally directed to increasing the image frame rate or reducing image artifacts, or both, in the CT fluoro scan. The image display generally provides enhanced images and control to the radiologist during a scan procedure.
摘要:
A method and apparatus for imaging a heart with a scanning computed tomography (CT) imaging system. A cardiac cycle of a patient is measured. The patient's heart is then scanned with the scanning CT imaging system at an angular rate asynchronous to the measured cardiac cycle to obtain image data. An image of the patient's heart is then assembled from chronologically discontinuous segments of the image data. The image is representative of a selected portion of the cardiac cycle.
摘要:
A method and system for reducing artifacts in an x-ray image generated by a computed tomography imaging system using an image space compensation scheme including obtaining reconstructed image data generated using an image reconstruction algorithm, determining a noise variation characteristic for the reconstruction algorithm, filtering the reconstructed image data so as to create smoothed image data and processing the smoothed image data and the reconstructed image data so as to create corrected image data. Also claimed is a medium encoded with a machine-readable computer program code for reducing artifacts in an x-ray image, the medium including instructions for causing controller to implement the aforementioned method.
摘要:
A CT imaging system and method are provided in which groups of adjacent detector elements of a detector array are ganged in an x-direction; and an object is scanned using the ganged groups of adjacent detector elements to acquire projection data. In one embodiment, to reduce degradation of images resulting from the ganged detector elements, an image of the object is reconstructed utilizing the acquired projection data and an adjusted iso-channel of the multislice detector array different from an iso-channel defined for scans performed without utilizing ganged groups of detector elements.
摘要:
A computed tomography system includes an x-ray source, an x-ray detector aligned with the x-ray source, a processor coupled to the x-ray detector, and a display for displaying reconstructed images. The processor is programmed to perform at least one of: generating a partially reconstructed image for display on the display; dynamically reformatting images for display on the display; communicating the partially reconstructed image, the reformatted images, or data associated with the system to a remote facility.
摘要:
There is therefore provided, in one aspect, a method for imaging an object utilizing a computed tomographic (CT) imaging system having a rotating gantry, a multislice detector array on the rotating gantry and using at least n>1 rows of detector channels, and a radiation source on the rotating gantry configured to project a beam of radiation towards the multislice detector array through an object to be imaged. The method includes helically scanning the object with the CT imaging system at a pitch p>n to acquire projection data from the n rows of detector channels; applying a combined helical weight and conjugate weight to at least a portion of the acquired projection data to produce virtual projection data compensating for incomplete helical row data of the acquired projection data; and reconstructing an image of the object utilizing the acquired projection data and the virtual projection data.
摘要:
A method for reconstructing a computed tomographic (CT) image of an object is provided. The method includes initializing a CT imaging system in a step-and-shoot mode, scanning an object to generate a plurality of adjacent axial scans, wherein the distance between the adjacent axial scans is approximately equal to a projected detector height at the detector iso-center, and reconstructing an image of the object using the adjacent axial scans.
摘要:
In one aspect, the present invention relates to tube-spit detection and correction. In an exemplary embodiment, and once a sample of projection data has been collected, the projection data is preprocessed in accordance with known preprocessing algorithms including applying a detector primary speed correction to the projection data. Such primary speed correction removes contamination of previous signal sample from the current sample. After primary speed correction, tube-spit detection is performed on the sample. Such detection can be performed using many different methods. Generally, the objective is to determine whether the x-ray source experienced a drop in power. If a tube-spit event is not detected, then processing proceeds with further preprocessing and image reconstruction. If a tube-spit event is detected, then a tube spit correction is performed. Generally, the objective of tube-spit correction is to remove image artifacts due to the occurrence of a tube-spit event. Many different methods can be utilized to perform tube-spit correction.